UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 

SCHEDULE 13G 

Under the Securities Exchange Act of 1934 

Amendment No.: 1* 

Name of Issuer: ANAPTYSBIO, INC. 

Title of Class of Securities: Common Stock 

CUSIP Number: 032724106 

Date of Event Which Requires Filing of this Statement: 5/31/2018 

Check the appropriate box to designate the rule pursuant to which this 
Schedule is filed. 

[X] Rule 13d-1(b) [ ] Rule 13d-1(c) [ ] Rule 13d-1(d) 

* The remainder of this cover page shall be filled out for a reporting 
person's initial filing on this form with respect to the subject class 
of securities, and for any subsequent amendment containing information 
which would alter the disclosures provided in a prior cover page. 

The information required in the remainder of this cover page shall not 
be deemed to be "filed" for the purpose of Section 18 of the Securities 
Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of 
that section of the Act but shall be subject to all other provisions of 
the Act (however, see the Notes). 

CUSIP No.: 032724106 

1. NAME OF REPORTING PERSON S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE 
PERSON Janus Henderson Group plc EIN #00-0000000 

2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP a. ___ b. ___ 3. SEC 
USE ONLY 

4. CITIZENSHIP OR PLACE OF ORGANIZATION Jersey, Channel Islands 

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH: 

5. SOLE VOTING POWER 0** 

6. SHARED VOTING POWER 2,353,880** 

7. SOLE DISPOSITIVE POWER 0** 

8. SHARED DISPOSITIVE POWER 2,353,880** 

9. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 
2,353,880** 

10. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES 
Not applicable 

11. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 10.0%** 

12. TYPE OF REPORTING PERSON IA, HC 

** See Item 4 of this filing 

Item 1. 

(a). Name of Issuer: ANAPTYSBIO, INC. ("Anaptysbio") 

(b). Address of Issuer's Principal Executive Offices: 

10421 Pacific Center Court, Suite 200 San Diego, CA 92121 

Item 2. 

(a).-(c). Name, Principal Business Address, and Citizenship of Persons 
Filing: 

(1) Janus Henderson Group plc 201 Bishopsgate EC2M 3AE, United Kingdom 
Citizenship: Jersey, Channel Islands 

(d). Title of Class of Securities: Common Stock 

(e). CUSIP Number: 032724106 

Item 3. 

This statement is filed pursuant to Rule 13d-1 (b) or 13d-2(b) and the 
person filing, Janus Henderson Group plc ("Janus Henderson") is a parent 
holding company/control person in accordance with Section 
240.13d-1(b)(ii)(G). See Item 4 for additional information. 

Item 4. Ownership 

The information in items 1 and 5 through 11 on the cover page(s) on 
Schedule 13G is hereby incorporated by reference. 

Janus Henderson has an indirect 97.11% ownership stake in Intech 
Investment Management LLC ("Intech") and a 100% ownership stake in Janus 
Capital Management LLC ("Janus Capital"), Janus Capital International 
Limited ("JCIL"), Perkins Investment Management LLC ("Perkins"), Geneva 
Capital Management LLC ("Geneva"), Henderson Global Investors Limited 
("HGIL"), Janus Henderson Investors Australia Institutional Funds 
Management Limited ("HGIAIFML") and Henderson Global Investors North 
America Inc ("HGINA"), (each an "Asset Manager" and collectively as the 
"Asset Managers"). Due to the above ownership structure, holdings for 
the Asset Managers are aggregated for purposes of this filing. Each 
Asset Manager is an investment adviser registered or authorized in its 
relevant jurisdiction and each furnishing investment advice to various 
fund, individual and/or institutional clients (collectively referred to 
herein as "Managed Portfolios"). 

As a result of its role as investment adviser or sub-adviser to the 
Managed Portfolios, Janus Capital may be deemed to be the beneficial 
owner of 1,997,152 shares or 8.5% of the shares outstanding of 
Anaptysbio Common Stock held by such Managed Portfolios. However, Janus 
Capital does not have the right to receive any dividends from, or the 
proceeds from the sale of, the securities held in the Managed Portfolios 
and disclaims any ownership associated with such rights. As a result of 
its role as investment adviser or sub-adviser to the Managed Portfolios, 
JCIL may be deemed to be the beneficial owner of 356,728 shares or 1.5% 
of the shares outstanding of Anaptysbio Common Stock held by such 
Managed Portfolios. However, JCIL does not have the right to receive any 
dividends from, or the proceeds from the sale of, the securities held in 
the Managed Portfolios and disclaims any ownership associated with such 
rights. 

Item 5. Ownership of Five Percent or Less of a Class 

Not applicable. 

Item 6. Ownership of More than Five Percent on Behalf of Another Person 

Not applicable. 

The Managed Portfolios, set forth in Item 4 above, have the right to 
receive all dividends from, and the proceeds from the sale of, the 
securities held in their respective accounts. 

The interest of any one such person does not exceed 5% of the class of 
securities. 

These shares were acquired in the ordinary course of business, and not 
with the purpose of changing or influencing control of the Issuer. 

Item 7. Identification and Classification of the Subsidiary Which 
Acquired the Security Being Reported on by the Parent Holding Company 

Janus Capital, JCIL, Intech, Perkins, Geneva, HGIL, HGIAIFML and HGINA 
are indirect subsidiaries of Janus Henderson and are registered 
investment advisers furnishing investment advice to Managed Portfolios. 

Item 8. Identification and Classification of Members of the Group 

Not applicable. 

Item 9. Notice of Dissolution of Group 

Not applicable. 

Item 10. Certification 

By signing below I certify that, to the best of my knowledge and belief, 
the securities referred to above were acquired in the ordinary course of 
business and were not acquired for the purpose of and do not have the 
effect of changing or influencing the control of the issuer of such 
securities and were not acquired in connection with or as a participant 
in any transaction having such purposes or effect. 

SIGNATURES 

After reasonable inquiry and to the best of my knowledge and belief, I 
certify that the information set forth in this statement is true, 
complete and correct. 

JANUS HENDERSON GROUP PLC 

By /s/ Bruce Koepfgen 
Bruce Koepfgen, 
Head of North America 
Date 6/8/2018