Quarterly report pursuant to Section 13 or 15(d)

Capital Stock - BVF Ownership (Details)

Capital Stock - BVF Ownership (Details) - BVF [Member]
Sep. 30, 2021
Feb. 29, 2020
Series Y Convertible Preferred Stock [Member]    
Sale of stock    
Beneficial ownership limitation (as a percent)   50.00%
Xoma Corporation    
Sale of stock    
Ownership interest (as a percent) 31.20%  
Ownership interest, if shares are converted (as a percent) 52.30%