Litifilimab efficacy on skin outcomes in cutaneous lupus erythematosus in the Phase 2 LILAC study

BACKGROUND: Cutaneous lupus erythematosus (CLE) has no approved targeted therapies. In Part B of the randomized, double-blind, placebo-controlled, Phase 2 LILAC study, litifilimab demonstrated a dose-response relationship for percentage change in Cutaneous Lupus Erythematosus Disease Area and Severity Index-Activity (CLASI-A) score from baseline to Week 16. OBJECTIVES: These post hoc analyses of Part B of the LILAC study aimed to assess the efficacy of litifilimab on additional skin-specific outcomes. METHODS: Adult participants with baseline CLASI-A score ≥8 and histologically confirmed CLE, with/without systemic manifestations, received litifilimab 50 mg, 150 mg or 450 mg, or placebo subcutaneously every 4 weeks through Week 16. Analyses included CLASI-20/50/70/90 responses (≥20%/50%/70%/90% decrease [improvement] from baseline in CLASI-A score), 7-point improvement from baseline in CLASI-A score, subgroup analyses of percentage change in CLASI-A scores by baseline characteristics and achievement of 'clear' (CLASI-A scores of 0-1) or 'almost clear' (0-3) skin status. Shifts from baseline in skin condition were evaluated by the Physician's Global Assessment (PGA) of CLE and the Physician's Global Impression (PGI) of change in CLE. RESULTS: Greater proportions of litifilimab-treated participants achieved CLASI-20/50/70/90 responses (3.8%-72.1%) than placebo-treated participants (0%-43.8%) at Week 16, with significant differences observed from Week 4 for CLASI-20/50. From Weeks 4 to 16, more litifilimab-treated participants had ≥7-point CLASI-A score decreases from baseline (13.8%-43.9%) compared with placebo (10.5%-21.1%). At Week 16, compared with placebo, more litifilimab-treated participants achieved 'clear' or 'almost clear' skin status; CLASI-A score improvements for subgroups were numerically higher with litifilimab, more litifilimab-treated participants shifted from 'severe' or 'moderate' to 'almost clear' skin status based on PGA of CLE, and more litifilimab-treated participants were 'much improved' based on PGI results. CONCLUSIONS: These analyses provide additional evidence to support litifilimab efficacy in clearing skin disease activity, as demonstrated in the LILAC study.