PARIS – A novel kinder, gentler topical retinoid met all of its primary and secondary endpoints in two identical phase 3 randomized trials totaling 2,420 patients with moderate acne vulgaris on both the face and trunk.
Trifarotene cream 50 mcg/g selectively targets the gamma retinoic acid receptor. This unique selectivity for just one of the three retinoic acid receptors results in less of the classic retinoid side effects – redness, scaling, dryness, stinging, burning – that can limit the clinical utility of existing retinoids. This was borne out by the high completion rates in trifarotene-treated participants in the two 12-week trials: 88.2% in the PERFECT 1 trial and 92.7% in PERFECT 2, compared with rates of 89.8% and 93.9% in vehicle-treated controls, Jerry K.L. Tan, MD, said at the annual congress of the European Academy of Dermatology and Venereology.
“Most adverse events involved local intolerance occurring at application sites and were mild and transient,” Dr. Tan, a dermatologist at the University of Western Ontario, Windsor, and head of Windsor Clinical Research, reported.
PERFECT 1 and 2 were multicenter, double-blind, randomized, vehicle-controlled, 12-week phase 3 trials. Of note, these were the first-ever large-scale randomized trials to simultaneously evaluate a topical therapy for treatment of both facial and truncal acne. This ambitious goal created some unique challenges, which Dr. Tan described.
Participants, all of whom had moderate acne vulgaris on the face and trunk, ranged in age from 9 to 58 years, with a mean age of 19 years. They were randomized to once-daily application of trifarotene cream 50 mcg/g or its vehicle in the evening.
Primary and secondary outcomes
One major efficacy endpoint on the face was achievement of Investigator Global Assessment success as defined by a score of 0 or 1, meaning clear or almost clear, coupled with at least a 2-grade improvement from baseline to week 12. In PERFECT 1 and 2 this was achieved by 29.7% and 42.8% of trifarotene cream-treated patients, response rates significantly better than the 20% and 25.8% in vehicle-treated controls.
Another endpoint for facial therapy were the absolute reductions from baseline in facial inflammatory and noninflammatory acne lesions. The mean reduction in inflammatory lesion count in trifarotene-treated patients was 19.6% in PERFECT 1 and 24.6% in PERFECT 2, both significantly better than the mean 15.8% and 19.6% decreases in controls. Noninflammatory facial lesion counts dropped by 26.7% and 30.4% with trifarotene, versus 18.9% and 22.3% with vehicle.
The efficacy yardsticks utilized on the trunk were the same as on the face except that Physician Global Assessment was the terminology utilized in lieu of Investigator Global Assessment. Physician Global Assessment success on the trunk was achieved by 35.8% and 41.1% of trifarotene-treated patients in the two trials, as compared with 25.7% and 30.1% of controls.
The mean reductions in truncal inflammatory lesion count obtained with trifarotene cream were 22% and 26.1%, both significantly better than the 18.8% and 20.3% rates with vehicle.
Treatment-emergent adverse events leading to study discontinuation occurred in 1.9% of trifarotene-treated patients in one trial and 1% in the other.
One audience member commented that the vehicle response rates looked too strong for that compound to be inert. Dr. Tan agreed. “The vehicle looks really good. One of the issues with vehicles is that many of them have to contain products to prevent decay, fermentation, and proliferation of yeast and bacteria. So I quite agree: I think many of our vehicles do have active ingredients,” he replied. “If you look at the topical dapsone trials, the vehicles look amazing.”
“The other possibility is that there’s what we call ‘investigator creep,’” the dermatologist continued. “It’s the notion that you have no idea what the patients are getting, but they look like maybe they’re getting better, so you grade it as better.”
Dr. Tan reported serving as an advisor and consultant to, speaker for, and recipient of research grants from Galderma, which sponsored the two phase 3 trials. The company is also developing trifarotene for the treatment of lamellar ichthyosis.