Elinzanetant Gets Priority Review for VMS From Breast Cancer Endocrine Therapy

The FDA has accepted a supplemental new drug application and granted priority review to elinzanetant (Lynkuet) for moderate to severe vasomotor symptoms (VMS) in patients undergoing endocrine therapy for the treatment or prevention of hormone receptor–positive (HR+) breast cancer.¹

Elinzanetant resulted in statistically significant drops in frequency of moderate to severe VMS or hot flashes from baseline through weeks 4 and 12 relative to placebo, meeting the primary end point of the phase 3 OASIS-4 trial (NCT05587296) among 474 patients treated with adjuvant endocrine therapy for HR+ breast cancer.²

“The positive results from the OASIS-4 study further support the potential of elinzanetant to address unmet needs in menopause care, including for women facing [VMS] associated with breast cancer treatment,” Cecilia Caetano, MD, vice president, global medical affairs and evidence generation lead for women's health at Bayer Pharmaceuticals Division, stated in a news release.¹

Trial Design and Findings

Conducted at 90 sites outside the United States, OASIS-4 was a 52-week, randomized, double-blind, placebo-controlled phase 3 study. It enrolled 474 patients between 18 and 70 years old who had moderate to severe VMS tied to adjuvant endocrine therapy (AET) for HR+ breast cancer or its prevention. Patients were randomly assigned 2:1 to either elinzanetant 120 mg once daily for the full 52 weeks (n = 316), or 12 weeks of once-daily placebo followed by 40 weeks of elinzanetant 120 mg once daily (n = 158). The coprimary end points tracked the change in average daily moderate to severe VMS frequency from baseline to week 4 and from baseline to week 12.²

Patients began the trial with a similar symptom burden in both arms: a mean of 11.4 daily episodes (95% CI, 10.7-12.2) in the elinzanetant group and 11.5 (95% CI, 10.5-12.5) in the placebo group. By week 4, daily VMS frequency had fallen by a mean of 6.5 episodes (95% CI, –7.2 to –5.8) among those on elinzanetant, compared with a 3.0-episode decline (95% CI, –3.9 to –2.2) on placebo (least-squares mean difference, –3.5 episodes; 95% CI, –4.4 to –2.6; P < .001). By week 12, the reduction reached 7.8 episodes (95% CI, –8.5 to –7.1) with elinzanetant vs 4.2 episodes (95% CI, –5.2 to –3.2) with placebo (least-squares mean difference, –3.4 episodes; 95% CI, –4.2 to –2.5; P < .001).

All key secondary end points were also met, with the severity of VMS also declining at weeks 4 and 12, frequency of events dropping by week 1, and sleep quality and menopause-related quality of life having improved relative to placebo by week 12, with those benefits persisting for the remainder of the study. The trial's findings were presented at the 2025 American Society of Clinical Oncology Annual Meeting and were published in The New England Journal of Medicine.

Safety Findings

Across the first 12 weeks, 220 patients in the elinzanetant group (69.8%) and 98 in the placebo group (62.0%) experienced at least 1 adverse event while on study drug or placebo; headache, fatigue, and somnolence were reported most often. Serious adverse events during that window were uncommon in both arms but more frequent with elinzanetant, affecting 8 patients (2.5%) vs 1 patient (0.6%) on placebo.

Drug Background and Regulatory Context

Elinzanetant works as a dual antagonist of the NK-1 and NK-3 neurokinin receptors and is taken as a single daily oral dose.¹ It was previously approved in the US to treat moderate to severe menopausal VMS on the strength of the OASIS-1, OASIS-2, and OASIS-3 trials (NCT05042362, NCT05099159, NCT05030584). Elinzanetant became the first agent approved specifically for adjuvant endocrine therapy–related VMS in breast cancer in the United Kingdom, Switzerland, and Canada, and the European Union approved it for both uses in November 2025. A NCCN survivorship guideline update issued in 2026 named elinzanetant a preferred nonhormonal option among NK-1/NK-3 antagonists for moderate to severe VMS stemming from medically or surgically induced menopause.³

“Endocrine therapy is a standard of care for many women facing HR+ breast cancer, which can commonly cause [adverse events] such as [VMS],” Fatima Cardoso, MD, OASIS-4 primary investigator, FESMO director of the breast unit at Centre Antoine Lacassagne, and member of the Advanced Breast Cancer Global Alliance, in Nice, France, stated in a news release. “It's important that we continue to learn more about vasomotor symptoms due to endocrine therapy as part of supporting women throughout their breast cancer care journey.”¹

REFERENCES

1. Bayer's Lynkuet™ (elinzanetant) granted priority review by U.S. FDA for additional indication. News release. Bayer AG. September 28, 2026. Accessed September 28, 2026. https://tinyurl.com/5eavnxt4

2. Cardoso F, Parke S, Brennan DJ, et al. Elinzanetant for vasomotor symptoms from endocrine therapy for breast cancer. N Engl J Med. 2025;393(8):753-763. doi:10.1056/NEJMoa2415566

3. NCCN. Clinical Practice Guidelines in Oncology. Survivorship, version 3.2026. Accessed September 28, 2026. https://tinyurl.com/3nshzpz2