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 (including additional amendments thereto) with respect to the shares of Common Stock, $0.0075 par value, of XOMA Corporation, a Delaware corporation. This Joint Filing Agreement shall be filed as an Exhibit to such Statement.

Dated:  February 21, 2017

BIOTECHNOLOGY VALUE FUND, L.P.
By:	BVF Partners L.P., its general partner
By:	BVF Inc., its general partner
By:	/s/ Mark N. Lampert
	Name:	Mark N. Lampert
	Title:	President

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
	Name:	Mark N. Lampert
	Title:	President

BIOTECHNOLOGY VALUE TRADING FUND OS, L.P.
By:	BVF Partners L.P., its investment manager
By:	BVF Inc., its general partner
By:	/s/ Mark N. Lampert
	Name:	Mark N. Lampert
	Title:	President

BVF PARTNERS OS LTD.
By:	BVF Partners L.P., its sole member
By:	BVF Inc., its general partner
By:	/s/ Mark N. Lampert
	Name:	Mark N. Lampert
	Title:	President

BVF PARTNERS L.P.
By:	BVF Inc., its general partner
By:	/s/ Mark N. Lampert
	Name:	Mark N. Lampert
	Title:	President

BVF INC.
By:	/s/ Mark N. Lampert
	Name:	Mark N. Lampert
	Title:	President

/s/ Mark N. Lampert

MARK N. LAMPERT

/s/ Matthew D. Perry

MATTHEW D. PERRY