Adapalene–benzoyl peroxide, a unique fixed-dose combination topical gel for the treatment of acne vulgaris: a transatlantic, randomized, double-blind, controlled study in 1670 patients

Background  Combination therapy utilizing agents with complementary mechanisms of action is recommended by acne guidelines to help simultaneously target multiple pathogenic factors. A unique, topical, fixed-dose combination gel with adapalene 0·1% and benzoyl peroxide (BPO) 2·5% has recently been developed for the once-daily treatment of acne.
Objectives  To evaluate the efficacy and safety of adapalene 0·1%–BPO 2·5% fixed-dose combination gel (adapalene–BPO) relative to adapalene 0·1% monotherapy (adapalene), BPO 2·5% monotherapy (BPO), and the gel vehicle (vehicle) in a large population for the treatment of acne vulgaris.
Methods  In total, 1670 subjects were randomized in a double-blind controlled trial to receive adapalene–BPO, adapalene, BPO or vehicle for 12 weeks (1 : 1 : 1 : 1 randomization). Evaluations included success rate (subjects 'clear' or 'almost clear'), percentage change in lesion count from baseline, cutaneous tolerability and adverse events.
Results  Adapalene–BPO was significantly more effective than corresponding monotherapies, with significant differences in percentage lesion count change observed as early as 1 week. Cutaneous tolerability profile was similar to adapalene. Adverse events were more frequent with the combination therapy (mainly due to an increase in mild-to-moderate dry skin), occurred early in the study, and were transient.
Conclusions  Adapalene–BPO provides significantly greater and synergistic efficacy and a faster onset of action with an acceptable safety profile in the treatment of acne vulgaris when compared with the corresponding vehicle and the adapalene and BPO monotherapies.