ABSTRACT: Although topical drugs are the mainstay of treatment for patients with mild-to-moderate psoriasis, the developments observed in this field in the last two decades have been limited. The most commonly used drugs are still vitamin D analogues and corticosteroids, both with several limitations. The aryl hydrocarbon receptor (AhR) plays a role in the pathogenesis of psoriasis, and tapinarof, a novel, first-in-class, small molecule topical therapeutic AhR-modulating agent has been recently approved by the FDA for the topical treatment of plaque psoriasis in adults. Two large, 12-week, phase III trials, PSOARING 1 and 2, showed that 35.4%-40.2% of patients in the tapinarof 1% cream arm achieved the primary endpoint (Physician's Global Assessment [PGA] score of 0 or 1 and a decrease of ≥2-5 points at week 12) compared with 6.0%-6.3% for vehicle arm, respectively. The most common adverse effects were folliculitis, contact dermatitis, headache and pruritus. In the open label, 40-week, extension trial, PSOARING 3, the efficacy and safety results were similar, with 40.9% of patients achieving a PGA = 0 at least one time during the trial and 58.2% of patients with PGA≥2 achieved PGA = 0/1 at least once during the trial, without tachyphylaxis. There were no new safety signals, with most frequent adverse events being folliculitis, contact dermatitis, and upper respiratory tract infection. Tapinarof 1% cream has shown to be effective and to have a favorable safety profile in the treatment of psoriatic patients, representing an alternative to the current therapeutic options, increasing our armamentarium in the topical treatment of psoriasis.
