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 9 Months Ended
Oct. 31, 2021
USD ($)
Sep. 30, 2021
USD ($)
Faculty
Sep. 30, 2020
USD ($)
Sep. 30, 2021
USD ($)
Faculty
Sep. 30, 2020
USD ($)
Jan. 31, 2021
USD ($)
Dec. 31, 2020
USD ($)
Collaborations, Licensing Agreements And Other Agreements [Line Items]              
Research and development expense   $ 8,169,000 $ 5,650,000 $ 22,575,000 $ 15,601,000    
Research Service Agreement | Children's Hospital of Philadelphia              
Collaborations, Licensing Agreements And Other Agreements [Line Items]              
Research and development expense   250,000 0 822,000 0    
Amounts due to agreement   250,000   250,000      
Remaining cost       900,000      
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   625,000 624,000 2,260,000 1,960,000    
Obligation to be paid   $ 12,290,000   $ 12,290,000      
Number of faculty member | Faculty   2   2      
Funding term end date       2023-02      
Cost incurred   $ 9,350,000   $ 9,350,000      
Sponsored Research Agreements | Penn | Prepaid Expenses and Other Current Assets              
Collaborations, Licensing Agreements And Other Agreements [Line Items]              
Advance payments   720,000   720,000     $ 1,851,000
Sponsored Research Agreements | Penn | Accrued and Other Current Liabilities              
Collaborations, Licensing Agreements And Other Agreements [Line Items]              
Obligation to be paid   0   0     $ 217,000
Master Translational Research Services Agreement              
Collaborations, Licensing Agreements And Other Agreements [Line Items]              
Research and development expense   418,000 259,000 1,441,000 1,997,000    
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  
Agreement with Contract Manufacturing Organization              
Collaborations, Licensing Agreements And Other Agreements [Line Items]              
Expense related to agreement       $ 469,000      
Agreement with Contract Manufacturing Organization | Subsequent Event              
Collaborations, Licensing Agreements And Other Agreements [Line Items]              
Total cost $ 1,620,000