Apremilast for genital erosive lichen planus in women (the AP-GELP Study): study protocol for a randomised placebo-controlled clinical trial

Background

Genital erosive lichen planus (GELP) is a genital subtype of lichen planus, a chronic autoimmune inflammatory disease of unknown aetiology. In women, GELP is characterised by painful vulvo-vaginal mucosal erosions and scarring, often resulting in poor sexual health and reduced quality of life. Treatment options are limited and often with little effect. Apremilast, a phosphodiesterase 4-inhibitor, has been shown to have a positive effect on psoriasis and other inflammatory skin diseases. We aim to investigate the effect and safety of peroral apremilast in women with GELP in a randomised placebo-controlled double-blinded clinical trial.

Methods

We will recruit 42 adult women with characteristic clinical and/or histological features of moderate-to-severe GELP from a specialised vulva clinic in Oslo, Norway. The patients will be randomised 1:1 to either apremilast 30 mg BID (with an initial dose titration on days 1–6) or a placebo for 24 weeks. The concomitant use of topical corticosteroids will be allowed. The primary end point will be the mean GELP score, a clinical scoring system, at week 24 in the apremilast-treated patients versus the placebo-treated patients. The secondary end points will include the mean GELP score improvement from weeks 0 to 24, patient-reported use of topical steroids, the pain score on a visual analogue scale and the number of patients with GELP score improvements at weeks 16 and 24. The Physician Global Assessment , Patient Global Assessment and selected quality of life and sexual function assessments will be recorded at weeks 0, 16 and 24. The exploratory endpoints include description of immunohistochemical changes before and after apremilast therapy, assessed in vulvar or vaginal biopsies at weeks 0 and 24. Regular follow-ups for possible adverse events will be conducted.

Discussion

The study design is based on experience from studies on apremilast in other inflammatory skin diseases using equivalent apremilast doses for approved indications. The trial may provide evidence for the use of apremilast in women with this burdensome genital dermatosis.

Trial registration

ClinicalTrials.govNCT0365666. Registered on 4 September 2018.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05428-w.

Genital lichen planus: An underrecognized entity

Genital lichen planus (LP) is an underrecogonized dermatosis. The appearance is often unlike classical LP elsewhere, and hence, the condition goes undiagnosed in many. Vulvo-vaginal LP in particular, can be a distressing condition often leading to scarring and a poor quality of life. Treatment for most of the genital LP variants is similar to managing LP elsewhere; however, the erosive variant requires special attention as treatment outcomes are often disappointing and the disease runs a protracted course. Potential for development of malignancy also exists, as in oral LP, and hence close follow up is essential.

Erosive lichen planus: a therapeutic challenge

Erosive lichen planus is an uncommon variant of lichen planus. Chronic erosions of the soles, accompanied by intense and disabling pain, are some of its most characteristic manifestations. We present the case of a woman who developed oral and plantar erosive lichen planus associated with lichen planus pigmentosus and ungueal lichen planus that were diagnosed after several years. The patient failed to respond to multiple therapies requiring longstanding medication but remained refractory. Knowledge of the treatment options for erosive lichen planus is insufficient. Further research is required to clarify their effectiveness, ideally adopting an evidence-based methodology.

Acitretin in erosive penile lichen planus

Lichen planus (LP) is an incompletely understood T-cell mediated auto-immune dermatosis. When LP involves the genitalia it may present as painful, pruritic erosions that can be exquisitely tender, causing distress and genitourinary and sexual dysfunction. Management of erosive genital LP is often suboptimal. Despite higher order evidence demonstrating the efficacy of oral acitretin in the management of cutaneous and oral LP, it still features below other immunosuppressive and immunomodulatory therapies in many clinicians' therapeutic ladder. We present a case of severe erosive penile LP, successfully treated with oral acitretin after topical and oral corticosteroids failed to induce remission.