Ownership Submission
FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
HOMCY CHARLES J
  2. Issuer Name and Ticker or Trading Symbol
Global Blood Therapeutics, Inc. [GBT]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
__X__ Director _____ 10% Owner
_____ Officer (give title below) _____ Other (specify below)
(Last)
(First)
(Middle)
C/O GLOBAL BLOOD THERAPEUTICS, INC., 400 EAST JAMIE COURT, SUITE 101
3. Date of Earliest Transaction (Month/Day/Year)
10/03/2017
(Street)

SOUTH SAN FRANCISCO, CA 94080
4. If Amendment, Date Original Filed(Month/Day/Year)
6. Individual or Joint/Group Filing(Check Applicable Line)
_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)
2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)
4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)
5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)
6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)
7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V Amount (A) or (D) Price
Common Stock 10/03/2017   S   0 (1) D $ 0 (1) 0 (2) I See Footnote (3)
Common Stock 10/03/2017   S   0 (4) D $ 0 (4) 0 (5) I See Footnote (6)
Common Stock 10/04/2017   S   0 (7) D $ 0 (7) 0 (8) I See Footnote (3)
Common Stock 10/04/2017   S   0 (9) D $ 0 (9) 0 (10) I See Footnote (6)
Common Stock 10/04/2017   S   0 (11) D $ 0 (11) 0 (12) I See Footnote (3)
Common Stock 10/04/2017   S   0 (13) D $ 0 (13) 0 (14) I See Footnote (6)
Common Stock               137,728 D  
Common Stock               1,600 I By Trust

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)
2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8)
5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)
6. Date Exercisable and Expiration Date
(Month/Day/Year)
7. Title and Amount of Underlying Securities
(Instr. 3 and 4)
8. Price of Derivative Security
(Instr. 5)
9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)
10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)
11. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
HOMCY CHARLES J
C/O GLOBAL BLOOD THERAPEUTICS, INC.
400 EAST JAMIE COURT, SUITE 101
SOUTH SAN FRANCISCO, CA 94080
  X      

Signatures

 /s/ Charles Homcy   10/05/2017
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) On October 3, 2017, Third Rock Ventures II, L.P. ("TRV II") sold 62,373 shares of Common Stock of the Issuer. The shares were sold at a weighted average price of $30.171. These shares were sold in multiple transactions at prices ranging from $29.75 to $30.55, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnotes (1), (4), (7), (9), (11) and (13) to this Form 4.
(2) After the transaction referenced in footnote (1), TRV II owned 1,273,032 shares.
(3) The reporting person is a partner of Third Rock Ventures GP II, L.P., which is the general partner of TRV II. The reporting person disclaims beneficial ownership over the shares held by TRV II, except to the extent of his pecuniary interest therein, if any, and this report shall not be deemed an admission that he is the beneficial owner of such shares.
(4) On October 3, 2017, Third Rock Ventures III, L.P. ("TRV III") sold 72,463 shares of Common Stock of the Issuer. The shares were sold at a weighted average price of $30.171. These shares were sold in multiple transactions at prices ranging from $29.75 to $30.55, inclusive.
(5) After the transaction referenced in footnote (4), TRV III owned 213,250 shares.
(6) The reporting person is a partner of Third Rock Ventures GP III, L.P., which is the general partner of TRV III. The reporting person disclaims beneficial ownership over the shares held by TRV III, except to the extent of his pecuniary interest therein, if any, and this report shall not be deemed an admission that he is the beneficial owner of such shares.
(7) On October 4, 2017, TRV II sold 53,652 shares of Common Stock of the Issuer. The shares were sold at a weighted average price of $30.38. These shares were sold in multiple transactions at prices ranging from $29.60 to $30.60, inclusive.
(8) After the transaction referenced in footnote (7), TRV II owned 1,219,380 shares.
(9) On October 4, 2017, TRV III sold 62,332 shares of Common Stock of the Issuer. The shares were sold at a weighted average price of $30.38. These shares were sold in multiple transactions at prices ranging from $29.60 to $30.60, inclusive.
(10) After the transaction referenced in footnote (9), TRV III owned 150,918 shares.
(11) On October 4, 2017, TRV II sold 129,902 shares of Common Stock of the Issuer. The shares were sold at a weighted average price of $30.86. These shares were sold in multiple transactions at prices ranging from $30.65 to $31.15, inclusive.
(12) After the transaction referenced in footnote (11), TRV II owned 1,089,478 shares.
(13) On October 4, 2017, TRV III sold 150,918 shares of Common Stock of the Issuer. The shares were sold at a weighted average price of $30.86. These shares were sold in multiple transactions at prices ranging from $30.65 to $31.15, inclusive.
(14) After the transaction referenced in footnote (13), TRV III owned no shares.

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