FDA Grants Breakthrough Status To Biogen’s Litifilimab For Treatment Of Cutaneous Lupus Erythematosus (CLE)

Biogen announced that the U.S. Food and Drug Administration has granted Breakthrough Therapy Designation to litifilimab (BIIB059) for the treatment of cutaneous lupus erythematosus (CLE), a chronic autoimmune disease primarily affecting the skin that currently lacks targeted treatment options. The designation is intended to accelerate the development and review of therapies that may offer substantial improvement over existing approaches.

"The breakthrough therapy designation for litifilimab illustrates the FDA’s recognition of cutaneous lupus as a serious disease that urgently requires new therapies," said Victoria Werth, MD, MS, a professor of Dermatology at the Perelman School of Medicine at the University of Pennsylvania, and one of the researchers who is conducting the phase 3 trial. "With topical steroids and antimalarials as the initial therapies for managing CLE and no alternatives specifically approved for CLE, there is a need for effective, targeted treatments, and that could be a drug like litifilimab.”

Litifilimab is a first-in-class, humanised IgG1 monoclonal antibody that targets blood dendritic cell antigen 2 (BDCA2), a receptor that drives inflammatory pathways in lupus. By blocking this target, the therapy aims to reduce immune overactivity that contributes to skin damage in CLE patients.

“The FDA grants breakthrough therapy designation to programs based on the seriousness of the condition and the potential of the therapeutic candidate to provide substantial improvements over available therapies. The FDA's designation reinforces Biogen’s belief that litifilimab could be a first-in-class therapy targeting BDCA2 for cutaneous lupus erythematosus,” said Priya Singhal, M.D., M.P.H., Executive Vice President and Head of Development at Biogen. “This designation is a significant milestone for litifilimab as we advance the ongoing AMETHYST Phase 3 study, with the goal of bringing a new potential therapeutic option to the millions of people living with CLE.”

Biogen continues to study litifilimab’s safety and effectiveness in the ongoing AMETHYST Phase 3 clinical trial. The company expects to report data from this late-stage program in 2027, which will play a key role in determining the therapy’s future regulatory path.

“The Lupus Research Alliance is dedicated to advancing lupus research, and today’s FDA Breakthrough Therapy designation for litifilimab reinforces our shared understanding of cutaneous lupus as a serious, debilitating condition that urgently needs therapies that can alter the course of the disease," said Albert T. Roy, President & CEO of the Lupus Research Alliance. "Incorporating the voices of people living with cutaneous lupus is vital to advancing drug development, and through our clinical affiliate, Lupus Therapeutics, we are proud to collaborate with Biogen on the cutaneous lupus erythematosus clinical trials for litifilimab. As a convenor bringing together leading industry partners, clinicians, patients, and FDA experts, the Lupus Research Alliance is encouraged by this progress to accelerate a potential new treatment that may improve the quality of life for those affected by CLE."

The Breakthrough Therapy Designation highlights the FDA’s recognition of litifilimab’s potential to address an important unmet medical need and underscores Biogen’s efforts to expand its immunology and rare disease pipeline.