Myovant Completes Patient Recruitment for Phase 3 Spirit 1 Trial of Relugolix

Myovant Completes Patient Recruitment for Phase 3 Spirit 1 Trial of Relugolix

Myovant Sciences has completed patient recruitment for its ongoing Phase 3 SPIRIT 1 clinical trial assessing the safety and effectiveness of relugolix in combination with estradiol and progestin to treat pain in women with endometriosis.

SPIRIT 1 (NCT03204318) and its twin study, SPIRIT 2 (NCT03204331), are part of a program that intends to gather evidence that will lead to the regulatory approval of relugolix as an oral therapy to manage moderate-to severe pain associated with endometriosis.

Myovant announced in August it had completed patient enrollment for SPIRIT 2. Now SPIRIT 1 has completed enrollment, having recruited participants from multiple sites in the U.S., Canada, Europe, Argentina, and South Africa.

“The completion of recruitment for the SPIRIT program marks another important step in achieving our goal to bring a best-in-class, non-invasive treatment option to women suffering from endometriosis, that has predictable efficacy and tolerability and is potentially suitable for long-term use,” Juan Camilo Arjona Ferreira, MD, chief medical officer of Myovant Sciences, said in a press release.

“We are extremely appreciative of the physicians and patients who participate in our clinical trials and have helped us reach this important milestone. We look forward to sharing the top-line results in the first and second quarters of 2020,” Ferreira said.

Relugolix is an investigational small molecule that blocks signals from gonadotropin-releasing hormone (GnRH), reducing the production of estrogen in the ovaries. Estrogen is known to stimulate the growth of uterine fibroids, noncancerous growths that can lead to heavy menstrual bleeding, pelvic pain, and endometriosis.

Each of the SPIRIT trials will enroll approximately 600 adults up to the age of 50, with a confirmed diagnosis of endometriosis by laparoscopy or laparotomy (surgical procedures in which a surgeon examines a patient’s abdominal cavity to look for lesions caused by endometriosis).

During the trials, all participants will be assigned randomly to one of three groups: the relugolix combination therapy, consisting of relugolix tablets (40 mg) plus capsules of estradiol (1.0 mg) and progestin (norethindrone acetate,  0.5 mg) once a day for 24 weeks; relugolix alone for 12 weeks, followed by the relugolix combination therapy for another 12 weeks; or to a placebo for 24 weeks.

Estradiol and progestin are forms of the female sex hormones estrogen and progesterone. They will be added to relugolix as a hormonal add-back to compensate the effects of the medication that naturally lowers the levels of estrogen in the body, and to minimize the risks of undesirable therapy side effects, including bone fragility and hot flushes.

The two main goals of both trials will be to assess the impact of the combination therapy on menstrual pelvic pain (dysmenorrhea) and on non-menstrual pelvic pain reported by patients.

Safety outcomes, including bone mineral density changes as measured by bone densitometry (DEXA, DXA), also will be assessed.

Women who complete any of the SPIRIT trials will have the option to continue treatment with relugolix in an open-label extension phase, in which the medication will be given for an additional period of 80 weeks, allowing those in the initial investigative group to use the combo treatment for a total of 104 weeks.

The main goal of the extension-study is to evaluate the long-term safety of the combination therapy, especially on bone health.

Top-line data from the studies is expected in the first months of 2020 for SPIRIT 2, and at mid-year for SPIRIT 1.