Ruxolitinib cream in the treatment of cutaneous lichen planus: A prospective, open-label study

Ruxolitinib is a Janus kinase 1/2 inhibitor (JAK1/2) 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 pre- and post-therapy. Twelve patients with cutaneous LP applied topical ruxolitinib twice daily for 8 weeks. Primary endpoints were change in total lesion count and modified Composite Assessment of Index Lesion Severity (mCAILS) 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). mCAILS 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 (ISGs). 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 ISGs correlated with disease response. Overall design: Whole transcriptomic analysis was performed on lesional and control (normal skin) tissue pre-therapy (n=19, 10 respectively) and lesional responsive and refractory post-therapy (n=13, 5 respectively).