NCT07427394 · AstraZeneca
Study to Evaluate the Safety and Tolerability of Camizestrant in Combination With Atirmociclib in Women With Advanced Breast Cancer
(SERENA-1b)
What this study is about
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.
View original scientific description
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.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Participants with advanced adenocarcinoma of the breast and must have received prior adequate therapy in accordance with local practice for their tumor type and stage of disease.
- Metastatic or locoregionally recurrent disease and radiological or objective evidence of progression on or after the last systemic therapy prior to starting investigational medicinal products.
- Eastern cooperative oncology group (ECOG)/World Health Organization (WHO) performance status 0 to 1, and a minimum life expectancy of 12 weeks.
- At least one lesion that is measurable and/or non-measurable, as per RECIST 1.1 and 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.
- Menopausal status
- Pre-menopausal women must start GnRH agonist therapy at least 4 weeks before study treatment and continue throughout the study.
- Post-menopausal women must meet one of these criteria: bilateral oophorectomy, age ≥60 years, age ≥50 years with ≥12 months amenorrhea and intact uterus without hormonal therapy, or age \<60 years with ≥12 months amenorrhea and post-menopausal hormone levels.
- Histological or cytological confirmation of adenocarcinoma of the breast.
- Participants of childbearing potential must agree to use one highly effective contraceptive measure.
- Documentation of ER-positive tumor irrespective of progesterone receptor status. Main
Exclusion criteria
- A participant who has received 2 or more lines of CDK4/6 inhibitors in the advanced disease setting.
- A participant who has received prior camizestrant or atirmociclib treatment in the advanced disease setting.
- Patients previously treated with other next generation selective estrogen receptor degrader (SERDs) or other experimental ETs in the advanced disease setting.
- Patients previously treated with other experimental cyclin-dependent kinase (CDK) inhibitors are not eligible.
- Inability to swallow oral medications.
- Any unresolved toxicities of Grade ≥ 2 from prior anti-cancer therapy (with the exception of alopecia).
- Presence of life-threatening metastatic visceral disease.
- Any evidence of severe or uncontrolled systemic diseases.
- Contraindication to or known intolerance/hypersensitivity of/to camizestrant or atirmociclib.
Where
- St Louis, Missouri
- East Providence, Rhode Island
- Nashville, Tennessee
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jun 16, 2026 · Source of record for eligibility and locations