Seeing the Treatment of Psoriasis in a New Light: A Novel Medical Device Utilizing Localized Coal Tar and Narrowband UVB for Targeted Treatment of Plaque Psoriasis

Psoriasis is a chronic, immune mediated skin disease that affects 2–4% of the world population.¹ Phototherapy has been a mainstay treatment for psoriasis given its high efficacy, potential to induce remission, and strong safety profile.¹ It is particularly useful in patients who may not be candidates for systemic treatment or biologics. Given the high costs of systemic psoriasis therapies, studies have also shown that phototherapy achieves significant cost savings by replacing or delaying drug-based systemic treatment in patients with moderate to severe disease.² However, this modality is often underutilized mainly due to the lack of phototherapy treatment centers across the country.³ Home phototherapy was designed to fill this treatment gap and allow patients to be treated with phototherapy despite living in areas that may not have a formal treatment facility. Inspired by the Goeckerman regimen, a preliminary pilot study showed that a novel, home phototherapy device utilizing a mobile phone-controlled L.E.D UVB light source and an occlusive hydrogel patch containing coal tar (Figure 1) was superior to control as well as both NB-UVB alone and a coal tar dressing alone. This larger study is designed to further explore the safety and efficacy of this novel modality.

This was a 30-week, multicenter, investigator-blinded, randomized study that enrolled adults with mild to severe plaque psoriasis (Investigator’s Global Assessment (IGA) score 2 to 4 and baseline target plaque assessment (TPA) score 5 to 12) with 2 roughly clinically equal target plaques selected per subject. Plaques were randomized to receive treatment daily with either the UVB plus coal tar dressing vs control (dressing without tar or phototherapy). The first treatment was done in office using a baseline estimated 90% of Minimal Erythema Dose (MED) with increasing dosing each day by 6%. The subjects were required to answer questions about tolerability before subsequent dosing, which impacted the algorithmic dosing schedule. Each plaque was randomly assigned a treatment arm that was unknown to the investigator. The primary endpoint was percent change in TPA score at week 6. Adverse events were assessed at each visit. The modified intent-to-treat efficacy data set using the last observation at the end of treatment compared to baseline is the primary analysis for this study. The study was performed in compliance with Good Clinical Practice and International Conference on Harmonisation guidelines.

In total, 26 patients were enrolled in the study, 3 patients withdrew for non-related medical issues. At week 6, there was a 66% reduction in baseline TPA score vs a 15% reduction in controls (Figure 2). After discontinuation of treatment, there was a 70%, 65%, and 66% reduction in baseline TPA scores at weeks