Findings of this small pilot study demonstrate high effectiveness of topical ruxolitinib in treating cutaneous lichen planus (LP). In transcriptomic analysis, LP was corroborated as an interferon-driven disease and downregulation of interferon-stimulated genes was shown to be correlated with disease response.

• Ruxolitinib is a Janus kinase 1/2 inhibitor that blocks signal transduction of interferon-gamma, an important cytokine implicated in the pathogenesis of cutaneous LP.

• This prospective phase II study included 12 patients with cutaneous LP who were instructed to apply topical ruxolitinib twice daily for 8 weeks.

• Total lesion count reduced by a median of 50 lesions (interquartile range 25, 723; p<0.001).

• At week 4, there was a decrease in modified Composite Assessment of Index Lesion Severity scores by a mean difference of 7.6 (standard deviation 8.8, p=0.016) between index treated and control lesions.