Hormone Receptor-positive Breast CancerPhase 1NCT06570031
ONO-4578-06:Phase I Study of ONO-4578 and Letrozole Plus CDK4 /6 Inhibitors in Breast Cancer
A Phase 1 study testing ONO-4578, letrozole and Palbociclib in people with Hormone Receptor-positive Breast Cancer and HER2-negative Breast Cancer, run by Ono Pharmaceutical Co., Ltd. at 13 sites in Japan.
Trial summary
This is a multicenter, open-label, non-controlled, phase I study to investigate the tolerability and safety of ONO-4578 used in combination with standard-of-care letrozole and a CDK4/6 inhibitor (palbociclib or Abemaciclib) as first-line endocrine therapy in postmenopausal patients with metastatic or recurrent hormone… Read more about this study
- Who is it for?
- Ages 20 years and older, women only
- Conditions the study is for
- Hormone Receptor-positive Breast Cancer, HER2-negative Breast Cancer, Metastatic Breast Cancer
- What is being tested?
- ONO-4578, letrozole and Palbociclib
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 46 participants
- Where
- 13 sitesJapan
- Study dates
- 9 Nov 2021to 30 Apr 2026
- Phase
- Phase 1
- 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 20 years and older
- Women only
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Patients with postmenopausal metastatic or recurrent breast cancer
- Patients with ECOG Performance Status 0 to 1
- ER-positive, PgR-positive and HER2-negative patients
Who cannot join
- Patients are unable to swallow oral medications
- Patients with severe complication
Trial locations and contacts
13 sites in 1 country.
13 sites in 1 country
Japan13 sites
Chiba Cancer Center
Chiba, Chiba
National Cancer Center Hospital
Chuo-ku, Tokyo
National Cancer Center Hospital East
Kashiwa-shi, Chiba
St. Marianna University Hospital
Kawasaki-shi, Kanagawa
The Cancer Institute Hospital Of JFCR
Koto-ku, Tokyo
University Hospital Kyoto Prefectural University of Medicine
Kyoto, Kyoto
Aichi Cancer Center Hospital
Nagoya, Aichi-ken
Nagoya University Hospital
Nagoya, Aichi-ken
Osaka International Cancer Institute
Osaka, Osaka
Tohoku University Hospital
Sendai, Miyagi
Saitama Cancer Center
Shinden, Saitama
Tokyo Medical University Hospital
Shinjuku-ku, Tokyo
Kanagawa Cancer Center
Yokohama, Kanagawa
About this study
Official title: ONO-4578-06: Phase I , Open-label, Non-blind, First-line Endocrine Therapy With ONO-4578 and Standard Treatment Letrozole and CDK4/6 Inhibitors (Palbociclib or Abemaciclib) in Patients With Metastatic or Recurrent Postmenopausal Hormone Receptor-positive HER2-negative Breast Cancer
This is a multicenter, open-label, non-controlled, phase I study to investigate the tolerability and safety of ONO-4578 used in combination with standard-of-care letrozole and a CDK4/6 inhibitor (palbociclib or Abemaciclib) as first-line endocrine therapy in postmenopausal patients with metastatic or recurrent hormone receptor-positive, HER2-negative breast cancer.
- Conditions
- Hormone Receptor-positive Breast Cancer, HER2-negative Breast Cancer, Metastatic Breast Cancer, Recurrent Breast Cancer
- Being tested
- ONO-4578, letrozole, Palbociclib, abemaciclib
- Keywords
- Breast Cancer, Hormone Receptor-positive, HER2-negative, Metastatic, Recurrent
- Medical subject headings
- Breast Neoplasms, Neoplasm Metastasis, Recurrence
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
ONO-4578Drug
Specified dose on specified days
letrozoleDrug
Specified dose on specified days
PalbociclibDrug
Specified dose on specified days
abemaciclibDrug
Specified dose on specified days
| Study group | Role | What they receive |
|---|---|---|
| ONO-4578 + letrozole + palbociclib | Experimental | Not described Receives: Drug: ONO-4578; Drug: letrozole; Drug: Palbociclib |
| ONO-4578 + letrozole + abemaciclib | Experimental | Not described Receives: Drug: ONO-4578; Drug: letrozole; Drug: abemaciclib |
What is being measured
The primary outcome is the main question the study is designed to answer.
Adverse events
Measured: Through study completion, an average of 4 year
Serious adverse events
Measured: Through study completion, an average of 4 year
Dose-limiting toxicity (Tolerability Confirmation part only)
Measured: 28 days
Laboratory abnormality profile of Drugs as measured by incidence and severity of clinical laboratory abnormalities
Measured: Through study completion, an average of 4 year
Body temperature
Measured: Through study completion, an average of 4 year
Pulse rate
Measured: Through study completion, an average of 4 year
Systolic/diastolic blood pressure
Measured: Through study completion, an average of 4 year
Saturation of Percutaneous Oxygen (SpO2)
Measured: Through study completion, an average of 4 year
Weight
Measured: Through study completion, an average of 4 year
Eastern Cooperative Oncology Group Performance Status
Measured: Through study completion, an average of 4 year
Chest X-ray
Measured: Through study completion, an average of 4 year
CT scan
Measured: Through study completion, an average of 4 year
12-lead electrocardiography (Heart rate)
Measured: Through study completion, an average of 4 year
12-lead electrocardiography (PR interval)
Measured: Through study completion, an average of 4 year
12-lead electrocardiography (RR interval)
Measured: Through study completion, an average of 4 year
12-lead electrocardiography (QRS width)
Measured: Through study completion, an average of 4 year
12-lead electrocardiography (QT interval)
Measured: Through study completion, an average of 4 year
Secondary outcomes (12)
Overall response rate (ORR)
Measured: Through study completion, an average of 4 year
Disease control rate (DCR)
Measured: Through study completion, an average of 4 year
Clinical benefit rate (CBR)
Measured: Through study completion, an average of 4 year
Overall survival (OS)
Measured: Through study completion, an average of 4 year
Progression-free survival (PFS)
Measured: Through study completion, an average of 4 year
Duration of response (DOR)
Measured: Through study completion, an average of 4 year
Time to response (TTR)
Measured: Through study completion, an average of 4 year
Best overall response (BOR)
Measured: Through study completion, an average of 4 year
Percent change in the sum of diameters of target lesions
Measured: Through study completion, an average of 4 year
Maximum percent change in the sum of diameters of target lesions
Measured: Through study completion, an average of 4 year
Changes in tumor markers
Measured: Through study completion, an average of 4 year
Plasma ONO-4578 concentration
Measured: Through study completion, an average of 4 year
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted26 Aug 2024
- Study start9 Nov 2021
- Primary completion30 Apr 2026
- Study completion30 Apr 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Hormone Receptor-positive Breast CancerStudies of the same condition, open and under way.
- More trials run by Ono Pharmaceutical Co., Ltd.The sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
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 1
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 46 participants (actual)
Sponsor and investigators
- Lead sponsor
- Ono Pharmaceutical Co., Ltd.
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Project Leader, Study director, Ono Pharmaceutical Co., Ltd.
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06570031
- Sponsor's protocol ID
- ONO-4578-06
- Status last verified
- Jun 2026
- First submitted
- 31 Jul 2024
- Last updated
- 5 Jun 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 5 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- ONO-4578-06: Phase I , Open-label, Non-blind, First-line Endocrine Therapy With ONO-4578 and Standard Treatment Letrozole and CDK4/6 Inhibitors (Palbociclib or Abemaciclib) in Patients With Metastatic or Recurrent Postmenopausal Hormone Receptor-positive HER2-negative Breast Cancer
- ClinicalTrials.gov ID
- NCT06570031
- Acronym / sponsor ID
- ONO-4578-06
- Conditions
- Hormone Receptor-positive Breast Cancer, HER2-negative Breast Cancer, Metastatic Breast Cancer, Recurrent Breast Cancer
- Keywords
- Breast Cancer, Hormone Receptor-positive, HER2-negative, Metastatic, Recurrent
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 46 participants (actual)
- Lead sponsor
- Ono Pharmaceutical Co., Ltd.Industry (pharma, biotech, devices)
- Study start
- 9 Nov 2021 (actual)
- Primary completion
- 30 Apr 2026 (actual)
- Study completion
- 30 Apr 2026 (actual)
- First posted
- 26 Aug 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This is a multicenter, open-label, non-controlled, phase I study to investigate the tolerability and safety of ONO-4578 used in combination with standard-of-care letrozole and a CDK4/6 inhibitor (palbociclib or Abemaciclib) as first-line endocrine therapy in postmenopausal patients with metastatic or recurrent hormone receptor-positive, HER2-negative breast cancer.
Study design
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| ONO-4578 + letrozole + palbociclib | Experimental | Drug: ONO-4578, Drug: letrozole, Drug: Palbociclib |
| ONO-4578 + letrozole + abemaciclib | Experimental | Drug: ONO-4578, Drug: letrozole, Drug: abemaciclib |
Who may qualify
- Ages
- 20 years and older
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Patients with postmenopausal metastatic or recurrent breast cancer
- Patients with ECOG Performance Status 0 to 1
- ER-positive, PgR-positive and HER2-negative patients
Key exclusion criteria (2 listed)
- Patients are unable to swallow oral medications
- Patients with severe complication
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| ONO-4578Specified dose on specified days | Drug | ONO-4578 + letrozole + abemaciclib, ONO-4578 + letrozole + palbociclib |
| letrozoleSpecified dose on specified days | Drug | ONO-4578 + letrozole + abemaciclib, ONO-4578 + letrozole + palbociclib |
| PalbociclibSpecified dose on specified days | Drug | ONO-4578 + letrozole + palbociclib |
| abemaciclibSpecified dose on specified days | Drug | ONO-4578 + letrozole + abemaciclib |
Primary outcome
Adverse events
Time frame: Through study completion, an average of 4 year
Serious adverse events
Time frame: Through study completion, an average of 4 year
Dose-limiting toxicity (Tolerability Confirmation part only)
Time frame: 28 days
Laboratory abnormality profile of Drugs as measured by incidence and severity of clinical laboratory abnormalities
Time frame: Through study completion, an average of 4 year
Body temperature
Time frame: Through study completion, an average of 4 year
Pulse rate
Time frame: Through study completion, an average of 4 year
Systolic/diastolic blood pressure
Time frame: Through study completion, an average of 4 year
Saturation of Percutaneous Oxygen (SpO2)
Time frame: Through study completion, an average of 4 year
Weight
Time frame: Through study completion, an average of 4 year
Eastern Cooperative Oncology Group Performance Status
Time frame: Through study completion, an average of 4 year
Chest X-ray
Time frame: Through study completion, an average of 4 year
CT scan
Time frame: Through study completion, an average of 4 year
12-lead electrocardiography (Heart rate)
Time frame: Through study completion, an average of 4 year
12-lead electrocardiography (PR interval)
Time frame: Through study completion, an average of 4 year
12-lead electrocardiography (RR interval)
Time frame: Through study completion, an average of 4 year
12-lead electrocardiography (QRS width)
Time frame: Through study completion, an average of 4 year
12-lead electrocardiography (QT interval)
Time frame: Through study completion, an average of 4 year
12 secondary outcomes
Overall response rate (ORR)
Time frame: Through study completion, an average of 4 year
Disease control rate (DCR)
Time frame: Through study completion, an average of 4 year
Clinical benefit rate (CBR)
Time frame: Through study completion, an average of 4 year
Overall survival (OS)
Time frame: Through study completion, an average of 4 year
Progression-free survival (PFS)
Time frame: Through study completion, an average of 4 year
Duration of response (DOR)
Time frame: Through study completion, an average of 4 year
Time to response (TTR)
Time frame: Through study completion, an average of 4 year
Best overall response (BOR)
Time frame: Through study completion, an average of 4 year
Percent change in the sum of diameters of target lesions
Time frame: Through study completion, an average of 4 year
Maximum percent change in the sum of diameters of target lesions
Time frame: Through study completion, an average of 4 year
Changes in tumor markers
Time frame: Through study completion, an average of 4 year
Plasma ONO-4578 concentration
Time frame: Through study completion, an average of 4 year
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 5 Jun 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Project Leader study director
Ono Pharmaceutical Co., Ltd.
13 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing ONO-4578, letrozole and Palbociclib in people with Hormone Receptor-positive Breast Cancer and HER2-negative Breast Cancer, run by Ono Pharmaceutical Co., Ltd. at 13 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 3 inclusion and 2 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 5 Jun 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 13 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. 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 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
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?
Adverse events (time frame: Through study completion, an average of 4 year). The study lists 17 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 5 Jun 2026.