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Fezolinetant for reducing hot flashes in women with breast cancer on hormone therapy

A Randomized, Placebo-controlled, Double-blind, Phase 3 Clinical Study to Investigate the Efficacy and Safety of Fezolinetant for Treatment of Moderate to Severe Vasomotor Symptoms (Hot Flashes) in Women With Stage 0 to 3 Hormone Receptor-positive Breast Cancer Who Are Receiving Adjuvant Endocrine Therapy

Phase 3 Interventional Astellas Pharma Inc · NCT06440967

This study is testing if a new medication called fezolinetant can help women with breast cancer who are on hormone therapy feel better by reducing their hot flashes.

Quick facts

PhasePhase 3
Study typeInterventional
Enrollment540 (estimated)
Ages18 Years and up
SexFemale
SponsorAstellas Pharma Inc Industry-sponsored
Drugs / interventionschemotherapy
Locations66 sites (Montreal, Quebec and 65 other locations)
Trial IDNCT06440967 on ClinicalTrials.gov

What this trial studies

This study investigates the effectiveness of fezolinetant, a medication designed to alleviate hot flashes, in women with breast cancer who are undergoing hormone therapy. Participants will be women aged 18 and older experiencing moderate to severe hot flashes while on stable maintenance endocrine therapy. They will be randomly assigned to receive either fezolinetant or a placebo, with the primary goal of determining if fezolinetant significantly reduces the frequency and severity of hot flashes compared to the placebo. The study aims to provide an alternative treatment option for managing vasomotor symptoms in this patient population.

Who should consider this trial

Good fit: Ideal candidates are women aged 18 and older with a history of hormone receptor positive breast cancer who are currently on stable hormone therapy and experiencing moderate to severe hot flashes.

Not a fit: Patients who are not experiencing hot flashes or those not on hormone therapy for breast cancer may not benefit from this study.

Why it matters

Potential benefit: If successful, this treatment could significantly improve the quality of life for women with breast cancer experiencing hot flashes.

How similar studies have performed: Previous studies have shown promise with fezolinetant in treating hot flashes in menopausal women, suggesting potential success in this similar patient population.

Eligibility criteria

Show full inclusion / exclusion criteria 
Inclusion Criteria:

* Participant has a personal history of stage 0-3 hormone receptor positive (HR+), either human epidermal growth factor receptor (HER)-2+ or HER-2- breast cancer; appropriate documentation includes a written or electronic report.
* Participant must be receiving stable maintenance adjuvant endocrine therapy (tamoxifen 20 mg daily or aromatase inhibitors, such as anastrozole, letrozole and exemestane) with or without gonadotropin-releasing hormone (GnRH) agonists/antagonists for a minimum of 4 months and be planning to continue on adjuvant endocrine therapy for the duration of the trial without change to therapy, brand or dose. Add-on therapies for breast cancer adjuvant treatment (e.g., cyclin dependent kinase-4 (CDK4) inhibitors) are allowed.
* Participant has a minimum average of 7 moderate to severe hot flashes (HFs) (vasomotor symptoms (VMS)) per day as recorded in the electronic daily diary (data must be available for at least 7 of the last 10 days prior to randomization).
* Has an European Cooperative Oncology Group (ECOG) score 0 or 1.
* Has at least 12-month life expectation.
* Participant is born female.
* Female participant: Is not pregnant and at least 1 of the following conditions apply:

  * Not a woman of childbearing potential (WOCBP)
  * WOCBP who has a negative urine or serum pregnancy test at screening and day 1 and agrees to follow the contraceptive guidance from the time of informed consent through at least 30 days after final investigational study intervention administration.
* Female participant: Must not be breastfeeding or lactating starting at screening and while the participant is taking investigational study intervention and for 30 days after final investigational study intervention administration.
* Female participant: Must not donate ova starting at first administration of study intervention and while the participant is taking investigational study intervention and for 30 days after final investigational study intervention administration.
* Participant agrees not to participate in another interventional study while participating in the present study until the end of the 1-year extension follow-up period.
* Participant's condition is stable as determined on the basis of medical history and general physical examination (including a bimanual clinical pelvic examination devoid of relevant clinical findings performed at the screening visit), hematology and biochemistry parameters, pulse rate and/or blood pressure and electrocardiogram (ECG) (or showing no clinically relevant deviations obtained within the last 3 months or at screening).
* Participant has no new clinically significant findings on breast examination or from imaging (mammogram or breast ultrasound). Results indicate that the participant is a good candidate for the study. Appropriate documentation includes a written or electronic report. In case of double mastectomy, imaging is not needed.
* Participant has a negative serology panel (including hepatitis B surface antigen (HBsAg), hepatitis C virus (HCV) antibody and human immunodeficiency virus (HIV) antibody screens).

Exclusion Criteria:

* Participant has diagnosis of metastatic breast cancer (stage 4).
* Participant has current or history (except complete remission for 5 years or more prior to signing informed consent) of any malignancy except for HR+ breast cancer (stage 0 to 3) or basal cell carcinoma.
* Participant has had surgery or non-surgical (chemotherapy or radiotherapy) treatment for breast cancer within the last 3 months prior to signing informed consent.
* Participant has active liver disease, jaundice, or elevated liver aminotransferases (alanine aminotransferase (ALT) or aspartate aminotransferase (AST)), elevated total bilirubin (TBL) or direct bilirubin (DBL), or elevated alkaline phosphatase (ALP) at screening. A participant with mildly elevated ALT or AST up to \< 2 × upper limit of normal (ULN) can be enrolled if TBL and DBL are normal. Participant with mildly elevated ALP (up to \< 1.5 × ULN) can be enrolled if cholestatic liver disease is excluded and no cause other than fatty liver is diagnosed. Participant with Gilbert's syndrome with elevated TBL may be enrolled as long as DBL, hemoglobin and reticulocytes are normal.
* Participant has creatinine \> 1.5 x ULN; or estimated glomerular filtration rate (eGFR) using the Modification of Diet in Renal Disease formula \< 30 mL/min/1.73 m2 at the screening visit.
* Participant has a history of endometrial hyperplasia or uterine/endometrial cancer.
* Participant has a medical condition or chronic disease (including history of neurological \[including cognitive\], hepatic, renal, cardiovascular, gastrointestinal, pulmonary \[e.g., moderate asthma\], endocrine, or gynecological disease) or malignancy that could confound interpretation of the study outcome.
* Participant uses a prohibited therapy (menopause hormone therapy (MHT), estradiol-containing hormonal contraceptive progestin and progesterone-only medicines, any treatment for VMS \[prescription medications, over-the-counter, or herbal\] or CYP1A2 (cytochrome P450) inhibitors) or is not willing to wash out such drugs; in addition, medications that are contraindicated due to underlying breast cancer diagnosis and the adjuvant endocrine therapy.
* Participant has a known substance abuse or alcohol addiction within 6 months of screening.
* Participant has received any investigational therapy within 90 days or 5 half-lives, whichever is longer, prior to screening.
* Participant has any condition, which makes the participant unsuitable for study participation.
* Participant has a known or suspected hypersensitivity to fezolinetant, the adjuvant endocrine therapy being used, or any components of the formulations used.

Where this trial is running

Montreal, Quebec and 65 other locations

+16 more sites — see ClinicalTrials.gov for the full list.

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
View on ClinicalTrials.gov → Find more trials like this →
Conditions Hot FlashesESN364vasomotor symptomsfezolinetantVEOZAH™
Last reviewed 2026-06-10 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.