SPIRIT 2: Efficacy and Safety Study of Relugolix in Women With Endometriosis-Associated Pain

This study is an international phase 3 randomized, double-blind, placebo-controlled efficacy and safety study to evaluate 24 weeks of oral, once-daily relugolix (40 mg) co-administered with either 12 or 24 weeks of low-dose E2 (1.0 mg) and NETA (0.5 mg), compared with placebo. Approximately 600 women with endometriosis-associated pain were enrolled and randomized 1:1:1 to Group A - relugolix plus low-dose hormonal add-back therapy, Group B - relugolix monotherapy for 12 weeks followed by co-administration with low-dose hormonal add-back therapy, or Group C - placebo (N = 200 per group). Eligible participants were randomized on Baseline Day 1 to Treatment Group A, B, or C, in the double-blind period. Eligible participants, including those randomized to placebo, were offered the opportunity to enroll in an 80-week open label extension study where participants received relugolix co-administered with low-dose E2 and NETA. Participants who did not enroll into the extension study had a Follow-Up visit approximately 30 days after the participant's last dose of study drug.