Quarterly report pursuant to Section 13 or 15(d)

License and Collaboration Agreements - Additional Information (Detail)

v3.8.0.1
License and Collaboration Agreements - Additional Information (Detail) - USD ($)
3 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Sep. 30, 2016
Dec. 31, 2015
Related Party Transaction [Line Items]        
Cash paid to exercise option agreement $ 4,500,000      
Potential milestone payments payable 33,000,000      
Research and development expense 28,460,000 $ 17,541,000    
Contractual obligations due MSK and QIMR 0 0    
QIMR Berghofer        
Related Party Transaction [Line Items]        
Research and development expense $ 1,200,000 $ 600,000    
License Agreement | QIMR Berghofer        
Related Party Transaction [Line Items]        
Research and development expense     $ 3,300,000  
Payments under license agreement       $ 3,000,000