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Study of Fezolinetant for Hot Flashes in Women with Hormone Receptor-Positive Breast Cancer Receiving Hormone Therapy

Fast replyInvestigationalNo placebo
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What is this trial about?

A plain-language summary of the goals, design and what participants do

This study focuses on women with hormone receptor-positive breast cancer who experience moderate to severe vasomotor symptoms (hot flashes) while receiving hormone therapy. These hot flashes can significantly impact daily life and occur as a side effect of breast cancer treatment. The study will test a medication called fezolinetant, which is being investigated to help reduce these symptoms.

The purpose of the study is to determine if fezolinetant 45 mg taken once daily can effectively reduce both the frequency and severity of hot flashes compared to placebo in women undergoing breast cancer hormone therapy. During the study, participants will take either fezolinetant as a film-coated tablet or a matching placebo tablet daily for up to 52 weeks.

The medication will be given to women who are currently receiving stable maintenance adjuvant endocrine therapy (hormone therapy) such as tamoxifen or aromatase inhibitors. Throughout the study, participants will need to record their hot flash symptoms in an electronic diary. The study will monitor how well the treatment works and any potential side effects that may occur.

The research process

The trial runs in 5 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Initial participation phase

    You will be assigned randomly to receive either fezolinetant 45 mg tablets or placebo tablets to be taken once daily

    You must continue your current hormone therapy (tamoxifen or aromatase inhibitors) throughout the study without changes

  2. Step 2

    First month evaluation

    At week 4, your hot flashes will be evaluated for frequency and severity

    You will complete questionnaires about your quality of life and sleep patterns

    Your overall impression of changes in symptoms will be recorded

  3. Step 3

    Three-month evaluation

    At week 12, another evaluation of hot flashes frequency and severity will be conducted

    Additional quality of life and sleep assessments will be performed

    Your blood samples will be analyzed to measure medication levels

  4. Step 4

    Six-month evaluation

    At week 24, final assessments of hot flash frequency and severity will be completed

    Final quality of life and sleep questionnaires will be administered

    Overall safety and effectiveness of the treatment will be evaluated

  5. Step 5

    Ongoing monitoring

    Throughout the study, you will need to record your hot flash symptoms daily in an electronic diary

    Regular safety assessments including vital signs and laboratory tests will be conducted

    Any side effects or health changes will be monitored and documented

Who can join the trial?

7 criteria

  • Must be born female and at least 18 years of age when signing the consent form
  • Must have a history of stage 0-3 hormone receptor-positive breast cancer (HR+), with proper documentation
  • Must be on stable maintenance therapy for breast cancer (using tamoxifen or aromatase inhibitors) for at least 4 months and plan to continue throughout the study without changes
  • Must experience an average of at least 7 moderate to severe hot flashes per day (recorded over at least 7 out of 10 days before starting the study)
  • Must have an ECOG score of 0 or 1 (meaning able to carry out all normal activities or light work)
  • Must have a life expectancy of at least 12 months
  • Must test negative for hepatitis B, hepatitis C, and HIV

Who cannot join the trial?

14 criteria

  • Age below 18 or above 65 years
  • Male patients (study is for females only)
  • Patients who do not have a confirmed diagnosis of hormone receptor-positive breast cancer (stages 0-3)
  • Patients not experiencing moderate to severe vasomotor symptoms (hot flashes and night sweats)
  • Patients not currently receiving adjuvant endocrine therapy (hormone treatment after primary cancer therapy)
  • Patients with breast cancer stage 4 (advanced/metastatic)
  • Patients not experiencing at least 7 moderate to severe hot flashes per day
  • Pregnant or breastfeeding women
  • Patients participating in other clinical trials
  • Patients with known allergies or sensitivity to the study medication (fezolinetant)
  • Patients with severe liver or kidney disease
  • Patients with uncontrolled high blood pressure
  • Patients with significant psychiatric disorders
  • Patients unable to provide informed consent
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Investigated drugs

  • Fezolinetant

    is a medication being studied for treating moderate to severe hot flashes (vasomotor symptoms) in women who have hormone receptor-positive breast cancer and are receiving endocrine therapy. It works by targeting the brain chemicals involved in regulating body temperature.

  • Endocrine therapy

    refers to treatments that lower or block hormones in the body to treat hormone receptor-positive breast cancer. This is a standard treatment that participants are already receiving as part of their cancer care.

What is already known about the treatment

Fezolinetant - An oral medication administered once daily as a 45 mg dose, specifically designed to treat moderate to severe vasomotor symptoms (hot flashes) in women receiving endocrine therapy for hormone receptor-positive breast cancer. This investigational drug works by targeting and blocking neurokinin-3 receptors in the brain's temperature control center, helping to regulate body temperature and reduce hot flashes. Fezolinetant belongs to the class of neurokinin receptor antagonists and represents a non-hormonal approach to managing hot flashes, which is particularly important for breast cancer patients who cannot use traditional hormone-based treatments. The medication is currently being studied in Phase 3 clinical trials to evaluate its efficacy and safety profile.

Investigated diseases

  • Vasomotor Symptoms (VMS)

    A condition characterized by sudden feelings of warmth (hot flashes) and sweating, particularly in the upper body, face, and chest. These symptoms often occur during menopause or as a side effect of certain medical treatments. Episodes can vary in frequency and intensity, lasting from a few seconds to several minutes. VMS can be accompanied by heart palpitations, anxiety, and reddening of the skin. The symptoms can disrupt sleep patterns and daily activities, affecting overall quality of life.

  • Breast Cancer (Hormone Receptor-Positive)

    A type of breast cancer where cancer cells grow in response to hormones estrogen and/or progesterone. This cancer begins when abnormal cells in breast tissue start growing uncontrollably. The presence of hormone receptors on cancer cells means that the tumor's growth is influenced by hormones. It typically develops slowly and can occur in different parts of the breast. This type of breast cancer is the most common form of breast cancer.

Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2024-510719-31-00Protocol code2693-CL-1303Estimated enrolment472 patientsSponsorAstellas Pharma Global Development Inc.

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On this site, “treatment” means an investigational medicine being studied in a clinical trial. Its safety and efficacy for the use being studied have not yet been confirmed, some participants may receive a placebo or a comparator medicine, and taking part does not guarantee any health benefit. The decision to take part is made by the doctor at the research site. This site is for information only and does not replace medical advice.

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