CClinicalTrials.gg
Sign In
RecruitingNCT07427394SERENA-1bUpdated Sep 29, 2026

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

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

Phase
Phase 2
Study type
Interventional
Enrollment
24
Allocation
Not applicable
Ages
18 Years and older
Sex
Female
01

Study 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.

Read the 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
02

Conditions studied

  • 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
03

Who can participate

Ages eligible
18 Years and older
Sexes eligible
Female
Accepts healthy volunteers
No

Eligibility 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.
04

Study design

Phase
Phase 2
Primary purpose
Treatment
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrollment
24 participants (estimated)

Study arms

  • Experimental
    Camizestrant + Atirmociclib

    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

  • DrugCamizestrant

    Camizestrant will be administered orally.

  • DrugAtirmociclib

    Atirmociclib will be administered orally.

05

What researchers measure

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.

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

Secondary outcomes

  1. 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

  2. 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

  3. 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

  4. 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

  5. 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

  6. 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

  7. 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

  8. 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

  9. 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

  10. 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

  11. 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

  12. 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

  13. 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

  14. 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

  15. 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

  16. 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

  17. 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

  18. 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

  19. 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

  20. 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

06

Study locations

6 of 6 sites recruiting
  • Research Site
    St Louis, Missouri 63108, United States
    Recruiting
  • Research Site
    East Providence, Rhode Island 02915, United States
    Recruiting
  • Research Site
    Nashville, Tennessee 37203, United States
    Recruiting
  • Research Site
    Cambridge, CB2 0QQ, United Kingdom
    Recruiting
  • Research Site
    London, EC1M6BQ, United Kingdom
    Recruiting
  • Research Site
    Manchester, M20 4GJ, United Kingdom
    Recruiting
07

References and documents

Individual participant data

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, Sap

No publications or documents are linked to this record.

08

Registry details

Key details

Study ID
NCT07427394
Lead sponsor
AstraZeneca
Responsible party
Sponsor
First posted
Feb 23, 2026
Start date
May 6, 2026
Primary completion
Dec 28, 2027 (estimated)
Completion
Dec 28, 2027 (estimated)
Last update
Sep 29, 2026

Study contacts

AstraZeneca Clinical Study Information Center
Contact
information.center@astrazeneca.com
1-877-240-9479

Oversight

Data monitoring committee
No
FDA-regulated drug
Yes
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

Interested in this study?

Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.

Contact study team

Follow this study

Get an email when the registry record changes — status, dates, results — or when someone posts here.

Sign in to follow

Discussion

Questions 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.

Other studies from this sponsor

AstraZeneca

Start the discussion