Efficacy and Safety Evaluation of Vipoglanstat in Moderate to Severe Endometriosis-Related Pain: A Phase 2 Randomized, Double-Blind, Placebo-Controlled Trial

The primary objective of this study is to evaluate the efficacy of vipoglanstat in reducing non-menstrual pelvic pain associated with endometriosis. This investigation aims to determine the therapeutic impact of two different doses of the study drug compared to a placebo. The trial also assesses safety and dose response.

This clinical trial involves 29 premenopausal females between the ages of 18 and 45 years. The study population consists of patients with a confirmed diagnosis of endometriosis, documented via surgical visualization, biopsy, transvaginal sonography, or magnetic resonance imaging within the previous 10 years. Participants must have a documented history of non-menstrual pelvic pain that significantly impacts daily activities. Inclusion requires the reporting of moderate, severe, or very severe pain during non-menstrual days in the month preceding the second visit, as assessed by the PGA-NMPP scale.

This Phase 2, randomized, double-blind, placebo-controlled trial is designed to investigate the efficacy and safety of two doses of vipoglanstat in patients experiencing endometriosis-related pain. The methodology involves comparing the test substance against an identical placebo capsule. The primary objective is to evaluate the effect of the treatment on non-menstrual pelvic pain (NMPP). The study includes a screening visit to confirm diagnosis via surgical or imaging methods and to assess pain history. Following screening, participants undergo treatment for a period of four months to evaluate changes in pain scores and safety laboratory variables. The trial aims to measure the proportion of participants achieving a reduction in the mean worst NMPP numerical rating scale (NRS) score without an increase in opioid rescue medication use. Secondary endpoints include changes in dysmenorrhea (DYS) NRS scores, EHP-30 scores, and the monitoring of adverse events.

The experimental treatment consists of vipoglanstat, administered in a capsule pharmaceutical form. This substance is intended for oral administration.

The experimental treatment also includes GS-248, which is provided as a hard capsule for oral use.

A placebo is utilized as a comparator, consisting of a capsule without the active ingredient. The placebo capsules are identical in appearance to the vipoglanstat capsules to maintain the double-blind design of the study regarding endometriosis-related pain.

The primary efficacy endpoint is the proportion of participants achieving a reduction of at least 2.0 points or at least 30% in the mean worst non-menstrual pelvic pain (NMPP) Numeric Rating Scale (NRS) score, without an increase in opioid rescue medication use, during non-menstrual days from baseline to the fourth month of treatment. Secondary efficacy parameters include the change in mean worst NMPP NRS score from baseline to the fourth month of treatment and the proportion of participants achieving at least a 2.0 point or 30% reduction in the mean worst dysmenorrhea (DYS) NRS score, without an increase in rescue medication use, during menstrual bleeding days from baseline to the fourth month of treatment. Further secondary measures involve the change in mean worst DYS NRS score from baseline to the fourth month of treatment, the change in the Endometriosis Health Profile-30 (EHP-30) score from Visit 3 to Visit 7, and the change in the EHP-30 sexual intercourse subscale score from Visit 3 to Visit 7.

Additional assessments include the following changes from baseline to the fourth month of treatment:

• Mean daily opioid rescue medication use for NMPP.
• Mean daily opioid rescue medication use for DYS.