A Phase 2 interventional study of Camizestrant and Atirmociclib in Advanced Breast Cancer, sponsored by AstraZeneca. Recruiting at 6 sites in 2 countries. Open to female participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-09-29.
Sponsored by AstraZeneca · Phase 2, Interventional, and Treatment
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Among 17 studies testing AZD9833 in Breast Neoplasms — 6 open to participants now, 10 under way, 7 of them phase 3. AZD9833 · Breast Neoplasms.
Among the 17 studies testing AZD9833 in Breast Neoplasms, this one is the 15th largest by planned enrollment, is one of 4 that started in 2026, is one of 3 in phase 2, and was the 15th registered.
14,832 studies on the registry are indexed under Breast Neoplasms; 3,320 are open to participants now.
Browse Breast Neoplasms studies →6 of the 17 studies testing AZD9833 in Breast Neoplasms are open now, in 12 countries. Recruiting first, the newest first:
AstraZeneca · Sites in United States, France, Germany and 6 more countries
Ages 18–130
MedSIR · Sites in Germany, Spain
Ages 18+
AstraZeneca · Sites in United States, Argentina, Australia and 26 more countries
Ages 18+
AstraZeneca · Sites in United States, Argentina, Australia and 36 more countries
Ages 18–130
UNICANCER
Ages 18+
By country, each count listing its studies:
AZD9833: first FDA approval 2026 (ETCAMAH), first EMA approval 2026. What it is approved for, and how studies give it, is on its page →
Of the 2,399 Breast Neoplasms studies recruiting now, 1,570 (65%) set no upper age limit and 592 (25%) stop at 75 or younger; 103 take children under 18; 215 take healthy volunteers.
This study: 18 Years and older · female · no healthy volunteers.
The full table on the hub →This tab as a report to print or save as PDF → With an account.
On this site’s reading of the record, AZD9833 is the treatment under test here. Read study by study →
17 studies; the count open now beside each. This study's row is marked.
First in 2018; this study’s year is marked. 4 started in 2026.
By drug class, each counting the studies that test any of its medicines:
This study's planned enrollment of 24 is below the median of 72 across 10,903 interventional studies indexed under Breast Neoplasms.
Median enrollment 150 across the 17 interventional studies. Of the 7 that completed or were terminated, 1 (14%) have results posted.
This tab as a report to print or save as PDF → With an account.
15 of 17 have an industry lead sponsor. The 3 most frequent:
AstraZeneca is the lead sponsor of 3,503 studies on the registry; 273 are open to participants now.
Of its 369 completed or terminated interventional studies of FDA-regulated products, 178 (48%) have results posted.
198 studies in Breast Neoplasms by AstraZeneca: 20 open now, 50 under way, 24 of them phase 3. Of 144 finished, 32 (22%) have results posted.
Among the 198 studies in Breast Neoplasms by AstraZeneca, this one is the 110th largest by planned enrollment of the 125 interventional ones that give a count, is one of 7 that started in 2026, is one of 31 in phase 2, reaches primary completion later than 35 of the 49 other live ones, and was the 192nd registered.
AstraZeneca’s Breast Neoplasms studies by the year they started, since 1996.
1 of the studies testing AZD9833 in Breast Neoplasms that are under way reach primary completion within a year, 1 of them phase 3. Phase 3 first, then by date:
| Study | Primary completion |
|---|---|
| NCT05774951Phase 3AstraZenecaA Study of Camizestrant in ER+/HER2- Early Breast Cancer After at Least 2 Years of Standard Adjuvant Endocrine Therapy | 2027-04-20 |
Add it to your calendar (.ics) → With an account.
Among the 17 studies testing AZD9833 in Breast Neoplasms, from their registry updates:
Among AstraZeneca’s 198 in Breast Neoplasms:
This tab as a report to print or save as PDF → With an account.
A study to investigate camizestrant in combination with atirmociclib in participants with estrogen receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced breast cancer previously treated with a cyclin dependent kinase 4/6 (CDK4/6) inhibitor.
This is a Phase IIa, sequential assignment, non- randomized, open-label treatment study to determine the safety, tolerability, pharmacokinetics (PK) and preliminary anti-tumor activity of camizestrant in combination with atirmociclib.
The single-arm study includes:
Main Inclusion Criteria:
Menopausal status
Main 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.
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
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.
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.
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
The standard rules for measuring tumours on CT or MRI scans, to tell whether a cancer is shrinking, stable or growing during treatment.
“Measurable disease per RECIST 1.1” usually means at least one tumour 10 mm or more at its longest on a CT scan, or a lymph node 15 mm or more across its short axis.
Periods have stopped for good: usually no period for 12 months in a row without another medical reason, sometimes confirmed by a blood test (FSH).
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
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.
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.
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.
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.
Life expectancy
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
RECIST
The standard rules for measuring tumours on CT or MRI scans, to tell whether a cancer is shrinking, stable or growing during treatment.
“Measurable disease per RECIST 1.1” usually means at least one tumour 10 mm or more at its longest on a CT scan, or a lymph node 15 mm or more across its short axis.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Postmenopausal
Periods have stopped for good: usually no period for 12 months in a row without another medical reason, sometimes confirmed by a blood test (FSH).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
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.
Participants will receive a single dose of atirmociclib on Day -1 followed by combination of camizestrant and atirmociclib from Day 1.
Drug: Camizestrant · Drug: Atirmociclib
Camizestrant will be administered orally.
Atirmociclib will be administered orally.
Number of participants with adverse events (AEs) and serious AEs
To investigate the safety and tolerability of camizestrant in combination with atirmociclib.
Time frame: Up to Post-Treatment Follow up (Day 30 Post Dose)
Maximum concentration observed (Cmax)
To characterize the PK profile and parameters of atirmociclib.
Time frame: At pre-defined intervals from Day -1 to Day 57
Area under plasma concentration-time curve from time 0 to infinity (AUCinf)
To characterize the PK profile and parameters of atirmociclib.
Time frame: At pre-defined intervals from Day -1 to Day 57
Area under plasma concentration-time curve from time 0 to last quantifiable concentration (AUClast)
To characterize the PK profile and parameters of atirmociclib.
Time frame: At pre-defined intervals from Day -1 to Day 57
Time to reach maximum (peak) plasma concentration following drug administration (tmax)
To characterize the PK profile and parameters of atirmociclib.
Time frame: At pre-defined intervals from Day -1 to Day 57
Terminal elimination rate constant (λz)
To characterize the PK profile and parameters of atirmociclib.
Time frame: At pre-defined intervals from Day -1 to Day 57
Terminal elimination half-life (t½λz)
To characterize the PK profile and parameters of atirmociclib.
Time frame: At pre-defined intervals from Day -1 to Day 57
Apparent total body clearance (CL/F)
To characterize the PK profile and parameters of atirmociclib.
Time frame: At pre-defined intervals from Day -1 to Day 57
Apparent volume of distribution at steady state (Vss/F)
To characterize the PK profile and parameters of atirmociclib.
Time frame: At pre-defined intervals from Day -1 to Day 57
Apparent volume of distribution based on the terminal phase (Vz/F)
To characterize the PK profile and parameters of atirmociclib.
Time frame: At pre-defined intervals from Day -1 to Day 57
Maximum concentration observed at steady state (Cssmax)
To characterise the PK profile and parameters of atirmociclib and camizestrant after administration in combination with each other.
Time frame: At pre-defined intervals from Day -1 to Day 57
Area under the curve from 0 to the end of dosing interval (AUC0-tau)
To characterise the PK profile and parameters of atirmociclib and camizestrant after administration in combination with each other.
Time frame: At pre-defined intervals from Day -1 to Day 57
Area under the curve from 0 to the end of dosing interval at steady state (AUCss0-tau)
To characterise the PK profile and parameters of atirmociclib and camizestrant after administration in combination with each other.
Time frame: At pre-defined intervals from Day -1 to Day 57
Time to reach maximum plasma concentration at steady state (tssmax)
To characterise the PK profile and parameters of atirmociclib and camizestrant after administration in combination with each other.
Time frame: At pre-defined intervals from Day -1 to Day 57
Objective Response Rate (ORR)
To assess the preliminary anti-tumor activity and efficacy of camizestrant in combination with atirmociclib.
Time frame: Up to 2 years
Duration of Response (DOR)
To assess the preliminary anti-tumor activity and efficacy of camizestrant in combination with atirmociclib.
Time frame: Up to 2 years
Clinical Benefit Rate at 24 Weeks (CBR24)
To assess the preliminary anti-tumor activity and efficacy of camizestrant in combination with atirmociclib.
Time frame: At 24 weeks
Percentage change in tumor size
To assess the preliminary anti-tumor activity and efficacy of camizestrant in combination with atirmociclib.
Time frame: Up to 2 years
Progression Free Survival (PFS)
To assess the preliminary anti-tumor activity and efficacy of camizestrant in combination with atirmociclib.
Time frame: Up to 2 years
Progression-free survival landmark 6 months (PFSLM6m)
To assess the preliminary anti-tumor activity and efficacy of camizestrant in combination with atirmociclib.
Time frame: At 6 months
Progression-free survival landmark 12 months (PFSLM12m)
To assess the preliminary anti-tumor activity and efficacy of camizestrant in combination with atirmociclib.
Time frame: At 12 months
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 Vivli.org. All requests 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 PhRMA 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 anonymized individual patient-level data via secure research environment Vivli.org. Signed Data Usage Agreement (non-negotiable contract for data accessors) must be in place before accessing requested information.
Data sharing details ↗ · vivli.org
No publications or documents are linked to this record.
Started May 2026 (actual). Primary completion is estimated for Dec 2027, 19 months after the start.
Of 232 industry-sponsored phase 2 interventional studies under Breast Neoplasms, half reached primary completion within 34 months of starting (the median), counting those still running; a quarter within 22 and three quarters within 53. This study's planned 19 months is below that.
Counting every sponsor, half of 1,302 studies reached it within 51 months; a quarter within 30 and three quarters within 82.
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.
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Studies of the drugs tested here: AZD9833 · Atirmociclib