v3.26.1
DESCRIPTION OF BUSINESS - Liquidity and Capital Resources (Details)
$ / shares in Units, ¥ in Millions
 1 Months Ended 12 Months Ended
Jan. 07, 2026
D
$ / shares
Jul. 31, 2023
USD ($)
Aug. 31, 2024
USD ($)
Aug. 31, 2024
CNY (¥)
Dec. 31, 2025
USD ($)
subsidiary
installment
item
$ / shares
Dec. 31, 2024
USD ($)
$ / shares
Dec. 31, 2023
USD ($)
Dec. 31, 2022
USD ($)
Dec. 31, 2025
CNY (¥)
subsidiary
installment
item
May 12, 2025
USD ($)
Apr. 30, 2025
CNY (¥)
Mar. 31, 2023
$ / shares
May 31, 2022
USD ($)
May 31, 2022
CNY (¥)
Description of Business and Basis of Presentation                            
Number of wholly owned subsidiaries | subsidiary         2       2          
Common stock par value (in dollars per share) | $ / shares         $ 0.0001 $ 0.0001           $ 0.0001    
Accumulated deficit         $ (748,133,000) $ (700,075,000)                
Net loss         (48,058,000) (39,258,000) $ (26,259,000)              
Cash outflow for operating activities         (20,754,000) (29,224,000) $ (19,967,000)              
Current assets, net         36,200,000                  
Payments to acquire equity investments         $ 1,624,000 $ 1,370,000                
Precision Autoimmune Therapeutics Co., Ltd                            
Description of Business and Basis of Presentation                            
Number of investors | item         2       2          
Equity ownership (as a percent)         19.8876%       19.8876%          
Aggregate consideration for equity investment         $ 8,100,000       ¥ 56.8       $ 3,000,000 ¥ 20.0
Equity Method Investment, Aggregate Number Of Installments | installment         5       5          
Payments to acquire equity investments     $ 5,100,000 ¥ 35.4                    
Sublicensing revenue from a related party               $ 5,000,000            
Subsequent event                            
Description of Business and Basis of Presentation                            
Common stock par value (in dollars per share) | $ / shares $ 0.0001                          
Dr. Wei Wu He | Related Party | Director | Subsequent event                            
Description of Business and Basis of Presentation                            
Proposed purchase price per share | $ / shares $ 1.15                          
Premium percentage over average closing price 30.00%                          
Threshold consecutive tradings days for computing average closing price | D 30                          
Disposal Group, Held-for-Sale or Disposed of by sale, not discontinued operations | Kaixin Pharmaceuticals Inc | Target companies                            
Description of Business and Basis of Presentation                            
Disposal group, ownership percentage                   100.00%        
Disposal group, including discontinued operation, consideration                   $ 20,000,000        
Liabilities of disposal group including discontinued operation                   $ 20,000,000        
License of FOLOTYN | License Agreement with Mundipharma International Corporation Limited                            
Description of Business and Basis of Presentation                            
License agreement, amount payable   $ 12,000,000                        
License agreement, one time payment, payable upon completion of quality audit   2,000,000                        
CASI China & Hongkong | Precision Autoimmune Therapeutics Co., Ltd                            
Description of Business and Basis of Presentation                            
Aggregate consideration for equity investment | ¥                     ¥ 28.4      
CASI China & Hongkong | License of FOLOTYN | License Agreement with Mundipharma International Corporation Limited                            
Description of Business and Basis of Presentation                            
License agreement, one time payment, payable upon completion of quality audit   $ 2,000,000                        
Percentage of net sales   10.00%                        
License agreement, aggregate amount payable in quarterly installment   $ 8,000,000                        
License agreement, amount payable on completion of audit and deferred quarterly payments becomes due immediately upon event of non payment   10,000,000                        
CASI China & Hongkong | License of FOLOTYN | License Agreement with Mundipharma International Corporation Limited | Minimum                            
Description of Business and Basis of Presentation                            
Sublicensing revenue from a related party   $ 30,000,000