Background: Acne vulgaris is a common chronic skin disease affecting roughly 15 percent of the general population and up to 85 percent of adolescents and young adults. Adapalene, a synthetic naphthoic acid derivative with retinoid activity, has demonstrated good clinical efficacy in the treatment of acne if used with full compliance.
Objectives: To evaluate the efficacy and assess safety of a new adapalene formulation, adapalene 0.1% lotion, versus the lotion vehicle in subjects with acne vulgaris.
Methods: Subjects were randomized to receive either adapalene 0.1% lotion or its vehicle once daily for 12 weeks in two multicenter, randomized, vehicle-controlled, double-blind, parallel group studies. Efficacy was evaluated using two co-primary endpoints: Investigator Global Assessment (IGA) of success rate (defined as the proportion of subjects who achieved at least a two point reduction, on a 5-point scale, from baseline to week 12 in IGA score); and the absolute change from baseline to week 12 in total, inflammatory and non-inflammatory lesions. Signs of local skin irritation and routine clinical safety parameters were evaluated throughout both studies.
Results: In total, 2,141 subjects were included in the two studies: 1,068 patients received adapalene 0.1 percent lotion and 1073 received the vehicle. In both studies, adapalene 0.1% lotion was shown to be significantly more effective than its vehicle in improvement in the IGA success rate. Adapalene 0.1% lotion was also significantly superior to its vehicle in all three lesion reduction measures: total, inflammatory and non-inflammatory. Reports of application site skin irritation in the adapalene 0.1% lotion treatment group were transient and mild or moderate in severity, with only a few being severe. Additionally, according to patient surveys, the lotion formulation was found to be easily spreadable, easily absorbed and pleasant to use.
Conclusion: Adapalene 0.1% lotion used once a day for 12 weeks is effective and well tolerated in the treatment of acne vulgaris.