On March 4, 2016, GSK presented late-breaking research on tapinarof, a topical non-steroidal, anti-inflammatory drug (NSAID), in patients with psoriasis at the 75th Annual American Academy of Dermatology (AAD) meeting. Novel topical therapies are needed in the psoriasis disease space, as currents topical drugs, including corticosteroids and vitamin D analogues, are associated with side effects, a long treatment duration, and low compliance. With a rapid onset of action, sustained efficacy after discontinuation of treatment, and an acceptable safety profile, tapinarof offers a potentially attractive alternative to the current standard of care for patients with mild-to-moderate psoriasis.
In a Phase II, evaluator blinded study, 227 adult patients with psoriasis were randomized to receive tapinarof topical cream (0.5% or 1.0%) or vehicle once- or twice-daily for 12 weeks. At the end of the treatment period, 65%, 56%, 46%, 36%, 11%, and 5% of patients receiving tapinarof 1% once- or twice-daily, tapinarof 0.5% once- or twice-daily, and vehicle once- or twice-daily, respectively, achieved the primary endpoint (proportion of patients with Physician Global Assessment score of clear or almost clear). In addition, Psoriasis and Severity Index 75 was reached faster in patients receiving tapinarof 1% than tapinarof 0.5%, with rates of 65%, 56%, 46%, 46%, 16%, and 5% in patients receiving tapinarof 1% once- or twice-daily, tapinarof 0.5% once- or twice-daily, and vehicle once- or twice-daily, respectively. Most notably, the efficacy of tapinarof was maintained four weeks after discontinuation of treatment, and no difference was observed between frequencies of administration. GSK proposes to administered tapinarof topical cream (1.0%) for the Phase III trial.