The consistent effects of a low-dose oral contraceptive in the treatment of women with moderate acne vulgaris across age and race.

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Objective: This analysis was conducted to determine whether a low-dose oral contraceptive (OC) would be equally effective in both adolescents and women over 18 in the treatment of moderate acne vulgaris. Data were also analyzed by race to establish equivalent efficacy across diverse ethnic groups. The analysis is based on a study that determined the efficacy of a low-dose OC containing 20, 30, and 35 mcg ethinyl estradiol (for 5, 7, and 9 days, respectively) with a constant low dose of 1 mg norethindrone acetate (Estrostep®) versus placebo in treating moderate acne vulgaris. Design: Two randomized, double-blind, placebo-controlled trials of essentially identical design. Materials/Methods: 593 subjects (female, any race, 14-49 yrs of age, ≥1 yr postmenarche, baseline menstrual cycle ≥42 days, moderate facial acne [20–100 comedones, 20–65 inflammatory lesions, ≥5 nodules] nonresponsive to topical therapy) were randomized to treatment with either Estrostep (n = 297) or placebo (n = 296) for six 28-day treatment cycles (Estrostep or placebo were administered for 21 days of each 28-day cycle followed by 7 days of ferrous fumarate 75 mg). Primary efficacy measures were mean change from baseline in total lesion count, inflammatory lesion count, comedo count, and an investigator-assessed Facial Acne Global Assessment at study exit. For each of these primary efficacy measures, a pooled analysis summarized the results by tertiles of age (<19 [33%]; 19 − <27 [38%]; 27 and greater [34%]) and by race (Caucasian [70%]; African-American [14%]; or Other [17%]). Data were pooled because the two studies were essentially identical, there were no meaningful differences between the study populations, and the results of the separate analyses of efficacy were statistically indistinguishable. Tertiles of age were determined from pooled data of all randomized subjects. Lesion count change differences between treatment groups adjusting for age and race separately were evaluated using a General Linear Model including effects for treatment group, baseline lesion count, study, and age or race. Analyses were performed for the intent-to-treat population. Results: The overall treatment effects adjusting for age or race were highly significant for all three lesion counts and the Facial Acne Global Assessment versus placebo (P < 0.05 for all measures). None of the interactions between treatment and age or race were significant, indicating a consistent effect of Estrostep across the age range and races in the two studies. Overall, there were no unexpected differences by age or race in the frequency of adverse events (AEs), associated AEs, or AEs resulting in withdrawals. AEs typically associated with OC use (breakthrough bleeding, migraine, nausea, and breast pain) were more common in Estrostep-treated subjects than placebo-treated subjects. Conclusions: Estrostep was shown to be equally efficacious in the treatment of moderate acne vulgaris in subjects of any race, ranging in age from 14–49 years. These results are important in light of the high association of acne with adolescence and young adulthood. Supported By: Pfizer, Inc., New York, NY.