Moderate and Severe Inflammatory Acne Vulgaris Effectively Treated with Single-Agent Therapy by a New Fixed-Dose Combination Adapalene 0.3 %/Benzoyl Peroxide 2.5 % Gel: A Randomized, Double-Blind, Parallel-Group, Controlled Study

A need exists for topical treatments in managing more severe inflammatory acne. The objectives of this study were to evaluate the efficacy and safety of adapalene 0.3 %/benzoyl peroxide 2.5 % (0.3 % A/BPO) topical gel in subjects with moderate and severe inflammatory acne. This was a multicenter, randomized, double-blind, parallel-group study. Randomization was stratified by acne severity (50 % moderate and 50 % severe). Subjects received 0.3 % A/BPO, 0.1 % A/BPO (benchmark), or vehicle (comparator) once daily for 12 weeks. Co-primary efficacy endpoints were success rate at week 12 (the percentage of subjects rated 'clear' or 'almost clear' with at least a 2-grade improvement on Investigator's Global Assessment [IGA]) and change in inflammatory (IN) and noninflammatory (NIN) lesion counts from baseline to week 12. Secondary efficacy endpoints were percent changes in IN and NIN lesion counts. Safety endpoints were incidence of adverse events (AEs) and local tolerability signs/symptoms. A total of 503 subjects were randomized: 217, 217, and 69 subjects in the 0.3 % A/BPO, 0.1 % A/BPO, and vehicle groups, respectively. For success rate (subjects rated 'clear' or 'almost clear' with a parts per thousand yen2-grade improvement in IGA), 0.3 % A/BPO was superior to vehicle, with a treatment difference of 22.7 % (33.7 vs. 11.0 %; 95 % confidence interval [CI] 12.8-32.6, p < 0.001). At week 12, 0.3 % A/BPO was superior to vehicle for mean reduction from baseline in IN (27.0 vs. 14.4) and NIN lesion counts (40.2 vs. 18.5), as well as for percentage reduction from baseline in IN (68.7 vs. 39.2 %) and NIN lesion counts (68.3 vs. 37.4 %) (all p < 0.001). Among subjects with severe inflammatory acne (IGA = 4), 0.1 % A/BPO did not reach statistical significance for success rate compared with vehicle (p = 0.443), whereas 0.3 % A/BPO demonstrated significantly greater efficacy (p = 0.029, requiring a parts per thousand yen3-point IGA improvement). Additionally, 0.3 % A/BPO was safe and well-tolerated. Results of this clinical trial demonstrate the significantly greater efficacy of adapalene 0.3 % A/BPO topical gel compared with vehicle as well as a good safety profile in the treatment of moderate to severe inflammatory non-nodulocystic acne, which increases patients' treatment options. NCT01880320.