Synergistic efficacy of adapalene 0.1%-benzoyl peroxide 2.5% in the treatment of 3855 acne vulgaris patients

The adapalene-benzoyl peroxide (adapalene-BPO) combination gel is efficacious and safe in the treatment of acne vulgaris. We aimed in this pooled analysis to determine whether the adapalene-BPO combination demonstrates synergistic efficacy. Data were pooled and analyzed from three double-blind controlled studies, in which patients were randomized to receive adapalene-BPO, adapalene, BPO or vehicle once daily for 12 weeks. Efficacy assessments included percent reduction in lesion counts and Investigator's Global Assessment (IGA) success. Benefit of each treatment relative to vehicle was calculated by subtracting the vehicle result from the efficacy result. Synergy was defined as the benefit of the combination greater than the sum of benefits of adapalene and BPO monotherapies. Adapalene-BPO was significantly more efficacious than its monotherapies in decreasing lesion counts as early as week 1 and throughout the study (p < 0.05). Synergy in total lesion count reduction was observed up to week 8, contributing 48.7% of the benefit of adapalene-BPO relative to vehicle in decreasing total lesions at week 1. Synergy of the combination in IGA success was observed at weeks 1, 4, 8 and 12. In conclusion, the fixed-dose adapalene-BPO combination gel provides synergistic and significantly greater efficacy than its monotherapies in the treatment of acne vulgaris.