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

A Phase IIa, Open-label Study to Evaluate the Safety, Pharmacokinetics and Preliminary Efficacy of Camizestrant in Combination With Atirmociclib in Participants With ER-positive, HER2-negative Advanced Breast Cancer (SERENA-1b)

Status
Recruiting
Phases
Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT07427394
Acronym
SERENA-1b
Enrollment
24
Registered
2026-02-23
Start date
2026-05-06
Completion date
2027-12-28
Last updated
2026-09-03

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

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

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.

Detailed description

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: * Screening period * Atirmociclib single dose period * Doublet intervention period * Post-treatment follow-up period

Interventions

DRUGCamizestrant

Camizestrant will be administered orally.

Atirmociclib will be administered orally.

Sponsors

AstraZeneca
Lead SponsorINDUSTRY

Study design

Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE

Eligibility

Sex/Gender
FEMALE
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

Main 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.

Design outcomes

Primary

MeasureTime frameDescription
Number of participants with adverse events (AEs) and serious AEsUp to Post-Treatment Follow up (Day 30 Post Dose)To investigate the safety and tolerability of camizestrant in combination with atirmociclib.

Secondary

MeasureTime frameDescription
Area under the curve from 0 to the end of dosing interval at steady state (AUCss0-tau)At pre-defined intervals from Day -1 to Day 57To characterise the PK profile and parameters of atirmociclib and camizestrant after administration in combination with each other.
Time to reach maximum plasma concentration at steady state (tssmax)At pre-defined intervals from Day -1 to Day 57To characterise the PK profile and parameters of atirmociclib and camizestrant after administration in combination with each other.
Objective Response Rate (ORR)Up to 2 yearsTo assess the preliminary anti-tumor activity and efficacy of camizestrant in combination with atirmociclib.
Duration of Response (DOR)Up to 2 yearsTo assess the preliminary anti-tumor activity and efficacy of camizestrant in combination with atirmociclib.
Clinical Benefit Rate at 24 Weeks (CBR24)At 24 weeksTo assess the preliminary anti-tumor activity and efficacy of camizestrant in combination with atirmociclib.
Percentage change in tumor sizeUp to 2 yearsTo assess the preliminary anti-tumor activity and efficacy of camizestrant in combination with atirmociclib.
Progression Free Survival (PFS)Up to 2 yearsTo assess the preliminary anti-tumor activity and efficacy of camizestrant in combination with atirmociclib.
Progression-free survival landmark 6 months (PFSLM6m)At 6 monthsTo assess the preliminary anti-tumor activity and efficacy of camizestrant in combination with atirmociclib.
Progression-free survival landmark 12 months (PFSLM12m)At 12 monthsTo assess the preliminary anti-tumor activity and efficacy of camizestrant in combination with atirmociclib.
Apparent volume of distribution based on the terminal phase (Vz/F)At pre-defined intervals from Day -1 to Day 57To characterize the PK profile and parameters of atirmociclib.
Maximum concentration observed at steady state (Cssmax)At pre-defined intervals from Day -1 to Day 57To characterise the PK profile and parameters of atirmociclib and camizestrant after administration in combination with each other.
Time to reach maximum (peak) plasma concentration following drug administration (tmax)At pre-defined intervals from Day -1 to Day 57To characterize the PK profile and parameters of atirmociclib.
Terminal elimination rate constant (λz)At pre-defined intervals from Day -1 to Day 57To characterize the PK profile and parameters of atirmociclib.
Terminal elimination half-life (t½λz)At pre-defined intervals from Day -1 to Day 57To characterize the PK profile and parameters of atirmociclib.
Apparent total body clearance (CL/F)At pre-defined intervals from Day -1 to Day 57To characterize the PK profile and parameters of atirmociclib.
Apparent volume of distribution at steady state (Vss/F)At pre-defined intervals from Day -1 to Day 57To characterize the PK profile and parameters of atirmociclib.
Maximum concentration observed (Cmax)At pre-defined intervals from Day -1 to Day 57To characterize the PK profile and parameters of atirmociclib.
Area under plasma concentration-time curve from time 0 to infinity (AUCinf)At pre-defined intervals from Day -1 to Day 57To characterize the PK profile and parameters of atirmociclib.
Area under the curve from 0 to the end of dosing interval (AUC0-tau)At pre-defined intervals from Day -1 to Day 57To characterise the PK profile and parameters of atirmociclib and camizestrant after administration in combination with each other.
Area under plasma concentration-time curve from time 0 to last quantifiable concentration (AUClast)At pre-defined intervals from Day -1 to Day 57To characterize the PK profile and parameters of atirmociclib.

Countries

United Kingdom, United States

Contacts

CONTACTAstraZeneca Clinical Study Information Center
information.center@astrazeneca.com1-877-240-9479

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Sep 4, 2026