A JAK-inhibitor cream cleared skin in lichen planus, in a small early trial

A cream form of ruxolitinib, a drug that blocks the JAK signalling enzymes inside immune cells, cleared or nearly cleared the skin in half of patients with cutaneous lichen planus over 16 weeks — against about a fifth on an inactive cream — in an early-stage randomised trial [s1]. The result is genuinely new, because lichen planus has no treatment approved specifically for it, but it comes with the caveats that attach to any small, industry-funded phase 2 study: modest numbers, a short horizon, and results that need a larger trial to confirm [s1].

Lichen planus is a chronic inflammatory disease that produces itchy, flat-topped purplish bumps on the skin, and it can also affect the mouth, nails and genitals. It is thought to be driven by T cells attacking the skin, and it can be intensely uncomfortable. In practice it is treated with topical or oral steroids and other off-label immune-suppressing drugs, none of which is formally approved for the condition — so evidence from a proper randomised trial is unusual and welcome, whatever its size. Ruxolitinib blocks the JAK1 and JAK2 enzymes that relay inflammatory signals inside cells, and the same cream is already approved in some countries for eczema and for the pigment-loss disease vitiligo; lichen planus is a new target for it.

What the trial did

This was a phase 2, 16-week, randomised, double-blind, vehicle-controlled trial with a further 16-week open-label extension, run at 19 sites in the United States and Canada and sponsored by Incyte, which makes ruxolitinib cream [s1][s2]. It enrolled 64 adults with predominantly cutaneous lichen planus who had active disease — an Investigator's Global Assessment (IGA) score of 3 or 4, meaning moderate or severe — significant itch, and disease covering 20% or less of the body surface [s1]. Patients were randomised 1:1 to ruxolitinib 1.5% cream twice daily or an identical vehicle cream for 16 weeks, after which eligible patients could use the active cream as needed in the extension [s1].

The main endpoint was IGA treatment success: reaching clear or almost-clear skin (a score of 0 or 1) with at least a two-grade improvement from the start [s1]. The "vehicle" cream — the same formulation without the drug — is the right comparator here, because applying any emollient and being watched in a trial can improve skin on its own.

What it found

Significantly more patients on ruxolitinib reached treatment success than on vehicle: 50.0% versus 21.9% at week 16, a difference of 29.4 percentage points (95% confidence interval 7.6 to 51.3; P = .01) [s1]. Itch, the symptom patients most want relief from, moved in step: 48.4% of the drug group achieved a clinically meaningful reduction on an itch rating scale, against 16.1% on vehicle (a difference of 33.5 points; P = .004) [s1]. Improvement continued out to week 32 in the open-label phase, and the trial reported no serious treatment-emergent adverse events and no discontinuations due to side effects [s1].

How to read it

The direction of the evidence is encouraging and the comparison is well designed — a blinded, vehicle-controlled trial with both a skin and a symptom endpoint is exactly what this under-studied disease has lacked [s1]. The size of the effect, a roughly two-to-one advantage over an inactive cream, is meaningful for a condition with no approved topical therapy.

But this is early evidence, and the trial's own limits should temper any conclusion. With 64 patients randomised, the confidence interval around the benefit is wide — the true difference could be as small as about 8 percentage points [s1]. Sixteen weeks is short for a relapsing, chronic disease, and the follow-on phase was open-label, so its continued gains are not placebo-controlled [s1]. The trial was funded by the manufacturer. And topical ruxolitinib carries a class boxed warning for JAK inhibitors covering serious infections, blood clots and cancers — warnings drawn largely from oral drugs in other diseases, but which a longer and larger trial would need to address directly. This is a promising signal, not a settled treatment.

What to watch

The natural next step is a larger, longer phase 3 trial to confirm the effect, measure how durable it is, and characterise safety with extended use. Whether the cream also helps the mucosal forms of lichen planus — in the mouth and genitals, which are often the most troublesome — is a separate question this skin-focused trial did not answer.

This article describes research and is not medical advice. Treatment of lichen planus is a decision for treating clinicians.

Sources

• Efficacy and Safety of Ruxolitinib Cream in Patients With Cutaneous Lichen Planus: A Randomized Clinical Trial — JAMA Dermatology, 23 September 2026
• Ruxolitinib cream in cutaneous lichen planus, trial record (NCT05593432) — ClinicalTrials.gov