A New Solution for Hot Flashes in Menopause and Breast Cancer: Elinzanetant

Hot flashes, which are common during menopause and in women receiving breast cancer treatment, can severely reduce quality of life. Elinzanetant is one of the newest and most promising drug candidates developed to address this problem.

What Is Elinzanetant?

Elinzanetantis an innovative molecule developed by Bayer that targets both NK-1 and NK-3 neurokinin receptors . It aims to reduce symptoms such as hot flashes and night sweats by targeting abnormal signaling in areas of the brainstem responsible for temperature regulation. It contains no hormones and is not an antidepressant.

Key features:

• Its hormone-free nature makes it a potential alternative for women unable to receive hormone therapy after breast cancer
• Targets the brain’s temperature-regulating center
• Acts quickly

What Do the Clinical Data Say?

Phase III clinical trials of Elinzanetant show that it is effective in reducing hot flashes and sleep problems, particularly during menopause.

Key findings:

OASIS-1 & OASIS-2 (Phase III):

• Up to a 50% reduction in the number of daily hot flashes
• Significant improvement in sleep disturbances
• Onset of action generally within the first 2 weeks

OASIS-4 (2025, breast cancer patients):

• Tested in patients receiving anti-estrogen treatment (tamoxifen, letrozole, etc.)
• Up to a 61% reduction in the frequency and severity of hot flashes
• Improved sleep quality
• Low rate of adverse effects (below 3%)

What Is the Status of Elinzanetant Worldwide and in Turkey?

International approval procedures are ongoing, and the drug is expected to become available in some countries soon.

Current status:

US: An FDA application has been submitted, with a decision expected in July 2025

Europe: The EMA review is ongoing

Turkey: Not yet licensed, but an application is expected after global approval

Who Might Be Eligible for Elinzanetant?

Elinzanetant may offer promise both for women undergoing natural menopause and for those experiencing hormone suppression due to cancer treatment.

Potentially eligible groups:

• Postmenopausal women experiencing hot flashes
• Breast cancer patients receiving treatment with hormone-suppressing drugs
• Individuals unable to receive hormone-containing treatment

Key Advantages of Elinzanetant

In addition to its efficacy, several distinct advantages make the drug stand out.

Main advantages:

• Contains no hormonesand may therefore be a safe option for patients unable to take estrogen supplementation
• Acts rapidly, producing a marked reduction in symptoms within 2 weeks
• Sleep quality and daily functioning may improve

The OASIS-4 Trial Published in NEJM: Elinzanetant in Breast Cancer Treatment

The Phase III OASIS-4 trial, published in the New England Journal of Medicine in June 2025, examined the effects of Elinzanetant in breast cancer patients receiving hormone-suppressing treatment.

Study details:

• 474 women aged 18–70
• Elinzanetant 120 mg daily or placebo for 52 weeks

Results:

• In the first 4 weeks, the number of hot flashes decreased by an average of 6.5 (placebo: 3)
• At week 12, a reduction of 7.8 episodes was observed
• The effect started rapidly and was sustained
• Most common adverse effects: headache, fatigue, drowsiness
• The rate of serious adverse effects was low (2.5%)

These results indicate that Elinzanetant may be an effective and safe option not only for menopausal women, but also for patients receiving breast cancer treatment.

Points to Consider

Although Elinzanetant is promising, some information remains limited.

Key uncertainties:

• Long-term safety data are still limited
• Not yet available in Turkey
• Targets hot flashes only; may have no effect on other symptoms caused by estrogen deficiency

Conclusion

In addressing hot flashes associated with menopause or symptoms caused by breast cancer treatment, Elinzanetant may usher in a new era . It is expected to be a strong option, particularly for women unable to receive hormone therapy. Although not yet available in Turkey, it is likely to attract attention soon if it receives FDA and EMA approval during 2025.