Astellas Pharma has shown its menopause medicine is safe, teeing up regulatory filings in the U.S. and EU—but analysts aren’t sure whether fezolinetant will find a market once approved.
The Japanese pharma reported said the study has met its primary objectives including safety and tolerability and improvements in endometrial health at week 52. The most common adverse events were headache and COVID-19, which matched the placebo arm.
The topline results come from the phase 3 trial called Skylight 4, which examined the long-term safety of non-hormonal menopause treatment fezolinetant. The study featured 1,800 women with moderate-to-severe vasomotor symptoms of menopause such as hot flashes and night sweats.
The readout will be used to inform future regulatory filings in the U.S. and EU, Astellas said. Also included in the future data package will be results from two other late-stage pivotal trials, Skylight 1 and Skylight 2, the latter of which previously found that fezolinetant reduced the frequency and severity of menopause symptoms.
Fezolinetant could have a huge market potential of up to $2.3 billion, according to Jefferies. However, the firm pointed to the disappointing performance of Pfizer-Myovant's MyFembree, which was approved in May 2021 for uterine fibroids, which makes them “worry about the commercial potential of women's health products generally.” Myovant reported sales of $2.4 million for MyFembree for the fiscal third quarter of 2021 in January.
What could be dogging MyFembree is a significant out-of-pocket cost, which Jefferies placed at several hundred dollars, for many U.S. women. This is a hindrance for the med because fibroids can be controlled, albeit less effectively, with inexpensive generic drugs. Hot flashes are, however, much more common than uterine fibroids, but also less serious, the firm noted.
Jefferies predicted that Astellas’ shares may “struggle after the event,” as investors had been waiting for the safety data. The company closed the day on the Japanese market up 13% to ¥1,845 ($16).
Astellas has positioned fezolinetant as a key growth driver, with sales forecasts of $2.6 billion to $3.5 billion, according to Jefferies. The company will not be able to meet its ambitious medium-term sales forecast of $15.6 billion without the menopause treatment.
Fezolinetant was picked up by Astellas in the acquisition of Ogeda SA in 2017.