v3.26.1
Document and Entity Information
 12 Months Ended
Dec. 31, 2025
shares
Document Information [Line Items]  
Document Type 20-F
Document Registration Statement false
Document Annual Report true
Document Period End Date Dec. 31, 2025
Current Fiscal Year End Date --12-31
Document Fiscal Year Focus 2025
Document Transition Report false
Document Shell Company Report false
Entity File Number 001-41666
Entity Registrant Name CASI PHARMACEUTICALS, INC.
Entity Incorporation, State or Country Code E9
Entity Address, Address Line One 1701-1702, China Central Office Tower 1
Entity Address, Address Line Two No. 81 Jianguo Road Chaoyang District
Entity Address, City or Town Beijing
Entity Address, Postal Zip Code 100025
Entity Address, Country CN
Title of 12(b) Security Ordinary shares, par value US$0.0001 per share
Trading Symbol casif
Entity Common Stock, Shares Outstanding 20,555,873
Entity Well-known Seasoned Issuer No
Entity Voluntary Filers No
Entity Current Reporting Status Yes
Entity Interactive Data Current Yes
Entity Filer Category Non-accelerated Filer
Entity Emerging Growth Company false
ICFR Auditor Attestation Flag false
Document Financial Statement Error Correction [Flag] false
Document Accounting Standard U.S. GAAP
Entity Shell Company false
Auditor Firm ID 1186
Auditor Name KPMG Huazhen LLP
Auditor Location Beijing, China
Entity Central Index Key 0001962738
Document Fiscal Period Focus FY
Amendment Flag false
Business Contact [Member]  
Document Information [Line Items]  
Contact Personnel Name Larry Zhang
Entity Address, Address Line One 601 Gateway Blvd
Entity Address, Address Line Two Suite 1250
Entity Address, City or Town South San Francisco
Entity Address, Postal Zip Code 94080
Entity Address, State or Province CA
Entity Address, Country US
City Area Code 240
Local Phone Number 205-5475
Contact Personnel Email Address larryz@casipharmaceuticals.com