Promising therapy for menstrual pain tested by Myovant Sciences, Pfizer

Myovant Sciences and Pfizer said Monday that the Phase 3 SPIRIT long-term extension study of the investigational once-daily relugolix combination therapy in women with endometriosis reported clinically meaningful reductions in dysmenorrhea (menstrual pain) and non-menstrual pelvic pain over one year (52 weeks) with minimal and stable bone mineral density loss.

According to Pfizer’s press release, the data are consistent with the efficacy and safety profile observed through 24 weeks in the Phase 3 SPIRIT 1 and SPIRIT 2 studies. These results will be included in the New Drug Application to the U.S. Food and Drug Administration for relugolix combination tablet for the treatment of women with endometriosis, anticipated to be submitted in the first half of 2021, Pfizer said.

Linda Giudice from the Center for Reproductive Sciences at the University of California, San Francisco (UCSF) and SPIRIT Program Steering Committee Member said that the one-year data from the Phase 3 SPIRIT extension study offers promising evidence that relugolix combination therapy has the potential to significantly and durably reduce pain in women with endometriosis, while remaining well tolerated.

As reported in the press announcement, in the SPIRIT long-term extension study, 84.8% and 73.3% of women receiving relugolix combination therapy over one year achieved clinically meaningful pain reductions in dysmenorrhea and non-menstrual pelvic pain, respectively. On average, women reported an 82.8% reduction on the 11-point Numerical Rating Scale (0-10) for dysmenorrhea from 7.4 (severe pain) to 1.3 (mild pain) over one year, the company said in the issued media statement.

Juan Camilo Arjona Ferreira, M.D., Chief Medical Officer of Myovant Sciences, Inc is looking forward to submitting a New Drug Application for this potential new treatment for women with endometriosis in the first half of this year.

Approximately 10 percent of women are affected by endometriosis during their reproductive lifetime, said James Rusnak, Senior Vice President, Chief Development Officer, Internal Medicine and Hospital, Global Product Development at Pfizer. He expects the results from the one-year extension study to show the encouraging potential of relugolix combination therapy to evolve the treatment paradigm for women with endometriosis.

In December 2020, Myovant and Pfizer entered into a collaboration for the development and commercialization of relugolix in oncology and women’s health in the U.S. and Canada. Under the terms of the agreement, Myovant and Pfizer will jointly develop and commercialize ORGOVYXTM (relugolix) in advanced prostate cancer and, if approved, relugolix combination tablet (relugolix 40 mg, estradiol 1.0 mg, and norethindrone acetate 0.5 mg) in uterine fibroids and endometriosis.