Efficacy and safety comparison of adapalene (CD271) gel and tretinoin gel in the topical treatment of acne vulgaris. A European multicentre trial

Abstract

BACKGROUND: Adapalene is a new chemical entity which binds with high affinity to specific nuclear retinoic acid receptors and exhibits tretinoin-like activities in the terminal differentiation process. OBJECTIVE: The purpose of the trial was to compare adapalene 0.1% gel (Differin Gel, Galderma Laboratories) with tretinoin 0.025% gel (Retin A Gel, Cilag Laboratories) in the treatment of acne patients, methods: A multicentre, investigator-masked, parallel-group study included 268 male and female patients with mild to moderate facial acne vulgaris. Treatments were applied once daily for 12 consecutive weeks. RESULTS A total of 134 patients (74 males and 60 females, mean age 19.7 years) received adapalene gel and 134 patients (69 males and 65 females, mean age 19.2 years) tretinoin gel. Among these patients, 259 were evaluable for efficacy and safety and 236 completed the study. The inflammatory, noninflammatory and total lesion counts, and the global facial acne grade were not significantly different between the two treatment groups after 12 weeks of treatment, but the onset of action of adapalene gel appeared to be slightly but not significantly more rapid in reducing inflammatory and total lesion counts at weeks 2 and 4. Some skin irritation was observed with both products, reaching a maximal intensity during week 2 of treatment. Significantly lower mean scores were obtained with adapalene gel than with tretinoin gel for burning (from weeks 2 to 12) dryness and scaling (at weeks 8 and 12). conclusions: Adapalene 0.1% gel was as effective as tretinoin 0.025% gel in a 12-week once-daily treatment of mild to moderate acne vulgaris. Adapalene gel was safe, with low systemic exposure, no detectable systemic toxicity and a significantly better skin tolerability than tretinoin gel.