Efficacy and Safety of a Fixed-Dose Clindamycin Phosphate 1.2%, Benzoyl Peroxide 3.1%, and Adapalene 0.15% Gel for Moderate-to-Severe Acne: A Randomized Phase II Study of the First Triple-Combination Drug

A three-pronged approach to acne treatment—combining an antibiotic, antibacterial, and retinoid—could provide greater efficacy and tolerability than single or dyad treatments, while potentially improving patient compliance and reducing antibiotic resistance. We aimed to evaluate the efficacy and safety of triple-combination, fixed-dose topical clindamycin phosphate 1.2%/benzoyl peroxide (BPO) 3.1%/adapalene 0.15% (IDP-126) gel for the treatment of acne. In a phase II, double-blind, multicenter, randomized, 12-week study, eligible participants aged ≥ 9 years with moderate-to-severe acne were equally randomized to once-daily IDP-126, vehicle, or one of three component dyad gels: BPO/adapalene; clindamycin phosphate/BPO; or clindamycin phosphate/adapalene. Coprimary endpoints were treatment success at week 12 (participants achieving a ≥ 2-grade reduction from baseline in Evaluator's Global Severity Score and clear/almost clear skin) and least-squares mean absolute changes from baseline in inflammatory and noninflammatory lesion counts to week 12. Treatment-emergent adverse events and cutaneous safety/tolerability were also assessed. A total of 741 participants were enrolled. At week 12, 52.5% of participants achieved treatment success with IDP-126 vs vehicle (8.1%) and dyads (range 27.8–30.5%; P ≤ 0.001, all). IDP-126 also provided significantly greater absolute reductions in inflammatory (29.9) and noninflammatory (35.5) lesions compared with vehicle or dyads (range inflammatory, 19.6–26.8; noninflammatory, 21.8–30.0; P < 0.05, all), corresponding to > 70% reductions with IDP-126. IDP-126 was well tolerated, with most treatment-emergent adverse events of mild-to-moderate severity. Once-daily treatment with the novel fixed-dose triple-combination clindamycin phosphate 1.2%/BPO 3.1%/adapalene 0.15% gel demonstrated superior efficacy to vehicle and all three dyad component gels, and was well tolerated over 12 weeks in pediatric, adolescent, and adult participants with moderate-to-severe acne. ClinicalTrials.gov identifier NCT03170388 (registered 31 May, 2017).