A study in Chinese women with endometriosis showed that a 3‑month injectable form of the hormone‑blocking peptide triptorelin works just as well as the standard monthly injection, with over 98% of patients reaching the desired low estrogen levels and similar pain relief. This means you can get the same effect with fewer shots, which may be easier to manage.

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. 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. 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. 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. NCT03232281.