SAT-LB003 Nonsmokers Benefit from Lower Doses of an Estradiol/Progesterone Combination: Results of the REPLENISH Trial

Abstract

Smoking has previously been reported to result in decreases in estradiol exogenous metabolism1,2,3 and may influence the efficacy of hormone therapy (HT) in postmenopausal women2,3. Importantly, differences in smoking rates among clinical trial populations may also contribute to differences in effects of HT observed across the trials.2 The REPLENISH trial (NCT01942668) was a 12-month, phase 3, randomized, double-blind, placebo-controlled, multicenter trial that evaluated 4 doses of TX-001HR (17β-estradiol and progesterone [E2/P4]; 1/100, 0.5/100, 0.5/50, 0.25/50) combined in a single, oral softgel capsule vs placebo in 1835 menopausal women (40−65 y; intact uterus) for the treatment of menopausal, moderate to severe vasomotor symptoms (VMS). The 1 mg E2/100 mg P4 dose is FDA approved as BIJUVATM (TherapeuticsMD, Boca Raton, FL). In this trial, statistically significant improvements in the frequency and severity of moderate to severe VMS were observed for the two highest doses of TX-001HR (1/100 and 0.5/100) and is reported in detail elsewhere.4 The objective of this analysis was to assess the impact of smoking on estradiol metabolism by analyzing estradiol and estrone concentrations measured throughout the study and to assess the potential impact on efficacy. The overall percentage of current smokers was higher in the Replenish trial (26%) than in many other trials of HT, making analysis of the impact of smoking on estrogen levels and efficacy possible. Estradiol and estrone concentrations at baseline were similar between current smokers and nonsmokers (former/never smokers) for all treatment groups (active and placebo). However, at Weeks 4 and 12, Months 6, 9, and 12, estradiol (25%-32%) and estrone (30%-36%) concentrations were statistically significantly lower in smokers than in nonsmokers for all active estradiol/progesterone treatment groups (1/100, 0.5/100, 0.5/50, 0.25/50). There were no significant differences at any time point in the placebo group. Efficacy in reducing the frequency and severity of VMS was greater in nonsmokers. When evaluating nonsmokers, the 0.25/50 dose also demonstrated statistically significant improvements at Weeks 4 and 12, with a weekly reduction of greater than 14 hot flushes compared to placebo beginning at Week 4 and sustained through week 12. Results from this large Phase 3 clinical trial demonstrated a significant impact of current smoking on estradiol and estrone concentrations and indicate that non-smokers may benefit from lower doses of estradiol and progesterone than smokers. 1. Jensen J, et al. NEJM. 1985;313(16):973-975. 2.Tansavatdi B, et al. Minerva Ginecol. 2004;56:105-114. 3. Ruan X and Mueck AO. Climacteric. 2015;18:38-46. 4. Lobo RA, et al. Obstet Gynecol. 2018;132:161-170. Unless otherwise noted, all abstracts presented at ENDO are embargoed until the date and time of presentation. For oral presentations, the abstracts are embargoed until the session begins. s presented at a news conference are embargoed until the date and time of the news conference. The Endocrine Society reserves the right to lift the embargo on specific abstracts that are selected for promotion prior to or during ENDO.