Quinagolide vaginal ring for reduction of endometriotic lesions: Results from the QLARITY trial

BACKGROUND: This study evaluated the effectiveness of quinagolide vaginal ring on reducing total lesion size in endometrioma, deep infiltrating endometriosis (DIE), and adenomyosis, as assessed using high-resolution MRI and imaging biomarkers. METHODS: QLARITY was a randomized, double-blind, placebo-controlled, phase 2 trial. Patients aged 18-45 years with endometrioma, DIE, and/or adenomyosis were randomized to quinagolide or placebo and monitored for four menstrual cycles. The primary endpoint was reduction in total lesion size. Secondary endpoints were pain reduction, changes in prolactin, changes in menstrual cycle, bleeding patterns, and safety. Exploratory analyses identified MRI-derived perfusion and diffusion-weighted imaging biomarkers. RESULTS: Of the 67 included subjects, 35 received quinagolide vaginal ring and 32 received placebo. No significant differences were noted between groups for the primary endpoint of reduction in lesion size. No significant differences were observed between groups in terms of patient-reported outcomes, serum prolactin levels, menstrual bleeding patterns, or adverse events. Exploratory analyses suggested lesions in the placebo group showed a greater increase in vascular permeability and worsening lesion structure. CONCLUSIONS: Our primary analysis showed no significant difference between treatment groups in terms of change in total lesion size. Many patients in this study presented with advanced disease, which may be less responsive to quinagolide than highly vascularized superficial lesions, as quinagolide inhibits the VEGF signaling pathway. TRIAL REGISTRATION: ClinicalTrials.gov NCT03749109.