Biogen Says Litifilimab Shows Efficacy in New 52-Week Phase 2 Data

12:01 PM EDT, 10/02/2026 (MT Newswires) -- Biogen (BIIB) said Friday that 52-week results from the ongoing Amethyst phase 2/3 study of litifilimab in people living with cutaneous lupus erythematosus showed that 27.2% of participants who received the drug candidate from the beginning of the study achieved the clinical endpoint of clear or almost clear skin, up from 19% at week 24. Participants who switched from placebo to litifilimab treatment at week 24 saw a treatment effect as early as four weeks, the company said. Litifilimab is being assessed as a potential once-monthly, first-in-class treatment to reduce inflammation at the source by selectively targeting blood dendritic cell antigen 2 receptors on plasmacytoid dendritic cells, which play a key role early in the inflammatory process in CLE. Over the course of the 52-week treatment period, litifilimab was generally well tolerated with a safety profile consistent with prior phase 2 studies and no new safety signals identified, Biogen said. Price: 221.18, Change: -1.64, Percent Change: -0.74