Novel Tretinoin 0.05% Lotion for the Once-daily Treatment of Moderate-to-Severe Acne Vulgaris in an Adult and Adolescent Female Population

BACKGROUND: Acne vulgaris (acne) is a common dermatological condition typically associated with adolescents, affecting about 85% of young people. However, it is also prevalent and persistent into adulthood, particularly in females. The efficacy of tretinoin in acne is well documented with large pivotal studies. The first lotion formulation of tretinoin was developed to provide an important alternative option to treat acne patients who may be sensitive to the irritant effects of other tretinoin formulations. OBJECTIVE: To determine whether efficacy and safety of tretinoin 0.05% lotion was similar in adolescent (less than 18 years) and adult (less than equal to18 years) women with moderate-to-severe acne. METHODS: Post hoc analysis of two multicenter, randomized, double-blind, vehicle-controlled Phase 3 studies in moderate or severe acne. Female subjects (aged 9 to 58 years, N=909) randomized (1:1) to receive tretinoin 0.05% lotion or vehicle, once-daily for 12 weeks. Efficacy assessments included changes in baseline inflammatory and noninflammatory lesions and treatment success (at least 2-grade reduction in Evaluator’s Global Severity Score [EGSS] and clear/almost clear). Safety, adverse events (AEs), and cutaneous tolerability were evaluated throughout. RESULTS: At week 12, mean percent reduction in inflammatory and noninflammatory lesion counts in female subjects were 56.9% and 51.7%, respectively, compared with 47.1% and 34.9% with vehicle (P equals less than 0.001). Similar results were seen in adult and adolescent females in terms of reduction in inflammatory lesion counts with tretinoin 0.05% lotion; reduction in noninflammatory lesions was significantly greater in adult females (P equals 0.002). Treatment success was achieved by 23.6% of female subjects by week 12, compared with 13.5% on vehicle (P less than 0.001). Although treatment success was somewhat greater in adult females (24.6% versus 21.6%), the difference was not significant. The majority of AEs were mild and transient. There were five serious AEs (SAEs) reported (4/1, adult/adolescent, respectively). The most frequently reported treatment related AEs with tretinoin 0.05% lotion were application site pain (3.0%/5.7%), and application site dryness (4.9%/6.4%). Local cutaneous safety and tolerability assessments were generally mild-to-moderate and improved by week 12. Slight increases in mean scores were observed for scaling, burning and stinging within the first four weeks and appeared to be transient. CONCLUSIONS: Tretinoin 0.05% lotion was significantly more effective than its vehicle in achieving treatment success and reducing inflammatory and noninflammatory lesions in female acne. Noninflammatory lesion count reduction was significantly greater in adult females compared with adolescent females. The new lotion formulation was well-tolerated. J Drugs Dermatol. 2019;18(2):178-188.