Quarterly report pursuant to Section 13 or 15(d)

Research and Development Agreements - Additional Information (Detail)

v3.19.2
Research and Development Agreements - Additional Information (Detail) - USD ($)
 1 Months Ended 3 Months Ended 6 Months Ended
Sep. 30, 2018
Jul. 31, 2018
Jun. 30, 2018
Apr. 30, 2018
Nov. 30, 2011
Jun. 30, 2019
Jun. 30, 2018
Jun. 30, 2019
Jun. 30, 2018
Dec. 31, 2018
Research And Development Collaboration Agreements [Line Items]                    
Research and development revenues from collaboration agreements           $ 5,211,000 $ 944,000 $ 11,624,000 $ 1,175,000  
Grant                    
Research And Development Collaboration Agreements [Line Items]                    
Revenue from grant           236,000 423,000 831,000 674,000  
Takeda Pharmaceuticals Inc                    
Research And Development Collaboration Agreements [Line Items]                    
Research and development revenues from collaboration agreements           5,211,000 932,000 11,624,000 1,095,000  
Deferred revenue           16,225,000   16,225,000   $ 28,901,000
CPRIT Agreement | Cancer Prevention and Research Institute of Texas                    
Research And Development Collaboration Agreements [Line Items]                    
Product development grant awarded $ 15,200,000                  
CPRIT Agreement | Cancer Prevention and Research Institute of Texas | ETB MT-3724                    
Research And Development Collaboration Agreements [Line Items]                    
Product development grant awarded         $ 10,600          
Grant Agreements | Grants Revenue Receivable                    
Research And Development Collaboration Agreements [Line Items]                    
Reimbursement amounts submitted in excess of amounts received are recorded as receivables     $ 4,300,000     5,200,000 4,300,000 5,200,000 4,300,000  
Takeda Development Agreement                    
Research And Development Collaboration Agreements [Line Items]                    
total transaction price               29,300,000    
Upfront payment               30,000,000    
Probable development milestone payment that is achievable               10,000,000    
Expected co share payment receivable           10,700,000   10,700,000    
Research and development revenues from collaboration agreements           5,000,000   11,100,000    
Research and development revenue             0   0  
Deferred revenue           12,600,000   12,600,000   24,800,000
Takeda Development Agreement | Takeda Pharmaceuticals Inc                    
Research And Development Collaboration Agreements [Line Items]                    
Research and development revenues from collaboration agreements           5,012,000 0 11,126,000 0  
Takeda Development Agreement | Clinical Development and Regulatory Milestones                    
Research And Development Collaboration Agreements [Line Items]                    
Milestone payments receivable if option is exercised               307,500,000    
Milestone payments receivable if option is not exercised               162,500,000    
Takeda Development Agreement | Sales Milestone                    
Research And Development Collaboration Agreements [Line Items]                    
Milestone payments receivable if option is exercised               325,000,000    
Milestone payments receivable if option is not exercised               175,000,000    
Takeda Multi Target Agreement | Takeda Pharmaceuticals Inc                    
Research And Development Collaboration Agreements [Line Items]                    
Research and development revenues from collaboration agreements           199,000 188,000 444,000 340,000  
Deferred revenue           3,700,000   3,700,000   $ 4,100,000
Cumulative payments received       $ 5,000,000            
Aggregate milestone payments upon exercise of option to license ETBS           25,000,000   25,000,000    
Additional preclinical, clinical development and commercialization milestone payment           397,000,000   397,000,000    
Takeda Multi Target Agreement | Takeda Pharmaceuticals Inc | Maximum                    
Research And Development Collaboration Agreements [Line Items]                    
Contractual contingency fees               10,000,000    
Commercial milestone payment               150,000,000    
Takeda Collaboration Agreement | Takeda Pharmaceuticals Inc                    
Research And Development Collaboration Agreements [Line Items]                    
Research and development revenues from collaboration agreements           0 81,000 0 92,000  
Takeda Individual Project Agreement | Takeda Pharmaceuticals Inc                    
Research And Development Collaboration Agreements [Line Items]                    
Research and development revenues from collaboration agreements           0 663,000 54,000 663,000  
Increase in transaction consideration related to research services   $ 1,100,000                
Takeda Individual Project Agreement | Takeda Pharmaceuticals Inc | Maximum                    
Research And Development Collaboration Agreements [Line Items]                    
Additional research and development revenue     $ 2,200,000              
Other Collaboration Agreements                    
Research And Development Collaboration Agreements [Line Items]                    
Research and development revenues from collaboration agreements           $ 0 $ 12,000 $ 0 $ 80,000