Quarterly report pursuant to Section 13 or 15(d)

License, Clinical Trial and Sponsored Research Agreements (Sponsored Research and Clinical Trial Agreements) (Details)

v3.21.2
License, Clinical Trial and Sponsored Research Agreements (Sponsored Research and Clinical Trial Agreements) (Details) - USD ($)
3 Months Ended 9 Months Ended
Sep. 30, 2021
Sep. 30, 2020
Sep. 30, 2021
Sep. 30, 2020
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]        
Research and development expense $ 14,083,000 $ 7,987,000 $ 36,603,000 $ 27,131,000
Sponsored Research and Clinical Trial Agreements [Member]        
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]        
Research and development expense 1,756,000 734,000 4,858,000 4,900,000
City of Hope National Medical Center ("COH") [Member] | Sponsored Research and Clinical Trial Agreements [Member]        
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]        
Research and development expense 0 0 0 500,000
Mayo Clinic [Member] | Sponsored Research and Clinical Trial Agreements [Member]        
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]        
Research and development expense 231,000 0 464,000 0
CD123 (MB-102) [Member] | City of Hope National Medical Center ("COH") [Member] | Sponsored Research and Clinical Trial Agreements [Member]        
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]        
Research and development expense 24,000 48,000 250,000 344,000
IL13Ra2 (MB-101) [Member] | City of Hope National Medical Center ("COH") [Member] | Sponsored Research and Clinical Trial Agreements [Member]        
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]        
Research and development expense 199,000 96,000 992,000 422,000
CS1 (MB-104) [Member] | City of Hope National Medical Center ("COH") [Member] | Sponsored Research and Clinical Trial Agreements [Member]        
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]        
Research and development expense 138,000 65,000 510,000 835,000
HER2 (MB 103) [Member] | City of Hope National Medical Center ("COH") [Member] | Sponsored Research and Clinical Trial Agreements [Member]        
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]        
Research and development expense 319,000 0 473,000 0
PSCA (MB-105) [Member] | City of Hope National Medical Center ("COH") [Member] | Sponsored Research and Clinical Trial Agreements [Member]        
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]        
Research and development expense 23,000 0 69,000 0
Research and Development (Income) Expenses 23,000      
CD20 (MB-106) [Member] | Fred Hutchinson Cancer Research Center [Member] | Sponsored Research and Clinical Trial Agreements [Member]        
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]        
Research and development expense 492,000 418,000 1,490,000 1,134,000
ST. Jude - XSCID [Member] | St. Jude Children's Research Hospital [Member] | Sponsored Research and Clinical Trial Agreements [Member]        
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]        
Research and development expense $ 330,000 $ 107,000 $ 610,000 $ 1,665,000