Litifilimab granted breakthrough therapy status by the FDA for CLE

On January 28, 2026, the U.S. Food and Drug Administration (FDA) granted breakthrough therapy status to litifilimab, a humanized immunoglobulin G1 (IgG1) monoclonal antibody targeting blood dendritic cell antigen 2 (BDCA2), for the treatment of patients with cutaneous lupus erythematosus (CLE). This designation was based on data from the phase II LILAC study (NCT02847598).¹ 

Results from the LILAC study revealed that greater changes in Cutaneous Lupus Erythematosus Disease Area and Severity Index-Activity (CLASI-A) from baseline to Week 16 were demonstrated across all litifilimab dose levels compared with placebo, with 150 mg litifilimab showing the largest least-squares mean difference (−33.4%; 95% confidence interval [CI], −52.7 to −14.1).² Across all litifilimab dose groups, 72% of patients experienced adverse events (AEs) compared with 67% of patients who received placebo. Serious AEs were reported in 7% and 9% of patients in the litifilimab and placebo groups, respectively.² 

The safety and efficacy of litifilimab is currently being investigated in the phase III AMETHYST trial (NCT05531565), with enrollment ongoing.^1,3