Astellas has menopause accelerated approval ambition thwarted by FDA at last minute

Astellas’ bid to bring menopause drug candidate fezolinetant to market has hit a last-minute snag. Just days before the approval decision date, the FDA has extended the review by three months to give it more time to complete its assessment. 

Japan’s Astellas used a priority-review voucher to shave four months off the review time when it filed for approval last year, resulting in an FDA decision date of Feb. 22. The use of the voucher reflected Astellas’ belief in the drug candidate, which it has identified (PDF) as one of a handful of assets that will collectively add $8.9 billion to sales by 2025, and the presence of a rival Bayer therapy following close behind.

Now, the FDA has thwarted Astellas’ accelerated approval ambition by failing to complete its review by the deadline. The need for more time to complete the review led the FDA to push the decision date back to May 22. Astellas brushed off the setback. 

“We remain confident in the clinical profile of fezolinetant and the potential benefits it could bring to women experiencing moderate to severe [vasomotor symptoms] due to menopause, and we will continue to work with the FDA on its review of the NDA for fezolinetant," Ahsan Arozullah, M.D., senior vice president and head of development therapeutic areas at Astellas, said in a release.

The delay is one of a series of small setbacks suffered by fezolinetant. After showing the neurokinin-3 receptor antagonist reduced hot flashes in two global phase 3 trials, Astellas was blindsided around one year ago by the failure of a study that enrolled 302 women in China, Korea and Taiwan. 

Then, the Institute for Clinical and Economic Review (ICER) judged the evidence that fezolinetant is better than no drug treatment to be “promising but inconclusive.” ICER found insufficient evidence of the efficacy of fezolinetant compared to menopausal hormone therapy, an established treatment for hot flashes that is contraindicated in some women. 

Any delay to Astellas, which acquired fezolinetant for 500 million euros ($534 million) upfront in 2017, is a potential boost to Bayer. The German conglomerate entered the race in 2020 by paying $425 million for KaNDy Therapeutics, and went on to start three late-phase clinical trials the following year. The primary completion dates of Bayer’s three studies run from March to July of this year.