Exhibit 99.1
Joint Filing Agreement

The undersigned hereby agree that the Statement on Schedule 13G dated November 18, 2016 with respect to the shares of Common Stock of XOMA Corporation, and any further amendments thereto executed by each and any of the undersigned shall be filed on behalf of each of the undersigned pursuant to and in accordance with the provisions of Rule 13d-1(k)(1) under the Securities Exchange Act of 1934, as amended.

Dated: November 18, 2016

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