Biogen has reported promising results for an experimental drug for skin lupus. Here is what the trial found.

The drug, litifilimab, was tested in the Phase 2 part of the AMETHYST study in people with cutaneous lupus erythematosus, which causes painful rashes, hair loss and permanent scarring. There are no approved targeted treatments for the condition.

After one year, 27.2 percent of participants had clear or almost clear skin, up from 19 percent at 24 weeks. Nearly 29 percent achieved at least a 70 percent reduction in skin disease activity.

Patients who switched from placebo to the drug saw improvement in as little as four weeks. The drug was generally well tolerated, with cold-like infections, influenza and joint pain the most common side effects.

The results were presented at the EADV 2026 Congress in Vienna. Phase 3 results are expected in the first half of 2027. The FDA granted the drug Breakthrough Therapy Designation in January 2026.

Why it matters: for a lifelong disease that can cause permanent disfigurement, clear skin is a transformative goal that is rarely achieved.