A 6-month maintenance therapy with adapalene-benzoyl peroxide gel prevents relapse and continuously improves efficacy among patients with severe acne vulgaris: results of a randomized controlled trial.

BACKGROUND: Acne vulgaris is a chronic and frequently recurring disease. A fixed-dose adapalene-benzoyl peroxide (adapalene-BPO) gel is an efficacious and safe acne treatment.

OBJECTIVES: To assess the long-term effect of adapalene-BPO on relapse prevention among patients with severe acne after successful initial treatments.

METHODS: This is a multicentre, double-blind, randomized and controlled study. In total, 243 subjects who had severe acne vulgaris and at least 50% global improvement after a previous 12-week treatment were randomized into the present study to receive adapalene-BPO gel or its vehicle once daily for 24 weeks.

RESULTS: At week 24, compared with vehicle, adapalene-BPO resulted in significantly higher lesion maintenance success rate (defined as having at least 50% improvement in lesion counts achieved in initial treatment) for all types of lesions (total lesions: 78·9% vs. 45·8%; inflammatory lesions: 78·0% vs. 48·3%; noninflammatory lesions: 78·0% vs. 43·3%; all P < 0·001). Significantly more subjects with adapalene-BPO than with vehicle had the same or better Investigator's Global Assessment score at week 24 than at baseline (70·7% vs. 34·2%; P < 0·001). The time when 25% of subjects relapsed was 175 days with adapalene-BPO and 56 days with vehicle (17 weeks earlier; P < 0·0001). Adapalene-BPO led to further decrease of lesion counts during the study and 45·7% of subjects were 'clear' or 'almost clear' at week 24. It was also safe and well tolerated in the study.

CONCLUSIONS: Adapalene-BPO not only prevents the occurrence of relapse among patients with severe acne, but also continues to reduce disease symptoms during 6 months.