Key Takeaways
- FDA Review Extension for Elinzanetant: The FDA has extended the review period for Bayer’s New Drug Application by up to 90 days to allow for comprehensive assessment, with no concerns raised regarding the drug’s general approvability.
- Positive Phase III OASIS Results: Elinzanetant demonstrated statistically significant reductions in vasomotor symptom frequency and severity in the OASIS 1 (NCT05042362), 2 (NCT05099159), and 3 (NCT05030584) trials, with sustained efficacy through 52 weeks in OASIS 3.
- Favorable Safety Profile Observed: Across all trials, elinzanetant showed a consistent safety profile with mostly mild to moderate adverse events—most commonly headache and fatigue—and no signals of malignancy, liver toxicity, or endometrial hyperplasia.
The FDA has extended the review period for Bayer’s New Drug Application (NDA) for elinzanetant, a first-in-class dual neurokinin-1 and -3 receptor antagonist for the treatment of moderate to severe vasomotor symptoms (VMS) associated with menopause. According to Bayer, the FDA indicated that up to 90 additional days are required to complete a thorough review of the submission, including the supporting data, but did not raise concerns about the drug’s general approvability. The NDA is supported by data from the Phase III OASIS 1, 2, and 3 trials.1
Why is the FDA Taking More Time to Review Elinzanetant?
“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 Christian Rommel, executive committee, pharmaceuticals division, global head, research and development, Bayer, in a press release.
OASIS 1 and 2 Trial Design and Outcomes
- The double-blind, randomized, placebo-controlled, multicenter OASIS-1 and OASIS-2 trials evaluated the efficacy and safety of elinzanetant in 396 and 400 postmenopausal women, respectively, who were experiencing moderate to severe VMS, such as hot flashes.
- Participants were randomly assigned to receive either elinzanetant or placebo once daily for 12 weeks. Those in the placebo group transitioned to elinzanetant for an additional 14 weeks.
- Primary endpoints included mean change in the frequency and severity of moderate to severe hot flashes from baseline to weeks four and 12.2,3
- Results showed that mean daily VMS frequency decreased by 7.5 episodes in OASIS-1 and 8.6 episodes in OASIS-2 by week four, while the placebo groups demonstrated decreases of 4.4 and 6.1 episodes, respectively.
- By week 12, elinzanetant reduced VMS frequency by 8.7 and 10 episodes per day in OASIS-1 and 2, respectively, translating to percentage reductions of 65% and 67%, versus 42% and 46% with placebo.
- In terms of reductions in VMS frequency, 62.8% of patients in OASIS-1 and 62.2% in OASIS-2 achieved at least a 50% reduction in VMS frequency when treated with elinzanetant compared to placebo. At week 12, these numbers increased to 71.4% and 74.7%, respectively.
- Treatment-emergent adverse events (TEAEs) were reported in 51.3% of participants receiving elinzanetant compared to 48.5% of those on placebo in OASIS-1, and in 44.3% and 38.2% of participants in OASIS-2, respectively.
- TEAEs in both trials were generally mild to moderate in severity, with headache and fatigue being the most commonly reported adverse events.4
OASIS 3 Trial Results Support Long-Term Use
- The double-blind, randomized, placebo-controlled, multicenter OASIS-3 trial evaluated the efficacy and long-term safety of elinzanetant over 52 weeks in 628 postmenopausal women with VMS.
- The primary endpoint was the change in the frequency of moderate to severe VMS from baseline to week 12.
- At baseline, the mean number of daily VMS episodes was 6.7 in the elinzanetant group compared to 6.8 in the placebo group.
- Results showed that by week 12, VMS numbers were reduced to 1.7 in the treatment group and 3.4 in the placebo group, with improvements sustained throughout the 52-week treatment period.
- The most common TEAEs were headache and COVID-19, with no signals of endometrial hyperplasia, malignancy, or liver toxicity observed.5
Global Regulatory Activity and Outlook
Elinzanetant was recently approved under the name Lynkuet in the United Kingdom and Canada, with regulatory submissions ongoing in the EU and other parts of the world.1
“As we continue to work with the FDA during the ongoing review, we are fully committed to making elinzanetant available to women in the US as soon as we receive FDA approval,” concluded Rommel, in the press release.
References
- Bayer provides regulatory update on elinzanetant in the U.S. Bayer. July 25, 2025. Accessed July 29, 2025. https://www.bayer.com/media/en-us/bayer-provides-regulatory-update-on-elinzanetant-in-the-us/
- A Study to Learn More About How Well Elinzanetant Works and How Safe it is for the Treatment of Vasomotor Symptoms (Hot Flashes) That Are Caused by Hormonal Changes Over 26 Weeks in Women Who Have Been Through the Menopause (OASIS-1). Clinicaltrials.gov. Accessed July 29, 2025. https://clinicaltrials.gov/study/NCT05042362
- A Study to Learn More About How Well Elinzanetant Works and How Safe it is for the Treatment of Vasomotor Symptoms (Hot Flashes) That Are Caused by Hormonal Changes Over 26 Weeks in Women Who Have Been Through the Menopause (OASIS-2). https://clinicaltrials.gov/study/NCT05099159?intr=Elinzanetant%20%5C(BAY3427080%5C)&rank=6
- Elinzanetant for the Treatment of Vasomotor Symptoms Associated With Menopause OASIS 1 and 2 Randomized Clinical Trials. JAMA. August 22, 2024. Accessed July 29, 2025. https://jamanetwork.com/journals/jama/fullarticle/2822766
- Data from Phase III study OASIS 3 support efficacy and long-term safety of investigational compound elinzanetant in the treatment of moderate to severe vasomotor symptoms associated with menopause. Bayer. Accessed July 29, 2025. https://www.bayer.com/en/us/news-stories/phase-iii-study-oasis-3
