Biogen's Litifilimab Demonstrates Rapid and Durable Efficacy in Cutaneous Lupus Erythematosus

New 52-week Phase 2 data from Biogen's ongoing AMETHYST study show that litifilimab, an investigational therapy, provides rapid and durable efficacy for cutaneous lupus erythematosus (CLE). The results, presented at the European Academy of Dermatology and Venereology (EADV) 2026 Congress, indicate continued clinical improvements in skin disease activity through Week 52, with participants switching from placebo experiencing rapid onset of treatment effect. Litifilimab received Breakthrough Therapy Designation from the FDA in January 2026 for CLE.