Results from the OASIS 4 clinical trial showed that elinzanetant, a neurokinin-targeted therapy, relieved hot flashes and night sweats that can occur because of menopause or hormone treatment for breast cancer. These findings were published in June 2025 in The New England Journal of Medicine.
Now, a new analysis of data from the trial shows that it also gives sustained relief regardless of the type of hormone treatment cancer patients receive.
Fatima Cardoso, MD, Head of Clinical Trials, Scientific Affairs and International Development in Breast Oncology at the Centre Antoine Lacassagne in Nice, France, and President of the Advanced Breast Cancer (ABC) Global Alliance, presented the findings for the first time at the 15th European Breast Cancer Conference (EBCC15) (Abstract 3).
“Women who have hormone receptor–positive breast cancer are usually treated with drugs that block the effects of estrogen, such as tamoxifen or aromatase inhibitors, or, in premenopausal women, goserelin and leuprorelin, which stop the ovaries from producing estrogen,” she said. “However, these often cause vasomotor symptoms, such as [hot flashes] and night sweats, that can be more severe than those that women experience during natural menopause. Breast cancer patients usually should not take hormone replacement therapy to alleviate these symptoms as this could negate the effect of the cancer treatment.”
Elinzanetant is a nonhormonal drug that works by blocking a protein called neurokinin. Neurokinin plays a role in triggering hot flashes and other menopausal symptoms, so by inhibiting it, elinzanetant reduces the frequency and severity of these symptms. Vasomotor symptoms (VMS) have a negative impact on patients’ quality of life and may lead to them stopping their breast cancer treatment prematurely.
New OASIS 4 Analysis
This new analysis by Dr. Cardoso and colleagues looked at the effect of elinzanetant on VMS frequency and severity according to the type of hormone therapy women received in the OASIS 4 trial.
Women aged between 18 and 70 years who were experiencing 35 or more moderate-to-severe VMS a week caused by hormone therapy for estrogen receptor–positive breast cancer were randomly assigned to receive elinzanetant for 52 weeks or placebo for 12 weeks followed by elinzanetant for 40 weeks.
The researchers analyzed the average change in daily moderate-to-severe VMS frequency and severity after 1 week (frequency only), and then 4 and 12 weeks according to whether patients had received tamoxifen, an aromatase inhibitor, an ovarian function suppressor or no ovarian function suppression.
“We found elinzanetant was effective and well tolerated by women experiencing moderate to severe VMS associated with endocrine therapy, independently of the type, such as tamoxifen or aromatase inhibitors, with or without ovarian function suppression,” said Dr. Cardoso.
For example, women taking tamoxifen and elinzanetant had, on average, 4 fewer VMS after week 1, compared to 1.6 in the tamoxifen and placebo group; 7 fewer after week 4 (2.5 fewer in the placebo group), and 8 fewer after week 12 (3 fewer in the placebo group). A similar pattern was seen across the other groups.
The average daily severity of VMS was also reduced in the groups taking elinzanetant compared to those taking placebo. At the beginning of the trial, women were experiencing moderate to severe VMS, with an average severity score of 2.5 (0 = none, 1 = mild, 2= moderate, 3 = severe). After 12 weeks, those taking elinzanetant were experiencing mild-to-moderate VMS with an average severity score between 1.5 and 1.6 in each of the hormone treatment groups, compared to moderate VMS with an average severity score between 1.9 and 2 in each of the groups receiving the placebo.
The reductions in frequency and severity were maintained for 52 weeks, and most side effects of elinzanetant were mild; the most common were diarrhea and fatigue. There were very low rates of serious side effects.
Dr. Cardoso said: “Elinzanetant is the first approved targeted agent for this very frequent symptom that deeply affects the quality of life of breast cancer patients. By helping patients to tolerate better their breast cancer treatment, elinzanetant may contribute to improved compliance and, therefore, better cancer outcomes.”
Now the researchers hope to evaluate potential interactions between elinzanetant and several other targeted agents used in combination with endocrine therapy in order to widen the patient population who could receive elinzanetant. They would also like to run trials in populations not included in the OASIS 4 trial, such as patients with metastatic breast cancer and male patients with breast cancer.
DISCLOSURE: For full disclosures of the study authors, visit cm.eortc.org/cmPortal/Searchable/ebcc15.
