Consistency of Effect with a Low-Dose, Estradiol Vaginal Capsule (TX-004HR): Evaluating Improvement in Vaginal Physiology and Moderate-to-Severe Dyspareunia in Subgroups of Postmenopausal Women

Background: The 12-week, randomized, double-blind, placebo-controlled, multicenter, phase 3 REJOICE trial demonstrated that TX-004HR, an investigational, applicator-free, low-dose vaginal softgel capsule containing solubilized 17β-estradiol, effectively and rapidly treats symptoms of vulvar and vaginal atrophy (VVA) with negligible to very low systemic absorption. The aim of this analysis was to assess whether the efficacy of TX-004HR varies with age, body mass index (BMI), uterine status, pregnancy status, and vaginal delivery.

Methods: The REJOICE trial evaluated the efficacy of 4-, 10-, and 25-μg doses of TX-004HR in postmenopausal women (40-75 years) with VVA and a self-identified most bothersome symptom of moderate-to-severe dyspareunia. Prespecified subgroup analyses of the four co-primary endpoints (percentages of superficial cells and parabasal cells, vaginal pH, and severity of dyspareunia) were analyzed with respect to age, BMI, uterine status, pregnancy status, and vaginal births. Each dose was compared with placebo for change from baseline to week 2 through week 12, respectively.

Results: TX-004HR significantly improved superficial cells, parabasal cells, and vaginal pH from baseline to weeks 2 and 12 in most subgroups. All TX-004HR doses numerically reduced the severity of dyspareunia by 2 weeks and maintained efficacy over 12 weeks, with many of the subgroups having statistically significant improvement relative to placebo.

Conclusions: TX-004HR was efficacious for treating symptomatic VVA, and it demonstrated a consistency of effect when women's age, BMI, uterine status, pregnancy status, and vaginal births were evaluated. Clinical Trial Identifier: NCT02253173.