Myovant Sciences is on a roll. Yesterday, it submitted its lead drug to the FDA as a monotherapy for prostate cancer. Today, it is unveiling positive phase 3 data for a combination built around the drug to treat endometriosis, a difficult-to-spot condition that can cause pelvic pain and infertility in women.
The pill, which combines Myovant’s relugolix with a pair of hormone medications, beat placebo at reducing both menstruation-linked pain and nonmenstrual pain. After six months of treatment, three-quarters of the women taking the relugolix combination reported a “clinically meaningful” reduction in dysmenorrhea, or painful periods, compared with just 30% of women on placebo. Those numbers were 66% and 42% for nonmenstrual pain, respectively.
Women taking relugolix said the treatment cut their pain back from severe to mild. Measured on a numerical scale of 1 to 11, the women reported an average reduction from 7.2 to 1.7—a 75% decrease. In addition to hitting its co-primary endpoints, the relugolix combo delivered on several secondary endpoints, including a reduction in opioid use to manage pain and a smaller impact of pain on patients’ daily activities.
Endometriosis is a disorder in which tissue that normally lines the uterus grows outside of the uterus. These growths are most often found in the ovaries and fallopian tubes but can be found elsewhere in the pelvic region or in other parts of the body. Some patients are unable to work because of their pain, especially during their periods when the pain is most severe.
“For many patients, endometriosis is a very severe disease that can be debilitating,” said James Segars, M.D., director of the Division of Reproductive Science and Women’s Health Research at Johns Hopkins University and a professor in the university’s department of gynecology and obstetrics. “It’s not lethal, but at the same time, it can cause significant impact on your life.”
There is only one approved treatment for endometriosis-related pain: AbbVie’s Orilissa, which is aiming for approval to treat uterine fibroids. First-line treatments include over-the-counter painkillers and hormonal contraceptives, but these don’t work for all patients, with some requiring opioids to manage their pain. Patients may undergo surgery to remove the growths, but there’s no guarantee they won’t recur after the procedure.
Relugolix works by blocking the gonadotropin-releasing hormone receptor, thereby reducing the production of estradiol, a hormone that drives the growth of uterine fibroids and endometriosis. Myovant is combining it with hormone medications estradiol and norethindrone.
“What we are particularly pleased about is to be able to see this degree of benefit in pain reduction with a generally well-tolerated safety profile without creating new problems for these women, such as loss of bone density,” Myovant CEO Lynn Seely told FierceBiotech. Although some treatments work well at easing pain, they can’t be used long term because of their effects on bone density. Orilissa, for one, lists decreased bone mineral density as a possible serious side effect on its label.
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“What’s exciting about these initial results from Myovant is that they tried to go into this sweet spot, a Goldilocks thing where estrogen levels are not too hot, not too cold, they’re just right … so patients preserve their bones, but at the same time, have pain relief,” said Segars, who did not participate in the study, but who saw the data.
Myovant is developing the relugolix combination for women who don’t find relief with available treatments or who can’t tolerate them, Seely said. The company will report data from a second phase 3 study later this quarter. Those studies will form the basis of an FDA submission in endometriosis. The company is also seeking approval to treat uterine fibroids and plans to file that application to the FDA next month.