Quarterly report pursuant to Section 13 or 15(d)

License, Collaboration and Manufacturing Agreements - Additional Information (Detail)

v3.10.0.1
License, Collaboration and Manufacturing Agreements - Additional Information (Detail) - USD ($)
1 Months Ended 3 Months Ended 9 Months Ended
Jun. 30, 2015
Sep. 30, 2018
Sep. 30, 2017
Sep. 30, 2016
Dec. 31, 2015
Sep. 30, 2018
Sep. 30, 2017
Dec. 31, 2017
Related Party Transaction [Line Items]                
Cash paid to exercise option agreement $ 4,500,000              
Potential milestone payments payable   $ 33,000,000       $ 33,000,000    
Research and development expense   43,355,000 $ 20,598,000     105,202,000 $ 56,435,000  
Contractual obligations due MSK and QIMR   $ 0       $ 0   $ 0
License Agreement | QIMR Berghofer                
Related Party Transaction [Line Items]                
Research and development expense       $ 3,300,000        
Payments under license agreement         $ 3,000,000      
Manufacturing Agreements | Cognate Agreement                
Related Party Transaction [Line Items]                
Written notice period for termination of agreement           6 months    
Manufacturing Agreements | Cognate Agreement | Minimum                
Related Party Transaction [Line Items]                
Standard mutual termination rights period           90 days