Bayer has started patient enrolment for a Phase III ASTEROID clinical trial of vilaprisan to treat patients with uterine fibroids in the US.

Vilaprisan is an oral, selective progesterone receptor modulator (SPRM) being developed to bind to the receptor of progesterone hormone and alter its activity.

The open-label, parallel-group, randomised, multi-centre Phase III trial is designed to evaluate the safety and efficacy of 2mg of vilaprisan for the treatment of symptomatic uterine fibroids, in comparison to standard of care.

The firm plans to screen a total of more than 1,400 women and enrol 750 subjects at around 240 centres in the country.

"The initiation of this trial reinforces our ongoing commitment to finding innovative solutions for women suffering from gynaecological conditions."

Bayer Americas medical affairs senior vice-president and head Dario Mirski said: “Bayer has a rich legacy in women's health research, and we are dedicated to investigating vilaprisan as a potential medical treatment option for women with symptomatic uterine fibroid.

"The initiation of this trial reinforces our ongoing commitment to finding innovative solutions for women suffering from gynaecological conditions."

Expected to be completed in November 2021, the primary outcome measure of the trial is percentage lumbar spine bone mineral density (BMD) change from baseline to approximately one year from the start of treatment (SoT).

Additional efficacy measures such as the effect of vilaprisan on heavy menstrual bleeding, including amenorrhea rate and controlled bleeding, and a decrease in fibroid size will also be assessed during the trial.


Image: A small uterine fibroid as seen on ultrasound. Photo: courtesy of James Heilman.