The results prompted a new Phase 3 clinical program, now recruiting patients, investigating relugolix in women with heavy menstrual bleeding associated with uterine fibroids — the LIBERTY 1 (NCT03049735), LIBERTY 2 (NCT03103087) and LIBERTY-EXTENSION (NCT03412890) studies — and in women with endometriosis-associated pain, the SPIRIT 1 (NCT03204318) and SPIRIT 2 (NCT03204331) trials.
In one of the two Japanese Phase 3 trials (NCT02655237), researchers compared the effectiveness and safety of relugolix to leuprorelin (sold under the brand name Lupron, among others) as a therapy for women with heavy menstrual bleeding associated with uterine fibroids.
Patients were randomized to receive either relugolix taken orally once daily or leuprorelin administered by injection once every four weeks. The treatment was administered over 24 weeks.
The response rate — meaning the proportion of patients who reported less menstrual blood loss — was 82.2% in women treated with relugolix, demonstrating the therapy’s non-inferiority compared to leuprorelin.
Also, the frequency of treatment-adverse events was similar between both treatment groups.
In the second Phase 3 study (NCT02655224), researchers evaluated the effectiveness and safety of relugolix as a pain treatment for uterine fibroids compared to a placebo (or control).
The results showed that 57.6% of women who received relugolix had a marked improvement in pain symptoms, while only 3.1% of women reported the improvements in the placebo group.
Relugolix blocks the secretion of luteinizing hormone (LH) and follicle-stimulating hormone (FSH), which suppresses estrogen and progesterone.
By inhibiting the secretion of the hormones, relugolix has the potential to improve the symptoms of uterine fibroids and endometriosis.
Takeda Pharmaceutical developed relugolix, but has granted Myovant, a clinical-stage biopharma developing new therapies for women’s health, the exclusive worldwide license to develop and commercialize the investigative therapy (except in Japan and certain other Asian countries, for which Takeda holds the rights).
Takeda plans to submit an application to Japanese regulatory authorities — and Myovant to the U.S. Food and Drug Administration— seeking approval of relugolix for the treatment of uterine fibroids.
“We continue to execute on each of our ongoing global Phase 3 development programs of relugolix for the treatment of endometriosis-associated pain, heavy menstrual bleeding associated with uterine fibroids, and advanced prostate cancer with the goal of completing enrollment in each program this year,” Lynn Seely, MD, president and CEO of Myovant Sciences, said in a press release.