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

Lynn Seely - Myovant
Myovant CEO Lynn Seely (Myovant)

A phase 3 trial of Myovant Sciences' uterine fibroid drug relugolix has hit its primary endpoint, moving the Roivant unit a step closer to a planned filing for approval. The drug comfortably beat placebo against a slew of efficacy endpoints and posted comparable safety and tolerability to the control.

Myovant, part of Roivant’s stable of biotechs, picked up the global rights to relugolix from Takeda Pharmaceutical in 2016 and moved it into a pair of phase 3 trials the following year. Results from the first trial are in.

The study enrolled 388 women with uterine fibroids and heavy menstrual bleeding. Among subjects randomized to receive relugolix on top of estradiol and norethindrone acetate for 24 weeks, 73.4% achieved the responder criteria, which looked at change in blood loss. In the placebo arm, 18.9% of women met the criteria, resulting in a primary endpoint success with a p-value of less than 0.0001.

Relugolix outperformed placebo against secondary endpoints, too, including in assessments of pain, quality of life, anemia and reduction in uterine volume. Myovant said it was “incredibly pleased” with the data. 

“These results substantiate our once daily oral combination therapy approach,” Myovant CEO Lynn Seely said in a statement. “The improvements in symptoms most relevant to women, such as reduction in menstrual blood loss and pain, and improvement in quality of life are particularly exciting.” 

The data also look to be free from significant safety and tolerability concerns. Bone mineral density was comparable in the treatment and placebo cohorts, as were the dropout rate and incidence of adverse events. 

Myovant is now racing toward a third-quarter readout from its second phase 3 trial. If that trial hits the mark, Myovant will file for FDA approval of relugolix in the fourth quarter.

The timeline sets the stage for a scrap in the uterine fibroid market. Allergan failed to get Esmya past the FDA amid safety concerns, but AbbVie and ObsEva are gearing up to challenge Myovant for the market. AbbVie has phase 3 data on its Neurocrine Biosciences-partnered elagolix that it thinks will support a filing for approval of the twice-daily drug. And ObsEva is running phase 3 trials of its prospect, OBE2109.