Myovant Sciences and Pfizer publish phase 3 results for endometriosis therapy

Myovant Sciences and Pfizer have published the results of the phase 3 SPIRIT 1 and SPIRIT 2 studies in The Lancet, assessing the investigational once-daily relugolix combination therapy in over 1,200 women with moderate to severe pain associated with endometriosis.

Endometriosis is a condition whereby tissue similar to the uterine lining occurs outside the uterine cavity, which can lead to symptoms like painful periods, fatigue, pain in the lower back and abdomen, heavy menstrual bleeding and even painful or difficult sexual intercourse.

For those living with endometriosis-associated pain, readily available treatments include prescription and over-the-counter pain medications, oral contraceptives, GnRH agonists and antagonists, while surgical options include adhesiolysis, cyst removal and hysterectomy. The impact of the condition can be severe, affecting the patient’s physical, mental and social well-being.

Around 200 million women suffer from symptoms of endometriosis worldwide and it can take between four to eleven years to get an endometriosis diagnosis. For some women, the currently available treatment options do not offer relief.

Both studies met their co-primary endpoints, showing clinically significant reductions in menstrual pain and non-menstrual pelvic pain in women with endometriosis. Specifically, 75% of women achieved a reduction in menstrual pain compared to 27% and 30% of women in the placebo groups at week 24, respectively.

“Approximately 7.5 million premenopausal women in the US have endometriosis and 75-80% of them are symptomatic,” said Juan Camilo Arjona Ferreira, chief medical officer of Myovant Sciences. “The data published in The Lancet underscores the value relugolix combination therapy may provide as a potential new treatment option for women with endometriosis-associated pain.”

Seven key secondary endpoints in SPIRIT 1 and six key secondary endpoints in SPIRIT 2,  comparing relugolix combination therapy with placebo at week 24 achieved statistical significance, including reductions in dyspareunia and the use of opioids.

A relugolix combination tablet is currently available in the US as Myfembree to support the management of heavy menstrual bleeding associated with uterine fibroids in premenopausal women.