Assessment of adapalene gel for the treatment of actinic keratoses and lentigines: a randomized trial

BACKGROUND: Adapalene is a synthetic retinoid with an established clinical efficacy against acne and good local tolerability. Its effectiveness in the treatment of photodamaged skin has not been studied. OBJECTIVE: We sought to determine the safety and efficacy of adapalene gel in the treatment of actinic keratoses and solar lentigines. METHODS: In a prospective, 2-center, randomized, controlled, investigator-masked, parallel-group study, 90 patients with actinic keratoses and solar lentigines were treated daily with either adapalene gel (0.1% or 0.3%) or its vehicle gel for 4 weeks, followed by twice-daily applications, if tolerated, for up to 9 months. RESULTS: Of the 90 Caucasian patients (69 male, 21 female; mean age 63.1 years) who were enrolled into the study, 83 patients completed 9 months of treatment. With adapalene gel 0.1% and 0.3%, the mean number of actinic keratoses was reduced by 0.5 +/- 0.9 (mean +/- SE) and 2.5 +/- 0.9, respectively. Whereas, with the vehicle gel, there was an increase of 1.5 +/- 1.3 (P <.05). After 1 month of treatment, the patients who received adapalene had significant lightening of solar lentigines as compared with the patients who were treated with vehicle gel (P <.05). After 9 months, 57% and 59% of the patients had lighter lesions in the adapalene 0.1% and 0.3% groups, respectively, in comparison with only 36% in the vehicle group (P <.05). Histologic evaluations revealed improved cellular atypia and reduced epidermal melanin in adapalene-, as compared with vehicle-treated group. The differences, however, were not statistically significant. A retrospective evaluation of paired clinical photographs (before and after 9-month treatment) by 2 dermatologists who were treatment-blinded revealed significant improvement in wrinkles and other clinical features of photoaged skin with adapalene as compared with its vehicle. CONCLUSION: Adapalene gel 0.1% and 0.3% were well tolerated and improved actinic keratoses, solar lentigines, and other features of photodamaged skin.