v3.26.1
COLLABORATION AND LICENSE AGREEMENTS (Details)
 1 Months Ended 3 Months Ended 6 Months Ended
Jun. 30, 2026
USD ($)
Jul. 31, 2025
USD ($)
performance_obligation
Sep. 30, 2024
USD ($)
Jan. 31, 2023
USD ($)
Jun. 30, 2026
USD ($)
Jun. 30, 2025
USD ($)
Jun. 30, 2026
USD ($)
Jun. 30, 2025
USD ($)
Jul. 31, 2026
USD ($)
Dec. 31, 2025
USD ($)
Jan. 31, 2024
Oct. 31, 2020
USD ($)
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]                        
Total revenues         $ 284,000 $ 75,000 $ 425,000 $ 147,000        
Research and development [1]         71,577,000 86,626,000 149,208,000 163,461,000        
Accrued liabilities $ 55,142,000       55,142,000   55,142,000     $ 62,013,000    
ImmunoGen, Inc                        
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]                        
Collaborative arrangement, rights and obligations, milestone payments 10,000,000.0                      
Potential royalty payments                       $ 48,000,000.0
Milestone payments                       $ 95,000,000.0
Accrued liabilities $ 10,000,000.0       10,000,000.0   10,000,000.0          
Milestones met         10,000,000.0 0 10,000,000.0 0        
Enable Injections                        
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]                        
Potential royalty payments       $ 150,000,000.0                
Milestone payments       49,000,000.0                
Collaborative arrangement, rights and licenses fee       $ 15,000,000.0                
Enable Injections | Subsequent Event                        
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]                        
Milestone payments                 $ 5,000,000.0      
Related Party                        
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]                        
Research and development         $ 0 0 $ 1,500,000 4,528,000        
Zenas BioPharma | Fairmount Funds Management                        
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]                        
Noncontrolling interest ownership (in percent) 5.00%       5.00%   5.00%          
Paragon Therapeutics                        
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]                        
Collaboration arrangement, future developments milestone payment obligation     $ 16,000,000.0                  
Collaboration arrangement, maximum milestone payments     40,000,000.0                  
Future developments milestone payments     3,100,000                  
Commercial milestone payments     $ 17,000,000.0                  
Paragon Therapeutics | Related Party                        
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]                        
Research and development         $ 0.0 0.0 $ 1,500,000 4,500,000        
Research and development unpaid $ 500,000       500,000   500,000          
Paragon Therapeutics | Fairmount Funds Management                        
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]                        
Noncontrolling interest ownership (in percent)                     5.00%  
Kissei Pharmaceutical Co., Ltd                        
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]                        
Collaborative arrangement, upfront fee payment   $ 70,000,000.0                    
Collaborative arrangement, rights and obligations, milestone payments   $ 315,000,000.0                    
Number of performance obligations | performance_obligation   2                    
Collaboration                        
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]                        
Total revenues         $ 51,000 $ 75,000 $ 186,000 $ 147,000        
[1] Includes related party amount of $0 and $1,500 and for the three and six months ended June 30, 2026, respectively, and $0 and $4,528 for the three and six months ended June 30, 2025.