Myovant's uterine fibroid med hits the mark in 2nd phase 3 trial

Myovant Sciences' uterine fibroid drug relugolix reduced blood loss in nearly three-quarters of patients, trouncing placebo in the second of two phase 3 studies. The drug, given in combination with two hormone medications, also met six secondary endpoints, teeing it up for an FDA filing in the fourth quarter. 

The studies enrolled a total of 770 women with uterine fibroids whose monthly menstrual blood loss exceeds 80 mL in two cycles or 160 mL in one cycle. Estimates vary, but the U.K.’s National Health Service and the Centers for Disease Control and Prevention peg normal blood loss at 30 mL to 45 mL.  

The latest study, dubbed LIBERTY 2, pitted a combination of relugolix, estradiol and norethindrone acetate—both hormone medications—against placebo in 382 women. They received once-daily doses of the relugolix combo for 24 weeks, relugolix on its own for 12 weeks followed by the combo for another 12 weeks or placebo for 24 weeks. The study found that 71.2% of the women taking the combo responded to treatment compared to just 14.7% of those on placebo. 

A patient was judged to be a responder if, over the 35 days of treatment, she lost less than 80 mL of blood and had a 50% or greater reduction in blood loss from baseline. On average, women taking relugolix had an 84.3% reduction in blood loss. The treatment also checked off six secondary endpoints, including reduction in pain and improvement in quality of life. 

RELATED: Myovant hits goal in uterine fibroid phase 3, teeing up AbbVie showdown 

The data echo results from the 388-patient LIBERTY 1 study, which read out in May, which found that 73.4% of patients responded to the relugolix combo versus 18.9% of patients on placebo. Myovant plans to file the combination treatment for FDA approval by the end of the year. 

Myovant also unveiled data from a study testing a version of the treatment that combines relugolix, estradiol and norethindrone acetate in a single tablet rather than in separate pills. The single-tablet form “met all required and pre-specified FDA criteria for bioequivalence” and will be included in the NDA submission for relugolix, the company said in a statement. 

“Millions of women suffer from heavy bleeding, pain, anemia, lost productivity, or pregnancy complications resulting from uterine fibroids,” said Andrea Lukes, M.D., founder of the Carolina Women’s Research and Wellness Center and a member on LIBERTY program's steering committee, in the statement. “The data from the two pivotal LIBERTY studies suggest we have a medicine that could offer meaningful improvement in symptoms without sacrificing safety and tolerability."

RELATED: AbbVie's Orilissa makes its uterine fibroids case with double phase 3 win 

Myovant is racing AbbVie and Neurocrine Biosciences to get a treatment for uterine fibroids to market. The noncancerous tumors can be treated with birth control to address bleeding and gonadotropin releasing hormone agonists, which can shrink fibroids. Patients with more severe symptoms may need surgery to remove fibroids or even the entire uterus. 

AbbVie and Neurocrine’s Orilissa (elagolix) scored the FDA nod in mid-2018 for endometriosis and topped placebo in a pair of phase 3 trials at reducing heavy menstrual bleeding related to uterine fibroids. The plan is to file the twice-daily med for uterine fibroids this year.