Aclaris' Stock Plummets as Rheumatoid Arthritis Drug Development Abandoned

Aclaris Therapeutics has announced that it will discontinue the development of its rheumatoid arthritis treatment, zunsemetinib, after it failed to show improvement in a mid-stage clinical trial. The drug, tested in combination with methotrexate, did not demonstrate any notable efficacy compared to placebo. As a result, Aclaris shares plummeted by 84% before the market opened. The company will also halt enrollment in an ongoing trial for the drug's use in psoriatic arthritis. Aclaris is currently studying another drug, ATI-1777, in patients with atopic dermatitis.