FXS6837

FXS6837 is an orally bioavailable small molecule immunomodulatory inhibitor being developed by **Fosun Pharma** for the treatment of primary IgA nephropathy (IgAN) and other immune-mediated diseases. The drug is designed to modulate immune responses that contribute to renal inflammation and damage in IgAN patients. As of 2025, FXS6837 is in Phase IIb clinical development in China, where it is being evaluated in a multicenter, randomized, double-blind, placebo-controlled study to assess its efficacy and safety. In August 2025, Fosun Pharma licensed the global rights for the drug (excluding mainland China, Hong Kong, and Macau) to the UK-based biotech **Sitala Bio** in a deal worth up to $670 million, while retaining rights for the Greater China region.