FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF 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 *   Tasker Seth A 2. Date of Event Requiring Statement (Month/Day/Year) 07/22/2016 3. Issuer Name and Ticker or Trading Symbol INFINITY PHARMACEUTICALS, INC. [INFI] (Last) (First) (Middle) C/O INFINITY PHARMACEUTICALS, INC., 784 MEMORIAL DRIVE 4. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) General Counsel 5. If Amendment, Date Original Filed(Month/Day/Year) (Street) CAMBRIDGE, MA 02139 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 Beneficially Owned

1.Title of Security (Instr. 4) 2. Amount of Securities Beneficially Owned (Instr. 4) 3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5) 4. Nature of Indirect Beneficial Ownership (Instr. 5) Common Stock 3,525.45 I By 401(k)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.			SEC 1473 (7-02)
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Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Stock Option (Right to Buy)	12/04/2008(1)	12/04/2018	Common Stock	1,190	$ 7.18	D	Â
Stock Option (Right to Buy)	01/05/2010(2)	01/05/2020	Common Stock	631	$ 6.25	D	Â
Stock Option (Right to Buy)	03/09/2010(2)	03/09/2020	Common Stock	2,000	$ 6.39	D	Â
Stock Option (Right to Buy)	01/06/2011(2)	01/06/2021	Common Stock	1,713	$ 5.94	D	Â
Stock Option (Right to Buy)	01/06/2012(2)	01/06/2022	Common Stock	2,240	$ 7.93	D	Â
Stock Option (Right to Buy)	  (3)	08/14/2022	Common Stock	1,000	$ 16.57	D	Â
Stock Option (Right to Buy)	  (4)	01/04/2023	Common Stock	4,730	$ 36.85	D	Â
Stock Option (Right to Buy)	  (5)	03/06/2023	Common Stock	2,000	$ 45.24	D	Â
Stock Option (Right to Buy)	  (6)	01/10/2024	Common Stock	6,711	$ 12.91	D	Â
Stock Option (Right to Buy)	  (7)	08/25/2024	Common Stock	10,000	$ 11.24	D	Â
Stock Option (Right to Buy)	  (8)	01/14/2025	Common Stock	8,214	$ 15.74	D	Â
Stock Option (Right to Buy)	  (9)	03/19/2025	Common Stock	5,300	$ 16.53	D	Â
Stock Option (Right to Buy)	  (10)	01/06/2026	Common Stock	11,938	$ 6.71	D	Â

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Tasker Seth A C/O INFINITY PHARMACEUTICALS, INC. 784 MEMORIAL DRIVE CAMBRIDGE, MA 02139	Â	Â	  General Counsel	Â

Signatures

/s/ Seth A. Tasker		07/29/2016
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 5(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)	The option vested as to 12/48th of the shares on December 4, 2008 and vested as to 1/48th of the shares at the end of each calendar month thereafter. The option has fully vested.
(2)	The option vested in equal monthly installments over four years beginning at the end of the calendar month during which the grant was made. The option has fully vested.
(3)	The option vests as to 1/48th of the shares on August 31, 2012 and vests as to 1/48th of the shares at the end of each calendar month thereafter.
(4)	The option vests as to 1/48th of the shares on January 31, 2013 and vests as to 1/48th of the shares at the end of each calendar month thereafter.
(5)	The option vests as to 1/48th of the shares on March 31, 2013 and vests as to 1/48th of the shares at the end of each calendar month thereafter.
(6)	The option vests as to 1/48th of the shares on January 31, 2014 and vests as to 1/48th of the shares at the end of each calendar month thereafter.
(7)	The option vests as to 1/48th of the shares on August 31, 2014 and vests as to 1/48th of the shares at the end of each calendar month thereafter.
(8)	The option vests as to 1/48th of the shares on January 31, 2015 and vests as to 1/48th of the shares at the end of each calendar month thereafter.
(9)	The option vests as to 1/48th of the shares on March 31, 2015 and vests as to 1/48th of the shares at the end of each calendar month thereafter.
(10)	The option vests as to 1/48th of the shares on January 31, 2016 and vests as to 1/48th of the shares at the end of each calendar month thereafter.

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