Efficacy and safety of litifilimab in cutaneous lupus erythematosus: 24-week results of the randomized phase 2 study, AMETHYST.
Abstract
Background
Cutaneous lupus erythematosus (CLE) is a serious autoimmune disease with no approved targeted treatments.
Objective
Evaluate the efficacy and safety of litifilimab in AMETHYST Part A (Phase 2).
Methods
AMETHYST is a randomized, double-blind, placebo-controlled, Phase 2/3 study that investigates litifilimab in participants with CLE. Participants were randomized to receive litifilimab 225 mg or placebo every 4 weeks during Weeks 0-24. The primary endpoint was the Cutaneous Lupus Activity Investigator's Global Assessment-Revised (CLA-IGA-R) erythema score of 0-1 at Week 16, with several Cutaneous Lupus Erythematosus Disease Area and Severity Index (CLASI)-based endpoints at Week 24 as secondary endpoints. Safety was also assessed.
Results
Significantly more participants treated with litifilimab achieved clear/almost clear skin (CLA-IGA-R erythema 0-1) than those treated with placebo at Week 16 (14.7% vs 2.9%, P= .0263). Additionally, more participants treated with litifilimab achieved CLASI-70 response vs placebo at Week 24 (21.7% vs 5.8%, P = .0195). Litifilimab was generally well tolerated; safety data were consistent with prior studies.
Limitations
Study was not powered to detect statistically significant differences in secondary endpoints.
Conclusion
Litifilimab treatment led to greater improvements in skin disease activity vs placebo and was well tolerated in participants with CLE through Week 24.