Oral Baricitinib in the Treatment of Cutaneous Lichen Planus.

Background: Cutaneous lichen planus (LP) is a recalcitrant, difficult-to-treat, inflammatory skin disease characterized by pruritic, flat-topped, violaceous papules on the skin. Baricitinib is an oral Janus kinase (JAK) 1/2 inhibitor that interrupts the signaling pathway of interferon (IFN)-γ, a cytokine implicated in the pathogenesis of LP. Methods: In this phase II trial, twelve patients with cutaneous LP received baricitinib 2 mg daily for 16 weeks, accompanied by in-depth spatial, single-cell, and bulk transcriptomic profiling of pre-and post-treatment samples. Results: An early and sustained clinical response was seen with 83.3% of patients responsive at week 16. Our molecular data identified a unique, oligoclonal IFN-γ, CD8+, CXCL13+ cytotoxic T-cell population in LP skin and demonstrate a rapid decrease in interferon signature within 2 weeks of treatment, most prominent in the basal layer of the epidermis. Conclusion: This study demonstrates the efficacy and molecular mechanisms of JAK inhibition in LP. Trial Registration Number : NCT05188521.

Ruxolitinib Cream in the Treatment of Cutaneous Lichen Planus: A Prospective, Open-Label Study.

Ruxolitinib is a Janus kinase 1/2 inhibitor that blocks signal transduction of interferon-gamma, a critical cytokine involved in the pathogenesis of cutaneous lichen planus (LP). In this prospective phase II study, we investigated the efficacy of topical ruxolitinib in cutaneous LP and performed transcriptomic analysis before and after therapy. Twelve patients with cutaneous LP applied topical ruxolitinib twice daily for 8 weeks. Primary endpoints were changes in total lesion count and changes in modified Composite Assessment of Index Lesion Severity score in index treated and untreated index control lesions at week 4. Total lesion count decreased by a median of 50 lesions (interquartile range 25, 723; P < 0.001). modified Composite Assessment of Index Lesion Severity scores decreased by a mean difference of 7.6 (standard deviation 8.8, P = 0.016) between index treated and control lesions. Type I and II interferon pathways were enriched in LP, and responsive disease displayed downregulation of interferon-stimulated genes. In this small pilot study, topical ruxolitinib was highly effective in the treatment of cutaneous LP. Transcriptomic analysis confirmed LP as an interferon-driven disease and downregulation of interferon-stimulated genes correlated with disease response.