A Phase 3 interventional study of Camizestrant and Tamoxifen in Breast Cancer, Early Breast Cancer, sponsored by AstraZeneca. Recruiting at 709 sites in 39 countries. Open to participants aged 18 Years to 130 Years. Per ClinicalTrials.gov, last updated 2026-10-13.
Sponsored by AstraZeneca · Phase 3, Interventional, and Treatment
This is a Phase III open-label study to assess if camizestrant improves outcomes compared to standard endocrine therapy in patients with ER+/HER2 - early breast cancer with intermediate or high risk for disease recurrence who completed definitive locoregional therapy (with or without chemotherapy) and standard adjuvant endocrine therapy (ET) for at least 2 years and up to 5 years. The planned duration of treatment in either arm of the study is 60 months.
This is a Phase III open-label study to assess if camizestrant improves outcomes compared to standard endocrine therapy in patients with ER+/HER2 - early breast cancer who completed definitive locoregional therapy (with or without chemotherapy) and standard adjuvant endocrine therapy (ET) for at least 2 years and up to 5 years. The planned duration of treatment in either arm of the study is 60 months. The eligible patients must have intermediate or high risk of recurrence, as defined by specified clinical and biologic criteria. Prior use of CDK4/6 inhibitors is permitted. The primary endpoint of the study is Invasive breast cancer-free survival (IBCFS) and main secondary endpoints include Invasive disease-free survival (IDFS), Distant relapse-free survival (DRFS), Overall survival (OS), Safety and Clinical Outcome Assessments (COAs).
Patients will be followed for 10 years from randomization of the last patient.
14,825 studies on the registry are indexed under Breast Neoplasms; 3,319 are open to participants now.
This study's planned enrollment of 4,300 is above the median of 72 across 10,896 interventional studies indexed under Breast Neoplasms.
Browse Breast Neoplasms studies →AstraZeneca is the lead sponsor of 3,499 studies on the registry; 270 are open to participants now.
Of its 368 completed or terminated interventional studies of FDA-regulated products, 178 (48%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The diagnosis was confirmed by looking at a sample under a microscope: tissue from a biopsy or surgery (histology), or cells from a fluid or needle sample (cytology).
Your pathology report is the document that shows this.
HER2 is a protein, made from the ERBB2 gene, that drives the growth of some cancers. A study may look for a level of the protein, extra copies of the gene, or a particular change in it.
In breast cancer, protein tests are read as HER2-positive, HER2-low or HER2-negative; other cancers use their own rules. Check which test result the study requires.
Neoadjuvant treatment is given before the main treatment (usually surgery), often to shrink a tumour. Adjuvant treatment is given after it, to lower the chance of the cancer coming back.
A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.
Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
The share of blood the heart’s main pumping chamber (the left ventricle) pushes out with each beat, measured by an echocardiogram (heart ultrasound) or a MUGA scan. About 50–70% is normal.
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
On an ECG, the QT interval is the time the heart’s lower chambers take to activate electrically and recover in each beat. QTc is that time adjusted for heart rate (QTcF by Fridericia’s formula, QTcB by Bazett’s). Some medicines lengthen it, and a long QTc can raise the risk of a dangerous heart rhythm.
The study may name a correction formula and a limit in milliseconds, often around 450–480.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.
Histologically or cytologically confirmed
The diagnosis was confirmed by looking at a sample under a microscope: tissue from a biopsy or surgery (histology), or cells from a fluid or needle sample (cytology).
Your pathology report is the document that shows this.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HER2
HER2 is a protein, made from the ERBB2 gene, that drives the growth of some cancers. A study may look for a level of the protein, extra copies of the gene, or a particular change in it.
In breast cancer, protein tests are read as HER2-positive, HER2-low or HER2-negative; other cancers use their own rules. Check which test result the study requires.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Adjuvant and neoadjuvant
Neoadjuvant treatment is given before the main treatment (usually surgery), often to shrink a tumour. Adjuvant treatment is given after it, to lower the chance of the cancer coming back.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ECOG performance status
A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.
Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Metastases
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
LVEF (left ventricular ejection fraction)
The share of blood the heart’s main pumping chamber (the left ventricle) pushes out with each beat, measured by an echocardiogram (heart ultrasound) or a MUGA scan. About 50–70% is normal.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
NYHA class (heart failure)
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
QT and QTc
On an ECG, the QT interval is the time the heart’s lower chambers take to activate electrically and recover in each beat. QTc is that time adjusted for heart rate (QTcF by Fridericia’s formula, QTcB by Bazett’s). Some medicines lengthen it, and a long QTc can raise the risk of a dangerous heart rhythm.
The study may name a correction formula and a limit in milliseconds, often around 450–480.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Excipients
The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Continue standard endocrine therapy of investigator's choice (aromatase inhibitors \[AI; exemestane, letrozole, anastrozole\] or tamoxifen)
Drug: Tamoxifen · Drug: Anastrozole · Drug: Letrozole · Drug: Exemestane
Camizestrant
Drug: Camizestrant
Camizestrant. Experimental. Administered orally
Also known as: AZD9833
Tamoxifen. Comparator. Administered per local approved label
Anastrozole. Comparator. Administered per local approved label
Letrozole. Comparator. Administered per local approved label
Exemestane. Comparator. Administered per local approved label
Invasive breast cancer-free survival (IBCFS)
IBCFS is defined as time from randomisation until date of first occurrence of: * Invasive ipsilateral breast tumour recurrence (invasive IBTR) * Locoregional invasive breast cancer recurrence * Distant recurrence * Invasive contralateral breast cancer * Death attributable to any cause.
Time frame: Up to 10 years
Invasive disease-free survival (IDFS)
IDFS is defined as time from randomisation until date of first occurrence of one of the following events: * Invasive ipsilateral breast tumor recurrence (invasive IBTR) * Locoregional invasive breast cancer recurrence * Distant recurrence * Invasive contralateral breast cancer * Second primary non-breast invasive cancer * Death attributable to any cause.
Time frame: Up to 10 years
Distant relapse-free survival (DRFS)
DRFS is defined as time from randomisation until date of first distant recurrence or death from any cause, whichever occurs first.
Time frame: Up to 10 years
Overall survival (OS)
OS is defined as time from randomisation until death from any cause.
Time frame: Up to 10 years
Incidence and Severity of Adverse Events, with Severity Determined According to National Cancer Institute Common Terminology Criteria for Adverse Events, version 5.0 (NCI-CTCAE v5.0)
Time frame: Until 28 days after the final dose of study treatment (up to 5 years)
Absolute and percent change from baseline in Clinical Laboratory Parameters
Time frame: Until 28 days after the final dose of study treatment (up to 5 years)
Absolute and percent change from baseline in Vital Sign Parameters
Time frame: Until 28 days after the final dose of study treatment (up to 5 years)
Change from baseline of arthralgia as measured by the EORTC-IL-194 (European Organisation for Research and Treatment of Cancer) item 10. EORTC-IL-194 uses 0 - 4 scale (higher score is worse)
Time frame: Until 28 days after the final dose of study treatment (up to 5 years)
Change from baseline of hot flush as measured by the EORTC-IL-194 item 4. EORTC-IL-194 uses 0 - 4 scale (higher score is worse)
Time frame: Until 28 days after the final dose of study treatment (up to 5 years)
Change from baseline of vaginal dryness as measured by the EORTC-IL-194 item 15. EORTC-IL-194 uses 0 - 4 scale (higher score is worse)
Time frame: Until 28 days after the final dose of study treatment (up to 5 years)
Proportion of patients experiencing each level of symptomatic AEs of arthralgia as measured by the EORTC-IL-194 item 10. EORTC-IL-194 uses 0 - 4 scale (higher score is worse)
Time frame: Until 28 days after the final dose of study treatment (up to 5 years)
Proportion of patients experiencing each level of symptomatic AEs of hot flush as measured by the EORTC-IL-194 item 4. EORTC-IL-194 uses 0 - 4 scale (higher score is worse)
Time frame: Until 28 days after the final dose of study treatment (up to 5 years)
Proportion of patients experiencing each level of symptomatic AEs of vaginal dryness as measured by the EORTC-IL-194 item 15. EORTC-IL-194 uses 0 - 4 scale (higher score is worse)
Time frame: Until 28 days after the final dose of study treatment (up to 5 years)
Change from baseline and TTD (time to deterioration ) of health-related QoL (quality of life) as measured by the 2 global QoL items from the EORTC-QLQ-C30 items 11 and 12. EORTC-QLQ-C30 uses 0 - 4 scale (higher score is worse)
Time frame: Until 28 days after the final dose of study treatment (up to 5 years)
Pharmacokinetics (PK)
• Plasma concentrations of camizestrant pre-dose (Ctrough)( trough concentration)
Time frame: Until 6 months from treatment start
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Showing the first 100 of 709 sites across 39 countries. Choose a country and city above to see the rest.
Plan to share: 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 Yes, indicates that AZ are accepting requests for IPD, but this does not mean all requests will be shared.
Supporting information: Study protocol, Statistical analysis plan
Time frame: AstraZeneca will meet or exceed data availability as per the commitments made to the EFPIA Pharma Data Sharing Principles. For details of our timelines, please rerefer to our disclosure commitment at https://astrazenecagrouptrials.pharmacm.com/ST/Submission/Disclosure.
Access criteria: When a request has been approved AstraZeneca will provide access to the deidentified individual patient-level data in an approved sponsored tool . Signed Data Sharing Agreement (non-negotiable contract for data accessors) must be in place before accessing requested information. Additionally, all users will need to accept the terms and conditions of the SAS MSE to gain access. For additional details, please review the Disclosure Statements at https://astrazenecagrouptrials.pharmacm.com/ST/Submission/Disclosure
Data sharing details ↗ · astrazenecagroup-dt.pharmacm.com
Started Mar 2023 (actual). Primary completion is estimated for Apr 2027, 48 months after the start.
Of 272 industry-sponsored phase 3 interventional studies under Breast Neoplasms, half reached primary completion within 40 months of starting (the median), counting those still running; a quarter within 28 and three quarters within 63. This study's planned 48 months is above that.
Counting every sponsor, half of 600 studies reached it within 59 months; a quarter within 36 and three quarters within 96.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
Contact study teamGet an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Studies of the drug tested here: AZD9833