Exhibit 99.1 

JOINT FILING AGREEMENT

In accordance with Rule 13d-1(k)(1)(iii) under the Securities Exchange Act of 1934, as amended, the persons named below agree to the joint filing on behalf of each of them of a Statement on Schedule 13D dated April 12, 2018 (including amendments thereto) with respect to the shares of Common Stock, $0.001 par value, of Infinity Pharmaceuticals, Inc. This Joint Filing Agreement shall be filed as an Exhibit to such Statement.

Dated: April 12, 2018

BIOTECHNOLOGY VALUE FUND, L.P.		BVF INC.
By:	BVF Partners L.P., its general partner	By:	/s/ Mark N. Lampert
By:	BVF Inc., its general partner		Mark N. Lampert
			President
By:	/s/ Mark N. Lampert
	Mark N. Lampert
	President	/s/ Mark N. Lampert
		MARK N. LAMPERT
BIOTECHNOLOGY VALUE FUND II, L.P.
By:	BVF Partners L.P., its general partner
By:	BVF Inc., its general partner
By:	/s/ Mark N. Lampert
	Mark N. Lampert
	President
BVF PARTNERS L.P.
By:	BVF Inc., its general partner
By:	/s/ Mark N. Lampert
	Mark N. Lampert
	President
BVF PARTNERS OS LTD.
By:	BVF Partners L.P., its sole member
By:	BVF Inc., its general partner
By:	/s/ Mark N. Lampert
	Mark N. Lampert
	President
Biotechnology Value Trading Fund OS LP
By:	BVF Partners L.P., its investment manager
By:	BVF Inc., its general partner
By:	/s/ Mark N. Lampert
	Mark N. Lampert
	President