Bayer Receives FDA Review Extension for Elinzanetant New Drug Application in the U.S.
Bayer has announced an important regulatory update concerning its investigational drug elinzanetant, a first-in-class dual neurokinin 1 (NK1) and neurokinin 3 (NK3) receptor antagonist developed for the treatment of moderate to severe vasomotor symptoms (VMS) associated with menopause—commonly referred to as hot flashes. According to the company, the U.S. Food and Drug Administration (FDA) has notified Bayer of an extension to the review period for the New Drug Application (NDA) submitted for elinzanetant.
The FDA informed Bayer that the additional time is necessary to complete a thorough evaluation of the NDA, including supplementary information that has been provided to support the application. As a result, the Prescription Drug User Fee Act (PDUFA) date—the target date by which the FDA aims to complete its review—has been extended by up to 90 days. Bayer emphasized that the FDA’s communication did not raise any concerns about the fundamental approvability of elinzanetant, nor did it request new clinical trials or signal a safety or efficacy issue with the drug.
This development marks a notable step in the regulatory journey of elinzanetant, which, if approved, would become the first therapy targeting both NK1 and NK3 receptors for the treatment of menopausal vasomotor symptoms in the United States.
Elinzanetant: A Novel Approach to Menopausal Symptom Relief
Vasomotor symptoms, including hot flashes and night sweats, are among the most common and bothersome symptoms experienced by women during the menopausal transition. These symptoms can significantly impair quality of life, disrupt sleep, affect daily functioning, and increase the risk of other health issues such as depression and cardiovascular conditions. While hormone therapy has traditionally been the mainstay of treatment, not all women are suitable candidates due to risks associated with estrogen use, particularly in women with certain cancers, cardiovascular risks, or a history of thromboembolism.
Elinzanetant represents a promising non-hormonal alternative. It works by modulating neurokinin signaling in the brain, a key mechanism involved in thermoregulation. By blocking NK1 and NK3 receptors, elinzanetant aims to normalize the disrupted temperature regulation that underlies hot flashes, without the need for estrogen or progesterone. This approach is seen as a potential game-changer in the management of menopause-related symptoms.
Bayer’s Statement: Confidence in Clinical Evidence
Dr. Christian Rommel, a member of Bayer’s Pharmaceuticals Executive Committee and the company’s Global Head of Research and Development, expressed confidence in the continued progress of elinzanetant’s regulatory pathway. In his statement, Dr. Rommel underscored the strong clinical foundation supporting the NDA, citing consistent and positive data from the drug’s comprehensive Phase III clinical program.
“With the consistent positive results from our clinical Phase III program assessing the efficacy and safety of elinzanetant, we remain confident about elinzanetant’s potential as a new treatment option for moderate to severe vasomotor symptoms associated with menopause,” said Dr. Rommel. “As we continue to work with the FDA during the ongoing review, we are fully committed to making elinzanetant available to women in the U.S. as soon as we receive FDA approval.”
Clinical Data Supporting the NDA
The NDA submitted to the FDA is based on a trio of pivotal Phase III trials—OASIS 1, OASIS 2, and OASIS 3—that collectively evaluated elinzanetant’s efficacy, safety, and long-term tolerability in women experiencing moderate to severe VMS due to menopause.
- OASIS 1 and 2: These placebo-controlled, double-blind studies investigated the drug’s ability to reduce the frequency and severity of vasomotor symptoms over a 12-week primary treatment period. The results from these studies were published in The Journal of the American Medical Association (JAMA) in August 2024, showing statistically significant improvements in symptom relief compared to placebo.
- OASIS 3: This longer-term extension study provided additional evidence on elinzanetant’s efficacy and safety over extended periods of use. The detailed results were presented at the annual meeting of The Menopause Society (TMS) in September 2024. This data was instrumental in addressing the FDA’s requirements for long-term safety and real-world applicability of the drug.
Across all three trials, elinzanetant was shown to be well tolerated, with a favorable safety profile and a low incidence of adverse events. Notably, the studies reported improvements not only in hot flash frequency and severity, but also in sleep quality, mood, and overall quality of life—areas that are frequently disrupted by menopausal symptoms.
Recent International Approvals Strengthen Global Momentum
While Bayer awaits the FDA’s final decision, the company has made notable strides in securing regulatory approvals in other regions. In the past month, elinzanetant was approved for use under the brand name Lynkuet™ in both the United Kingdom and Canada. These approvals mark the drug’s first market entries and are a significant validation of Bayer’s clinical development program.
Beyond North America and the UK, Bayer has submitted applications for marketing authorization in the European Union and other countries, indicating a global rollout strategy for elinzanetant. The company continues to engage with health authorities in multiple jurisdictions, aiming to make the drug widely available to women experiencing disruptive menopausal symptoms.
Addressing an Unmet Medical Need
The market for non-hormonal treatments for vasomotor symptoms remains underserved. An estimated 60 to 80 percent of women going through menopause experience hot flashes, with around one-third reporting symptoms severe enough to require medical intervention. Despite this, there are limited effective non-hormonal options currently available.
Elinzanetant’s novel mechanism of action and strong efficacy data position it as a potentially transformative option in this space. Its dual action on NK1 and NK3 receptors distinguishes it from previous candidates that targeted only NK3, some of which failed to achieve adequate results in clinical trials or were discontinued due to safety concerns.
If approved in the U.S., elinzanetant could serve not only as an alternative to hormone replacement therapy (HRT) but also as a frontline option for the millions of women who are either ineligible for HRT or prefer to avoid it.
