A Comparative Study of AZD9833 Plus Palbociclib Versus Anastrozole Plus Palbociclib in Patients With ER-Positive HER2 Negative Breast Cancer Who Have Not Received Any Systemic Treatment for Advanced Disease (SERENA-4)
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ClinicalTrials.gov Identifier: NCT04711252 |
Recruitment Status :
Recruiting
First Posted : January 15, 2021
Last Update Posted : April 28, 2023
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The study is intended to show superiority of AZD9833 in combination with palbociclib (a CDK4/6 inhibitor) versus anastrozole (an aromatase inhibitor) and palbociclib as the initial treatment of patients with hormone receptor-positive (ER-positive), human epidermal growth factor 2-negative (HER2-negative) advanced/metastatic breast cancer.
INFORMATION FOR TRIAL PARTICIPANTS
In this trial, the researchers will look at how well camizestrant with palbociclib works, compared with anastrozole with palbociclib, in participants with breast cancer that has either spread into other parts of the body at the time of diagnosis, or has come back after at least 2 years of standard endocrine treatment.
Participants in this trial will have breast cancer that has ER proteins but does not have overexpression of HER2 protein.
Condition or disease | Intervention/treatment | Phase |
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ER-Positive HER2-Negative Breast Cancer | Drug: AZD9833 Drug: Anastrozole Drug: Anastrozole placebo Drug: AZD9833 placebo Drug: Palbociclib Drug: Luteinizing hormone-releasing hormone (LHRH) agonist | Phase 3 |

Study Type : | Interventional (Clinical Trial) |
Estimated Enrollment : | 1342 participants |
Allocation: | Randomized |
Intervention Model: | Parallel Assignment |
Masking: | Triple (Participant, Care Provider, Investigator) |
Primary Purpose: | Treatment |
Official Title: | SERENA-4: A Randomised, Multicentre, Double-Blind, Phase III Study of AZD9833 (an Oral SERD) Plus Palbociclib Versus Anastrozole Plus Palbociclib for the Treatment of Patients With Estrogen Receptor-Positive, HER2-Negative Advanced Breast Cancer Who Have Not Received Any Systemic Treatment for Advanced Disease |
Actual Study Start Date : | January 28, 2021 |
Estimated Primary Completion Date : | August 24, 2026 |
Estimated Study Completion Date : | February 1, 2029 |

Arm | Intervention/treatment |
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Experimental: AZD9833 + palbociclib
The patients will receive AZD9833 (75 mg, PO, once daily) + palbociclib (PO, once daily, 125 mg for 21 consecutive days followed by 7 days off treatment) + anastrozole placebo (1 mg, PO, once daily)
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Drug: AZD9833
Dosage formulation: AZD9833 tablets will be administered orally Drug: Anastrozole placebo Dosage formulation: anastrozole placebo tablets will be administrated orally. Drug: Palbociclib Dosage formulation: palbociclib tablets/capsules will be administered orally Drug: Luteinizing hormone-releasing hormone (LHRH) agonist Men (when medically applicable) and pre- or peri-menopausal women are required to receive a monthly LHRH agonist. |
Active Comparator: Anastrozole + palbociclib
The patients will recieve Anastrozole (1 mg, PO, once daily) + palbociclib (PO, once daily, 125 mg for 21 consecutive days followed by 7 days off treatment) + AZD9833 placebo (PO, once daily)
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Drug: Anastrozole
Dosage formulation: Anastrozole tablets will be administered orally. Drug: AZD9833 placebo Dosage formulation: AZD9833 placebo tablets will be administrated orally. Drug: Palbociclib Dosage formulation: palbociclib tablets/capsules will be administered orally Drug: Luteinizing hormone-releasing hormone (LHRH) agonist Men (when medically applicable) and pre- or peri-menopausal women are required to receive a monthly LHRH agonist. |
- Progression-free survival (PFS) assessed by the Investigator as defined by response evaluation criteria in solid tumors (RECIST) version 1.1 [ Time Frame: From randomization until progression per RECIST 1.1 as assessed by the investigator at local site or death due to any cause (up to 5 years) ]PFS is defined as the time from randomization to objective disease progression (as assessed by RECIST) or death.
- Overall survival (OS) [ Time Frame: From randomization until the date of death due to any cause (up to 8 years) ]The OS is defined as the time from randomization to death due to any cause.
- Second progression-free survival (PFS2) [ Time Frame: From randomization to the earliest of the progression event (following the initial progression), subsequent to first subsequent therapy or death (up to 5 years) ]Time to second progression or death (PFS2) will be defined as the time from randomisation to the earliest of the progression event (following the initial progression), subsequent to first subsequent therapy or death.
- Objective response rate (ORR) assessed by the Investigator as defined by RECIST version 1.1 [ Time Frame: From randomization until a response or in the absence of a response from randomization up until progression, or the last evaluable assessment in the absence of progression (up to 5 years) ]ORR is defined as the proportion of patients who have a CR or partial response, as determined by the investigator at local site per RECIST 1.1.
- Duration of response (DoR) assessed by the Investigator as defined by RECIST version 1.1 [ Time Frame: From the date of first documented response until date of documented progression per RECIST 1.1 as assessed by the investigator at local site or death due to any cause (up to 5 years) ]The DoR will be defined as the time from the date of first documented response until date of documented progression or death in the absence of disease progression.
- Time to chemotherapy (TTC) [ Time Frame: From randomization until the earlier of the start date of chemotherapy or death due to any cause (up to 5 years) ]Time to chemotherapy is defined as the time from randomization until the earlier of the start date of chemotherapy or death due to any cause.
- Time to first subsequent anti-cancer therapy (TFST) [ Time Frame: From randomization until the earlier of start date of the first subsequent anti-cancer therapy after discontinuation of randomized treatment, or death due to any cause (up to 5 years) ]TFST is defined as time from randomization until the earlier of start date of the first subsequent anti-cancer therapy after discontinuation of randomized treatment, or death due to any cause.
- Clinical benefit rate at 24 weeks (CBR24) [ Time Frame: At least 23 weeks after randomisation ]CBR at 24 weeks is defined as the percentage of participants who have a complete response (CR) or partial response or who have stable disease (SD) per RECIST 1.1 as assessed by the investigator at local site for at least 23 weeks after randomization (to allow for an early assessment within the assessment window).
- Time to second subsequent therapy (TSST) [ Time Frame: From randomization until the earlier of start date of the second subsequent anti-cancer therapy after discontinuation of first subsequent treatment, or death due to any cause (up to 5 years) ]TSST is defined as time from randomization until the earlier of start date of the second subsequent anti-cancer therapy after discontinuation of first subsequent treatment, or death due to any cause.
- Plasma concentration of AZD9833 at specified timepoints [ Time Frame: on Day 15 ]To assess the steady state PK of AZD9833 in combination with palbociclib in all participants who receive at least one dose of AZD9833 per the protocol, for whom there are at least one reportable PK concentration.
- Change from baseline in EORTC QLQ-C30 scale scores [ Time Frame: From baseline to 24 weeks post progression (up to approximately 5 years) ]Change from baseline in EORTC QLQ-C30 scale scores for each patient at each post-baseline visit. The comparison will include all randomised patients, as randomised, with baseline and at least one post-baseline visit score for the scale score.
- Change from baseline in EORTC QLQ-BR45 scale scores [ Time Frame: From baseline to 24 weeks post progression (up to approximately 5 years) ]Change from baseline in EORTC QLQ-BR45 scale scores for each patient at each post-baseline visit. The comparison will include all randomised patients, as randomised, with baseline and at least one post-baseline visit score for the scale score.

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.
Ages Eligible for Study: | 18 Years to 130 Years (Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | No |
INCLUSION CRITERIA
Full list of inclusion criteria
- Pre-/peri-menopausal women or men can be enrolled if amenable to be treated with concomitant, approved LHRH agonists for the duration of the study treatment.
- De novo Stage 4 disease, or recurrence from early stage disease after at least 24 months of standard adjuvant endocrine therapy. Note that at least 12 months must have elapsed since the patient's last dose of adjuvant AI therapy without disease progression on treatment. Note that a 2-week washout period is required after the last dose of tamoxifen prior to randomisation.
- Histologically or cytologically documented diagnosis of ER+, HER2-negative breast cancer based on local laboratory results.
- Previously untreated with any systemic anti-cancer therapy for their locoregionally recurrent or metastatic ER+ disease.
- Measurable disease as defined per RECIST v.1.1 OR at least one lytic or mixed (lytic + sclerotic) bone lesion with a soft tissue component that can be assessed by CT or MRI.
- Eastern Cooperative Oncology Group performance status of 0 or 1.
- Adequate organ and marrow function.
- Willingness and ability to comply with scheduled visits, treatment plan, laboratory tests, and other study procedures.
INFORMATION FOR TRIAL PARTICIPANTS
Participants can join the trial if they:
- Have breast cancer that cannot be treated with surgery or radiation
- Have breast cancer that has already spread into other parts of the body at the time of diagnosis, or has come back after at least 2 years of a standard endocrine treatment
- Have ER proteins but not overexpression of HER2 protein in their tumors
- Have never received any type of cancer therapy that affects the whole body for advanced breast cancer
- Are able to do their daily activities
EXCLUSION CRITERIA
Full list of exclusion criteria
- Previous neoadjuvant or adjuvant treatment with an AI treatment +/- CDK4/6 inhibitor with disease recurrence while on or within 12 months of completing treatment.
- Prior exposure to AZD9833, other investigational SERDs/endocrine agents or fulvestrant.
- Participation in another clinical study with a study treatment or investigational medicinal device administered in the last 4 weeks prior to randomization or concurrent enrollment in another clinical study, unless it is an observational (non-interventional) clinical study or during the follow-up period of an interventional study.
- Advanced, symptomatic, visceral spread, that are at risk of life-threatening complications in the short term and/or impending visceral crisis
- Known active uncontrolled or symptomatic CNS metastases, carcinomatous meningitis, or leptomeningeal disease.
- Any clinically important and symptomatic heart disease .
- Currently pregnant (confirmed with positive pregnancy test) or breast-feeding.
- As judged by the investigator, any evidence of diseases (such as severe or uncontrolled systemic diseases, renal transplant and active bleeding diseases) which, in the investigator's opinion, makes it undesirable for the participant to participate in the study or that would jeopardize compliance with the protocol.
- Any concurrent anti-cancer treatment.
- Active infection including tuberculosis, HBV and HCV.
INFORMATION FOR TRIAL PARTICIPANTS
Participants cannot join the trial if they:
- Have uncontrolled cancer that has spread to the brain or the spinal cord
- Have received certain treatments for cancer in the past but the cancer came back within 1 year
- Had certain types of tumors in the past, which the study doctors think could come back
- Are currently taking any treatment for cancer or are taking medications or supplements that affect certain proteins in the body
- Have any major health problem, infection, or surgery that could make it difficult or dangerous to participate in this trial, such as tuberculosis, HIV, heart problems, or a kidney transplant
The above information is not intended to contain all considerations relevant to a patient's potential participation in a clinical trial.

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT04711252
Contact: AstraZeneca Clinical Study Information Center | 1-877-240-9479 | information.center@astrazeneca.com | |
Contact: AZ Breast Cancer Study Navigators | +1-877-400-4656 | AstraZeneca@CareboxHealth.com |

Responsible Party: | AstraZeneca |
ClinicalTrials.gov Identifier: | NCT04711252 |
Other Study ID Numbers: |
D8532C00001 2020-002276-12 ( EudraCT Number ) |
First Posted: | January 15, 2021 Key Record Dates |
Last Update Posted: | April 28, 2023 |
Last Verified: | April 2023 |
Individual Participant Data (IPD) Sharing Statement: | |
Plan to Share IPD: | Yes |
Plan Description: | Qualified researchers can request access to anonymized individual patient-level data from AstraZeneca group of companies sponsored clinical trials via the request portal. All request 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 Materials: |
Study Protocol Statistical Analysis Plan (SAP) |
Time Frame: | AstraZeneca will meet or exceed data availability as per the commitments made to the EFPIA Pharma 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 deidentified individual patient-level data in an approved sponsored tool. Signed Data Sharing Agreement (non-negotiable contract for data accessors) must be in place before accessing requested information. Additionally, all users will need to accept the terms and conditions of the SAS MSE to gain access. For additional details, please review the Disclosure Statements at https://astrazenecagrouptrials.pharmacm.com/ST/Submission/Disclosure. |
URL: | https://astrazenecagroup-dt.pharmacm.com/DT/Home |
Studies a U.S. FDA-regulated Drug Product: | Yes |
Studies a U.S. FDA-regulated Device Product: | No |
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