Study to Evaluate the Safety and Tolerability of Camizestrant in Combination With Atirmociclib in Women With Advanced Breast Cancer

NCT07427394 | Not Yet Recruiting Phase 2 FDA Drug

• 1 other identifier: D853CC00001
• Study Type: interventional
• Target: 24
• Locations: 2 countries
• Sites: 6

Brief Summary

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.

Conditions

Advanced Breast Cancer

Keywords

Estrogen receptor (ER)-positive; Human epidermal growth factor receptor 2 (HER2)-negative; Cyclin-Dependent Kinase (CDK) 4 inhibitors; Pharmacokinetics; Anti-tumor activity; Selective Estrogen Receptor Degrader (SERD); Safety; Tolerability

Outcome Measures

Primary Outcomes (1)

• Number of participants with adverse events (AEs) and serious AEs

  To investigate the safety and tolerability of camizestrant in combination with atirmociclib.

  Up to Post-Treatment Follow up (Day 30 Post Dose)

Secondary Outcomes (20)

• Maximum concentration observed (Cmax)

  At pre-defined intervals from Day -1 to Day 57

• Area under plasma concentration-time curve from time 0 to infinity (AUCinf)

  At pre-defined intervals from Day -1 to Day 57

• Area under plasma concentration-time curve from time 0 to last quantifiable concentration (AUClast)

  At pre-defined intervals from Day -1 to Day 57

• Time to reach maximum (peak) plasma concentration following drug administration (tmax)

  At pre-defined intervals from Day -1 to Day 57

• Terminal elimination rate constant (λz)

  At pre-defined intervals from Day -1 to Day 57

Study Arms (1)

Camizestrant + Atirmociclib

EXPERIMENTAL

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

Interventions

Camizestrant DRUG

Camizestrant will be administered orally.

Camizestrant + Atirmociclib

Atirmociclib DRUG

Atirmociclib will be administered orally.

Camizestrant + Atirmociclib

Eligibility Criteria

• Age: 18 Years+
• Gender Eligibility Details: Females with ER-positive HER2-negative ABC and who have experienced disease progression on a CDK4/6 inhibitor in combination with endocrine therapy.
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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.

You may not qualify if:

• 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.

Sponsors & Collaborators

• AstraZeneca: lead

Study Sites (6)

Research Site

St Louis, Missouri, 63108, United States

Location

Research Site

East Providence, Rhode Island, 02915, United States

Location

Research Site

Nashville, Tennessee, 37203, United States

Location

Research Site

Cambridge, CB2 0QQ, United Kingdom

Location

Research Site

London, EC1M6BQ, United Kingdom

Location

Research Site

Manchester, M20 4GJ, United Kingdom

Location

MeSH Terms

Interventions

AZD9833

Central Study Contacts

AstraZeneca Clinical Study Information Center

CONTACT

1-877-240-9479; information.center@astrazeneca.com

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: February 16, 2026
• First Posted: February 23, 2026
• Study Start: April 10, 2026
• Primary Completion (Estimated): December 3, 2027
• Study Completion (Estimated): December 3, 2027
• Last Updated: February 23, 2026

Record last verified: 2026-02

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP
• 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.

Locations

GB (3); US (3)