<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with Wdesk from Workiva-->
<!--Copyright 2023 Workiva-->
<!--r:ecafda64-ef65-471d-861b-b2576b92b10b,g:d0944a5a-37ad-463d-80c0-3456005ce3ca-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member"/>
  <link:roleRef roleURI="http://www.anaptysbio.com/role/ConsolidatedStatementofStockholdersEquity" xlink:type="simple" xlink:href="anab-20230331.xsd#ConsolidatedStatementofStockholdersEquity"/>
  <link:definitionLink xlink:role="http://www.anaptysbio.com/role/ConsolidatedStatementofStockholdersEquity" xlink:type="extended" id="i78292d88066e46f2bf15b979f10ec11b_ConsolidatedStatementofStockholdersEquity">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_5ca19f7a-db00-487d-bd19-988b28c2bb63" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_c9ce1abc-4b4b-450f-93e2-71e99be00049" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_5ca19f7a-db00-487d-bd19-988b28c2bb63" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_c9ce1abc-4b4b-450f-93e2-71e99be00049" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharesOutstanding_c0087506-f5a8-4b93-9305-66ef99795b54" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_c9ce1abc-4b4b-450f-93e2-71e99be00049" xlink:to="loc_us-gaap_SharesOutstanding_c0087506-f5a8-4b93-9305-66ef99795b54" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_edd48b64-b603-4d41-a540-89cba02d7377" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_c9ce1abc-4b4b-450f-93e2-71e99be00049" xlink:to="loc_us-gaap_StockholdersEquity_edd48b64-b603-4d41-a540-89cba02d7377" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAndEmployeeStockPurchasePlan_732e2ae6-eb67-4af9-9c92-f9c40103a7df" xlink:href="anab-20230331.xsd#anab_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAndEmployeeStockPurchasePlan"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_c9ce1abc-4b4b-450f-93e2-71e99be00049" xlink:to="loc_anab_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAndEmployeeStockPurchasePlan_732e2ae6-eb67-4af9-9c92-f9c40103a7df" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_StockIssuedDuringPeriodValueOptionsAndEmployeeStockPurchasePlan_33f8bd16-c064-4449-ae12-e4ee12ba5296" xlink:href="anab-20230331.xsd#anab_StockIssuedDuringPeriodValueOptionsAndEmployeeStockPurchasePlan"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_c9ce1abc-4b4b-450f-93e2-71e99be00049" xlink:to="loc_anab_StockIssuedDuringPeriodValueOptionsAndEmployeeStockPurchasePlan_33f8bd16-c064-4449-ae12-e4ee12ba5296" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures_58c566bd-255d-4fce-a36f-583903fa26b6" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_c9ce1abc-4b4b-450f-93e2-71e99be00049" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures_58c566bd-255d-4fce-a36f-583903fa26b6" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodShares_fd8f8efa-d568-44cb-9ede-8ad0deec35b1" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockRepurchasedAndRetiredDuringPeriodShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_c9ce1abc-4b4b-450f-93e2-71e99be00049" xlink:to="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodShares_fd8f8efa-d568-44cb-9ede-8ad0deec35b1" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodValue_992a6846-440b-4713-a80e-5efd40b638dd" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockRepurchasedAndRetiredDuringPeriodValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_c9ce1abc-4b4b-450f-93e2-71e99be00049" xlink:to="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodValue_992a6846-440b-4713-a80e-5efd40b638dd" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationStockOptionsRequisiteServicePeriodRecognition_54b213f8-0863-4c18-83f4-9d3ee4e49e6d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationStockOptionsRequisiteServicePeriodRecognition"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_c9ce1abc-4b4b-450f-93e2-71e99be00049" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationStockOptionsRequisiteServicePeriodRecognition_54b213f8-0863-4c18-83f4-9d3ee4e49e6d" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_90fc59d0-81de-4bce-9228-600c8e3e12b8" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_c9ce1abc-4b4b-450f-93e2-71e99be00049" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_90fc59d0-81de-4bce-9228-600c8e3e12b8" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_4c065a02-8383-4c8c-b63c-06380bbce410" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_c9ce1abc-4b4b-450f-93e2-71e99be00049" xlink:to="loc_us-gaap_NetIncomeLoss_4c065a02-8383-4c8c-b63c-06380bbce410" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharesOutstanding_82cc63e6-abf4-49ce-b5c2-41e6caa3c45b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SharesOutstanding"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_0810d613-81e3-4025-a411-19960eea1ab7" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockholdersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_d16e2327-7574-45b9-b26c-257930d13e81" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_5ca19f7a-db00-487d-bd19-988b28c2bb63" xlink:to="loc_us-gaap_StatementTable_d16e2327-7574-45b9-b26c-257930d13e81" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_4dda85d9-6b8b-4677-9a61-c18368444492" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_d16e2327-7574-45b9-b26c-257930d13e81" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_4dda85d9-6b8b-4677-9a61-c18368444492" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_4dda85d9-6b8b-4677-9a61-c18368444492_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_4dda85d9-6b8b-4677-9a61-c18368444492" xlink:to="loc_us-gaap_EquityComponentDomain_4dda85d9-6b8b-4677-9a61-c18368444492_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_02a1454a-81cd-4e27-9452-9fb2e26998da" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_4dda85d9-6b8b-4677-9a61-c18368444492" xlink:to="loc_us-gaap_EquityComponentDomain_02a1454a-81cd-4e27-9452-9fb2e26998da" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_f6f58058-2ec4-4ae2-a0e0-e68b11c437c3" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_02a1454a-81cd-4e27-9452-9fb2e26998da" xlink:to="loc_us-gaap_CommonStockMember_f6f58058-2ec4-4ae2-a0e0-e68b11c437c3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_1e00a123-fa5c-4194-8269-ba7566c03012" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AdditionalPaidInCapitalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_02a1454a-81cd-4e27-9452-9fb2e26998da" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_1e00a123-fa5c-4194-8269-ba7566c03012" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_66b57964-05f0-4efe-b860-42d0cf1a911c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_02a1454a-81cd-4e27-9452-9fb2e26998da" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_66b57964-05f0-4efe-b860-42d0cf1a911c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_ae466278-aa9b-4078-b8b0-07eaf07ce800" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RetainedEarningsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_02a1454a-81cd-4e27-9452-9fb2e26998da" xlink:to="loc_us-gaap_RetainedEarningsMember_ae466278-aa9b-4078-b8b0-07eaf07ce800" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.anaptysbio.com/role/SummaryofSignificantAccountingPoliciesSummaryofPotentiallyDilutiveSecuritiesDetails" xlink:type="simple" xlink:href="anab-20230331.xsd#SummaryofSignificantAccountingPoliciesSummaryofPotentiallyDilutiveSecuritiesDetails"/>
  <link:definitionLink xlink:role="http://www.anaptysbio.com/role/SummaryofSignificantAccountingPoliciesSummaryofPotentiallyDilutiveSecuritiesDetails" xlink:type="extended" id="i72af3a89ad4c45049f277a30147c09fa_SummaryofSignificantAccountingPoliciesSummaryofPotentiallyDilutiveSecuritiesDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_3e026eac-6eef-41d6-8e4e-593fc428b98c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_6766d7a5-629b-4e45-b492-c19abc3854aa" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_3e026eac-6eef-41d6-8e4e-593fc428b98c" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_6766d7a5-629b-4e45-b492-c19abc3854aa" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_9558dc2d-efce-4a58-bef8-9c3babc74ddc" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_3e026eac-6eef-41d6-8e4e-593fc428b98c" xlink:to="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_9558dc2d-efce-4a58-bef8-9c3babc74ddc" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_c6062e85-bc01-4548-b35c-4a8d85d98c51" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_9558dc2d-efce-4a58-bef8-9c3babc74ddc" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_c6062e85-bc01-4548-b35c-4a8d85d98c51" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_c6062e85-bc01-4548-b35c-4a8d85d98c51_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_c6062e85-bc01-4548-b35c-4a8d85d98c51" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_c6062e85-bc01-4548-b35c-4a8d85d98c51_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_e2f20b7a-617b-4b20-b182-76261129f5b5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_c6062e85-bc01-4548-b35c-4a8d85d98c51" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_e2f20b7a-617b-4b20-b182-76261129f5b5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_1febfc2b-5c66-494b-8714-d608599162e2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_e2f20b7a-617b-4b20-b182-76261129f5b5" xlink:to="loc_us-gaap_EmployeeStockOptionMember_1febfc2b-5c66-494b-8714-d608599162e2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_63165b6b-bc5b-4587-9a00-6c0f5bf79adb" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_e2f20b7a-617b-4b20-b182-76261129f5b5" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_63165b6b-bc5b-4587-9a00-6c0f5bf79adb" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.anaptysbio.com/role/BalanceSheetAccountsandSupplementalDisclosuresPropertyandEquipmentnetDetails" xlink:type="simple" xlink:href="anab-20230331.xsd#BalanceSheetAccountsandSupplementalDisclosuresPropertyandEquipmentnetDetails"/>
  <link:definitionLink xlink:role="http://www.anaptysbio.com/role/BalanceSheetAccountsandSupplementalDisclosuresPropertyandEquipmentnetDetails" xlink:type="extended" id="ia4ae103a348d4ad9813822a982700b8d_BalanceSheetAccountsandSupplementalDisclosuresPropertyandEquipmentnetDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_74903471-0c5c-4162-9645-b3e6b878ff75" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PropertyPlantAndEquipmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentGross_4467a056-0381-4c33-b5ee-b111b200e541" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PropertyPlantAndEquipmentGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_74903471-0c5c-4162-9645-b3e6b878ff75" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentGross_4467a056-0381-4c33-b5ee-b111b200e541" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_ba789020-c1d9-4707-ad33-b780c0b7c529" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_74903471-0c5c-4162-9645-b3e6b878ff75" xlink:to="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_ba789020-c1d9-4707-ad33-b780c0b7c529" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_9ea5ee97-e1d4-44cc-bd5d-210549d1c204" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_74903471-0c5c-4162-9645-b3e6b878ff75" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_9ea5ee97-e1d4-44cc-bd5d-210549d1c204" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_d350eac2-7a08-4360-87c5-783dc77a5281" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_74903471-0c5c-4162-9645-b3e6b878ff75" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_d350eac2-7a08-4360-87c5-783dc77a5281" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_02d3d85b-02ee-4b78-bf4e-df1c0e120765" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_d350eac2-7a08-4360-87c5-783dc77a5281" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_02d3d85b-02ee-4b78-bf4e-df1c0e120765" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_02d3d85b-02ee-4b78-bf4e-df1c0e120765_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_02d3d85b-02ee-4b78-bf4e-df1c0e120765" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_02d3d85b-02ee-4b78-bf4e-df1c0e120765_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_eb63c757-6d42-48b3-839f-ed064dc77793" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_02d3d85b-02ee-4b78-bf4e-df1c0e120765" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_eb63c757-6d42-48b3-839f-ed064dc77793" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_LaboratoryEquipmentMember_bc26f926-9a81-4fc3-bd6f-b7871eb1ccee" xlink:href="anab-20230331.xsd#anab_LaboratoryEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_eb63c757-6d42-48b3-839f-ed064dc77793" xlink:to="loc_anab_LaboratoryEquipmentMember_bc26f926-9a81-4fc3-bd6f-b7871eb1ccee" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OfficeEquipmentMember_f0f535ce-67e0-4c8b-951f-ae2bb7394f2b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OfficeEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_eb63c757-6d42-48b3-839f-ed064dc77793" xlink:to="loc_us-gaap_OfficeEquipmentMember_f0f535ce-67e0-4c8b-951f-ae2bb7394f2b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LeaseholdImprovementsMember_939f8bb0-933b-41ea-9175-70398eec93ee" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LeaseholdImprovementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_eb63c757-6d42-48b3-839f-ed064dc77793" xlink:to="loc_us-gaap_LeaseholdImprovementsMember_939f8bb0-933b-41ea-9175-70398eec93ee" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.anaptysbio.com/role/CollaborativeResearchandDevelopmentAgreementsNarrativeDetails" xlink:type="simple" xlink:href="anab-20230331.xsd#CollaborativeResearchandDevelopmentAgreementsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.anaptysbio.com/role/CollaborativeResearchandDevelopmentAgreementsNarrativeDetails" xlink:type="extended" id="i0f5fdeeb7272449e927f78de94ff981f_CollaborativeResearchandDevelopmentAgreementsNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_6b7e62f5-7f63-4ca6-bcca-ed7880f7e255" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DisaggregationOfRevenueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_RevenueRecognitionMultipledeliverableArrangementsUpfrontFeeReceived_d0d8d0d8-c0cf-4ab7-ab0f-7946d2bc11b4" xlink:href="anab-20230331.xsd#anab_RevenueRecognitionMultipledeliverableArrangementsUpfrontFeeReceived"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_6b7e62f5-7f63-4ca6-bcca-ed7880f7e255" xlink:to="loc_anab_RevenueRecognitionMultipledeliverableArrangementsUpfrontFeeReceived_d0d8d0d8-c0cf-4ab7-ab0f-7946d2bc11b4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_RevenueRecognitionMilestoneMethodNumberOfOutstandingResearchAndDevelopmentTargets_06b40aaa-bdcc-46dd-80e1-a3f31404c3d3" xlink:href="anab-20230331.xsd#anab_RevenueRecognitionMilestoneMethodNumberOfOutstandingResearchAndDevelopmentTargets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_6b7e62f5-7f63-4ca6-bcca-ed7880f7e255" xlink:to="loc_anab_RevenueRecognitionMilestoneMethodNumberOfOutstandingResearchAndDevelopmentTargets_06b40aaa-bdcc-46dd-80e1-a3f31404c3d3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_RevenueRecognitionMilestoneMethodContingentUponPreClinicalRegulatoryAndCommercialEvents_5cea0bea-76b3-441f-9f4d-653fd19049f8" xlink:href="anab-20230331.xsd#anab_RevenueRecognitionMilestoneMethodContingentUponPreClinicalRegulatoryAndCommercialEvents"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_6b7e62f5-7f63-4ca6-bcca-ed7880f7e255" xlink:to="loc_anab_RevenueRecognitionMilestoneMethodContingentUponPreClinicalRegulatoryAndCommercialEvents_5cea0bea-76b3-441f-9f4d-653fd19049f8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_RevenueRecognitionMilestoneMethodContingentUponCertainUnitedStatesAndEuropeanRegulatorySubmissionsAndApprovals_d50bc5a2-95b2-48f8-9c99-a44587564d9b" xlink:href="anab-20230331.xsd#anab_RevenueRecognitionMilestoneMethodContingentUponCertainUnitedStatesAndEuropeanRegulatorySubmissionsAndApprovals"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_6b7e62f5-7f63-4ca6-bcca-ed7880f7e255" xlink:to="loc_anab_RevenueRecognitionMilestoneMethodContingentUponCertainUnitedStatesAndEuropeanRegulatorySubmissionsAndApprovals_d50bc5a2-95b2-48f8-9c99-a44587564d9b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_RevenueRecognitionMilestoneMethodContingentUponAchievementOfSpecifiedLevelsOfWorldwideSales_0f113874-3c51-41fe-b850-e9b4bc88df01" xlink:href="anab-20230331.xsd#anab_RevenueRecognitionMilestoneMethodContingentUponAchievementOfSpecifiedLevelsOfWorldwideSales"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_6b7e62f5-7f63-4ca6-bcca-ed7880f7e255" xlink:to="loc_anab_RevenueRecognitionMilestoneMethodContingentUponAchievementOfSpecifiedLevelsOfWorldwideSales_0f113874-3c51-41fe-b850-e9b4bc88df01" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_NetSalesRoyaltyPercent_ccda3a57-e95e-4f31-a46f-b0a7fee92be3" xlink:href="anab-20230331.xsd#anab_NetSalesRoyaltyPercent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_6b7e62f5-7f63-4ca6-bcca-ed7880f7e255" xlink:to="loc_anab_NetSalesRoyaltyPercent_ccda3a57-e95e-4f31-a46f-b0a7fee92be3" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_RevenueRecognitionMilestoneMethodAgreementTermFollowingFirstCommercialSaleOrExpirationOfTheLastToExpirePatent_8eeafc31-a2d4-466d-bc3a-657a2fcd80e0" xlink:href="anab-20230331.xsd#anab_RevenueRecognitionMilestoneMethodAgreementTermFollowingFirstCommercialSaleOrExpirationOfTheLastToExpirePatent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_6b7e62f5-7f63-4ca6-bcca-ed7880f7e255" xlink:to="loc_anab_RevenueRecognitionMilestoneMethodAgreementTermFollowingFirstCommercialSaleOrExpirationOfTheLastToExpirePatent_8eeafc31-a2d4-466d-bc3a-657a2fcd80e0" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_NetSalesRoyaltyThreshold_66f21d2d-9f8f-466f-b7e5-4d5b69d92d67" xlink:href="anab-20230331.xsd#anab_NetSalesRoyaltyThreshold"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_6b7e62f5-7f63-4ca6-bcca-ed7880f7e255" xlink:to="loc_anab_NetSalesRoyaltyThreshold_66f21d2d-9f8f-466f-b7e5-4d5b69d92d67" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_RevenueRecognitionMultipleDeliverableArrangementsUpfrontFees_552bf368-f1f4-4e2d-a3ad-9bd753d048ea" xlink:href="anab-20230331.xsd#anab_RevenueRecognitionMultipleDeliverableArrangementsUpfrontFees"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_6b7e62f5-7f63-4ca6-bcca-ed7880f7e255" xlink:to="loc_anab_RevenueRecognitionMultipleDeliverableArrangementsUpfrontFees_552bf368-f1f4-4e2d-a3ad-9bd753d048ea" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_RevenueRecognitionMilestoneMethodContingent_3096ab31-81c2-4c5c-85bc-f5d6e436e8e6" xlink:href="anab-20230331.xsd#anab_RevenueRecognitionMilestoneMethodContingent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_6b7e62f5-7f63-4ca6-bcca-ed7880f7e255" xlink:to="loc_anab_RevenueRecognitionMilestoneMethodContingent_3096ab31-81c2-4c5c-85bc-f5d6e436e8e6" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_d1bb85bd-dd35-4405-a898-65c758b3c9c9" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_6b7e62f5-7f63-4ca6-bcca-ed7880f7e255" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_d1bb85bd-dd35-4405-a898-65c758b3c9c9" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_NoncashAdvanceFutureRoyaltiesRevenue_b4b721ef-6f07-4dd8-af0a-8ee44ab7d80f" xlink:href="anab-20230331.xsd#anab_NoncashAdvanceFutureRoyaltiesRevenue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_6b7e62f5-7f63-4ca6-bcca-ed7880f7e255" xlink:to="loc_anab_NoncashAdvanceFutureRoyaltiesRevenue_b4b721ef-6f07-4dd8-af0a-8ee44ab7d80f" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_RevenueRecognitionMilestoneMethodNumberOfMilestonesAchievedDuringPeriod_43218ae5-fcf2-48e4-80dd-3709986ba90a" xlink:href="anab-20230331.xsd#anab_RevenueRecognitionMilestoneMethodNumberOfMilestonesAchievedDuringPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_6b7e62f5-7f63-4ca6-bcca-ed7880f7e255" xlink:to="loc_anab_RevenueRecognitionMilestoneMethodNumberOfMilestonesAchievedDuringPeriod_43218ae5-fcf2-48e4-80dd-3709986ba90a" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerTimingOfSatisfactionOfPerformanceObligationAndPayment_1a0fe470-df69-45e5-8fb8-8c703cb0c4c5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ContractWithCustomerTimingOfSatisfactionOfPerformanceObligationAndPayment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_6b7e62f5-7f63-4ca6-bcca-ed7880f7e255" xlink:to="loc_us-gaap_ContractWithCustomerTimingOfSatisfactionOfPerformanceObligationAndPayment_1a0fe470-df69-45e5-8fb8-8c703cb0c4c5" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable_83c11247-a736-4372-9dc5-fba724f083ac" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DisaggregationOfRevenueTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_6b7e62f5-7f63-4ca6-bcca-ed7880f7e255" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_83c11247-a736-4372-9dc5-fba724f083ac" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CounterpartyNameAxis_71657ba2-7d9e-4e05-a396-5c44d8430577" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_CounterpartyNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_83c11247-a736-4372-9dc5-fba724f083ac" xlink:to="loc_srt_CounterpartyNameAxis_71657ba2-7d9e-4e05-a396-5c44d8430577" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_71657ba2-7d9e-4e05-a396-5c44d8430577_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_CounterpartyNameAxis_71657ba2-7d9e-4e05-a396-5c44d8430577" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_71657ba2-7d9e-4e05-a396-5c44d8430577_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_bc10a03d-9ec9-4aa8-a942-a8d19968a3e9" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_CounterpartyNameAxis_71657ba2-7d9e-4e05-a396-5c44d8430577" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_bc10a03d-9ec9-4aa8-a942-a8d19968a3e9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_GlaxoSmithKlineMember_cc6ba2d7-481f-4f2e-a569-afceaa52a505" xlink:href="anab-20230331.xsd#anab_GlaxoSmithKlineMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_bc10a03d-9ec9-4aa8-a942-a8d19968a3e9" xlink:to="loc_anab_GlaxoSmithKlineMember_cc6ba2d7-481f-4f2e-a569-afceaa52a505" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TypeOfArrangementAxis_8d4726c7-92ae-4e95-8b6c-168aa3f5d69f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TypeOfArrangementAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_83c11247-a736-4372-9dc5-fba724f083ac" xlink:to="loc_us-gaap_TypeOfArrangementAxis_8d4726c7-92ae-4e95-8b6c-168aa3f5d69f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_8d4726c7-92ae-4e95-8b6c-168aa3f5d69f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_TypeOfArrangementAxis_8d4726c7-92ae-4e95-8b6c-168aa3f5d69f" xlink:to="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_8d4726c7-92ae-4e95-8b6c-168aa3f5d69f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_1fec0834-7725-481b-8dde-87464df3768f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_TypeOfArrangementAxis_8d4726c7-92ae-4e95-8b6c-168aa3f5d69f" xlink:to="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_1fec0834-7725-481b-8dde-87464df3768f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollaborativeArrangementMember_0e20d2ed-9488-4170-ae52-f4e793b2db0f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CollaborativeArrangementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_1fec0834-7725-481b-8dde-87464df3768f" xlink:to="loc_us-gaap_CollaborativeArrangementMember_0e20d2ed-9488-4170-ae52-f4e793b2db0f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_RoyaltyAgreementMember_c56a3e43-2239-4cb5-a120-cecb8cc27daf" xlink:href="anab-20230331.xsd#anab_RoyaltyAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollaborativeArrangementMember_0e20d2ed-9488-4170-ae52-f4e793b2db0f" xlink:to="loc_anab_RoyaltyAgreementMember_c56a3e43-2239-4cb5-a120-cecb8cc27daf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_RoyaltyAgreementUpTo10BillionMember_f4963b6e-fa74-4d24-999c-de177ae5da7f" xlink:href="anab-20230331.xsd#anab_RoyaltyAgreementUpTo10BillionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_anab_RoyaltyAgreementMember_c56a3e43-2239-4cb5-a120-cecb8cc27daf" xlink:to="loc_anab_RoyaltyAgreementUpTo10BillionMember_f4963b6e-fa74-4d24-999c-de177ae5da7f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_RoyaltyAgreementAbove10BillionMember_3ec2dc3b-48c3-47bc-b6be-9af31ad53461" xlink:href="anab-20230331.xsd#anab_RoyaltyAgreementAbove10BillionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_anab_RoyaltyAgreementMember_c56a3e43-2239-4cb5-a120-cecb8cc27daf" xlink:to="loc_anab_RoyaltyAgreementAbove10BillionMember_3ec2dc3b-48c3-47bc-b6be-9af31ad53461" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_CollaborationAndExclusiveLicenseAgreementMember_c0580c90-7204-445b-9af8-e9c5b045b418" xlink:href="anab-20230331.xsd#anab_CollaborationAndExclusiveLicenseAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_anab_RoyaltyAgreementMember_c56a3e43-2239-4cb5-a120-cecb8cc27daf" xlink:to="loc_anab_CollaborationAndExclusiveLicenseAgreementMember_c0580c90-7204-445b-9af8-e9c5b045b418" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_JEMPERLIRoyaltyMonetizationAgreementMember_fe633c60-7ead-4374-a737-5e61be5264d4" xlink:href="anab-20230331.xsd#anab_JEMPERLIRoyaltyMonetizationAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_anab_RoyaltyAgreementMember_c56a3e43-2239-4cb5-a120-cecb8cc27daf" xlink:to="loc_anab_JEMPERLIRoyaltyMonetizationAgreementMember_fe633c60-7ead-4374-a737-5e61be5264d4" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_ZejulaRoyaltyMonetizationAgreementMember_f2ab7724-d56e-45d9-badb-99e7caa5fa4b" xlink:href="anab-20230331.xsd#anab_ZejulaRoyaltyMonetizationAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_1fec0834-7725-481b-8dde-87464df3768f" xlink:to="loc_anab_ZejulaRoyaltyMonetizationAgreementMember_f2ab7724-d56e-45d9-badb-99e7caa5fa4b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_634fb8b2-f44e-4ecc-8a9b-acfbe91c8f99" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_83c11247-a736-4372-9dc5-fba724f083ac" xlink:to="loc_srt_RangeAxis_634fb8b2-f44e-4ecc-8a9b-acfbe91c8f99" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_634fb8b2-f44e-4ecc-8a9b-acfbe91c8f99_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_634fb8b2-f44e-4ecc-8a9b-acfbe91c8f99" xlink:to="loc_srt_RangeMember_634fb8b2-f44e-4ecc-8a9b-acfbe91c8f99_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_2c0af3cc-5f32-4ffa-9faa-6413c26909b1" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_634fb8b2-f44e-4ecc-8a9b-acfbe91c8f99" xlink:to="loc_srt_RangeMember_2c0af3cc-5f32-4ffa-9faa-6413c26909b1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_26e7c6e2-694a-4d3a-bcab-5a432f8538ed" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_2c0af3cc-5f32-4ffa-9faa-6413c26909b1" xlink:to="loc_srt_MinimumMember_26e7c6e2-694a-4d3a-bcab-5a432f8538ed" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_1b6c5a4b-ee38-43c6-99f6-20b6aba58bc9" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_2c0af3cc-5f32-4ffa-9faa-6413c26909b1" xlink:to="loc_srt_MaximumMember_1b6c5a4b-ee38-43c6-99f6-20b6aba58bc9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_01f29573-d684-407c-802d-cab88b546660" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_83c11247-a736-4372-9dc5-fba724f083ac" xlink:to="loc_srt_ProductOrServiceAxis_01f29573-d684-407c-802d-cab88b546660" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_01f29573-d684-407c-802d-cab88b546660_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_01f29573-d684-407c-802d-cab88b546660" xlink:to="loc_srt_ProductsAndServicesDomain_01f29573-d684-407c-802d-cab88b546660_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_687aa37f-dc6e-4f2d-8ed5-6a8c0d57e11e" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_01f29573-d684-407c-802d-cab88b546660" xlink:to="loc_srt_ProductsAndServicesDomain_687aa37f-dc6e-4f2d-8ed5-6a8c0d57e11e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_AnaptysBioGeneratedAntiPD1JEMPERLIDostarlimabMember_6bc624a9-be23-4122-bc7e-c516cb20d6a1" xlink:href="anab-20230331.xsd#anab_AnaptysBioGeneratedAntiPD1JEMPERLIDostarlimabMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_687aa37f-dc6e-4f2d-8ed5-6a8c0d57e11e" xlink:to="loc_anab_AnaptysBioGeneratedAntiPD1JEMPERLIDostarlimabMember_6bc624a9-be23-4122-bc7e-c516cb20d6a1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_AnaptysBioGeneratedAntiPD1AntagonistAntibodyCC90006Member_c22e2174-d7c1-4ca3-a72c-0db172c0845c" xlink:href="anab-20230331.xsd#anab_AnaptysBioGeneratedAntiPD1AntagonistAntibodyCC90006Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_687aa37f-dc6e-4f2d-8ed5-6a8c0d57e11e" xlink:to="loc_anab_AnaptysBioGeneratedAntiPD1AntagonistAntibodyCC90006Member_c22e2174-d7c1-4ca3-a72c-0db172c0845c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_ZejulaAndAnaptysBioGeneratedJEMPERLIMember_8eb2c162-fb1c-4fae-945e-77c4e7f96b8e" xlink:href="anab-20230331.xsd#anab_ZejulaAndAnaptysBioGeneratedJEMPERLIMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_687aa37f-dc6e-4f2d-8ed5-6a8c0d57e11e" xlink:to="loc_anab_ZejulaAndAnaptysBioGeneratedJEMPERLIMember_8eb2c162-fb1c-4fae-945e-77c4e7f96b8e" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.anaptysbio.com/role/CollaborativeResearchandDevelopmentAgreementsScheduleofMilestoneAchievedDetails" xlink:type="simple" xlink:href="anab-20230331.xsd#CollaborativeResearchandDevelopmentAgreementsScheduleofMilestoneAchievedDetails"/>
  <link:definitionLink xlink:role="http://www.anaptysbio.com/role/CollaborativeResearchandDevelopmentAgreementsScheduleofMilestoneAchievedDetails" xlink:type="extended" id="i695732cd98b3461283aa338a5a85eabb_CollaborativeResearchandDevelopmentAgreementsScheduleofMilestoneAchievedDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_f3e7ee10-5c62-422c-8a70-8e65606de2bb" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DisaggregationOfRevenueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_e6f51d55-d54a-48eb-acfc-44a251fc7652" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_f3e7ee10-5c62-422c-8a70-8e65606de2bb" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_e6f51d55-d54a-48eb-acfc-44a251fc7652" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_RevenueRecognitionMilestoneMethodContingent_de678410-e8e6-47f0-bb7a-a24b02ea9707" xlink:href="anab-20230331.xsd#anab_RevenueRecognitionMilestoneMethodContingent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_f3e7ee10-5c62-422c-8a70-8e65606de2bb" xlink:to="loc_anab_RevenueRecognitionMilestoneMethodContingent_de678410-e8e6-47f0-bb7a-a24b02ea9707" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable_0a591ad3-925f-420c-be70-fd636684dd7c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DisaggregationOfRevenueTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_f3e7ee10-5c62-422c-8a70-8e65606de2bb" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_0a591ad3-925f-420c-be70-fd636684dd7c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CounterpartyNameAxis_94948b4e-48db-4d92-99a3-9712b0939adc" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_CounterpartyNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_0a591ad3-925f-420c-be70-fd636684dd7c" xlink:to="loc_srt_CounterpartyNameAxis_94948b4e-48db-4d92-99a3-9712b0939adc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_94948b4e-48db-4d92-99a3-9712b0939adc_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_CounterpartyNameAxis_94948b4e-48db-4d92-99a3-9712b0939adc" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_94948b4e-48db-4d92-99a3-9712b0939adc_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_ab39de35-0a91-437c-aa44-143806150f3e" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_CounterpartyNameAxis_94948b4e-48db-4d92-99a3-9712b0939adc" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_ab39de35-0a91-437c-aa44-143806150f3e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_GlaxoSmithKlineMember_5b49432a-21ca-41ac-8519-f978ed0efb9f" xlink:href="anab-20230331.xsd#anab_GlaxoSmithKlineMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_ab39de35-0a91-437c-aa44-143806150f3e" xlink:to="loc_anab_GlaxoSmithKlineMember_5b49432a-21ca-41ac-8519-f978ed0efb9f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_c4e04263-d7a6-4ea5-a7d7-1981a673ac6b" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_0a591ad3-925f-420c-be70-fd636684dd7c" xlink:to="loc_srt_ProductOrServiceAxis_c4e04263-d7a6-4ea5-a7d7-1981a673ac6b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_c4e04263-d7a6-4ea5-a7d7-1981a673ac6b_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_c4e04263-d7a6-4ea5-a7d7-1981a673ac6b" xlink:to="loc_srt_ProductsAndServicesDomain_c4e04263-d7a6-4ea5-a7d7-1981a673ac6b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_ff681242-28ec-4a49-a869-13f8e0385bac" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_c4e04263-d7a6-4ea5-a7d7-1981a673ac6b" xlink:to="loc_srt_ProductsAndServicesDomain_ff681242-28ec-4a49-a869-13f8e0385bac" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_AnaptysBioGeneratedAntiPD1JEMPERLIDostarlimabMember_6308681c-88f6-4963-84e3-d6ba1a28669d" xlink:href="anab-20230331.xsd#anab_AnaptysBioGeneratedAntiPD1JEMPERLIDostarlimabMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_ff681242-28ec-4a49-a869-13f8e0385bac" xlink:to="loc_anab_AnaptysBioGeneratedAntiPD1JEMPERLIDostarlimabMember_6308681c-88f6-4963-84e3-d6ba1a28669d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_AnaptysBioGeneratedAntiTIM3GSK4069889ACobolimabMember_3452d54c-5afe-4d22-a023-88969d0540bc" xlink:href="anab-20230331.xsd#anab_AnaptysBioGeneratedAntiTIM3GSK4069889ACobolimabMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_ff681242-28ec-4a49-a869-13f8e0385bac" xlink:to="loc_anab_AnaptysBioGeneratedAntiTIM3GSK4069889ACobolimabMember_3452d54c-5afe-4d22-a023-88969d0540bc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_AnaptysBioGeneratedAntiLAG3GSK40974386Member_6334eb71-2ec0-4ef5-ac23-0f2dfe0ad233" xlink:href="anab-20230331.xsd#anab_AnaptysBioGeneratedAntiLAG3GSK40974386Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_ff681242-28ec-4a49-a869-13f8e0385bac" xlink:to="loc_anab_AnaptysBioGeneratedAntiLAG3GSK40974386Member_6334eb71-2ec0-4ef5-ac23-0f2dfe0ad233" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TypeOfArrangementAxis_d274ab8b-7888-432d-8e3c-956770b097a7" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TypeOfArrangementAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_0a591ad3-925f-420c-be70-fd636684dd7c" xlink:to="loc_us-gaap_TypeOfArrangementAxis_d274ab8b-7888-432d-8e3c-956770b097a7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_d274ab8b-7888-432d-8e3c-956770b097a7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_TypeOfArrangementAxis_d274ab8b-7888-432d-8e3c-956770b097a7" xlink:to="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_d274ab8b-7888-432d-8e3c-956770b097a7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_ffc21389-009d-420c-a77e-7ec4d74f27e3" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_TypeOfArrangementAxis_d274ab8b-7888-432d-8e3c-956770b097a7" xlink:to="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_ffc21389-009d-420c-a77e-7ec4d74f27e3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_InVivoToxicologyStudiesMember_7e229432-5127-4d11-821c-2dab72a55b09" xlink:href="anab-20230331.xsd#anab_InVivoToxicologyStudiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_ffc21389-009d-420c-a77e-7ec4d74f27e3" xlink:to="loc_anab_InVivoToxicologyStudiesMember_7e229432-5127-4d11-821c-2dab72a55b09" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_ClearanceOfInvestigationalNewDrugFromFDAMember_d7315236-6963-4aca-9921-2f734900f9c1" xlink:href="anab-20230331.xsd#anab_ClearanceOfInvestigationalNewDrugFromFDAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_ffc21389-009d-420c-a77e-7ec4d74f27e3" xlink:to="loc_anab_ClearanceOfInvestigationalNewDrugFromFDAMember_d7315236-6963-4aca-9921-2f734900f9c1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_Phase2ClinicalTrialInitiationMember_79344b7f-5ec6-4fa8-9b94-74c6be8bcf74" xlink:href="anab-20230331.xsd#anab_Phase2ClinicalTrialInitiationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_ffc21389-009d-420c-a77e-7ec4d74f27e3" xlink:to="loc_anab_Phase2ClinicalTrialInitiationMember_79344b7f-5ec6-4fa8-9b94-74c6be8bcf74" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_Phase3ClinicalTrialInitiationFirstIndicationMember_54b8476b-1ca5-494a-a987-cf63ee3ae3f0" xlink:href="anab-20230331.xsd#anab_Phase3ClinicalTrialInitiationFirstIndicationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_ffc21389-009d-420c-a77e-7ec4d74f27e3" xlink:to="loc_anab_Phase3ClinicalTrialInitiationFirstIndicationMember_54b8476b-1ca5-494a-a987-cf63ee3ae3f0" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_Phase3ClinicalTrialInitiationSecondIndicationMember_511014ab-5aac-4796-afa1-161121f53981" xlink:href="anab-20230331.xsd#anab_Phase3ClinicalTrialInitiationSecondIndicationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_ffc21389-009d-420c-a77e-7ec4d74f27e3" xlink:to="loc_anab_Phase3ClinicalTrialInitiationSecondIndicationMember_511014ab-5aac-4796-afa1-161121f53981" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_FilingOfBiologicsLicenseApplicationFirstIndicationMember_2706f2f1-87c7-4dbd-8356-fcc8ec5b7933" xlink:href="anab-20230331.xsd#anab_FilingOfBiologicsLicenseApplicationFirstIndicationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_ffc21389-009d-420c-a77e-7ec4d74f27e3" xlink:to="loc_anab_FilingOfBiologicsLicenseApplicationFirstIndicationMember_2706f2f1-87c7-4dbd-8356-fcc8ec5b7933" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_FilingOfMMAFirstIndicationMember_b6e91b8c-4237-4c4b-93f3-42476be441cd" xlink:href="anab-20230331.xsd#anab_FilingOfMMAFirstIndicationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_ffc21389-009d-420c-a77e-7ec4d74f27e3" xlink:to="loc_anab_FilingOfMMAFirstIndicationMember_b6e91b8c-4237-4c4b-93f3-42476be441cd" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_FilingOfBiologicsLicenseApplicationSecondIndicationMember_1239a0a9-0348-4b44-a473-3221a5a54fe0" xlink:href="anab-20230331.xsd#anab_FilingOfBiologicsLicenseApplicationSecondIndicationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_ffc21389-009d-420c-a77e-7ec4d74f27e3" xlink:to="loc_anab_FilingOfBiologicsLicenseApplicationSecondIndicationMember_1239a0a9-0348-4b44-a473-3221a5a54fe0" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_FirstBiologicsLicenseApplicationApprovalDMMRECMember_93240e5e-00de-4688-8529-28366fbb1869" xlink:href="anab-20230331.xsd#anab_FirstBiologicsLicenseApplicationApprovalDMMRECMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_ffc21389-009d-420c-a77e-7ec4d74f27e3" xlink:to="loc_anab_FirstBiologicsLicenseApplicationApprovalDMMRECMember_93240e5e-00de-4688-8529-28366fbb1869" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_FirstMarketingAuthorizationApplicationApprovalFirstIndicationMember_ca36ec48-7e15-4ce7-a677-00abe32129f4" xlink:href="anab-20230331.xsd#anab_FirstMarketingAuthorizationApplicationApprovalFirstIndicationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_ffc21389-009d-420c-a77e-7ec4d74f27e3" xlink:to="loc_anab_FirstMarketingAuthorizationApplicationApprovalFirstIndicationMember_ca36ec48-7e15-4ce7-a677-00abe32129f4" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_FirstBiologicsLicenseApplicationApprovalSecondIndicationMember_9df09790-6937-437d-9dc2-0d60e5ad10fe" xlink:href="anab-20230331.xsd#anab_FirstBiologicsLicenseApplicationApprovalSecondIndicationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_ffc21389-009d-420c-a77e-7ec4d74f27e3" xlink:to="loc_anab_FirstBiologicsLicenseApplicationApprovalSecondIndicationMember_9df09790-6937-437d-9dc2-0d60e5ad10fe" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_FilingOfMMASecondIndicationMember_905c4e91-2028-4103-b148-0063e5714bcc" xlink:href="anab-20230331.xsd#anab_FilingOfMMASecondIndicationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_ffc21389-009d-420c-a77e-7ec4d74f27e3" xlink:to="loc_anab_FilingOfMMASecondIndicationMember_905c4e91-2028-4103-b148-0063e5714bcc" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_FirstMarketingAuthorizationApplicationApprovalSecondIndicationMember_a168ebd1-ab8e-40d0-8cc0-ca539c3d7831" xlink:href="anab-20230331.xsd#anab_FirstMarketingAuthorizationApplicationApprovalSecondIndicationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_ffc21389-009d-420c-a77e-7ec4d74f27e3" xlink:to="loc_anab_FirstMarketingAuthorizationApplicationApprovalSecondIndicationMember_a168ebd1-ab8e-40d0-8cc0-ca539c3d7831" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_FirstCommercialSalesMilestoneMember_3ee56457-3807-4c65-8326-a5aeb18a5368" xlink:href="anab-20230331.xsd#anab_FirstCommercialSalesMilestoneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_ffc21389-009d-420c-a77e-7ec4d74f27e3" xlink:to="loc_anab_FirstCommercialSalesMilestoneMember_3ee56457-3807-4c65-8326-a5aeb18a5368" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_SecondCommercialSalesMilestoneMember_cd32a1cc-5606-4268-a154-3226576fac53" xlink:href="anab-20230331.xsd#anab_SecondCommercialSalesMilestoneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_ffc21389-009d-420c-a77e-7ec4d74f27e3" xlink:to="loc_anab_SecondCommercialSalesMilestoneMember_cd32a1cc-5606-4268-a154-3226576fac53" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_ThirdCommercialSalesMilestoneMember_23e35fb7-57fa-42f9-9661-c1851b6610a5" xlink:href="anab-20230331.xsd#anab_ThirdCommercialSalesMilestoneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_ffc21389-009d-420c-a77e-7ec4d74f27e3" xlink:to="loc_anab_ThirdCommercialSalesMilestoneMember_23e35fb7-57fa-42f9-9661-c1851b6610a5" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_FourthCommercialSalesMilestoneMember_d398292a-cac1-4cd4-866f-5c68034a3b0a" xlink:href="anab-20230331.xsd#anab_FourthCommercialSalesMilestoneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_ffc21389-009d-420c-a77e-7ec4d74f27e3" xlink:to="loc_anab_FourthCommercialSalesMilestoneMember_d398292a-cac1-4cd4-866f-5c68034a3b0a" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_CumulativeMilestonesRecognizedMember_5c092fb9-c33d-4d7c-b2e6-d4fe9a9ceb83" xlink:href="anab-20230331.xsd#anab_CumulativeMilestonesRecognizedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_ffc21389-009d-420c-a77e-7ec4d74f27e3" xlink:to="loc_anab_CumulativeMilestonesRecognizedMember_5c092fb9-c33d-4d7c-b2e6-d4fe9a9ceb83" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_MilestonesYetToBeRecognizedMember_173deb4d-4ce6-496f-949f-b652a36adf3d" xlink:href="anab-20230331.xsd#anab_MilestonesYetToBeRecognizedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_ffc21389-009d-420c-a77e-7ec4d74f27e3" xlink:to="loc_anab_MilestonesYetToBeRecognizedMember_173deb4d-4ce6-496f-949f-b652a36adf3d" xlink:type="arc" order="18"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.anaptysbio.com/role/SaleofFutureRoyaltiesNarrativesDetails" xlink:type="simple" xlink:href="anab-20230331.xsd#SaleofFutureRoyaltiesNarrativesDetails"/>
  <link:definitionLink xlink:role="http://www.anaptysbio.com/role/SaleofFutureRoyaltiesNarrativesDetails" xlink:type="extended" id="i6d68de410a924f22a580fa244c8ab822_SaleofFutureRoyaltiesNarrativesDetails">
    <link:loc xlink:type="locator" xlink:label="loc_anab_LiabilitiesRelatedToSaleOfFutureRoyaltiesLineItems_3abcb3b3-0c97-482b-8618-b5eae1751682" xlink:href="anab-20230331.xsd#anab_LiabilitiesRelatedToSaleOfFutureRoyaltiesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_ProceedsFromAdvanceFutureRoyalties_15213a86-898d-47de-8be3-2e3e6875cef7" xlink:href="anab-20230331.xsd#anab_ProceedsFromAdvanceFutureRoyalties"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_anab_LiabilitiesRelatedToSaleOfFutureRoyaltiesLineItems_3abcb3b3-0c97-482b-8618-b5eae1751682" xlink:to="loc_anab_ProceedsFromAdvanceFutureRoyalties_15213a86-898d-47de-8be3-2e3e6875cef7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_AdvanceFutureRoyaltiesAnnualSalesThreshold_6797541d-3957-4d4e-a1e4-ded566954382" xlink:href="anab-20230331.xsd#anab_AdvanceFutureRoyaltiesAnnualSalesThreshold"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_anab_LiabilitiesRelatedToSaleOfFutureRoyaltiesLineItems_3abcb3b3-0c97-482b-8618-b5eae1751682" xlink:to="loc_anab_AdvanceFutureRoyaltiesAnnualSalesThreshold_6797541d-3957-4d4e-a1e4-ded566954382" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_AdvanceFutureRoyaltiesAggregateAdditionalPayment_24ef99e2-b0d8-4497-bcbd-0867e445f047" xlink:href="anab-20230331.xsd#anab_AdvanceFutureRoyaltiesAggregateAdditionalPayment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_anab_LiabilitiesRelatedToSaleOfFutureRoyaltiesLineItems_3abcb3b3-0c97-482b-8618-b5eae1751682" xlink:to="loc_anab_AdvanceFutureRoyaltiesAggregateAdditionalPayment_24ef99e2-b0d8-4497-bcbd-0867e445f047" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_AdvanceFutureRoyaltiesAggregatePaymentThresholdPercent_699a7aa6-6080-48b1-995b-f33f96f3fa2c" xlink:href="anab-20230331.xsd#anab_AdvanceFutureRoyaltiesAggregatePaymentThresholdPercent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_anab_LiabilitiesRelatedToSaleOfFutureRoyaltiesLineItems_3abcb3b3-0c97-482b-8618-b5eae1751682" xlink:to="loc_anab_AdvanceFutureRoyaltiesAggregatePaymentThresholdPercent_699a7aa6-6080-48b1-995b-f33f96f3fa2c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_AdvanceFutureRoyaltyAndMilestonePayments_ccba9668-3606-4e5a-9b0d-3876c9cf3bcf" xlink:href="anab-20230331.xsd#anab_AdvanceFutureRoyaltyAndMilestonePayments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_anab_LiabilitiesRelatedToSaleOfFutureRoyaltiesLineItems_3abcb3b3-0c97-482b-8618-b5eae1751682" xlink:to="loc_anab_AdvanceFutureRoyaltyAndMilestonePayments_ccba9668-3606-4e5a-9b0d-3876c9cf3bcf" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_AdvanceFutureRoyaltiesLiabilityNoncurrent_b4c74fde-3a8c-4523-b97f-ad995978486f" xlink:href="anab-20230331.xsd#anab_AdvanceFutureRoyaltiesLiabilityNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_anab_LiabilitiesRelatedToSaleOfFutureRoyaltiesLineItems_3abcb3b3-0c97-482b-8618-b5eae1751682" xlink:to="loc_anab_AdvanceFutureRoyaltiesLiabilityNoncurrent_b4c74fde-3a8c-4523-b97f-ad995978486f" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_AdvanceFutureRoyaltiesIssuanceCosts_cf546bd4-6a7f-4167-b8ba-508c2aaa5309" xlink:href="anab-20230331.xsd#anab_AdvanceFutureRoyaltiesIssuanceCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_anab_LiabilitiesRelatedToSaleOfFutureRoyaltiesLineItems_3abcb3b3-0c97-482b-8618-b5eae1751682" xlink:to="loc_anab_AdvanceFutureRoyaltiesIssuanceCosts_cf546bd4-6a7f-4167-b8ba-508c2aaa5309" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_AdvanceFutureRoyaltiesLiabilityNoncurrentNet_4d7104f8-1751-4091-a136-0a92c50ed31c" xlink:href="anab-20230331.xsd#anab_AdvanceFutureRoyaltiesLiabilityNoncurrentNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_anab_LiabilitiesRelatedToSaleOfFutureRoyaltiesLineItems_3abcb3b3-0c97-482b-8618-b5eae1751682" xlink:to="loc_anab_AdvanceFutureRoyaltiesLiabilityNoncurrentNet_4d7104f8-1751-4091-a136-0a92c50ed31c" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_AdvanceFutureRoyaltiesInterestRateEffectivePercentage_e53c8b64-5951-4e4d-a7e2-53003cfd2695" xlink:href="anab-20230331.xsd#anab_AdvanceFutureRoyaltiesInterestRateEffectivePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_anab_LiabilitiesRelatedToSaleOfFutureRoyaltiesLineItems_3abcb3b3-0c97-482b-8618-b5eae1751682" xlink:to="loc_anab_AdvanceFutureRoyaltiesInterestRateEffectivePercentage_e53c8b64-5951-4e4d-a7e2-53003cfd2695" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_NoncashAdvanceFutureRoyaltiesRevenue_9bf2a8a4-69e7-4465-be44-e56d80f7294b" xlink:href="anab-20230331.xsd#anab_NoncashAdvanceFutureRoyaltiesRevenue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_anab_LiabilitiesRelatedToSaleOfFutureRoyaltiesLineItems_3abcb3b3-0c97-482b-8618-b5eae1751682" xlink:to="loc_anab_NoncashAdvanceFutureRoyaltiesRevenue_9bf2a8a4-69e7-4465-be44-e56d80f7294b" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_NoncashAdvanceFutureRoyaltiesInterestExpense_ce437270-feec-4fab-8cba-d1bf2a53eba6" xlink:href="anab-20230331.xsd#anab_NoncashAdvanceFutureRoyaltiesInterestExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_anab_LiabilitiesRelatedToSaleOfFutureRoyaltiesLineItems_3abcb3b3-0c97-482b-8618-b5eae1751682" xlink:to="loc_anab_NoncashAdvanceFutureRoyaltiesInterestExpense_ce437270-feec-4fab-8cba-d1bf2a53eba6" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_AdvanceFutureRoyaltiesRate_6065c048-b2cf-4f3d-9371-81a19cb9d019" xlink:href="anab-20230331.xsd#anab_AdvanceFutureRoyaltiesRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_anab_LiabilitiesRelatedToSaleOfFutureRoyaltiesLineItems_3abcb3b3-0c97-482b-8618-b5eae1751682" xlink:to="loc_anab_AdvanceFutureRoyaltiesRate_6065c048-b2cf-4f3d-9371-81a19cb9d019" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_AdvanceFutureRoyaltiesMinimumGlobalNetSalesRate_0fdae3b7-6014-4b34-ac2d-0b878a915d60" xlink:href="anab-20230331.xsd#anab_AdvanceFutureRoyaltiesMinimumGlobalNetSalesRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_anab_LiabilitiesRelatedToSaleOfFutureRoyaltiesLineItems_3abcb3b3-0c97-482b-8618-b5eae1751682" xlink:to="loc_anab_AdvanceFutureRoyaltiesMinimumGlobalNetSalesRate_0fdae3b7-6014-4b34-ac2d-0b878a915d60" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_AdvanceFutureRoyaltiesEffectiveRoyaltyRate_ed7d969e-4ea5-4d05-9cc7-09038647bb74" xlink:href="anab-20230331.xsd#anab_AdvanceFutureRoyaltiesEffectiveRoyaltyRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_anab_LiabilitiesRelatedToSaleOfFutureRoyaltiesLineItems_3abcb3b3-0c97-482b-8618-b5eae1751682" xlink:to="loc_anab_AdvanceFutureRoyaltiesEffectiveRoyaltyRate_ed7d969e-4ea5-4d05-9cc7-09038647bb74" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_e2eaff74-1161-4724-b9ff-a0cdf34a9c8d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_anab_LiabilitiesRelatedToSaleOfFutureRoyaltiesLineItems_3abcb3b3-0c97-482b-8618-b5eae1751682" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_e2eaff74-1161-4724-b9ff-a0cdf34a9c8d" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_LiabilitiesRelatedToSaleOfFutureRoyaltiesTable_805da742-ccfd-467d-ad78-8d3cbd6fc08c" xlink:href="anab-20230331.xsd#anab_LiabilitiesRelatedToSaleOfFutureRoyaltiesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_anab_LiabilitiesRelatedToSaleOfFutureRoyaltiesLineItems_3abcb3b3-0c97-482b-8618-b5eae1751682" xlink:to="loc_anab_LiabilitiesRelatedToSaleOfFutureRoyaltiesTable_805da742-ccfd-467d-ad78-8d3cbd6fc08c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TypeOfArrangementAxis_df694445-8245-49f4-b7a7-16386b407cb6" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TypeOfArrangementAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_anab_LiabilitiesRelatedToSaleOfFutureRoyaltiesTable_805da742-ccfd-467d-ad78-8d3cbd6fc08c" xlink:to="loc_us-gaap_TypeOfArrangementAxis_df694445-8245-49f4-b7a7-16386b407cb6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_df694445-8245-49f4-b7a7-16386b407cb6_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_TypeOfArrangementAxis_df694445-8245-49f4-b7a7-16386b407cb6" xlink:to="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_df694445-8245-49f4-b7a7-16386b407cb6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_0683384b-2553-4954-94c1-0ab2105f98a4" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_TypeOfArrangementAxis_df694445-8245-49f4-b7a7-16386b407cb6" xlink:to="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_0683384b-2553-4954-94c1-0ab2105f98a4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_JEMPERLIRoyaltyMonetizationAgreementMember_393d8b4c-7b30-4456-9bd3-9d460ea0b9b9" xlink:href="anab-20230331.xsd#anab_JEMPERLIRoyaltyMonetizationAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_0683384b-2553-4954-94c1-0ab2105f98a4" xlink:to="loc_anab_JEMPERLIRoyaltyMonetizationAgreementMember_393d8b4c-7b30-4456-9bd3-9d460ea0b9b9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_ZejulaRoyaltyMonetizationAgreementMember_625bcb1b-3191-48f7-a2e0-4e44ae0b9b4f" xlink:href="anab-20230331.xsd#anab_ZejulaRoyaltyMonetizationAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_0683384b-2553-4954-94c1-0ab2105f98a4" xlink:to="loc_anab_ZejulaRoyaltyMonetizationAgreementMember_625bcb1b-3191-48f7-a2e0-4e44ae0b9b4f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CounterpartyNameAxis_83cabb08-0bac-4fe4-848a-5fd346d866c8" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_CounterpartyNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_anab_LiabilitiesRelatedToSaleOfFutureRoyaltiesTable_805da742-ccfd-467d-ad78-8d3cbd6fc08c" xlink:to="loc_srt_CounterpartyNameAxis_83cabb08-0bac-4fe4-848a-5fd346d866c8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_83cabb08-0bac-4fe4-848a-5fd346d866c8_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_CounterpartyNameAxis_83cabb08-0bac-4fe4-848a-5fd346d866c8" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_83cabb08-0bac-4fe4-848a-5fd346d866c8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_cd357cc4-3490-42af-88a7-9b16b503f252" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_CounterpartyNameAxis_83cabb08-0bac-4fe4-848a-5fd346d866c8" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_cd357cc4-3490-42af-88a7-9b16b503f252" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_SagardHealthcareRoyaltyPartnersLPMember_ecc57ba7-473e-4a43-bd33-35e724b10bc8" xlink:href="anab-20230331.xsd#anab_SagardHealthcareRoyaltyPartnersLPMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_cd357cc4-3490-42af-88a7-9b16b503f252" xlink:to="loc_anab_SagardHealthcareRoyaltyPartnersLPMember_ecc57ba7-473e-4a43-bd33-35e724b10bc8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_GlaxoSmithKlineMember_64fd40e2-5557-4545-8d8e-03c4e056100d" xlink:href="anab-20230331.xsd#anab_GlaxoSmithKlineMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_cd357cc4-3490-42af-88a7-9b16b503f252" xlink:to="loc_anab_GlaxoSmithKlineMember_64fd40e2-5557-4545-8d8e-03c4e056100d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_DRIHealthcareTrustMember_9f7a3d3e-3e64-44c5-afa5-a13301f2d4d6" xlink:href="anab-20230331.xsd#anab_DRIHealthcareTrustMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_cd357cc4-3490-42af-88a7-9b16b503f252" xlink:to="loc_anab_DRIHealthcareTrustMember_9f7a3d3e-3e64-44c5-afa5-a13301f2d4d6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_AdvanceFutureRoyaltiesPaymentAxis_fa04eeab-c997-48b9-baef-54d0bd97568f" xlink:href="anab-20230331.xsd#anab_AdvanceFutureRoyaltiesPaymentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_anab_LiabilitiesRelatedToSaleOfFutureRoyaltiesTable_805da742-ccfd-467d-ad78-8d3cbd6fc08c" xlink:to="loc_anab_AdvanceFutureRoyaltiesPaymentAxis_fa04eeab-c997-48b9-baef-54d0bd97568f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_AdvanceFutureRoyaltiesPaymentDomain_fa04eeab-c997-48b9-baef-54d0bd97568f_default" xlink:href="anab-20230331.xsd#anab_AdvanceFutureRoyaltiesPaymentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_anab_AdvanceFutureRoyaltiesPaymentAxis_fa04eeab-c997-48b9-baef-54d0bd97568f" xlink:to="loc_anab_AdvanceFutureRoyaltiesPaymentDomain_fa04eeab-c997-48b9-baef-54d0bd97568f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_AdvanceFutureRoyaltiesPaymentDomain_e2460616-945d-4ee6-9fbf-9643f53c8219" xlink:href="anab-20230331.xsd#anab_AdvanceFutureRoyaltiesPaymentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_anab_AdvanceFutureRoyaltiesPaymentAxis_fa04eeab-c997-48b9-baef-54d0bd97568f" xlink:to="loc_anab_AdvanceFutureRoyaltiesPaymentDomain_e2460616-945d-4ee6-9fbf-9643f53c8219" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_FirstInstallmentMember_c8f3b428-de80-487e-b7cf-b1915201dd96" xlink:href="anab-20230331.xsd#anab_FirstInstallmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_anab_AdvanceFutureRoyaltiesPaymentDomain_e2460616-945d-4ee6-9fbf-9643f53c8219" xlink:to="loc_anab_FirstInstallmentMember_c8f3b428-de80-487e-b7cf-b1915201dd96" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_SecondInstallmentMember_274bc104-21a4-4275-8a6b-2b333cdf373e" xlink:href="anab-20230331.xsd#anab_SecondInstallmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_anab_AdvanceFutureRoyaltiesPaymentDomain_e2460616-945d-4ee6-9fbf-9643f53c8219" xlink:to="loc_anab_SecondInstallmentMember_274bc104-21a4-4275-8a6b-2b333cdf373e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_ThirdInstallmentMember_f69f9378-df85-419d-9f4f-a0224f7f749d" xlink:href="anab-20230331.xsd#anab_ThirdInstallmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_anab_AdvanceFutureRoyaltiesPaymentDomain_e2460616-945d-4ee6-9fbf-9643f53c8219" xlink:to="loc_anab_ThirdInstallmentMember_f69f9378-df85-419d-9f4f-a0224f7f749d" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.anaptysbio.com/role/SaleofFutureRoyaltiesScheduleofRoyaltyTransactionActivityDetails" xlink:type="simple" xlink:href="anab-20230331.xsd#SaleofFutureRoyaltiesScheduleofRoyaltyTransactionActivityDetails"/>
  <link:definitionLink xlink:role="http://www.anaptysbio.com/role/SaleofFutureRoyaltiesScheduleofRoyaltyTransactionActivityDetails" xlink:type="extended" id="i0398bafa48514d42b930c454a68e8d46_SaleofFutureRoyaltiesScheduleofRoyaltyTransactionActivityDetails">
    <link:loc xlink:type="locator" xlink:label="loc_anab_LiabilitiesRelatedToSaleOfFutureRoyaltiesLineItems_479cf188-ff52-42f8-ae2c-7c02fce90ce1" xlink:href="anab-20230331.xsd#anab_LiabilitiesRelatedToSaleOfFutureRoyaltiesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_LiabilitiesRelatedToSaleOfFutureRoyaltiesRollForward_3b9325e2-ac4a-466b-8736-348b006fb38c" xlink:href="anab-20230331.xsd#anab_LiabilitiesRelatedToSaleOfFutureRoyaltiesRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_anab_LiabilitiesRelatedToSaleOfFutureRoyaltiesLineItems_479cf188-ff52-42f8-ae2c-7c02fce90ce1" xlink:to="loc_anab_LiabilitiesRelatedToSaleOfFutureRoyaltiesRollForward_3b9325e2-ac4a-466b-8736-348b006fb38c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_AdvanceFutureRoyaltiesLiabilities_5a9c453d-63dc-4bc6-90a3-0faf12d35a45" xlink:href="anab-20230331.xsd#anab_AdvanceFutureRoyaltiesLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_anab_LiabilitiesRelatedToSaleOfFutureRoyaltiesRollForward_3b9325e2-ac4a-466b-8736-348b006fb38c" xlink:to="loc_anab_AdvanceFutureRoyaltiesLiabilities_5a9c453d-63dc-4bc6-90a3-0faf12d35a45" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_AdvanceFutureRoyaltiesIssuanceCosts_a0e8f4ad-7b4a-4d5f-a90b-879b0fbf7275" xlink:href="anab-20230331.xsd#anab_AdvanceFutureRoyaltiesIssuanceCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_anab_LiabilitiesRelatedToSaleOfFutureRoyaltiesRollForward_3b9325e2-ac4a-466b-8736-348b006fb38c" xlink:to="loc_anab_AdvanceFutureRoyaltiesIssuanceCosts_a0e8f4ad-7b4a-4d5f-a90b-879b0fbf7275" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_AmortizationOfAdvanceFutureRoyaltiesIssuanceCosts_3d7b4db8-2ef2-437f-b07a-13a2912a2b79" xlink:href="anab-20230331.xsd#anab_AmortizationOfAdvanceFutureRoyaltiesIssuanceCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_anab_LiabilitiesRelatedToSaleOfFutureRoyaltiesRollForward_3b9325e2-ac4a-466b-8736-348b006fb38c" xlink:to="loc_anab_AmortizationOfAdvanceFutureRoyaltiesIssuanceCosts_3d7b4db8-2ef2-437f-b07a-13a2912a2b79" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_RepaymentOfAdvanceFutureRoyaltyAndMilestones_4d53f5c8-2385-4f18-9080-a5c3880c94a2" xlink:href="anab-20230331.xsd#anab_RepaymentOfAdvanceFutureRoyaltyAndMilestones"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_anab_LiabilitiesRelatedToSaleOfFutureRoyaltiesRollForward_3b9325e2-ac4a-466b-8736-348b006fb38c" xlink:to="loc_anab_RepaymentOfAdvanceFutureRoyaltyAndMilestones_4d53f5c8-2385-4f18-9080-a5c3880c94a2" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_NoncashAdvanceFutureRoyaltiesInterestExpense_c7f01b3c-c959-427b-9a17-4a7816bde59d" xlink:href="anab-20230331.xsd#anab_NoncashAdvanceFutureRoyaltiesInterestExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_anab_LiabilitiesRelatedToSaleOfFutureRoyaltiesRollForward_3b9325e2-ac4a-466b-8736-348b006fb38c" xlink:to="loc_anab_NoncashAdvanceFutureRoyaltiesInterestExpense_c7f01b3c-c959-427b-9a17-4a7816bde59d" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_AdvanceFutureRoyaltiesLiabilities_c0efab1f-fb80-4a38-996e-8235d6d6b0e0" xlink:href="anab-20230331.xsd#anab_AdvanceFutureRoyaltiesLiabilities"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_LiabilitiesRelatedToSaleOfFutureRoyaltiesTable_3564748e-ada8-4f25-9d2e-76eddabae9c0" xlink:href="anab-20230331.xsd#anab_LiabilitiesRelatedToSaleOfFutureRoyaltiesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_anab_LiabilitiesRelatedToSaleOfFutureRoyaltiesLineItems_479cf188-ff52-42f8-ae2c-7c02fce90ce1" xlink:to="loc_anab_LiabilitiesRelatedToSaleOfFutureRoyaltiesTable_3564748e-ada8-4f25-9d2e-76eddabae9c0" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TypeOfArrangementAxis_5216989a-e30c-40f3-99f3-41566841c443" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TypeOfArrangementAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_anab_LiabilitiesRelatedToSaleOfFutureRoyaltiesTable_3564748e-ada8-4f25-9d2e-76eddabae9c0" xlink:to="loc_us-gaap_TypeOfArrangementAxis_5216989a-e30c-40f3-99f3-41566841c443" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_5216989a-e30c-40f3-99f3-41566841c443_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_TypeOfArrangementAxis_5216989a-e30c-40f3-99f3-41566841c443" xlink:to="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_5216989a-e30c-40f3-99f3-41566841c443_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_ec55ffa2-490f-42d8-b314-4a1b6f48dc51" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_TypeOfArrangementAxis_5216989a-e30c-40f3-99f3-41566841c443" xlink:to="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_ec55ffa2-490f-42d8-b314-4a1b6f48dc51" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_JEMPERLIRoyaltyMonetizationAgreementMember_71078cd1-217c-4c2b-a65e-e2ed37fac22d" xlink:href="anab-20230331.xsd#anab_JEMPERLIRoyaltyMonetizationAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_ec55ffa2-490f-42d8-b314-4a1b6f48dc51" xlink:to="loc_anab_JEMPERLIRoyaltyMonetizationAgreementMember_71078cd1-217c-4c2b-a65e-e2ed37fac22d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_ZejulaRoyaltyMonetizationAgreementMember_932d5a58-8456-4b5a-ada7-ee8a30fce077" xlink:href="anab-20230331.xsd#anab_ZejulaRoyaltyMonetizationAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_ec55ffa2-490f-42d8-b314-4a1b6f48dc51" xlink:to="loc_anab_ZejulaRoyaltyMonetizationAgreementMember_932d5a58-8456-4b5a-ada7-ee8a30fce077" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.anaptysbio.com/role/FairValueMeasurementsandAvailableforSaleInvestmentsAssetsandLiabilitiesMeasuredatFairValueonaRecurringBasisDetails" xlink:type="simple" xlink:href="anab-20230331.xsd#FairValueMeasurementsandAvailableforSaleInvestmentsAssetsandLiabilitiesMeasuredatFairValueonaRecurringBasisDetails"/>
  <link:definitionLink xlink:role="http://www.anaptysbio.com/role/FairValueMeasurementsandAvailableforSaleInvestmentsAssetsandLiabilitiesMeasuredatFairValueonaRecurringBasisDetails" xlink:type="extended" id="i6ec4d194748246df86149d56043e654b_FairValueMeasurementsandAvailableforSaleInvestmentsAssetsandLiabilitiesMeasuredatFairValueonaRecurringBasisDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_5b091ab1-7dc5-4549-9426-53327e13f4ca" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_CashAndCashEquivalentsAndRestrictedCashFairValueDisclosure_30c33569-a235-4c35-ab9f-3ae3b022eae3" xlink:href="anab-20230331.xsd#anab_CashAndCashEquivalentsAndRestrictedCashFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_5b091ab1-7dc5-4549-9426-53327e13f4ca" xlink:to="loc_anab_CashAndCashEquivalentsAndRestrictedCashFairValueDisclosure_30c33569-a235-4c35-ab9f-3ae3b022eae3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_93eec65d-8e83-4540-a666-bc479f6a3542" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_5b091ab1-7dc5-4549-9426-53327e13f4ca" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_93eec65d-8e83-4540-a666-bc479f6a3542" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_8ee494d3-7256-41be-9723-2a1ab9149a09" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_5b091ab1-7dc5-4549-9426-53327e13f4ca" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_8ee494d3-7256-41be-9723-2a1ab9149a09" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByMeasurementFrequencyAxis_6f54a161-d92f-482f-a3d2-ca73a51c7fd7" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueByMeasurementFrequencyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_8ee494d3-7256-41be-9723-2a1ab9149a09" xlink:to="loc_us-gaap_FairValueByMeasurementFrequencyAxis_6f54a161-d92f-482f-a3d2-ca73a51c7fd7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_6f54a161-d92f-482f-a3d2-ca73a51c7fd7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_6f54a161-d92f-482f-a3d2-ca73a51c7fd7" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_6f54a161-d92f-482f-a3d2-ca73a51c7fd7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_4f28a644-5364-4c31-a0bc-2462d67e236e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_6f54a161-d92f-482f-a3d2-ca73a51c7fd7" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_4f28a644-5364-4c31-a0bc-2462d67e236e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsRecurringMember_e8978480-e50a-41e5-81d4-cd871462c3ad" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueMeasurementsRecurringMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementFrequencyDomain_4f28a644-5364-4c31-a0bc-2462d67e236e" xlink:to="loc_us-gaap_FairValueMeasurementsRecurringMember_e8978480-e50a-41e5-81d4-cd871462c3ad" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_ba02fa27-fe4a-409a-9039-0ddcd2eccb31" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_8ee494d3-7256-41be-9723-2a1ab9149a09" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_ba02fa27-fe4a-409a-9039-0ddcd2eccb31" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_ba02fa27-fe4a-409a-9039-0ddcd2eccb31_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_ba02fa27-fe4a-409a-9039-0ddcd2eccb31" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_ba02fa27-fe4a-409a-9039-0ddcd2eccb31_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_9481e7cc-0d4b-49a6-83ef-0ed94bdee417" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_ba02fa27-fe4a-409a-9039-0ddcd2eccb31" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_9481e7cc-0d4b-49a6-83ef-0ed94bdee417" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_92da00de-d84c-4716-8800-35de9d1ef5e3" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_9481e7cc-0d4b-49a6-83ef-0ed94bdee417" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_92da00de-d84c-4716-8800-35de9d1ef5e3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_74e432d3-3bdc-4a0c-b8a2-b56de302bf30" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_9481e7cc-0d4b-49a6-83ef-0ed94bdee417" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_74e432d3-3bdc-4a0c-b8a2-b56de302bf30" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_844f86ff-2b57-464c-801a-e2f0479e1053" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_9481e7cc-0d4b-49a6-83ef-0ed94bdee417" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_844f86ff-2b57-464c-801a-e2f0479e1053" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAxis_334c02df-fb6b-4e9c-b7c0-59fb0e671711" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CashAndCashEquivalentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_8ee494d3-7256-41be-9723-2a1ab9149a09" xlink:to="loc_us-gaap_CashAndCashEquivalentsAxis_334c02df-fb6b-4e9c-b7c0-59fb0e671711" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_334c02df-fb6b-4e9c-b7c0-59fb0e671711_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CashAndCashEquivalentsAxis_334c02df-fb6b-4e9c-b7c0-59fb0e671711" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_334c02df-fb6b-4e9c-b7c0-59fb0e671711_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_82c59200-cffb-42bb-9184-159399ae00ca" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CashAndCashEquivalentsAxis_334c02df-fb6b-4e9c-b7c0-59fb0e671711" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_82c59200-cffb-42bb-9184-159399ae00ca" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MoneyMarketFundsMember_5dbf83a2-962e-4e2d-9374-5fa5ac2f1cb4" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_MoneyMarketFundsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_82c59200-cffb-42bb-9184-159399ae00ca" xlink:to="loc_us-gaap_MoneyMarketFundsMember_5dbf83a2-962e-4e2d-9374-5fa5ac2f1cb4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MutualFundMember_5a92c66c-8426-4bdf-b077-d04352c7abc7" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_MutualFundMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_82c59200-cffb-42bb-9184-159399ae00ca" xlink:to="loc_us-gaap_MutualFundMember_5a92c66c-8426-4bdf-b077-d04352c7abc7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_3279dfe0-bc42-46d7-b154-7bed58492adb" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_8ee494d3-7256-41be-9723-2a1ab9149a09" xlink:to="loc_us-gaap_FinancialInstrumentAxis_3279dfe0-bc42-46d7-b154-7bed58492adb" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_3279dfe0-bc42-46d7-b154-7bed58492adb_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_3279dfe0-bc42-46d7-b154-7bed58492adb" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_3279dfe0-bc42-46d7-b154-7bed58492adb_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_cc328de5-77fa-4685-8186-9a16bd21dc84" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_3279dfe0-bc42-46d7-b154-7bed58492adb" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_cc328de5-77fa-4685-8186-9a16bd21dc84" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_USTreasurySecuritiesMember_69d0c7f4-eebb-4bc1-8f2b-fa69470c9f76" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_USTreasurySecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_cc328de5-77fa-4685-8186-9a16bd21dc84" xlink:to="loc_us-gaap_USTreasurySecuritiesMember_69d0c7f4-eebb-4bc1-8f2b-fa69470c9f76" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CertificatesOfDepositMember_93aa2b1a-d630-4755-8b09-b5ecdb358c7d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CertificatesOfDepositMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_cc328de5-77fa-4685-8186-9a16bd21dc84" xlink:to="loc_us-gaap_CertificatesOfDepositMember_93aa2b1a-d630-4755-8b09-b5ecdb358c7d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_USGovernmentAgenciesDebtSecuritiesMember_99f31063-0ae5-4db3-8803-012f0f9f3c02" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_USGovernmentAgenciesDebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_cc328de5-77fa-4685-8186-9a16bd21dc84" xlink:to="loc_us-gaap_USGovernmentAgenciesDebtSecuritiesMember_99f31063-0ae5-4db3-8803-012f0f9f3c02" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_CommercialAndCorporateObligationsMember_d6771abf-f8fb-4c78-8b16-b68800571924" xlink:href="anab-20230331.xsd#anab_CommercialAndCorporateObligationsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_cc328de5-77fa-4685-8186-9a16bd21dc84" xlink:to="loc_anab_CommercialAndCorporateObligationsMember_d6771abf-f8fb-4c78-8b16-b68800571924" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.anaptysbio.com/role/FairValueMeasurementsandAvailableforSaleInvestmentsAvailableforsaleInvestmentsDetails" xlink:type="simple" xlink:href="anab-20230331.xsd#FairValueMeasurementsandAvailableforSaleInvestmentsAvailableforsaleInvestmentsDetails"/>
  <link:definitionLink xlink:role="http://www.anaptysbio.com/role/FairValueMeasurementsandAvailableforSaleInvestmentsAvailableforsaleInvestmentsDetails" xlink:type="extended" id="i0f81fe0911cf4f9ba76d657decf20b47_FairValueMeasurementsandAvailableforSaleInvestmentsAvailableforsaleInvestmentsDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_a259708e-5984-46ea-8bb7-a95eaecc7af8" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_9a1485a5-951f-48c3-846e-e9748f70e3e9" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_a259708e-5984-46ea-8bb7-a95eaecc7af8" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_9a1485a5-951f-48c3-846e-e9748f70e3e9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_c906ce01-3b3a-42ef-931c-e374d26520fd" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_a259708e-5984-46ea-8bb7-a95eaecc7af8" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_c906ce01-3b3a-42ef-931c-e374d26520fd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_0488c07c-6ce5-4f57-8e79-ea5f9dcc33ba" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_a259708e-5984-46ea-8bb7-a95eaecc7af8" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_0488c07c-6ce5-4f57-8e79-ea5f9dcc33ba" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_0b2327be-5f7d-4f8c-84c3-7de27d8a3614" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_a259708e-5984-46ea-8bb7-a95eaecc7af8" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_0b2327be-5f7d-4f8c-84c3-7de27d8a3614" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecuritiesCurrent_e6b59787-2026-4b7f-b212-dcddd82edd47" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecuritiesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_a259708e-5984-46ea-8bb7-a95eaecc7af8" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtSecuritiesCurrent_e6b59787-2026-4b7f-b212-dcddd82edd47" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecuritiesNoncurrent_aa51f3cb-08bb-4832-b54a-ecd928967866" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecuritiesNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_a259708e-5984-46ea-8bb7-a95eaecc7af8" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtSecuritiesNoncurrent_aa51f3cb-08bb-4832-b54a-ecd928967866" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_AvailableforsaleDebtSecuritiesRemainingMaturity_40b3e54c-822f-4c8a-8f51-27040cfc7027" xlink:href="anab-20230331.xsd#anab_AvailableforsaleDebtSecuritiesRemainingMaturity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_a259708e-5984-46ea-8bb7-a95eaecc7af8" xlink:to="loc_anab_AvailableforsaleDebtSecuritiesRemainingMaturity_40b3e54c-822f-4c8a-8f51-27040cfc7027" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_a7664eff-92f9-4f0f-8e55-a9864753d844" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtSecuritiesAvailableForSaleTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_a259708e-5984-46ea-8bb7-a95eaecc7af8" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_a7664eff-92f9-4f0f-8e55-a9864753d844" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_566dea5d-fdaf-4e2d-9add-e7fd492757d0" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_a7664eff-92f9-4f0f-8e55-a9864753d844" xlink:to="loc_us-gaap_FinancialInstrumentAxis_566dea5d-fdaf-4e2d-9add-e7fd492757d0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_566dea5d-fdaf-4e2d-9add-e7fd492757d0_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_566dea5d-fdaf-4e2d-9add-e7fd492757d0" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_566dea5d-fdaf-4e2d-9add-e7fd492757d0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_4dcc9d1e-7e65-4b3e-a0de-6b80f54c5d43" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_566dea5d-fdaf-4e2d-9add-e7fd492757d0" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_4dcc9d1e-7e65-4b3e-a0de-6b80f54c5d43" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_USGovernmentAgenciesDebtSecuritiesMember_d5dd71a5-4ac4-4073-8d5d-972eb58af803" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_USGovernmentAgenciesDebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_4dcc9d1e-7e65-4b3e-a0de-6b80f54c5d43" xlink:to="loc_us-gaap_USGovernmentAgenciesDebtSecuritiesMember_d5dd71a5-4ac4-4073-8d5d-972eb58af803" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CertificatesOfDepositMember_337b22cc-7857-4219-90ce-7d5a9f239aff" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CertificatesOfDepositMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_4dcc9d1e-7e65-4b3e-a0de-6b80f54c5d43" xlink:to="loc_us-gaap_CertificatesOfDepositMember_337b22cc-7857-4219-90ce-7d5a9f239aff" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_CommercialAndCorporateObligationsMember_15c6a202-5c9f-4e37-bec2-49bc90216bf4" xlink:href="anab-20230331.xsd#anab_CommercialAndCorporateObligationsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_4dcc9d1e-7e65-4b3e-a0de-6b80f54c5d43" xlink:to="loc_anab_CommercialAndCorporateObligationsMember_15c6a202-5c9f-4e37-bec2-49bc90216bf4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_USTreasurySecuritiesMember_da49f957-bba3-4970-8369-8a3c71a6f92e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_USTreasurySecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_4dcc9d1e-7e65-4b3e-a0de-6b80f54c5d43" xlink:to="loc_us-gaap_USTreasurySecuritiesMember_da49f957-bba3-4970-8369-8a3c71a6f92e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_cde5f1df-8ee3-4e1d-9459-7463ccf72e43" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_a7664eff-92f9-4f0f-8e55-a9864753d844" xlink:to="loc_srt_RangeAxis_cde5f1df-8ee3-4e1d-9459-7463ccf72e43" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_cde5f1df-8ee3-4e1d-9459-7463ccf72e43_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_cde5f1df-8ee3-4e1d-9459-7463ccf72e43" xlink:to="loc_srt_RangeMember_cde5f1df-8ee3-4e1d-9459-7463ccf72e43_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_b34a60e7-9c1b-4263-9cee-9fa2cc49a627" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_cde5f1df-8ee3-4e1d-9459-7463ccf72e43" xlink:to="loc_srt_RangeMember_b34a60e7-9c1b-4263-9cee-9fa2cc49a627" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_b47cf6b7-6eb6-4332-9e90-18b0f80422c2" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_b34a60e7-9c1b-4263-9cee-9fa2cc49a627" xlink:to="loc_srt_MinimumMember_b47cf6b7-6eb6-4332-9e90-18b0f80422c2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_c35e968d-8810-4231-a636-4d18aa709c05" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_b34a60e7-9c1b-4263-9cee-9fa2cc49a627" xlink:to="loc_srt_MaximumMember_c35e968d-8810-4231-a636-4d18aa709c05" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.anaptysbio.com/role/FairValueMeasurementsandAvailableforSaleInvestmentsScheduleofUnrealizedLossandFairValuesinaLossPositionDetails" xlink:type="simple" xlink:href="anab-20230331.xsd#FairValueMeasurementsandAvailableforSaleInvestmentsScheduleofUnrealizedLossandFairValuesinaLossPositionDetails"/>
  <link:definitionLink xlink:role="http://www.anaptysbio.com/role/FairValueMeasurementsandAvailableforSaleInvestmentsScheduleofUnrealizedLossandFairValuesinaLossPositionDetails" xlink:type="extended" id="i0ab246fddd6a41d992c6a65be6d7cbff_FairValueMeasurementsandAvailableforSaleInvestmentsScheduleofUnrealizedLossandFairValuesinaLossPositionDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_05d10f59-c4da-4f30-8eed-511ccea84e15" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months_fa686a4f-af11-43af-ace5-b8135edb18e2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_05d10f59-c4da-4f30-8eed-511ccea84e15" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months_fa686a4f-af11-43af-ace5-b8135edb18e2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss_db78de3c-0b04-4b73-8bce-d03a4f27f782" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_05d10f59-c4da-4f30-8eed-511ccea84e15" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss_db78de3c-0b04-4b73-8bce-d03a4f27f782" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger_2abbc92d-3048-4823-925b-4169f4f04fb3" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_05d10f59-c4da-4f30-8eed-511ccea84e15" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger_2abbc92d-3048-4823-925b-4169f4f04fb3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss_d2e8dedf-cc57-4403-b7e1-3f3853bf2097" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_05d10f59-c4da-4f30-8eed-511ccea84e15" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss_d2e8dedf-cc57-4403-b7e1-3f3853bf2097" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition_f1ecf08c-b1a9-4354-90e9-c4dd641c4de5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_05d10f59-c4da-4f30-8eed-511ccea84e15" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition_f1ecf08c-b1a9-4354-90e9-c4dd641c4de5" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss_df5b62c7-986a-4849-955d-08063f63b8e8" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_05d10f59-c4da-4f30-8eed-511ccea84e15" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss_df5b62c7-986a-4849-955d-08063f63b8e8" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_a1db465d-0c99-4c99-9490-9e72bcc322d4" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtSecuritiesAvailableForSaleTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_05d10f59-c4da-4f30-8eed-511ccea84e15" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_a1db465d-0c99-4c99-9490-9e72bcc322d4" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_ff61bd60-766a-4794-b11c-46fdc27f3070" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_a1db465d-0c99-4c99-9490-9e72bcc322d4" xlink:to="loc_us-gaap_FinancialInstrumentAxis_ff61bd60-766a-4794-b11c-46fdc27f3070" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_ff61bd60-766a-4794-b11c-46fdc27f3070_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_ff61bd60-766a-4794-b11c-46fdc27f3070" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_ff61bd60-766a-4794-b11c-46fdc27f3070_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_e6431b1e-b192-4abc-a76a-b261fa6c8f39" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_ff61bd60-766a-4794-b11c-46fdc27f3070" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_e6431b1e-b192-4abc-a76a-b261fa6c8f39" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_USGovernmentAgenciesDebtSecuritiesMember_918926e8-0f6b-461e-9d00-25ea90e30c52" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_USGovernmentAgenciesDebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_e6431b1e-b192-4abc-a76a-b261fa6c8f39" xlink:to="loc_us-gaap_USGovernmentAgenciesDebtSecuritiesMember_918926e8-0f6b-461e-9d00-25ea90e30c52" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_CommercialAndCorporateObligationsMember_1281e221-68c5-4187-a7f2-6f8c2211cde2" xlink:href="anab-20230331.xsd#anab_CommercialAndCorporateObligationsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_e6431b1e-b192-4abc-a76a-b261fa6c8f39" xlink:to="loc_anab_CommercialAndCorporateObligationsMember_1281e221-68c5-4187-a7f2-6f8c2211cde2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CertificatesOfDepositMember_2ea44988-b525-4e15-8e6a-5f01909cd4b5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CertificatesOfDepositMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_e6431b1e-b192-4abc-a76a-b261fa6c8f39" xlink:to="loc_us-gaap_CertificatesOfDepositMember_2ea44988-b525-4e15-8e6a-5f01909cd4b5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_USTreasurySecuritiesMember_6949e194-3067-4f26-a4d8-2aebc635bb54" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_USTreasurySecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_e6431b1e-b192-4abc-a76a-b261fa6c8f39" xlink:to="loc_us-gaap_USTreasurySecuritiesMember_6949e194-3067-4f26-a4d8-2aebc635bb54" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.anaptysbio.com/role/StockholdersEquityNarrativeDetails" xlink:type="simple" xlink:href="anab-20230331.xsd#StockholdersEquityNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.anaptysbio.com/role/StockholdersEquityNarrativeDetails" xlink:type="extended" id="if9b584001f6043539ffbffb18be7f656_StockholdersEquityNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockLineItems_852ac5aa-ec63-498f-861f-0e212b774b27" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ClassOfStockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesAuthorized_75250e84-1829-4b0d-8ad9-dad8081e7376" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonStockSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_852ac5aa-ec63-498f-861f-0e212b774b27" xlink:to="loc_us-gaap_CommonStockSharesAuthorized_75250e84-1829-4b0d-8ad9-dad8081e7376" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesIssued_83fb4787-88c9-47e9-bda1-1661b5f2434b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonStockSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_852ac5aa-ec63-498f-861f-0e212b774b27" xlink:to="loc_us-gaap_CommonStockSharesIssued_83fb4787-88c9-47e9-bda1-1661b5f2434b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_349ed13a-9192-463b-8feb-33d1e99e2db7" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_852ac5aa-ec63-498f-861f-0e212b774b27" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_349ed13a-9192-463b-8feb-33d1e99e2db7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchaseProgramAuthorizedAmount1_10aebe60-3097-4a36-b540-fa0f02d256d3" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockRepurchaseProgramAuthorizedAmount1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_852ac5aa-ec63-498f-861f-0e212b774b27" xlink:to="loc_us-gaap_StockRepurchaseProgramAuthorizedAmount1_10aebe60-3097-4a36-b540-fa0f02d256d3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockParOrStatedValuePerShare_e1c0f9b1-206b-488f-852a-a1339fafd2d1" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonStockParOrStatedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_852ac5aa-ec63-498f-861f-0e212b774b27" xlink:to="loc_us-gaap_CommonStockParOrStatedValuePerShare_e1c0f9b1-206b-488f-852a-a1339fafd2d1" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1_281b59ae-d8c5-4620-a6ff-9d9e7c5d1f2c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_852ac5aa-ec63-498f-861f-0e212b774b27" xlink:to="loc_us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1_281b59ae-d8c5-4620-a6ff-9d9e7c5d1f2c" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_SaleOfStockAuthorizedAggerageteOfferingMaximum_41a4118a-78ec-404d-a6be-bbd086e5d239" xlink:href="anab-20230331.xsd#anab_SaleOfStockAuthorizedAggerageteOfferingMaximum"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_852ac5aa-ec63-498f-861f-0e212b774b27" xlink:to="loc_anab_SaleOfStockAuthorizedAggerageteOfferingMaximum_41a4118a-78ec-404d-a6be-bbd086e5d239" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_5753a192-220f-4b43-be26-0a597a5c8c52" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_852ac5aa-ec63-498f-861f-0e212b774b27" xlink:to="loc_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_5753a192-220f-4b43-be26-0a597a5c8c52" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfStockByClassTable_5078cd60-1678-4ff8-be3d-81bab4be4565" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfStockByClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ClassOfStockLineItems_852ac5aa-ec63-498f-861f-0e212b774b27" xlink:to="loc_us-gaap_ScheduleOfStockByClassTable_5078cd60-1678-4ff8-be3d-81bab4be4565" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsidiarySaleOfStockAxis_e4ac812e-79fb-4861-bd73-bd5c6c40a0b5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsidiarySaleOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_5078cd60-1678-4ff8-be3d-81bab4be4565" xlink:to="loc_us-gaap_SubsidiarySaleOfStockAxis_e4ac812e-79fb-4861-bd73-bd5c6c40a0b5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain_e4ac812e-79fb-4861-bd73-bd5c6c40a0b5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsidiarySaleOfStockAxis_e4ac812e-79fb-4861-bd73-bd5c6c40a0b5" xlink:to="loc_us-gaap_SaleOfStockNameOfTransactionDomain_e4ac812e-79fb-4861-bd73-bd5c6c40a0b5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain_bae622c5-04ff-484c-bcf6-1dc96888a0a7" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsidiarySaleOfStockAxis_e4ac812e-79fb-4861-bd73-bd5c6c40a0b5" xlink:to="loc_us-gaap_SaleOfStockNameOfTransactionDomain_bae622c5-04ff-484c-bcf6-1dc96888a0a7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_OpenMarketSalesAgreementMember_b5ade8ef-642a-46b1-8331-5409b56f259d" xlink:href="anab-20230331.xsd#anab_OpenMarketSalesAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SaleOfStockNameOfTransactionDomain_bae622c5-04ff-484c-bcf6-1dc96888a0a7" xlink:to="loc_anab_OpenMarketSalesAgreementMember_b5ade8ef-642a-46b1-8331-5409b56f259d" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.anaptysbio.com/role/EquityIncentivePlansNarrativeDetails" xlink:type="simple" xlink:href="anab-20230331.xsd#EquityIncentivePlansNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.anaptysbio.com/role/EquityIncentivePlansNarrativeDetails" xlink:type="extended" id="i14a3b4dd526740118aa8346744fa04b0_EquityIncentivePlansNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_de70e3df-2068-4a86-8c39-1ac1d6f6a621" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_CommonStockCapitalSharesReservedForFutureIssuanceAnnualIncreasePercentOfAggregateSharesOutstanding_5dc6a4ae-b4ba-4b97-8876-b2ad1acf7621" xlink:href="anab-20230331.xsd#anab_CommonStockCapitalSharesReservedForFutureIssuanceAnnualIncreasePercentOfAggregateSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_de70e3df-2068-4a86-8c39-1ac1d6f6a621" xlink:to="loc_anab_CommonStockCapitalSharesReservedForFutureIssuanceAnnualIncreasePercentOfAggregateSharesOutstanding_5dc6a4ae-b4ba-4b97-8876-b2ad1acf7621" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_CommonStockCapitalSharesReservedForFutureIssuanceIncrease_5533c4e1-b443-49b2-beef-361d4105e140" xlink:href="anab-20230331.xsd#anab_CommonStockCapitalSharesReservedForFutureIssuanceIncrease"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_de70e3df-2068-4a86-8c39-1ac1d6f6a621" xlink:to="loc_anab_CommonStockCapitalSharesReservedForFutureIssuanceIncrease_5533c4e1-b443-49b2-beef-361d4105e140" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_5c5aeecd-9161-491c-b912-03f3d4d4e789" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_de70e3df-2068-4a86-8c39-1ac1d6f6a621" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_5c5aeecd-9161-491c-b912-03f3d4d4e789" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsed_64414d37-844c-49ac-a7ae-c3b631937632" xlink:href="anab-20230331.xsd#anab_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsed"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_de70e3df-2068-4a86-8c39-1ac1d6f6a621" xlink:to="loc_anab_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsed_64414d37-844c-49ac-a7ae-c3b631937632" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_771ea52c-57ed-4904-a973-aaaa672e9aa8" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_de70e3df-2068-4a86-8c39-1ac1d6f6a621" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_771ea52c-57ed-4904-a973-aaaa672e9aa8" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_733edc8f-861e-484b-86f2-efb410740bd7" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_de70e3df-2068-4a86-8c39-1ac1d6f6a621" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_733edc8f-861e-484b-86f2-efb410740bd7" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromStockOptionsExercised_88ba0b25-42ea-47c3-ad96-4e2bf383a3e5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ProceedsFromStockOptionsExercised"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_de70e3df-2068-4a86-8c39-1ac1d6f6a621" xlink:to="loc_us-gaap_ProceedsFromStockOptionsExercised_88ba0b25-42ea-47c3-ad96-4e2bf383a3e5" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_ShareBasedCompensationArrangementByShareBasedPaymentAwardCommonShareEquivalent_507e2f72-3194-4c16-890e-31361911264d" xlink:href="anab-20230331.xsd#anab_ShareBasedCompensationArrangementByShareBasedPaymentAwardCommonShareEquivalent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_de70e3df-2068-4a86-8c39-1ac1d6f6a621" xlink:to="loc_anab_ShareBasedCompensationArrangementByShareBasedPaymentAwardCommonShareEquivalent_507e2f72-3194-4c16-890e-31361911264d" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAcceleratedCompensationCost_665c8209-ca41-494e-a2fa-80f7cc0840da" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAcceleratedCompensationCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_de70e3df-2068-4a86-8c39-1ac1d6f6a621" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAcceleratedCompensationCost_665c8209-ca41-494e-a2fa-80f7cc0840da" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_84629227-fb67-44b6-a058-8b154763f774" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_de70e3df-2068-4a86-8c39-1ac1d6f6a621" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_84629227-fb67-44b6-a058-8b154763f774" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensation_8e08715a-7fd8-462c-a7d1-b76d6fba51de" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_de70e3df-2068-4a86-8c39-1ac1d6f6a621" xlink:to="loc_us-gaap_ShareBasedCompensation_8e08715a-7fd8-462c-a7d1-b76d6fba51de" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions_9322c1c2-53e8-46ff-834d-9210e02280b6" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_de70e3df-2068-4a86-8c39-1ac1d6f6a621" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions_9322c1c2-53e8-46ff-834d-9210e02280b6" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_be2f4192-2570-4774-8533-2fa6beb447ab" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_de70e3df-2068-4a86-8c39-1ac1d6f6a621" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_be2f4192-2570-4774-8533-2fa6beb447ab" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_f3e6970e-8355-40a3-9768-823c00c54734" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_de70e3df-2068-4a86-8c39-1ac1d6f6a621" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_f3e6970e-8355-40a3-9768-823c00c54734" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameAxis_538410e2-6c0b-4bec-8081-2c63596ad15c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PlanNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_f3e6970e-8355-40a3-9768-823c00c54734" xlink:to="loc_us-gaap_PlanNameAxis_538410e2-6c0b-4bec-8081-2c63596ad15c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_538410e2-6c0b-4bec-8081-2c63596ad15c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_538410e2-6c0b-4bec-8081-2c63596ad15c" xlink:to="loc_us-gaap_PlanNameDomain_538410e2-6c0b-4bec-8081-2c63596ad15c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_5a70c9bd-fc69-48a4-a536-9ada2710e887" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_538410e2-6c0b-4bec-8081-2c63596ad15c" xlink:to="loc_us-gaap_PlanNameDomain_5a70c9bd-fc69-48a4-a536-9ada2710e887" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_EquityIncentivePlan2017Member_f8d5ef54-ad4b-43ea-be44-7117a1578aaf" xlink:href="anab-20230331.xsd#anab_EquityIncentivePlan2017Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_5a70c9bd-fc69-48a4-a536-9ada2710e887" xlink:to="loc_anab_EquityIncentivePlan2017Member_f8d5ef54-ad4b-43ea-be44-7117a1578aaf" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_EmployeeStockPurchasePlan2017Member_6a91945d-eb79-47df-b847-52368677e7ca" xlink:href="anab-20230331.xsd#anab_EmployeeStockPurchasePlan2017Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_5a70c9bd-fc69-48a4-a536-9ada2710e887" xlink:to="loc_anab_EmployeeStockPurchasePlan2017Member_6a91945d-eb79-47df-b847-52368677e7ca" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_0ec0a26c-0246-48f8-9ec6-c4dd7f14acfa" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_f3e6970e-8355-40a3-9768-823c00c54734" xlink:to="loc_us-gaap_AwardTypeAxis_0ec0a26c-0246-48f8-9ec6-c4dd7f14acfa" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_0ec0a26c-0246-48f8-9ec6-c4dd7f14acfa_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_0ec0a26c-0246-48f8-9ec6-c4dd7f14acfa" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_0ec0a26c-0246-48f8-9ec6-c4dd7f14acfa_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_0c2bcf70-a50b-457e-aed9-4399a31cd40a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_0ec0a26c-0246-48f8-9ec6-c4dd7f14acfa" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_0c2bcf70-a50b-457e-aed9-4399a31cd40a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockMember_ec0f8103-016c-4484-bbca-bc34cc3d4461" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EmployeeStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_0c2bcf70-a50b-457e-aed9-4399a31cd40a" xlink:to="loc_us-gaap_EmployeeStockMember_ec0f8103-016c-4484-bbca-bc34cc3d4461" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_6f3ee424-4828-4b18-b6f7-2128b3c81967" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_0c2bcf70-a50b-457e-aed9-4399a31cd40a" xlink:to="loc_us-gaap_EmployeeStockOptionMember_6f3ee424-4828-4b18-b6f7-2128b3c81967" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_29318586-989c-4625-ac00-dad8b47231d6" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_0c2bcf70-a50b-457e-aed9-4399a31cd40a" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_29318586-989c-4625-ac00-dad8b47231d6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_TitleOfIndividualAxis_6b85114d-dda4-4cd3-a978-b825752d4a60" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_TitleOfIndividualAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_f3e6970e-8355-40a3-9768-823c00c54734" xlink:to="loc_srt_TitleOfIndividualAxis_6b85114d-dda4-4cd3-a978-b825752d4a60" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_6b85114d-dda4-4cd3-a978-b825752d4a60_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_TitleOfIndividualWithRelationshipToEntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_TitleOfIndividualAxis_6b85114d-dda4-4cd3-a978-b825752d4a60" xlink:to="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_6b85114d-dda4-4cd3-a978-b825752d4a60_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_3c86fdd8-ac60-4d22-8620-4f462f803c8d" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_TitleOfIndividualWithRelationshipToEntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_TitleOfIndividualAxis_6b85114d-dda4-4cd3-a978-b825752d4a60" xlink:to="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_3c86fdd8-ac60-4d22-8620-4f462f803c8d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_DirectorMember_cc7aa4d3-fcf1-4a28-8c28-29925160e6c5" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_DirectorMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_3c86fdd8-ac60-4d22-8620-4f462f803c8d" xlink:to="loc_srt_DirectorMember_cc7aa4d3-fcf1-4a28-8c28-29925160e6c5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ChiefExecutiveOfficerMember_3de9c1fd-0494-4e4c-a81b-ffebe9949295" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ChiefExecutiveOfficerMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_3c86fdd8-ac60-4d22-8620-4f462f803c8d" xlink:to="loc_srt_ChiefExecutiveOfficerMember_3de9c1fd-0494-4e4c-a81b-ffebe9949295" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CounterpartyNameAxis_059e0df6-b26f-4e35-92a4-dceb3b492470" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_CounterpartyNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_f3e6970e-8355-40a3-9768-823c00c54734" xlink:to="loc_srt_CounterpartyNameAxis_059e0df6-b26f-4e35-92a4-dceb3b492470" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_059e0df6-b26f-4e35-92a4-dceb3b492470_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_CounterpartyNameAxis_059e0df6-b26f-4e35-92a4-dceb3b492470" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_059e0df6-b26f-4e35-92a4-dceb3b492470_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_6b8905ff-6c41-4770-af4a-29787d730f6b" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_CounterpartyNameAxis_059e0df6-b26f-4e35-92a4-dceb3b492470" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_6b8905ff-6c41-4770-af4a-29787d730f6b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_FormerChiefExecutiveOfficerMember_dc4b2990-d065-4f56-950b-3e6ff5162214" xlink:href="anab-20230331.xsd#anab_FormerChiefExecutiveOfficerMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_6b8905ff-6c41-4770-af4a-29787d730f6b" xlink:to="loc_anab_FormerChiefExecutiveOfficerMember_dc4b2990-d065-4f56-950b-3e6ff5162214" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_InterimPresidentAndChiefExecutiveOfficerMember_3ca29d70-0dbb-4e12-877c-547cf04d6db8" xlink:href="anab-20230331.xsd#anab_InterimPresidentAndChiefExecutiveOfficerMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_6b8905ff-6c41-4770-af4a-29787d730f6b" xlink:to="loc_anab_InterimPresidentAndChiefExecutiveOfficerMember_3ca29d70-0dbb-4e12-877c-547cf04d6db8" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.anaptysbio.com/role/EquityIncentivePlansTimebasedRestrictedStockUnitsDetails" xlink:type="simple" xlink:href="anab-20230331.xsd#EquityIncentivePlansTimebasedRestrictedStockUnitsDetails"/>
  <link:definitionLink xlink:role="http://www.anaptysbio.com/role/EquityIncentivePlansTimebasedRestrictedStockUnitsDetails" xlink:type="extended" id="ib265ad30dfaf477a898b867e95d44dcf_EquityIncentivePlansTimebasedRestrictedStockUnitsDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_40ffafbd-95f9-4b82-aabe-8764acb4ef7f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_0487940e-6096-4e79-86dc-b5375ebc68db" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_40ffafbd-95f9-4b82-aabe-8764acb4ef7f" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_0487940e-6096-4e79-86dc-b5375ebc68db" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_7f5e4ed2-7a29-4395-9ccc-a91ad4ecc08b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_0487940e-6096-4e79-86dc-b5375ebc68db" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_7f5e4ed2-7a29-4395-9ccc-a91ad4ecc08b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_590abcda-a8da-4c26-bd23-469d773b901d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_0487940e-6096-4e79-86dc-b5375ebc68db" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_590abcda-a8da-4c26-bd23-469d773b901d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_5efde20d-ac11-4dac-a7a9-c6ed9149e98f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_0487940e-6096-4e79-86dc-b5375ebc68db" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_5efde20d-ac11-4dac-a7a9-c6ed9149e98f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_8219d80f-0dbe-409f-b931-f5fef7036267" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_0487940e-6096-4e79-86dc-b5375ebc68db" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_8219d80f-0dbe-409f-b931-f5fef7036267" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_b3ec7e9e-3ba9-4594-bdd1-e982fbef2c92" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedAndExpectedToVestOutstandingNumber_bf470feb-91f1-47c0-b2b7-b3dd24fd51a3" xlink:href="anab-20230331.xsd#anab_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedAndExpectedToVestOutstandingNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_40ffafbd-95f9-4b82-aabe-8764acb4ef7f" xlink:to="loc_anab_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedAndExpectedToVestOutstandingNumber_bf470feb-91f1-47c0-b2b7-b3dd24fd51a3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_2549a5e3-2b7c-46d6-af8d-34295fba3e7d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_40ffafbd-95f9-4b82-aabe-8764acb4ef7f" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_2549a5e3-2b7c-46d6-af8d-34295fba3e7d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_29650bcc-6c0f-4c03-a597-fab1190a41d1" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_2549a5e3-2b7c-46d6-af8d-34295fba3e7d" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_29650bcc-6c0f-4c03-a597-fab1190a41d1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_1627cc4f-4952-434e-8f2c-e104e80a60a9" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_2549a5e3-2b7c-46d6-af8d-34295fba3e7d" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_1627cc4f-4952-434e-8f2c-e104e80a60a9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_204aaadd-e3a2-4a94-ae46-4bdd6a35bd47" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_2549a5e3-2b7c-46d6-af8d-34295fba3e7d" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_204aaadd-e3a2-4a94-ae46-4bdd6a35bd47" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_c36a15fc-ad92-4d99-a30b-898cae94a868" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_2549a5e3-2b7c-46d6-af8d-34295fba3e7d" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_c36a15fc-ad92-4d99-a30b-898cae94a868" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_9944c798-0fdd-446c-b6bc-2f6fe6d2466f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedAndExpectedToVestOutstandingWeightedAverageGrantDateFairValue_5af91241-ec2b-4ed8-91c8-6b962e06a0c6" xlink:href="anab-20230331.xsd#anab_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedAndExpectedToVestOutstandingWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_40ffafbd-95f9-4b82-aabe-8764acb4ef7f" xlink:to="loc_anab_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedAndExpectedToVestOutstandingWeightedAverageGrantDateFairValue_5af91241-ec2b-4ed8-91c8-6b962e06a0c6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueAbstract_201c35b1-e9c7-4710-8a48-397069bcb8eb" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_40ffafbd-95f9-4b82-aabe-8764acb4ef7f" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueAbstract_201c35b1-e9c7-4710-8a48-397069bcb8eb" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageRemainingContractualTerms_3c028808-68bb-4576-b977-c3c4bd60dd05" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageRemainingContractualTerms"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueAbstract_201c35b1-e9c7-4710-8a48-397069bcb8eb" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageRemainingContractualTerms_3c028808-68bb-4576-b977-c3c4bd60dd05" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerms_32168753-80a9-424d-83a9-f81d605adcb3" xlink:href="anab-20230331.xsd#anab_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerms"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueAbstract_201c35b1-e9c7-4710-8a48-397069bcb8eb" xlink:to="loc_anab_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerms_32168753-80a9-424d-83a9-f81d605adcb3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueNonvested_9157f861-300a-4065-b061-f0f9a6f0b80c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueNonvested"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueAbstract_201c35b1-e9c7-4710-8a48-397069bcb8eb" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueNonvested_9157f861-300a-4065-b061-f0f9a6f0b80c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValue_8b793af4-07ad-434e-8a67-a5fb711f40e6" xlink:href="anab-20230331.xsd#anab_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueAbstract_201c35b1-e9c7-4710-8a48-397069bcb8eb" xlink:to="loc_anab_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValue_8b793af4-07ad-434e-8a67-a5fb711f40e6" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_f52d3f9a-5fcb-4862-aa6a-785b489295d5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_40ffafbd-95f9-4b82-aabe-8764acb4ef7f" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_f52d3f9a-5fcb-4862-aa6a-785b489295d5" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_ed1c8482-1ec2-4683-9180-9e3702fb4f69" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_f52d3f9a-5fcb-4862-aa6a-785b489295d5" xlink:to="loc_us-gaap_AwardTypeAxis_ed1c8482-1ec2-4683-9180-9e3702fb4f69" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_ed1c8482-1ec2-4683-9180-9e3702fb4f69_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_ed1c8482-1ec2-4683-9180-9e3702fb4f69" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_ed1c8482-1ec2-4683-9180-9e3702fb4f69_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_cab12f50-2645-4380-848e-c18b1600a364" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_ed1c8482-1ec2-4683-9180-9e3702fb4f69" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_cab12f50-2645-4380-848e-c18b1600a364" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_f173bd15-f043-4d19-95fe-d42d168c2461" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_cab12f50-2645-4380-848e-c18b1600a364" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_f173bd15-f043-4d19-95fe-d42d168c2461" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.anaptysbio.com/role/EquityIncentivePlansSummaryofWeightedAverageAssumptionsusedtoEstimateFairValueDetails" xlink:type="simple" xlink:href="anab-20230331.xsd#EquityIncentivePlansSummaryofWeightedAverageAssumptionsusedtoEstimateFairValueDetails"/>
  <link:definitionLink xlink:role="http://www.anaptysbio.com/role/EquityIncentivePlansSummaryofWeightedAverageAssumptionsusedtoEstimateFairValueDetails" xlink:type="extended" id="i0e575cc4906645629b9240bbe8d35669_EquityIncentivePlansSummaryofWeightedAverageAssumptionsusedtoEstimateFairValueDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_8429e17f-5632-4d17-87d5-d96e33bf02ab" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_60de7e29-0f43-4cbb-be1f-1fb382a8d34a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_8429e17f-5632-4d17-87d5-d96e33bf02ab" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_60de7e29-0f43-4cbb-be1f-1fb382a8d34a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_2de0352a-95a0-48af-a0fa-e4c3b7f863ee" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_8429e17f-5632-4d17-87d5-d96e33bf02ab" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_2de0352a-95a0-48af-a0fa-e4c3b7f863ee" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate_96f72fda-1f98-48b8-bbba-7f765e805fc2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_8429e17f-5632-4d17-87d5-d96e33bf02ab" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate_96f72fda-1f98-48b8-bbba-7f765e805fc2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_aae9eb87-7307-4945-8fc0-deb994e25db9" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_8429e17f-5632-4d17-87d5-d96e33bf02ab" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_aae9eb87-7307-4945-8fc0-deb994e25db9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_4fe88a58-814a-4daa-b307-1a1da3716a0d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_8429e17f-5632-4d17-87d5-d96e33bf02ab" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_4fe88a58-814a-4daa-b307-1a1da3716a0d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_6cd2b650-2df8-4538-9c4c-beb5f7943e06" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_8429e17f-5632-4d17-87d5-d96e33bf02ab" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_6cd2b650-2df8-4538-9c4c-beb5f7943e06" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_71271333-9ab0-470a-88eb-443c1934f6d5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_6cd2b650-2df8-4538-9c4c-beb5f7943e06" xlink:to="loc_us-gaap_AwardTypeAxis_71271333-9ab0-470a-88eb-443c1934f6d5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_71271333-9ab0-470a-88eb-443c1934f6d5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_71271333-9ab0-470a-88eb-443c1934f6d5" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_71271333-9ab0-470a-88eb-443c1934f6d5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_820fb194-1985-4677-8980-202535e7483b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_71271333-9ab0-470a-88eb-443c1934f6d5" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_820fb194-1985-4677-8980-202535e7483b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_8eca8522-5cad-473b-b821-5c375f7c4642" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_820fb194-1985-4677-8980-202535e7483b" xlink:to="loc_us-gaap_EmployeeStockOptionMember_8eca8522-5cad-473b-b821-5c375f7c4642" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.anaptysbio.com/role/EquityIncentivePlansAllocationofSharebasedCompensationExpenseDetails" xlink:type="simple" xlink:href="anab-20230331.xsd#EquityIncentivePlansAllocationofSharebasedCompensationExpenseDetails"/>
  <link:definitionLink xlink:role="http://www.anaptysbio.com/role/EquityIncentivePlansAllocationofSharebasedCompensationExpenseDetails" xlink:type="extended" id="ifac6eba345e843009be23c5c002c76f8_EquityIncentivePlansAllocationofSharebasedCompensationExpenseDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_e9d379a2-dc21-4d4c-a56a-27cd59b29ce2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_83dc1efc-0924-47f5-9e7c-0fef65dedd34" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_e9d379a2-dc21-4d4c-a56a-27cd59b29ce2" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_83dc1efc-0924-47f5-9e7c-0fef65dedd34" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_a569d7f3-76bc-4964-8719-c168238e02bc" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_e9d379a2-dc21-4d4c-a56a-27cd59b29ce2" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_a569d7f3-76bc-4964-8719-c168238e02bc" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_47d500a4-b3ea-402e-ad26-a58f456c8084" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeStatementLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_a569d7f3-76bc-4964-8719-c168238e02bc" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_47d500a4-b3ea-402e-ad26-a58f456c8084" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_47d500a4-b3ea-402e-ad26-a58f456c8084_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_47d500a4-b3ea-402e-ad26-a58f456c8084" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_47d500a4-b3ea-402e-ad26-a58f456c8084_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_c83e73dd-2c2c-4b9b-93fb-cb103e55c3d2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_47d500a4-b3ea-402e-ad26-a58f456c8084" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_c83e73dd-2c2c-4b9b-93fb-cb103e55c3d2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpenseMember_ca091a45-d74f-4731-a2da-ef7c41801074" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ResearchAndDevelopmentExpenseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_c83e73dd-2c2c-4b9b-93fb-cb103e55c3d2" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpenseMember_ca091a45-d74f-4731-a2da-ef7c41801074" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpenseMember_79ab3e8f-47ab-4321-9fd1-01aa68ad77f7" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_GeneralAndAdministrativeExpenseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_c83e73dd-2c2c-4b9b-93fb-cb103e55c3d2" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpenseMember_79ab3e8f-47ab-4321-9fd1-01aa68ad77f7" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.anaptysbio.com/role/CommitmentsandContingenciesNarrativeDetails" xlink:type="simple" xlink:href="anab-20230331.xsd#CommitmentsandContingenciesNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.anaptysbio.com/role/CommitmentsandContingenciesNarrativeDetails" xlink:type="extended" id="i036f85adaf1e404298321664bb769655_CommitmentsandContingenciesNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeLeaseDescriptionLineItems_5c55c1fc-653a-4d0f-8449-a3b0eb34f6c0" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LesseeLeaseDescriptionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AreaOfRealEstateProperty_7a28114e-2d47-48ec-87ac-c09ba45b5d8b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AreaOfRealEstateProperty"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_5c55c1fc-653a-4d0f-8449-a3b0eb34f6c0" xlink:to="loc_us-gaap_AreaOfRealEstateProperty_7a28114e-2d47-48ec-87ac-c09ba45b5d8b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseTermOfContract_6be9dc5b-51da-441e-84fe-23bd63396738" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LesseeOperatingLeaseTermOfContract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_5c55c1fc-653a-4d0f-8449-a3b0eb34f6c0" xlink:to="loc_us-gaap_LesseeOperatingLeaseTermOfContract_6be9dc5b-51da-441e-84fe-23bd63396738" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseRenewalTerm_8b9f7d4c-0fe7-40fd-af30-f0a60b4831a4" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LesseeOperatingLeaseRenewalTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_5c55c1fc-653a-4d0f-8449-a3b0eb34f6c0" xlink:to="loc_us-gaap_LesseeOperatingLeaseRenewalTerm_8b9f7d4c-0fe7-40fd-af30-f0a60b4831a4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_LesseeOperatingLeaseExpirationPeriod_3e2a5afd-83f9-4464-b5e7-f8222ca92f44" xlink:href="anab-20230331.xsd#anab_LesseeOperatingLeaseExpirationPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_5c55c1fc-653a-4d0f-8449-a3b0eb34f6c0" xlink:to="loc_anab_LesseeOperatingLeaseExpirationPeriod_3e2a5afd-83f9-4464-b5e7-f8222ca92f44" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_RentPerSquareFoot_863ec50c-c828-4962-8522-14c6537c9f4a" xlink:href="anab-20230331.xsd#anab_RentPerSquareFoot"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_5c55c1fc-653a-4d0f-8449-a3b0eb34f6c0" xlink:to="loc_anab_RentPerSquareFoot_863ec50c-c828-4962-8522-14c6537c9f4a" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_AnnualRentIncreasePercent_2eab5b18-2b4e-4b0f-9f37-e995d1fde15d" xlink:href="anab-20230331.xsd#anab_AnnualRentIncreasePercent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_5c55c1fc-653a-4d0f-8449-a3b0eb34f6c0" xlink:to="loc_anab_AnnualRentIncreasePercent_2eab5b18-2b4e-4b0f-9f37-e995d1fde15d" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseRightOfUseAsset_1566674c-042a-4bd5-b18d-c1d07e8b18b6" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingLeaseRightOfUseAsset"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_5c55c1fc-653a-4d0f-8449-a3b0eb34f6c0" xlink:to="loc_us-gaap_OperatingLeaseRightOfUseAsset_1566674c-042a-4bd5-b18d-c1d07e8b18b6" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiability_641a27da-2572-4510-b336-6f85752d9091" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingLeaseLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_5c55c1fc-653a-4d0f-8449-a3b0eb34f6c0" xlink:to="loc_us-gaap_OperatingLeaseLiability_641a27da-2572-4510-b336-6f85752d9091" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecurityDeposit_e07471d4-b2d2-4224-95cb-dc40a8b8a05f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SecurityDeposit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_5c55c1fc-653a-4d0f-8449-a3b0eb34f6c0" xlink:to="loc_us-gaap_SecurityDeposit_e07471d4-b2d2-4224-95cb-dc40a8b8a05f" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent_a556ccaf-40ac-46e2-87da-478a917cb579" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_5c55c1fc-653a-4d0f-8449-a3b0eb34f6c0" xlink:to="loc_us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent_a556ccaf-40ac-46e2-87da-478a917cb579" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1_2ae10e4f-55f1-499f-aa31-48f73f9e1465" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_5c55c1fc-653a-4d0f-8449-a3b0eb34f6c0" xlink:to="loc_us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1_2ae10e4f-55f1-499f-aa31-48f73f9e1465" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeLeaseDescriptionTable_ea9be351-43c0-45aa-ac38-388d240fccc9" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LesseeLeaseDescriptionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_5c55c1fc-653a-4d0f-8449-a3b0eb34f6c0" xlink:to="loc_us-gaap_LesseeLeaseDescriptionTable_ea9be351-43c0-45aa-ac38-388d240fccc9" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis_b1a1651f-d81d-46d4-977a-5528877f2350" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LesseeLeaseDescriptionTable_ea9be351-43c0-45aa-ac38-388d240fccc9" xlink:to="loc_srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis_b1a1651f-d81d-46d4-977a-5528877f2350" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain_b1a1651f-d81d-46d4-977a-5528877f2350_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis_b1a1651f-d81d-46d4-977a-5528877f2350" xlink:to="loc_srt_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain_b1a1651f-d81d-46d4-977a-5528877f2350_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain_657e5546-1520-4bd9-b205-b86efaf9fb58" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis_b1a1651f-d81d-46d4-977a-5528877f2350" xlink:to="loc_srt_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain_657e5546-1520-4bd9-b205-b86efaf9fb58" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_A10770WateridgeCircleSanDiegoCalifornia92121Member_4580e962-3edb-43bd-8073-831cfceafa5b" xlink:href="anab-20230331.xsd#anab_A10770WateridgeCircleSanDiegoCalifornia92121Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain_657e5546-1520-4bd9-b205-b86efaf9fb58" xlink:to="loc_anab_A10770WateridgeCircleSanDiegoCalifornia92121Member_4580e962-3edb-43bd-8073-831cfceafa5b" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.anaptysbio.com/role/SubsequentEventsScheduleOfStockRepurchaseActivityDetails" xlink:type="simple" xlink:href="anab-20230331.xsd#SubsequentEventsScheduleOfStockRepurchaseActivityDetails"/>
  <link:definitionLink xlink:role="http://www.anaptysbio.com/role/SubsequentEventsScheduleOfStockRepurchaseActivityDetails" xlink:type="extended" id="i01c073b3f0d14befb85fca2478f47ad4_SubsequentEventsScheduleOfStockRepurchaseActivityDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityClassOfTreasuryStockLineItems_7e06ae81-5470-4724-9c0e-afd1f4ceb40a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EquityClassOfTreasuryStockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockSharesAcquired_65e60441-8e70-4f24-858b-a6d85ab5e21c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TreasuryStockSharesAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityClassOfTreasuryStockLineItems_7e06ae81-5470-4724-9c0e-afd1f4ceb40a" xlink:to="loc_us-gaap_TreasuryStockSharesAcquired_65e60441-8e70-4f24-858b-a6d85ab5e21c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockAcquiredAverageCostPerShare_b62300bb-8f19-4a88-8417-f83ebd7ea90f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TreasuryStockAcquiredAverageCostPerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityClassOfTreasuryStockLineItems_7e06ae81-5470-4724-9c0e-afd1f4ceb40a" xlink:to="loc_us-gaap_TreasuryStockAcquiredAverageCostPerShare_b62300bb-8f19-4a88-8417-f83ebd7ea90f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_9337d35a-d0e8-4f79-bc48-901f96c0e0d0" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TreasuryStockValueAcquiredCostMethod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityClassOfTreasuryStockLineItems_7e06ae81-5470-4724-9c0e-afd1f4ceb40a" xlink:to="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_9337d35a-d0e8-4f79-bc48-901f96c0e0d0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfTreasuryStockTable_42fc9bac-92af-4f30-abb0-ebe77842c535" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ClassOfTreasuryStockTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EquityClassOfTreasuryStockLineItems_7e06ae81-5470-4724-9c0e-afd1f4ceb40a" xlink:to="loc_us-gaap_ClassOfTreasuryStockTable_42fc9bac-92af-4f30-abb0-ebe77842c535" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_a2ac7a8e-3a52-4303-9744-4a694ade4e07" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ClassOfTreasuryStockTable_42fc9bac-92af-4f30-abb0-ebe77842c535" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_a2ac7a8e-3a52-4303-9744-4a694ade4e07" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_a2ac7a8e-3a52-4303-9744-4a694ade4e07_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_a2ac7a8e-3a52-4303-9744-4a694ade4e07" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_a2ac7a8e-3a52-4303-9744-4a694ade4e07_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_98773695-90f4-49f6-8124-ce35351ba47b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_a2ac7a8e-3a52-4303-9744-4a694ade4e07" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_98773695-90f4-49f6-8124-ce35351ba47b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_9c50c7dc-3fe8-42a5-a907-84371abb65c3" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_98773695-90f4-49f6-8124-ce35351ba47b" xlink:to="loc_us-gaap_SubsequentEventMember_9c50c7dc-3fe8-42a5-a907-84371abb65c3" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://fasb.org/us-gaap/role/eedm/ExtensibleEnumerationLists" xlink:type="simple" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-roles-2022.xsd#eedm"/>
  <link:definitionLink xlink:role="http://fasb.org/us-gaap/role/eedm/ExtensibleEnumerationLists" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ProductsAndServicesDomain"/>
    <link:loc xlink:type="locator" xlink:label="loc_anab_CollaborationRevenueMember_d6cc2e5c-6c95-4d25-a5c8-245abf11d48c" xlink:href="anab-20230331.xsd#anab_CollaborationRevenueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain" xlink:to="loc_anab_CollaborationRevenueMember_d6cc2e5c-6c95-4d25-a5c8-245abf11d48c" xlink:type="arc" order="1"/>
  </link:definitionLink>
</link:linkbase>
