Quarterly report pursuant to Section 13 or 15(d)

Collaborations, Licensing Agreements and other Agreements - Additional Information (Details)

v3.21.2
Collaborations, Licensing Agreements and other Agreements - Additional Information (Details)
 3 Months Ended 6 Months Ended
Jun. 30, 2021
USD ($)
Faculty
Jun. 30, 2020
USD ($)
Jun. 30, 2021
USD ($)
Faculty
Jun. 30, 2020
USD ($)
Jan. 31, 2021
USD ($)
Dec. 31, 2020
USD ($)
Collaborations, Licensing Agreements And Other Agreements [Line Items]            
Research and development expense $ 7,850,000 $ 5,331,000 $ 14,406,000 $ 9,951,000    
Research Service Agreement | Children's Hospital of Philadelphia            
Collaborations, Licensing Agreements And Other Agreements [Line Items]            
Research and development expense 350,000 0 572,000 0    
Amounts due to agreement 350,000   350,000      
Remaining cost     1,145,000      
License Agreement            
Collaborations, Licensing Agreements And Other Agreements [Line Items]            
Amounts due to agreement 0   0      
Obligation to be paid 2,000,000   $ 2,000,000      
Payment term     3 years      
Payment commencement date     2018-08      
License maintenance fee     $ 10,000      
Total milestone payments     21,000,000      
Sponsored Research Agreements | Penn            
Collaborations, Licensing Agreements And Other Agreements [Line Items]            
Research and development expense 798,000 733,000 1,635,000 1,336,000    
Obligation to be paid $ 11,781,000   $ 11,781,000      
Number of faculty member | Faculty 2   2      
Funding term end date     2023-02      
Cost incurred $ 8,725,000   $ 8,725,000      
Sponsored Research Agreements | Penn | Prepaid Expenses and Other Current Assets            
Collaborations, Licensing Agreements And Other Agreements [Line Items]            
Advance payments 816,000   816,000     $ 1,851,000
Sponsored Research Agreements | Penn | Accrued and Other Current Liabilities            
Collaborations, Licensing Agreements And Other Agreements [Line Items]            
Obligation to be paid 27,000   27,000     $ 217,000
Master Translational Research Services Agreement            
Collaborations, Licensing Agreements And Other Agreements [Line Items]            
Research and development expense 628,000 1,027,000 1,023,000 1,738,000    
Maximum research and development additional expense incurred     1,360,000      
Subscription and Technology Transfer Agreement            
Collaborations, Licensing Agreements And Other Agreements [Line Items]            
Expense related to agreement $ 0 $ 0 $ 150,000 $ 0    
Wuxi Agreement | WuXi Advanced Therapies            
Collaborations, Licensing Agreements And Other Agreements [Line Items]            
Early termination fee         $ 1,500,000