Quarterly report pursuant to Section 13 or 15(d)

Research and Development Agreements - Additional Information (Detail)

v3.10.0.1
Research and Development Agreements - Additional Information (Detail) - USD ($)
 1 Months Ended 3 Months Ended 6 Months Ended 12 Months Ended 80 Months Ended
Aug. 31, 2017
Jun. 23, 2017
Sep. 30, 2016
Nov. 30, 2011
Jun. 30, 2018
Sep. 30, 2017
Jun. 30, 2017
Jun. 30, 2018
Jun. 30, 2017
Dec. 31, 2017
Jun. 30, 2018
Oct. 31, 2016
Research And Development Collaboration Agreements [Line Items]                        
Date when performance obligations are expected to be fulfilled and revenue fully recognized.               Sep. 30, 2019        
Revenue remaining performance obligations not yet satisfied         $ 5,200,000     $ 5,200,000     $ 5,200,000  
Research and development revenue         944,000   $ 0 1,175,000 $ 1,760,000      
Grant revenue         423,000   42,000 674,000 167,000      
Other Collaboration Agreements                        
Research And Development Collaboration Agreements [Line Items]                        
Research and development revenue         12,000   0 80,000 500,000      
Other Collaboration Agreements | ETBs                        
Research And Development Collaboration Agreements [Line Items]                        
Research and development revenue     $ 500,000                  
Contingent milestone payment upon delivery and acceptance of additional ETB materials         250,000     250,000     250,000  
Takeda Pharmaceuticals Inc                        
Research And Development Collaboration Agreements [Line Items]                        
Aggregate Purchase Price   $ 20,000,000                    
Takeda Pharmaceuticals Inc | Takeda Collaboration Agreement                        
Research And Development Collaboration Agreements [Line Items]                        
Payment for technology access fees and cost reimbursement                       $ 2,000,000
Research and development revenue         81,000   0 92,000 1,300,000      
Takeda Pharmaceuticals Inc | Takeda Individual Project Agreement                        
Research And Development Collaboration Agreements [Line Items]                        
Additional research and development revenue entitled to potentially receive         1,100,000              
Research and development revenue         663,000              
Takeda Pharmaceuticals Inc | Takeda Multi Target Agreement                        
Research And Development Collaboration Agreements [Line Items]                        
Research and development revenue         188,000   $ 0 340,000 $ 0      
Upfront technology access fee               1,000,000        
Additional contingent milestone payments upon designation of each of two targets         2,000,000     2,000,000     2,000,000  
Accounts received from Takeda               5,000,000   $ 5,000,000    
Aggregate milestone payments upon exercise of option to license ETBS         25,000,000     25,000,000     25,000,000  
Additional preclinical, clinical development and commercialization milestone payments entitled to potentially receive         $ 547,000,000     547,000,000     547,000,000  
Contractual contingency fees               $ 10,000,000        
Proceeds from signing of stock purchase agreement           $ 20,000,000            
Aggregate Purchase Price $ 20,000,000                      
Cancer Prevention and Research Institute of Texas | ETB MT-3724 | Grant Agreements                        
Research And Development Collaboration Agreements [Line Items]                        
Product development grant awarded       $ 10,600,000                
Aggregate proceeds received from award granted                     $ 9,500,000