Tretinoin 0.05% Lotion for the Once-Daily Treatment of Moderate-to-Severe Acne Vulgaris: Impact of Gender and Race on Efficacy and Safety

Background: There has been an increasing interest in gender and racial differences both in the pathogenesis and treatment of acne vulgaris (acne), and postinflammatory hyperpigmentation (PIH) is a major concern in patients of color. Female acne patients report more anxiety and depression with acne improvement positively influencing Quality of Life (QoL) than their male counterparts, and there are differences in acne presentation. The first lotion formulation of tretinoin was developed using novel polymeric emulsion technology to provide an important alternative option to treat these acne patients, especially those who may be sensitive to the irritant effects of other tretinoin formulations.

Objective: To determine the impact of gender and race on the efficacy and safety of tretinoin 0.05% lotion in treating moderate or severe acne.

Methods: Post hoc analysis of 2 multicenter, randomized, double-blind, vehicle-controlled Phase 3 studies in moderate-to-severe acne. Subjects (aged 9 to 58 years, N=1640) were 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). Quality of Life was assessed using the validated Acne QoL scale. Safety, adverse events (AEs), cutaneous tolerability, and hypo-/hyper-pigmentation (using a 4-point scale where 0=none and 3=severe) were evaluated at each study visit.

Results: At week 12, mean percent reduction in inflammatory lesion counts were 56.9% and 53.4% respectively in female and male patients compared with 47.1% and 39.4% with vehicle (P≤0.001), with females statistically significant to males at week 8 [P=0.026]). Mean percent reduction in noninflammatory lesion counts in females and males were 51.7% and 46.1% respectively, compared with 34.9% and 29.7% with vehicle (P<0.001), with females statistically significant to males at week 12 (P=0.035). Treatment success was achieved by 23.6% and 16.1% of female and male patients treated with tretinoin 0.05% lotion by week 12 (P≤0.001 vs vehicle) with females statistically significant compared with males (P=0.013). Significant differences in inflammatory lesion count reductions were reported in Caucasian patients from week 8, and Black African/American male patients at week 12. Only male patients reported significant differences in both races in terms of noninflammatory lesions, and only Caucasian patients reported significant differences in treatment success. Female patients treated with tretinoin 0.05% lotion had statistically significant improvements in each Acne QoL domain (except role-social) compared with vehicle. Improvements in QoL in male subjects were only statistically different for acne symptoms. Tretinoin 0.05% lotion was well-tolerated in both genders. There were more treatment-related AEs in the female subpopulation, with a significantly greater incidence of skin dryness (P=0.006), that was more common in the younger Caucasian females. Conclusions: Tretinoin 0.05% lotion has been shown to be effective and well tolerated in moderate-to-severe acne. Treatment was significantly more effective in females than males. Tretinoin 0.05% lotion was well tolerated by both genders, although there was a higher incidence of treatment-related AEs, especially skin dryness, in females. There were racial and gender differences in QoL and beneficial effects on PIH in those patients most at risk.

J Drugs Dermatol. 2019;18(11):1128-1138.