Litifilimab (BIIB059), a promising investigational drug for cutaneous lupus erythematosus.

There are no U.S. Food and Drug Administration (FDA) approved therapies for cutaneous lupus erythematosus (CLE). Litifilimab is a monoclonal antibody against BDCA2, a plasmacytoid dendritic cell-specific antigen, currently under investigation for systemic lupus erythematosus (SLE) and CLE. The LILAC study, published in the New England Journal of Medicine, is a phase II randomized controlled trial for CLE which demonstrated superiority of Litifilimab over placebo using a skin directed outcome measure. This review identifies challenges that have hindered the development of any approved treatments for CLE, recent SLE trials that include skin disease data, and the pharmacological properties of litifilimab. We review the clinical efficacy and safety of litifilimab for both SLE and CLE in the phase I and II clinical trials. This review aims to highlight the need for more CLE-specific clinical trials and examine the potential of litifilimab as the first FDA approved therapy for CLE. (Clinical trial registration: www.clinicaltrials.gov identifier is NCT02847598.). Litifilimab demonstrated efficacy in a randomized phase II clinical trial as a standalone CLE trial using validated skin-specific outcome measures, making it the first successful clinical trial for a CLE targeted therapy. If approved, litifilimab will be a pivotal change in the landscape of CLE management especially for severe and refractory disease.