Quarterly report pursuant to Section 13 or 15(d)

Research and Development Agreements - Additional Information (Detail)

v3.21.1
Research and Development Agreements - Additional Information (Detail) - USD ($)
$ / shares in Units, $ in Thousands
 1 Months Ended 3 Months Ended 107 Months Ended
Feb. 28, 2021
Nov. 30, 2019
Sep. 30, 2018
Mar. 31, 2021
Mar. 31, 2020
Nov. 30, 2019
Dec. 31, 2020
Research And Development Collaboration Agreements [Line Items]              
Common stock, shares issued       56,082,931     49,984,333
Common stock, par value       $ 0.001     $ 0.001
Revenue from grant       $ 3,220 $ 4,141    
Grant Agreements | Grants Revenue Receivable              
Research And Development Collaboration Agreements [Line Items]              
Reimbursement amounts submitted in excess of amounts received are recorded as receivables       0     $ 0
Grant              
Research And Development Collaboration Agreements [Line Items]              
Revenue from grant       0 2,341    
Takeda Pharmaceuticals Inc              
Research And Development Collaboration Agreements [Line Items]              
Deferred revenue, current       1,072     789
Deferred revenue, non-current       2,586     3,106
Cancer Prevention and Research Institute of Texas | CPRIT Agreement              
Research And Development Collaboration Agreements [Line Items]              
Product development grant awarded     $ 15,200        
Cancer Prevention and Research Institute of Texas | ETB MT-3724 | CPRIT Agreement              
Research And Development Collaboration Agreements [Line Items]              
Aggregate proceeds received from award granted           $ 10,600  
Revenue from grant       20,000      
Grants Receivable       0      
Takeda Development Agreement              
Research And Development Collaboration Agreements [Line Items]              
Total transaction price       29,800      
Upfront payment       30,000      
Development milestone payment that is achievable         $ 10,000    
Expected co-share payments payable       10,200      
Deferred revenue       1,100     1,300
Takeda Multi Target Agreement | Takeda Pharmaceuticals Inc              
Research And Development Collaboration Agreements [Line Items]              
Deferred revenue       2,600     2,600
Cumulative payments received       5,000      
Aggregate milestone payments upon exercise of option to license ETBS       30,000      
Milestone payments receivable if option is exercised       397,000      
Takeda Multi Target Agreement | Takeda Pharmaceuticals Inc | Maximum              
Research And Development Collaboration Agreements [Line Items]              
Contractual contingency fees       10,000      
Commercial milestone payment       150,000      
Vertex Collaboration Agreement              
Research And Development Collaboration Agreements [Line Items]              
Upfront payment   $ 38,000          
Milestone payments receivable if option is exercised   180,000          
Upfront payment, cash   23,000          
Upfront payment, equity method investments   $ 15,000       $ 15,000  
Deferred revenue, current       14,700     13,900
Deferred revenue, non-current       1,700     4,500
Common stock, shares issued   1,666,666       1,666,666  
Common stock, par value   $ 0.001       $ 0.001  
Vertex Collaboration Agreement | Common Stock              
Research And Development Collaboration Agreements [Line Items]              
Purchase price per share   $ 9.00       $ 9.00  
Fair value of allocated consideration   $ 4,500          
Vertex Collaboration Agreement | Sales Milestone              
Research And Development Collaboration Agreements [Line Items]              
Milestone payments receivable if option is exercised   70,000          
Vertex Collaboration Agreement | ETBs              
Research And Development Collaboration Agreements [Line Items]              
Aggregate milestone payments upon exercise of option to license ETBS   $ 22,000       $ 22,000  
Bristol Myers Squibb Collaboration Agreement              
Research And Development Collaboration Agreements [Line Items]              
Upfront payment $ 70,000            
Milestone payments receivable if option is exercised 874,500            
Deferred revenue, current       34,600     0
Deferred revenue, non-current       $ 34,400     $ 0
Bristol Myers Squibb Collaboration Agreement | Sales Milestone              
Research And Development Collaboration Agreements [Line Items]              
Milestone payments receivable if option is exercised $ 450,000