Biogen has announced 52-week results from the phase 2 part of the ongoing AMETHYST phase 2/3 study (Part A) of litifilimab in people living with cutaneous lupus erythematosus (CLE).
The updated results, presented at the European Academy of Dermatology and Venereology (EADV) 2026 Congress in Vienna, Austria, represent the longest data set reported for litifilimab in CLE and further support its potential to achieve rapid and durable improvements in skin disease activity.
In the study, participants treated with litifilimab in the double-blind, placebo-controlled period showed continued clinical improvements in skin disease activity through Week 52. Notably, participants who switched from placebo to litifilimab treatment at Week 24 experienced a rapid onset of treatment effect as early as four weeks.
“People living with cutaneous lupus erythematosus face debilitating symptoms, including scarring, hair loss and extreme sensitivity to light, yet they have long relied on treatments not specifically developed or studied for CLE,” said Albert T Roy, President and CEO of the Lupus Research Alliance. “The new data on litifilimab is encouraging because it points to the potential for both rapid symptom relief and durable improvement for people living with this condition.”
Litifilimab is being evaluated as a potential once-monthly, first-in-class treatment designed to reduce inflammation at its source by selectively targeting blood dendritic cell antigen 2 (BDCA2) receptors on plasmacytoid dendritic cells (pDCs), which play a central role early in the inflammatory process in CLE.
In January 2026, litifilimab was granted Breakthrough Therapy Designation by the US FDA for the treatment of CLE.
“Living with cutaneous lupus erythematosus carries a heavy physical toll, including dyspigmentation, pain, and scarring, which can be associated with comorbidities like depression and anxiety that can have a profound impact on daily life. The 52-week data reinforce litifilimab’s potential to deliver rapid improvement and demonstrate its durable skin clearance effects,” said Daniel Quirk, Chief Medical Officer at Biogen.