Health Canada approves drug that treats hot flashes for use by breast cancer patients

Health Canada has approved the use of a drug called Elinzanetant, also known as Lynkuet, to alleviate moderate to severe hot flashes and night sweats in breast cancer patients. First approved in July 2025 for menopausal women, the drug's effectiveness in breast cancer patients was confirmed by a subsequent study reviewed by Health Canada.

Hormone-receptor positive breast cancers rely on estrogen for growth, and treatments often block estrogen production, leading to vasomotor symptoms like hot flashes and night sweats. Bayer manufactured Elinzanetant, a non-hormonal medication that targets neurons potentially overactive due to low estrogen levels.

Dr. Christine Brezden-Masley, medical director of the cancer program at Sinai Health, explained that breast cancer patients have few options to manage these symptoms, as they cannot take hormone replacement therapy. Oncologists typically prescribe anti-estrogen medications like tamoxifen or aromatase inhibitors for five to ten years.

Hot flashes and night sweats disrupt daily functioning and sleep, making patients' adherence to cancer therapy a priority. Some patients may discontinue cancer treatment to mitigate symptoms, which oncologists aim to prevent.

Dr. Dave Cescon, a medical oncologist, emphasized that menopausal symptoms are a significant issue for breast cancer patients and often unaddressed. Health Canada's approval of Elinzanetant as an effective therapy for these symptoms in breast cancer patients is welcomed.

Laurie Legere, a 47-year-old hospital administrator, experienced hot flashes during chemotherapy, which disrupted her life. She was prescribed gabapentin for about a year but could not take higher doses due to drowsiness. Legere is now awaiting the effects of Elinzanetant, which she hopes will improve her condition.

The expansion of Health Canada's authorization for Elinzanetant specifically for breast cancer patients was supported by Bayer's OASIS-4 study. The drug is a neurokinin receptor antagonist that targets KNDy neurons, which become hyperactive due to low estrogen, causing hot flashes and night sweats. A Phase 3 randomized placebo-controlled clinical trial involving 395 women aged 18 to 70 who received endocrine therapy for breast cancer over 52 weeks showed significant improvements in daily hot flashes, night sweats, and sleep disturbances among those taking Elinzanetant compared to the placebo group. The most common side effects were daytime drowsiness, fatigue, and diarrhea.