FDA undoes Astellas’ bid for fast review of menopause drug

Shares in Astellas Pharma were weaker this morning on the news that the FDA has delayed its review of one of its top pipeline prospects – menopause drug fezolinetant – by three months.

A brief statement from the company left investors guessing at the reasons for the delay, which will set back an FDA decision on the oral neurokinin antagonist as a treatment for moderate to severe vasomotor symptoms (VMS) linked to menopause to 22 May.

Shares were down a little over 2% as investors reacted to the news, although Astellas said it remains “confident in the clinical profile of fezolinetant and the potential benefits it could bring to women experiencing moderate to severe VMS due to menopause.”

It also said the impact of the delay on its financial results for the year ending 31 March would be “minor.” Nevertheless, the delay is a big disappointment for Astellas, which used a priority review voucher – typically worth around $100 million – to reduce the FDA’s review time from ten months to six.

The delay also narrows Astellas’ fragile lead in the race to bring a neurokinin-targeting drug for VMS symptoms to market. Hot on its heels is Bayer with elinzanetant, which is due for a phase 3 readout very soon. If those results are positive, Bayer is expected to file as quickly as possible to try to catch up with Astellas, chasing what it has predicted could be a $1 billion sales opportunity for the drug.

VMS, such as hot flushes, are reported by up to 80% of women at some point during menopause and the leading cause for seeking medical attention during this phase of a woman’s life. Around a third of women report severe VMS, which can last ten years or more after the last menstrual period.

Hormone replacement therapy (HRT) can be used to successfully treat symptoms, but can also raise the risk of endometrial cancer and heart disease slightly, so there is a demand for non-hormonal alternatives.

In clinical trials, fezolinetant was able to significantly reduce the frequency and severity of VMS episodes after four and 12 weeks of treatment compared to placebo.

Astellas acquired fezolinetant as part of its 2017 takeover of Ogeda for €500 million (at the time equivalent to around $550 million) upfront, plus €300 million in potential milestones.

Bayer meanwhile acquired elinzanetant as part of its $875 million takeover of UK biotech KaNDy Therapeutics in 2020.