Assessment of Two Formulations of Triptorelin in Chinese Patients with Endometriosis: A Phase 3, Randomized Controlled Trial.

Introduction: This phase 3, randomized, open-label, active-controlled, multicenter study investigated the efficacy of triptorelin pamoate prolonged-release (PR) 3-month in Chinese patients with endometriosis by demonstrating the noninferiority of the 3-month formulation to the standard of care, triptorelin acetate PR 1-month.

Methods: The trial was conducted in 24 clinical centers in China, and included 300 Chinese women (18-45 years) with endometriosis and regular menstrual cycles who required treatment with a gonadotropin-releasing hormone agonist for 6 months. One group of patients (n = 150) was treated with triptorelin pamoate PR 3-month (15 mg per injection, once every 12 weeks), and the other (n = 150) with triptorelin acetate PR 1-month (3.75 mg per injection, once every 4 weeks). The primary outcome measure was the proportion of patients with estradiol (E2) concentrations suppressed to castration levels (≤ 184 pmol/L, or 50 pg/mL) after 12 weeks of treatment.

Results: Triptorelin pamoate PR 3-month was noninferior to triptorelin acetate PR 1-month for the treatment of endometriosis: over 98% of patients in both groups were chemically castrated at week 12. Both formulations were also equally efficacious in reducing endometriosis-associated pelvic pain, and reducing serum concentrations of E2, luteinizing hormone, and follicle-stimulating hormone over time. No new safety concerns were identified.

Conclusion: Triptorelin pamoate PR 3-month is a valid alternative to triptorelin acetate PR 1-month for the treatment of Chinese women with endometriosis, with fewer injections and a potentially lower burden of care.

Trial Registration: NCT03232281.