Quarterly report pursuant to Section 13 or 15(d)

Collaboration and License Agreements - Additional Information (Detail)

v3.8.0.1
Collaboration and License Agreements - Additional Information (Detail)
1 Months Ended
Feb. 15, 2017
USD ($)
Dec. 31, 2016
USD ($)
Deliverable
Sep. 30, 2017
USD ($)
Jul. 05, 2017
USD ($)
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]        
Convertible note payable     $ 13,000,000  
Collaboration Agreement [Member] | Novartis [Member]        
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]        
Proceeds from option exercised       $ 7,000,000
Maximum milestone payments to be received upon achievement of certain milestones   $ 650,000,000    
Percentage of development costs   50.00%    
Required prior written notice period for termination of collaboration agreement   180 days    
Percentage of reduction in milestone and royalty payments   50.00%    
Number of significant deliverables | Deliverable   2    
Collaboration revenue recognized over the period from upfront payment received   $ 50,000,000    
Collaboration revenue recognized over the period from option exercise fee   7,000,000    
Collaboration Agreement [Member] | Novartis [Member] | Upfront Payment [Member]        
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]        
Non-refundable payment received   50,000,000    
Investment Agreement [Member] | Novartis [Member]        
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]        
Debt instrument, maximum borrowing capacity   $ 15,000,000    
Debt instrument, interest rate   6.00%    
Debt instrument, maturity date   Dec. 31, 2019    
Debt instrument, conversion price percentage   120.00%    
Number of days trailing average closing price of common stock immediately prior to the conversion date   20 days    
Deferred revenue   $ 2,500,000    
Investment Agreement [Member] | Novartis [Member] | Convertible Promissory Note [Member]        
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]        
Principal amount of note issued $ 15,000,000      
Proceeds from issuance of convertible note payable 15,000,000      
Convertible note payable 12,500,000      
Reduction of outstanding receivable $ 2,500,000      
Investment Agreement [Member] | Novartis [Member] | Maximum [Member]        
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]        
Percentage of outstanding shares will receive upon debt instrument conversion   19.00%