Recruiting
Phase 3

Camizestrant

Sponsor:

AstraZeneca

Code:

NCT05774951

Conditions

Breast Cancer, Early Breast Cancer

Eligibility Criteria

Sex: All

Age: 18 - 70+

Healthy Volunteers: Not accepted

Interventions

Camizestrant

Tamoxifen

Anastrozole

Letrozole

Exemestane

Study Details

Brief summary:

This is a Phase III open-label study to assess if camizestrant improves outcomes compared to standard endocrine therapy in patients with ER+/HER2 - early breast cancer with intermediate or high risk for disease recurrence who completed definitive locoregional therapy (with or without chemotherapy) and standard adjuvant endocrine therapy (ET) for at least 2 years and up to 5 years. The planned duration of treatment in either arm of the study is 60 months.

Conditions

Breast Cancer, Early Breast Cancer

Study ID

NCT05774951

Start date

Mar 31, 2023

Status verified date

Oct, 2026

Completion date

May 29, 2036

Anticipated

Primary completion date

Apr 20, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 70+

Healthy Volunteers: Not accepted

Inclusion Criteria:

  • Women and Men, ≥18 years at the time of screening (or per national guidelines)
  • Histologically confirmed ER+/HER2- early-stage resected invasive breast cancer with high or intermediate risk of recurrence, based on clinical-pathological risk features, as defined in the protocol.
  • Completed adequate (definitive) locoregional therapy (surgery with or without radiotherapy) for the primary breast tumour(s), with or without (neo)adjuvant chemotherapy
  • Completed at least 2 years but no more than 5 years (+3 months) of adjuvant ET (+/- CDK4/6 inhibitor)
  • Eastern Cooperative Oncology Group (ECOG) performance status of ≤ 1
  • Adequate organ and marrow function

Exclusion criteria:

  • Inoperable locally advanced or metastatic breast cancer
  • Pathological complete response following treatment with neoadjuvant therapy
  • History of any other cancer (except non-melanoma skin cancer or carcinoma in situ of the cervix or considered at very low risk of recurrence per investigator judgement) unless in complete remission with no therapy for a minimum of 5 years from the date of randomisation
  • Any evidence of severe or uncontrolled systemic diseases which, in the investigator's opinion precludes participation in the study or compliance
  • Known LVEF <50% with heart failure NYHA Grade ≥2.
  • Mean resting QTcF interval >480 ms at screening
  • Concurrent exogenous sex hormone therapy
  • Any concurrent anti-cancer treatment not specified in the protocol with the exception of bisphosphonates (e.g. zoledronic acid) or RANKL inhibitors (eg, denosumab)
  • Previous treatment with camizestrant, investigational SERDs/investigational ER targeting agents, or fulvestrant
  • Currently pregnant (confirmed with positive serum pregnancy test) or breastfeeding
  • Patients with known hypersensitivity to active or inactive excipients of camizestrant or drugs with a similar chemical structure or class to camizestrant. In pre-/peri-menopausal female and male patients, known hypersensitivity or intolerance to LHRH agonists, that would preclude the patient from receiving any LHRH agonist

Study Design

Enrollment

4300 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

active comparator: Arm A: standard endocrine therapy of investigator´s choice

Continue standard endocrine therapy of investigator's choice (aromatase inhibitors \[AI; exemestane, letrozole, anastrozole\] or tamoxifen)

experimental: Arm B: camizestrant

Camizestrant

Interventions

Camizestrant

Camizestrant. Experimental. Administered orally

Tamoxifen

Tamoxifen. Comparator. Administered per local approved label

Anastrozole

Anastrozole. Comparator. Administered per local approved label

Letrozole

Letrozole. Comparator. Administered per local approved label

Exemestane

Exemestane. Comparator. Administered per local approved label

Primary outcome measure

  • Invasive breast cancer-free survival (IBCFS) [ Time Frame: Up to 10 years ]

Central Contacts and Locations

Central contacts

AstraZeneca Clinical Study Information Center

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

AstraZeneca Breast Cancer Study Locator Service

1-877-400-4655az-bcsl@careboxhealth.com

Locations

Research Site

Recruiting

Winston-Salem, North Carolina, United States, 27103

Research Site

Recruiting

Aberdeen, South Dakota, United States, 57401

Research Site

Recruiting

Pierre, South Dakota, United States, 57501

Research Site

Recruiting

Irving, Texas, United States, 75063

More Information

Sponsor

AstraZeneca

Last update posted

Oct 13, 2026

Last verified

Oct, 2026

Keywords

  • ER+
  • HER2-
  • breast cancer

Trial information was received from ClinicalTrials.gov and was last updated on 2026-10-23. This information was provided to ClinicalTrials.gov by AstraZeneca on 2026-10-13. Recruitment status is synced daily from ClinicalTrials.gov and may not reflect the sponsor's current status. Confirm during your call.