Tapinarof, an investigative topical psoriasis treatment, successfully reduced plaque psoriasis severity in adults with mild to severe psoriasis compared with a vehicle cream, according to data from phase 3 randomized trials published in The New England Journal of Medicine. The aryl hydrocarbon receptor-modulating agent was also associated with local adverse reactions, headache, and upper respiratory symptoms.
Investigators conducted 2 identical phase 3 trials of adults with mild to severe plaque psoriasis. In each trial, they randomly assigned patients 2:1 to receive treatment with tapinarof 1% cream or vehicle cream once daily for 12 weeks. The primary endpoints were achieving Physician’s Global Assessment (PGA) response, defined as a score to 0 (clear) or 1 (almost clear), and a decrease in PGA score by at least 2 points from baseline by week 12.
There were 510 patients in trial 1 and 515 patients in trial 2. The mean age of patients in all groups was about 50 years. In trial 1, 62.6% of patients in the tapinarof group and 50.6% of patients in the vehicle cream group were men. In trial 2, 54.8% of patients in the tapinarof group and 59.3% of patients in the vehicle cream group were men.
In trial 1, 35.4% of patients in the tapinarof group achieved PGA response, compared with 6% in the vehicle group (P <.001). In trial 2, 40.2% of patients in the tapinarof group achieved PGA response, compared with 6.3% in the vehicle group (P <.001).
Adverse events were reported by 50.3% and 54.5% of patients given tapinarof in trial 1 and 2, respectively, and by 22.4% and 26.6% in patients given a vehicle cream in trial 1 and 2, respectively. Adverse events reported by patients receiving tapinarof treatment included folliculitis, nasopharyngitis, contact dermatitis, headache, upper respiratory tract infection, and pruritus. There were no differences between groups regarding laboratory values, vital signs, electrocardiograms, or physical (nondermatologic) examinations.
The study researchers used multiple imputation to adjust for 15% to 20% of end-point data that was missing. Local adverse events may have revealed which cream was tapinarof in the trials, and most adults (80%) enrolled had a baseline PGA score of 3 which limits the generalizability of the results.
“Larger and longer trials are needed to evaluate the efficacy and safety of tapinarof cream as compared with existing treatments for psoriasis,” the study authors concluded.