What the trial was testing
The SPIRIT 1 enrolled 638 patients with endometriosis. The study was sponsored by Myovant Sciences and tracked outcomes across the full group of patients who matched the trial's eligibility profile.
It was a large trial designed to confirm whether the treatment works well enough for wider use. Trials at this stage are designed to produce evidence regulators and physicians can act on — not just observations to follow up later.
What the results showed
~75% had a meaningful drop in period pain at 24 weeks.
The Lancet · 2022 · NCT03204318
These findings — that had a meaningful drop in period pain on relugolix combination at 24 weeks — were published in the The Lancet and represent the headline result of the study.
Researchers tracked outcomes across 638 patients enrolled in the trial. The result was consistent enough across the group that the team felt confident reporting it.
What this means for patients
For patients with endometriosis, this result changes the calculus on what to ask their care team about. Whether it changes day-to-day care depends on factors like disease subtype, prior treatments, and where the patient is in their care journey.
What you can do now
Relugolix combination therapy (Myfembree) is FDA-approved for moderate-to-severe endometriosis pain in pre-menopausal women and available now. It is a once-daily pill — no injections. Treatment is generally limited to two years because of bone-density concerns. Ask your gynecologist whether it is right for you.
Eligibility for the treatments mentioned above depends on specific test results and clinical history. Bring this summary, the trial name, and your most recent labs or pathology report to your next visit.
Open endometriosis trials
Clinical Validation of the Role of microRNA Binding Site Mutations in Cancer Risk, Prevention and Treatment
The investigators will recruit and enroll individuals that may have the KRAS-variant or other microRNA binding site mutations to join registry studies. The investigators will allow individuals to obtain their results through a physician at the completion of the studies. The investigators current focus is cancer and autoimmunity.
Letrozole in Preventing Recurrence of Endometrioma Following Laparoscopic Ovarian Cystectomy
Endometriosis is a chronic inflammatory disease that affects approximately 10-15% of women of reproductive age. Symptoms include dysmenorrhoea, chronic pelvic pain, dyspareunia and infertility. Removal of the endometriotic cyst (chocolate cyst) by surgery is a well-established treatment for symptomatic relief. However, recurrence of endometriotic cyst after surgical removal of the cyst is up to 30-50% after ovarian surgery. Oral contraceptive pills for 18-24 months after the surgery is widely used as a postoperative hormonal therapy because it has been shown to reduce the chance of recurrence of the endometriotic cyst, but recurrence is still high even after taking oral contraceptive pills. Letrozole is an aromatase inhibitor. There are some preliminary reports that letrozole can cause shrinkage of endometriotic cysts and improve endometriosis-related pelvic pain by reducing oestrogen level, inflammation and stem cell recruitment that may be important in recurrence of endometriotic cyst. This is a randomized double-blinded placebo-controlled trial. The aim of this study is to assess whether taking letrozole in addition to oral contraceptive pills in the first 6 months after laparoscopic surgery (key-hole surgery) to remove the endometriotic cyst can reduce the risk of recurrence compared to oral contraceptive pills alone. The study also involves laboratory parts from a small portion of the endometriotic cyst specimens (removed during laparoscopy ovarian cystectomy) and endometrial biopsy (if the patient agrees) to assess the role of stem cells in the pathogenesis of endometriotic cysts.