FDA Grants Priority Review to Bayer Lynkuet for Second Indication

The U.S. Food and Drug Administration has accepted Bayer’s supplemental new drug application (sNDA) and granted Priority Review designation for Lynkuet (elinzanetant) for the treatment of moderate to severe vasomotor symptoms (VMS), also known as hot flashes, in women receiving endocrine therapy for the treatment or prevention of hormone receptor-positive (HR+) breast cancer, Bayer announced on 28. september 2026.

Elinzanetant was first approved in the United States in oktober 2025 for the treatment of moderate to severe VMS due to menopause, with that approval supported by data from three Phase III clinical trials: OASIS-1, OASIS-2 and OASIS-3. Bayer describes the compound as the first dual neurokinin-targeted therapy, an antagonist of NK-1 and NK-3 receptors, administered orally once daily.

Bayer explains that declining estrogenic activity, whether from natural menopause or endocrine therapy, leads to hyperactivity of hypothalamic KNDy neurons, named for kisspeptin, neurokinin B and dynorphin, which express both NK-1 and NK-3 receptors and play a role in thermoregulation. The resulting dysregulation of the thermoregulatory center produces VMS, and NK-1 receptors may also play a role in the cooling response through sweating and peripheral vasodilatation, as well as in sleep disturbances.

OASIS-4 Trial Design and Findings

The new submission is based on results from OASIS-4, a 52-week, double-blind, randomized, placebo-controlled Phase III study conducted at 90 sites outside the United States. The trial enrolled 474 women aged 18 to 70 with moderate to severe VMS caused by adjuvant endocrine therapy (AET) for HR+ breast cancer or its prevention. Participants were randomized 2:1 to receive elinzanetant for 52 weeks (n=316) or placebo for 12 weeks followed by elinzanetant for 40 weeks (n=158).

Bayer reported that the study met its primary endpoints, demonstrating statistically significant reductions in the frequency of moderate to severe VMS from baseline to weeks 4 and 12 compared with placebo. The trial also achieved all secondary endpoints, including reductions in VMS severity at weeks 4 and 12, a reduction in VMS frequency at week 1, and improvements in sleep disturbances and menopause-related quality of life from baseline to week 12 versus placebo, with the effects maintained over the study period.

Key findings from the study were presented at ASCO 2025 and simultaneously published in the New England Journal of Medicine in juni 2025 (Cardoso et al., N Engl J Med 2025;393:753-763). “Endocrine therapy is a standard of care for many women facing HR+ breast cancer, which can commonly cause side effects such as vasomotor symptoms,” said OASIS-4 Primary Investigator Fatima Cardoso of the Breast Unit at Centre Antoine Lacassagne in Nice, France. She added that it is important to continue learning more about vasomotor symptoms due to endocrine therapy as part of supporting women throughout their breast cancer care.

Cecilia Caetano, vice president and Global Medical Affairs and Evidence Generation Lead for Women’s Health in Bayer’s Pharmaceuticals Division, said the positive OASIS-4 results “further support the potential of elinzanetant to address unmet needs in menopause care, including for women facing vasomotor symptoms associated with breast cancer treatment.” She said the findings confirm the compound’s potential in broadening treatment options for women across different life stages and health circumstances.

Regulatory Status and Clinical Context

Lynkuet also became the first therapy indicated for the treatment of moderate to severe VMS caused by AET for breast cancer in the United Kingdom, Switzerland and Canada, in addition to the initial indication of VMS associated with menopause, according to Bayer. In the European Union, the compound was approved in november 2025 for moderate to severe VMS associated with menopause or caused by AET related to breast cancer. The U.S. application, the indication extensions in Canada, Switzerland and the UK, and the EU approval are all based on the OASIS-4 results.

Elinzanetant is approved under the Lynkuet brand in Australia and the United States for VMS associated with menopause, and in the EU, UK, Switzerland and Canada for moderate to severe VMS associated with menopause or caused by AET related to breast cancer.

Breast cancer remains the most commonly diagnosed cancer among women globally, according to the announcement. Approximately 2.3 million women were diagnosed with the disease in 2022, accounting for 30% of all cancers in women, and nearly 70% of these cases are hormone receptor-positive. AET is an established standard of care for treating HR+ breast cancer, with duration of use varying between 5 and 10 years based on cancer type and other clinical considerations, and treatment with AET for up to 10 years has been shown to substantially reduce breast cancer mortality over the two decades after diagnosis. Hot flashes are a common side effect of AET, and because of the HR+ diagnosis, many women are discouraged from using hormone-releasing medicines.

Earlier in 2026, the National Comprehensive Cancer Network updated its survivorship guidelines (Version 3.2025), listing Lynkuet as a preferred non-hormonal pharmacologic treatment in the selective NK-1 and/or NK-3 receptor antagonist category for the treatment of moderate to severe VMS due to medically and surgically induced menopause.

By 2030, nearly 500 million women will be in the menopausal transition years, according to an FP Analytics report cited by Bayer. The announcement identifies VMS and sleep disturbances as the most frequently reported and disruptive menopause symptoms, which can substantially affect a woman’s health, quality of life and work productivity. Bayer said submissions for marketing authorizations for elinzanetant are ongoing in further countries around the world.