(Beijing, Shanghai, Boston), Jul 27, 2026 –  Jacobio Pharma (1167.HK) today announced that its independently developed BET inhibitor JAB-8263 has completed the dosing of the first patient in a Phase IIa clinical trial for rheumatoid arthritis (RA) in China. This milestone marks JAB-8263’s expansion from oncology into autoimmune diseases. It is also the first clinical trial globally to evaluate a BET inhibitor for the treatment of RA.

The Phase IIa clinical trial will primarily evaluate the safety, tolerability, pharmacokinetic profile and preliminary efficacy of JAB-8263 in patients with RA.

Preclinical data suggest that BET inhibitors may have significant therapeutic potential in autoimmune diseases, including RA, while potentially avoiding certain safety risks associated with existing oral targeted immunosuppressants. As an oral small-molecule drug, JAB-8263 is expected to improve long-term treatment outcomes by modulating epigenetic states.

JAB-8263 has previously generated encouraging clinical data in oncology. Nearly 100 patients with cancer have participated in clinical trials of JAB-8263 in China and the United States, demonstrating a favorable safety profile.

About Jacobio
Jacobio Pharma (1167.HK) is committed to providing breakthrough treatments for patients. With an induced allosteric drug discovery platform, the company’s core projects focus on the KRAS pathway. The company envisions becoming a global leader in research and development, fostering strategic partnerships to drive innovation. Jacobio’s  R&D centers are located in Beijing, Shanghai (China), and Boston (USA). Clinical trials are conducted at over 180 sites in China, more than 30 sites in the USA, and over 10 sites across several European countries.
For more information, please visit: http://www.jacobiopharma.com