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Hot FlashesPhase 3Starlight 2NCT06206408

A Study to Confirm if Fezolinetant Helps Reduce Hot Flashes in Japanese Women Going Through Menopause

A Phase 3 study testing Fezolinetant in people with Hot Flashes, run by Astellas Pharma Inc at 64 sites in Japan.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

Hot flashes are the most common reason women going through menopause seek medical attention. Hormone replacement therapy, or HRT, is most often prescribed to treat hot flashes. However, HRT can't be used by all women or for as long as may be needed. Researchers want to find other ways to treat hot flashes. Read more about this study

Who is it for?
Ages 40 to 65 years, women only
Conditions the study is for
Hot Flashes
What is being tested?
Fezolinetant
Type of treatment
Pill or oral medicine
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
410 participants
Where
64 sitesJapan
Study dates
16 Feb 2024to 18 Dec 2025
Phase
Phase 3
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 40 to 65 years
  • Women only
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Participant confirmed as menopausal per one of the following criteria at the screening visit (visit 1):
  • Spontaneous amenorrhea for >/=12 consecutive months;
  • Spontaneous amenorrhea for >/=6 months with biochemical criteria of menopause (follicle-stimulating hormone (FSH) > 40 IU/L);
  • Having had bilateral oophorectomy >/=6 weeks prior to the screening visit (visit 1) (with or without hysterectomy); or
  • Having had hysterectomy without bilateral oophorectomy with the biochemical criteria of menopause (FSH > 40 IU/L).
  • Participant must be seeking treatment or relief for vasomotor symptoms (VMS) associated with menopause and meet some set criteria related to hot flash(es) (HFs) (VMS) prior to randomization.
  • Participant agrees not to participate in another interventional study while participating in the present study.

Who cannot join

  • Participant has a history of an undiagnosed uterine bleeding within the 6 months prior to the screening visit (visit 1).
  • Participant has a current malignant tumor or history (except for a participant who has not received treatment for malignant tumors for at least 5 years before informed consent acquisition and was not considered to have recurrence) of a malignant tumor except for non-metastatic basal cell carcinoma of the skin.
  • 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) that could confound interpretation of the study outcome.
  • Participant uses a prohibited therapy (hormone therapy, hormone replacement therapy (HRT), hormonal contraceptive, any treatment for menopausal symptoms [prescription medications, over-the-counter, or herbal/Kampo medicines] or strong or moderate cytochrome P450 1A2 (CYP1A2) inhibitors) and is not willing to wash out or discontinue use of such drugs from screening visit (visit 1) through the follow-up visit (visit 6) or it is not medically appropriate to discontinue such drugs for the duration of the study.
  • Participant has been randomized/registered in a clinical study with fezolinetant previously or had previous exposure to marketed fezolinetant elsewhere.
  • Participant has a present or previous history of participation in this study.
Show all 19Show fewer
  • Participant has received any investigational therapy within 28 days or 5 half-lives, whichever is longer, prior to screening (visit 1).
  • Participant has an unacceptable result from the transvaginal ultrasound (TVU) assessment at screening (i.e., full length of endometrial cavity cannot be visualized or presence of clinically significant abnormal findings).
  • Participant has documentation of a clinically significant abnormal Papanicolaou (Pap) test (or equivalent cervical cytology) within the 12 months prior to the screening visit (visit 1) or at screening.
  • 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), elevated international normalized ratio (INR), or elevated alkaline phosphatase (ALP) at screening. A participant with mildly elevated ALT or AST up to < 1.5 × 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 × ULN or estimated glomerular filtration rate using the Modification of Diet in Renal Disease formula </=30 mL/min/1.73 m^2 at screening.
  • Participant has positive hepatitis serology panel (i.e., positive hepatitis B surface (HBs) antigen and/or positive hepatitis C virus (HCV) antibody) at screening. If HCV antibody test result is equivocal, hepatitis C virus ribonucleic acid (HCV RNA) test at study site is allowed. Participant can be enrolled if that result is normal or not abnormal.
  • Participant is not in good general health as determined on the basis of medical history and general physical examination performed at the screening; hematology parameters, biochemistry parameters, pulse rate, blood pressure, electrocardiogram (ECG) outside the reference range for the population studied, or is showing clinically relevant deviations.
  • Participant has a history of suicide attempt or suicidal behavior within the 12 months prior to study enrollment or suicidal ideation within the 12 months prior to study enrollment (a response of "yes" to question 4 or 5 on the suicidal ideation portion of the Columbia Suicide Severity Rating Scale (C-SSRS)), or is at significant risk to commit suicide at day 1 (visit 2).
  • Participant is unable or unwilling to complete the study procedures.
  • Participant has any condition which makes the participant unsuitable for study participation.
  • Participant has a known or suspected hypersensitivity to fezolinetant or any components of the formulation used.
  • Participant is the investigator or a member of the study site staff.
  • Participant is an employee of Astellas, the study-related contract research organizations (CROs) or site management organization.

Trial locations and contacts

64 sites in 1 country.

64 sites in 1 country

Japan64 sites

  • National Hospital Organization Beppu Medical Center

    Beppu-shi, Oita Prefecture

  • Sei Women's Clinic

    Bunkyo-ku, Tokyo

  • Chiba Aoba Municipal Hospital

    Chiba, Chiba

  • Chita Kosei Hospital

    Chita-gun, Aichi-ken

  • Marunouchi no Mori Ladies Clinic

    Chiyoda-ku, Tokyo

  • Medical Corporation Asbo Tokyo Asbo Clinic

    Chuo-ku, Tokyo

  • Fukuoka Mirai Hospital

    Fukuoka, Fukuoka

  • Mori Ladies Clinic

    Fukuoka, Fukuoka

  • Nishiguchi Clinic Fujinka

    Fukushima, Fukushima

  • Aiiku Ladies Clinic

    Funabashi-shi, Chiba

  • Medical Corp. SEIKOUKAI New Medical Research System Clinic

    Hachioji-shi, Tokyo

  • Sadamori Ladies Clinic

    Hiroshima, Hiroshima

  • Kosumo Clinic

    Kako-gun, Hyōgo

  • Shonan Kamakura General Hospital

    Kamakura, Kanagawa

  • National Hospital Organization Kanazawa Medical Center

    Kanazawa, Ishikawa-ken

  • Tsujinaka Hospital Kashiwanoha

    Kashiwa-shi, Chiba

  • National Hospital Organization Osaka Minami Medical Center

    Kawachinagano-shi, Osaka

  • Kawasakieki Fumi Ladies Clinic

    Kawasaki-shi, Kanagawa

  • Koukan Clinic

    Kawasaki-shi, Kanagawa

  • Shinkawasaki Kobiki Womens Clinic

    Kawasaki-shi, Kanagawa

  • Konan Kosei Hospital

    Kōnan, Aichi-ken

  • Omi Medical Center, Social Medical Corporation Seikoukai

    Kusatsu-shi, Shiga

  • Rakuwakai Otowa Hospital

    Kyoto, Kyoto

  • Machida Municipal Hospital

    Machida-shi, Tokyo

  • Juno Vesta Clinic hatta

    Matsudo-shi, Chiba

  • Social Medical Care Corporation Hosei-kai Marunouchi Hospital

    Matsumoto-shi, Nagano

  • Toranomon Womens Clinic

    Minato-ku, Tokyo

  • Kichijyoji Ladies Clinic

    Musashino-shi, Tokyo

  • Daido Clinic

    Nagoya, Aichi-ken

  • MEITETSU Hospital

    Nagoya, Aichi-ken

  • Shimamura Memorial Hospital

    Nerima-ku, Tokyo

  • Yukawa Women'S Clinic

    Nishi-Tokyo-shi, Tokyo

  • Mari Women'S Clinic

    Nisinomiya-shi, Hyōgo

  • Miyabi Uro-Gyne Clinic

    Okayama, Okayama-ken

  • Omihachiman Community Medical Center

    Ōmihachiman, Shiga

  • Chayamachi Ladies Clinic

    Osaka, Osaka

  • Chiharu Clinic

    Osaka, Osaka

  • GyNet Medical Corporation Minamimorimachi Ladies' Clinic

    Osaka, Osaka

  • Kitahorie Kanade Ladies Clinic

    Osaka, Osaka

  • Komorebi Ladies Clinic Osaka Honmachi

    Osaka, Osaka

  • Ninomiya Ladies Clinic

    Osaka, Osaka

  • Rikako Ladies Clinic

    Osaka, Osaka

  • Tennoji Chihiro Women's Clinic

    Osaka, Osaka

  • OHARA Clinic

    Saitama, Saitama

  • Maruyama Memorial General Hospital

    Saitama-shi, Saitama

  • Shimizu Ladies Clinic

    Sakai-shi, Osaka

  • Kotoni Ladies Clinic

    Sapporo, Hokkaido

  • M's Ladies Clinic

    Sapporo, Hokkaido

  • Miyanomori Ladies' Clinic

    Sapporo, Hokkaido

  • Social Medical Corporation Caress Sapporo Caress Memorial Hospital

    Sapporo, Hokkaido

  • NISHIKAWA Women's Health Clinic

    Sapporo

  • Chieko Yukika Lady's Clinic

    Sendai, Miyagi

  • Japan Community Health care Organization Tokuyama Central Hospital

    Shunan-shi, Yamaguchi

  • Shimodaira Ladies Clinic

    Suginami-ku, Tokyo

  • Asahi Clinic

    Takamatsu, Kagawa-ken

  • National Hospital Organization Takasaki General Medical Center

    Takasaki-shi, Gunma

  • Sato Hospital

    Takasaki-shi, Gunma

  • jMOG Medical Corporation Tanabe Ladies' Clinic

    Takatsuki-shi, Osaka

  • Medical Corporation Associa Tamacenter Ladies Clinic

    Tama-Shi, Tokyo

  • JA Toride Medical Center

    Toride, Ibaraki

  • Toyota Kosei Hospital

    Toyota-shi, Aichi-ken

  • Tsukuba Urocare Clinic

    Tsukuba, Ibaraki

  • Motomachi Ladies Clinic

    Yokohama, Kanagawa

  • Women's Clinic LUNA Yokohama Motomachi

    Yokohama, Kanagawa

Other trials in Japan

About this study

Official title: A Phase 3, Randomized, Placebo-controlled, Double-blind Study to Assess the Efficacy and Safety of Fezolinetant in Japanese Women Experiencing Vasomotor Symptoms (Hot Flashes) Associated With Menopause

Hot flashes are the most common reason women going through menopause seek medical attention. Hormone replacement therapy, or HRT, is most often prescribed to treat hot flashes. However, HRT can't be used by all women or for as long as may be needed.

Researchers want to find other ways to treat hot flashes. Fezolinetant is a medicine to treat hot flashes in women going through menopause. Fezolinetant is an approved medicine in the US. Further studies are needed before it is available in other regions such as Asia.

Read more

This study will confirm if fezolintant helps reduce the number of hot flashes in Japanese women going through menopause.

Women that want to take part in the study will be given an electronic handheld device with an app to track their hot flashes. Some women may be able to use the app on their own smartphone. Before the women are assigned a treatment, they will record information about their hot flashes.

Women will either take a lower or higher dose of fezolinetant, or a placebo. This is decided by chance alone. The placebo looks like fezolinetant but will not have any medicine in it.

The women will take 2 tablets of the study medicine (lower or higher dose of fezolinetant, or the placebo) once a day for up to 12 weeks. They will either take 1 tablet of fezolinetant (higher or lower dose) and 1 placebo tablet, or they will take 2 placebo tablets. The women will continue to record information about their hot flashes on the electronic device or their smartphone.

During the study, the women will visit the study clinic a few times. At each visit they will be asked if they had any medical problems and will use an electronic device at the clinic to answer questions about how the hot flashes affect their daily life. Other checks will include a medical examination, vital signs (temperature, blood pressure and pulse). Some blood and urine samples will be taken for laboratory tests. At some visits, the women will also have an ECG to check their heart rhythm. Women who have a womb (uterus) will also have a test called a transvaginal ultrasound. A probe is gently placed inside the vagina. Sound waves will create a picture of the organs in the pelvis. This will allow the study doctor to look more closely at the uterus and surrounding organs.

The last clinic visit will be 3 weeks after the women take their final tablets of the study medicine (1 tablet of lower or higher dose of fezolinetant and 1 placebo tablet, or 2 placebo tablets).

Conditions
Hot Flashes
Being tested
Fezolinetant, Placebo
Keywords
menopause;, ESN364;, vasomotor symptoms;, fezolinetant;, VEOZAH™
Medical subject headings
Hot Flashes

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • FezolinetantDrug

    Also called ESN364;, VEOZAH™

    oral

  • PlaceboDrug

    oral

Study groups in NCT06206408
Study groupRoleWhat they receive
Fezolinetant low doseExperimentalParticipants will receive low dose of fezolinetant and placebo once daily for 12 weeks.
Receives: Drug: Fezolinetant; Drug: Placebo
Fezolinetant high doseExperimentalParticipants will receive high dose of fezolinetant and placebo once daily for 12 weeks.
Receives: Drug: Fezolinetant; Drug: Placebo
PlaceboPlacebo comparatorParticipants will receive matching placebo once daily for 12 weeks.
Receives: Drug: Placebo

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Mean change from baseline in the frequency of mild to severe vasomotor symptoms (VMS)

    Frequency of mild, moderate or severe VMS events will be calculated as the sum of mild, moderate or severe VMS events per day.

    Measured: Baseline and Week 8

Secondary outcomes (17)

  1. Mean change from baseline in the frequency of mild to severe VMS

    Frequency of mild, moderate or severe VMS events will be calculated as the sum of mild, moderate or severe VMS events per day.

    Measured: Baseline and up to Week 12

  2. Mean change from baseline in the frequency of moderate to severe VMS

    Frequency of moderate or severe VMS events will be calculated as the sum of moderate or severe VMS events per day.

    Measured: Baseline and up to Week 12

  3. Mean percent reduction in the frequency of mild to severe VMS from baseline

    Frequency of mild, moderate or severe VMS events will be calculated as the sum of mild, moderate or severe VMS events per day. Mean percent reduction will be reported.

    Measured: Baseline and up to Week 12

  4. Mean percent reduction in the frequency of moderate to severe VMS from baseline

    Frequency of moderate and severe VMS events will be calculated as the sum of moderate or severe VMS events per day. Mean percent reduction will be reported.

    Measured: Baseline and up to Week 12

  5. Percent reduction of >/= 50% in the frequency of mild to severe VMS from baseline

    Frequency of mild, moderate or severe VMS events will be calculated as the sum of mild, moderate or severe VMS events per day. Percent reduction of >/= 50% will be reported.

    Measured: Baseline and up to Week 12

  6. Percent reduction of >/= 75% in the frequency of mild to severe VMS from baseline

    Frequency of mild, moderate or severe VMS events will be calculated as the sum of mild, moderate or severe VMS events per day. Percent reduction of >/= 75% will be reported.

    Measured: Baseline and up to Week 12

  7. Percent reduction of 100% in the frequency of mild to severe VMS from baseline

    Frequency of mild, moderate or severe VMS events will be calculated as the sum of mild, moderate or severe VMS events per day. Percent reduction of 100% will be reported.

    Measured: Baseline and up to Week 12

  8. Percent reduction of >/= 50% in the frequency of moderate to severe VMS from baseline

    Frequency of moderate and severe VMS events will be calculated as the sum of moderate or severe VMS events per day. Percent reduction of >/= 50% will be reported.

    Measured: Baseline and up to Week 12

  9. Percent reduction of >/= 75% in the frequency of moderate to severe VMS from baseline

    Frequency of moderate and severe VMS events will be calculated as the sum of moderate or severe VMS events per day. Percent reduction of >/= 75% will be reported.

    Measured: Baseline and up to Week 12

  10. Percent reduction of 100% in the frequency of moderate to severe VMS from baseline

    Frequency of moderate and severe VMS events will be calculated as the sum of moderate or severe VMS events per day. Percent reduction of 100% will be reported.

    Measured: Baseline and up to Week 12

  11. Number of participants with Adverse Events (AEs)

    An AE is any untoward medical occurrence in a patient or clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention.

    An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of study intervention. This includes events related to the comparator, if applicable, and events related to the (study) procedures.

    Measured: Up to Week 15

  12. Change from baseline in endometrial thickness

    Endometrial thickness is a measure of how thick the lining of the uterus is. Endometrial thickness will be measured by transvaginal ultrasound (TVU).

    Measured: Baseline and up to Week 12

  13. Number of participants with laboratory value abnormalities and/or AEs

    Number of participants with potentially clinically significant laboratory values.

    Measured: Up to Week 15

  14. Number of participants with vital sign abnormalities and/or AEs

    Number of participants with potentially clinically significant vital sign values.

    Measured: Up to Week 15

  15. Number of participants with electrocardiogram (ECG) abnormalities and/or AEs

    Number of participants with potentially clinically significant ECG values.

    Measured: Up to Week 12

  16. Pharmacokinetics (PK) of fezolinetant in plasma: Concentration

    Concentration will be recorded from the PK plasma samples collected.

    Measured: Up to Week 12

  17. Pharmacokinetics (PK) of metabolite ES259564 in plasma: Concentration

    Concentration will be recorded from the PK plasma samples collected.

    Measured: Up to Week 12

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted16 Jan 2024
  2. Study start16 Feb 2024
  3. Primary completion22 Oct 2025
  4. Study completion18 Dec 2025

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 3
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Masking
Triple blind
Who is masked
Participant, Investigator, Outcomes assessor
Enrolment
410 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT06206408
Sponsor's protocol ID
2693-CL-0310
Other IDs
jRCT2031230571
Acronym
Starlight 2
Status last verified
Dec 2025
First submitted
4 Jan 2024
Last updated
23 Dec 2025
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
Yes: Access to anonymized individual participant level data collected during the study, in addition to study-related supporting documentation, is planned for studies conducted with approved product indications and formulations, as well as products terminated during development. Studies conducted with product indications or formulations that remain active in development are assessed after study completion to determine if Individual Participant Data can be shared. Further details on Astellas' data sharing policy can be found at https://www.clinicaltrials.astellas.com/transparency/.

Questions about this trial

What is this clinical trial studying?

A Phase 3 study testing Fezolinetant in people with Hot Flashes, run by Astellas Pharma Inc at 64 sites in Japan.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 7 inclusion and 19 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 23 Dec 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 64 sites in Japan. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Mean change from baseline in the frequency of mild to severe vasomotor symptoms (VMS) (time frame: Baseline and Week 8). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT06206408.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 23 Dec 2025.

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