Exhibit 99.1
Joint Filing Agreement

The undersigned hereby agree that the Statement on Schedule 13G dated June 17, 2016 with respect to the shares of Common Stock of Pieris Pharmaceuticals, Inc., 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: June 17, 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
      
         
       
MARK N. LAMPERT
BIOTECHNOLOGY VALUE FUND II, L.P.
    
        /s/ Mark N. Lampert 
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