Tapinarof Cream 1% for Extensive Plaque Psoriasis: A Maximal Use Trial on Safety, Tolerability, and Pharmacokinetics

Background Tapinarof is a novel topical therapeutic aryl hydrocarbon receptor modulating agent in development for the treatment of psoriasis and atopic dermatitis. Objective This multicenter, open-label trial assessed the safety, tolerability, pharmacokinetics (PK), and efficacy of tapinarof cream 1% once daily (QD) under maximal use conditions in extensive plaque psoriasis. Methods Adults with a baseline Physician Global Assessment (PGA) score of >= 3 and body surface area (BSA) involvement >= 20% received tapinarof cream 1% QD for 29 days. Safety and tolerability assessments included adverse events (AEs) and local tolerability scales. PK parameters were calculated using non-compartmental analysis. Efficacy assessments included change in PGA, Psoriasis Area and Severity Index score, and %BSA affected. Results Twenty-one patients were enrolled. Common AEs were folliculitis, headache, back pain, and pruritus (none led to discontinuation). Tapinarof plasma exposure was low, with the majority of concentrations being below detectable limits. At day 29, 14 patients (73.7%) had a >= 1-grade improvement in PGA score and six patients (31.6%) had a >= 2-grade improvement; four patients (21.1%) achieved treatment success (PGA 0 or 1 and >= 2-grade improvement). Conclusion Tapinarof cream 1% QD was well tolerated, with limited systemic exposure and significant efficacy at 4 weeks in patients with extensive plaque psoriasis. ClinicalTrials.gov Identifier NCT04042103.