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ER+ HER2- Advanced Breast CancerPhase 1NCT04541433

A Phase 1 Study of AZD9833 in Japanese Women With ER Positive, HER2 Negative Advanced Breast Cancer

A Phase 1 study testing AZD9833 in people with ER+ HER2- Advanced Breast Cancer, run by AstraZeneca at 3 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

This is a Phase 1, open-label study designed to evaluate the safety, tolerability, pharmacokinetics, and anti-tumor activity of AZD9833 in Japanese women with endocrineresistant ER+ HER2- breast cancer that is not amenable to treatment with curative intent. This study consists of 2 cohorts, Cohort1 and Cohort2. Read more about this study

Who is it for?
Ages 20 to 130 years, women only
Conditions the study is for
ER+ HER2- Advanced Breast Cancer
What is being tested?
AZD9833
Type of treatment
Pill or oral medicine
Could I receive a placebo?
No, everyone receives an active treatment
How many people
10 participants
Where
3 sitesJapan
Study dates
29 Sep 2020to 23 Jun 2025
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 to 130 years
  • Women only
  • No healthy volunteers
  • Adult, Older adult

Major Inclusion Criteria:

  1. Signed written informed consent.
  2. >= 20 years.
  3. Any menopausal status: Pre and Post menopausal defined according to standard criteria in the protocol.
  4. Histological or cytological confirmation of adenocarcinoma of the breast.
  5. Documented positive estrogen receptor status of primary or metastatic tumor tissue, according to the local laboratory parameters. HER-2 negative.
  6. Metastatic or locoregionally recurrent disease and radiological or objective evidence of progression on or after the last systemic therapy prior to starting IMP.
  7. Prior chemotherapy, endocrine therapy and other therapy in the advanced setting is restricted as follows:
  8. No more than 2 lines of chemotherapy for advanced disease.
  9. Recurrence or progression on at least one line of endocrine therapy in the advanced/metastatic disease setting.
  10. There is no limit on the number of lines of prior endocrine therapies.
  11. Prior treatment with CDK4/6 inhibitors is permitted.
  12. At least one lesion (measurable and/or non-measurable, as per RECIST 1.1) that can be accurately assessed at baseline and is suitable for repeated assessment by computed tomography (CT), magnetic resonance imaging (MRI), or plain X-ray; or clinical examination.
  13. Eastern Cooperative Oncology Group (ECOG)/World Health Organisation (WHO) performance status 0 to 1

Major Exclusion Criteria:

  1. Intervention with any of the following:
  2. Any cytotoxic chemotherapy, investigational agents, or other anti-cancer drugs for the treatment of advanced breast cancer from a previous treatment regimen or clinical study within 14 days of the first dose of study treatment.
  3. Medications or herbal supplements known to be strong inhibitors/inducers of cytochrome P450 (CYP) 3A4/5 sensitive CYP2B6 substrates and drugs which are substrates of CYP2C9 and/or CYP2C19.
  4. Drugs that are known to prolong QT and have a known risk of Torsades de Pointes.
  5. Radiotherapy with a limited field of radiation for palliation within one week of the first dose of IMP, radiotherapy to more than 30% of the bone marrow or a wide field of radiation within 4 weeks of the first dose of IMP.
  6. Major surgical procedure or significant traumatic injury.
  7. Any unresolved toxicities from prior therapy greater than CTCAE Grade 1 at the time of starting IMP.
  8. Presence of life-threatening metastatic visceral disease.
  9. Evidence of severe or uncontrolled systemic diseases, including uncontrolled hypertension and active bleeding diatheses.
  10. Refractory nausea and vomiting, uncontrolled chronic gastrointestinal diseases, inability to swallow the formulated product, or previous significant bowel resection that would preclude adequate absorption of AZD9833.
  11. History of another primary malignancy.
  12. Male subjects are excluded from this study.
  13. History of hypersensitivity to active or inactive excipients of AZD9833.
  14. The following cardiovascular criteria: QTcF >470 ms, resting heart rate <45 bpm, clinically significant abnormalities of resting electrocardiogram, uncontrolled hypertension, symptomatic hypotension, factors that increase the risk for QTc prolongation, left ventricular ejection fraction <50%.
  15. Inadequate bone marrow reserve or organ function
  16. Involvement in the planning and conduct of the study.
  17. Judgment by the investigator that the patient should not participate in the study.

Trial locations and contacts

3 sites in 1 country.

Japan3 sites

  • Research Site

    Chūōku, 104-0045

  • Research Site

    Kashiwa, 277-8577

  • Research Site

    Kōtoku, 135-8550

Other trials in Japan

About this study

Official title: A Phase 1, Open-label Study to Assess the Safety, Tolerability, Pharmacokinetics and Anti- Tumor Activity of AZD9833 in Japanese Women With ER Positive, HER2 Negative Advanced Breast Cancer

This is a Phase 1, open-label study designed to evaluate the safety, tolerability, pharmacokinetics, and anti-tumor activity of AZD9833 in Japanese women with endocrineresistant ER+ HER2- breast cancer that is not amenable to treatment with curative intent. This study consists of 2 cohorts, Cohort1 and Cohort2. In cohort 1 (for tolerability evaluation), a minimum of 3, or up to 6, evaluable Japanese patients with ER+ HER2- breast cancer will be enrolled. In cohort 2 (for exploratory research), at least 6 to maximum 12 evaluable Japanese patients with ER+ HER2- breast cancer will be enrolled.

Read the detailed description

Objectives:

Primary objective:

To investigate the safety and tolerability of AZD9833 in Japanese women with ER+ HER2- advanced breast cancer

Secondary objective:

To assess the anti-tumor activity and efficacy of AZD9833

Exploratory objectives:

To investigate AZD9833 activity in tumor cells

Overall design:

This is a Phase 1, open-label study designed to evaluate the safety, tolerability, pharmacokinetics, and anti-tumor activity of AZD9833 in Japanese women with endocrineresistant ER+ HER2- breast cancer that is not amenable to treatment with curative intent. Eligible patients will receive AZD9833. In cohort 1 (for tolerability evaluation), a minimum of 3 to maximum 6 evaluable patients will be enrolled.

For cohort 2, if paired biopsy after administration of the study drug becomes inoperable during administration of the study drug, additional subjects can be added to obtain an evaluable biopsy sample.

In cohort 2 (for exploratory research), eligible patients will receive AZD9833 once daily and at least 6 to maximum 12 patients will be enrolled. In cohort 2, paired biopsy sample will be collected from at least 6 and maximum 12 patients. If paired biopsy after administration of the study drug becomes inoperable during administration of the study drug, additional subjects can be added to obtain an evaluable biopsy sample.

Number of Subjects:

Maximum 18 evaluable subjects will be enrolled in this study.

Being tested
AZD9833
Keywords
Breast Cancer, Phase 1, Safety, Tolerability, Pharmacokinetics, ER Positive, HER2 Negative, Advanced Breast Cancer
Medical subject headings
Breast Neoplasms

What participants receive

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

  • AZD9833Drug

    AZD9833 taken orally

Study groups in NCT04541433
Study groupRoleWhat they receive
AZD9833 monotherapyExperimentalDose escalation of AZD9833 monotherapy for patients with ER+ HER2- advanced breast cancer
Receives: Drug: AZD9833

What is being measured

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

  1. The number of subjects with dose-limiting toxicity, as defined in the protocol.

    Dose-limiting toxicity as described in the protocol that is not related to disease progression, intercurrent illness or concomitant medications and that, despite optimal therapeutic intervention, meets protocol-defined criteria.

    Measured: From the first dose of study treatment up to and including Cycle1 Day28.

  2. The number of subjects with treatment-related adverse events as assessed by CTCAE v5.0.

    Safety data will be assessed as the number of subjects with treatment-related adverse events.

    Measured: Minimum observation period 28 days on treatment or 28 days with at least 75% of the required dose and will continue until the subject is off the study (approximately 1 year).

Secondary outcomes (7)

  1. Objective Response Rate

    Antitumour activity by evaluation of tumour response assessments using Response Evaluation Criteria in Solid Tumours (RECIST 1.1)

    Measured: At Cycle3 Day1, Cycle5 Day1, Cycle7 Day1 (each cycle is 28 days) and every 12 weeks until the end of the study (approximately 1 year).

  2. Duration of Response

    Antitumour activity by evaluation of tumour response assessments using Response Evaluation Criteria in Solid Tumours (RECIST 1.1)

    Measured: At Cycle3 Day1, Cycle5 Day1, Cycle7 Day1 (each cycle is 28 days) and every 12 weeks until the end of the study (approximately 1 year).

  3. Clinical benefit rate at 24 weeks

    Antitumour activity by evaluation of tumour response assessments using Response Evaluation Criteria in Solid Tumours (RECIST 1.1)

    Measured: Up to 24 weeks

  4. Percentage Change in Tumour Size

    Antitumour activity by evaluation of tumour response assessments using Response Evaluation Criteria in Solid Tumours (RECIST 1.1)

    Measured: At Cycle3 Day1, Cycle5 Day1, Cycle7 Day1 (each cycle is 28 days) and every 12 weeks until the end of the study (approximately 1 year).

  5. Progression Free Survival

    Antitumour activity by evaluation of tumour response assessments using Response Evaluation Criteria in Solid Tumours (RECIST 1.1)

    Measured: Up to objective disease progression or death (approximately 1 year).

  6. Maximum Observed Plasma Concentration (Cmax) of AZD9833

    Blood samples will be collected to assess plasma concentrations of AZD9833 at a series of timepoints to derive Cmax

    Measured: At predefined intervals throughout the AZD9833 treatment period (approximately 12 weeks )

  7. Time to observed Cmax (Tmax) for AZD9833

    Blood samples will be collected to assess plasma concentrations of AZD9833 at a series of timepoints to derive Tmax

    Measured: At predefined intervals throughout the AZD9833 treatment period (approximately 12 weeks )

Timeline

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

  1. First posted9 Sep 2020
  2. Study start29 Sep 2020
  3. Primary completion29 Jul 2022
  4. Study completion23 Jun 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 1
Primary purpose
Treatment
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrolment
10 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT04541433
Sponsor's protocol ID
D8530C00006
Status last verified
Aug 2025
First submitted
20 Aug 2020
Last updated
7 Aug 2025
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
Yes: Qualified researchers can request access to anonymized individual patient-level data from AstraZeneca group of companies sponsored clinical trials via the request portal. All request will be evaluated as per the AZ disclosure commitment: https://astrazenecagrouptrials.pharmacm.com/ST/Submission/Disclosure.

Questions about this trial

What is this clinical trial studying?

A Phase 1 study testing AZD9833 in people with ER+ HER2- Advanced Breast Cancer, run by AstraZeneca at 3 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?

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 7 Aug 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 3 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?

The number of subjects with dose-limiting toxicity, as defined in the protocol. (time frame: From the first dose of study treatment up to and including Cycle1 Day28.). The study lists 2 primary outcomes in all. 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 NCT04541433.

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 7 Aug 2025; AzTrials last refreshed its copy on 8 Nov 2026.

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