Annual report pursuant to Section 13 and 15(d)

Commitments and Contingencies - License Agreements (Details)

v3.6.0.2
Commitments and Contingencies - License Agreements (Details) - USD ($)
$ in Millions
 1 Months Ended 12 Months Ended
Sep. 30, 2016
May 31, 2016
Sep. 30, 2015
Apr. 30, 2013
Dec. 31, 2016
Dec. 31, 2015
Feb. 28, 2013
Common Stock              
License Agreements              
Shares issued         4,600,000    
Dana Farber              
License Agreements              
Payments due when the Company achieves certain milestones per the license agreement             $ 3.4
Future potential milestone payments due         $ 0.0 $ 0.0  
Payments made upon achievement of development milestone         0.0    
Whitehead              
License Agreements              
Payments due when the Company achieves certain milestones per the license agreement       $ 3.6      
Future potential milestone payments due         0.0 0.0  
Service fees paid         0.5 0.5  
Payment of up-front license fee           $ 1.0  
Payments made upon achievement of development milestone         0.0    
Whitehead | Common Stock              
License Agreements              
Shares issued       171,674      
TMRC              
License Agreements              
Up-front license fee     $ 1.0        
Payment of up-front license fee   $ 0.5 0.5        
Payments per indication due upon the successful achievement of clinical and regulatory milestones     $ 13.0        
Payments made upon achievement of development milestone $ 1.0       $ 0.0