A Phase IIIb Study to Evaluate Camizestrant Plus Ribociclib in ER-positive, HER2-negative Advanced Breast Cancer (SERAFA-1)

June 9, 2026 updated by: AstraZeneca

SERAFA-1: A Single Arm, Open Label, Multicentre, Phase IIIb Study Of Camizestrant Plus Ribociclib in 1st Line Treatment of ER Positive, HER2-negative Advanced Breast Cancer Patients

The purpose of this study is to investigate the efficacy, safety, and tolerability of camizestrant in combination with ribociclib in patients with ER+ HER2- BC who have not received any other systemic treatment for advanced disease. Participants will be treated within the trial until they discontinue the study treatment for any reason.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

This global, multicenter, Phase IIIb, single-arm study will evaluate the efficacy, safety, and tolerability of camizestrant combined with ribociclib in patients with ER+ HER2- advanced breast cancer who have not previously received systemic therapy for advanced disease.

Approximately 150 participants will be enrolled, and all enrolled participants will receive standard daily oral doses of camizestrant 75 mg and ribociclib 600 mg until treatment discontinuation.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
150

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 3

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • France
      • Angers, France, 49933
        • Research Site
      • Bayonne, France, 64109
        • Research Site
      • Bobigny, France, 93000
        • Research Site
      • Caen, France, 14000
        • Research Site
      • Chambray-lès-Tours, France, 37170
        • Research Site
      • Grenoble, France, 38043
        • Research Site
      • Montpellier, France, 34070
        • Research Site
      • Nancy, France, 54100
        • Research Site
      • Nîmes, France, 30029
        • Research Site
      • Pierre-Bénite, France, 69310
        • Research Site
      • Valenciennes, France, 59300
        • Research Site
      • Vandœuvre-lès-Nancy, France, 54519
        • Research Site
      • Villejuif, France, 94805
        • Research Site
  • Germany
      • Berlin, Germany, 13125
        • Research Site
      • Düsseldorf, Germany, 40235
        • Research Site
      • Freiburg im Breisgau, Germany, 79110
        • Research Site
      • Mönchengladbach, Germany, 41061
        • Research Site
      • München, Germany, 81675
        • Research Site
      • Paderborn, Germany, 33098
        • Research Site
      • Trier, Germany, 54290
        • Research Site
      • Velbert, Germany, 42551
        • Research Site
  • Italy
      • Aviano, Italy, 33081
        • Research Site
      • Bergamo, Italy, 24127
        • Research Site
      • Genova, Italy, 16132
        • Research Site
      • Milan, Italy, 20127
        • Research Site
      • Naples, Italy, 80131
        • Research Site
  • Poland
      • Gdansk, Poland, 80-952
        • Research Site
      • Konin, Poland, 62-500
        • Research Site
      • Krakow, Poland, 30-688
        • Research Site
      • Lodz, Poland, 90-302
        • Research Site
      • Lublin, Poland, 20-090
        • Research Site
      • Poznan, Poland, 61-485
        • Research Site
      • Przemyśl, Poland, 37-700
        • Research Site
      • Wroclaw, Poland, 53-413
        • Research Site
  • South Korea
      • Cheonan-si, South Korea, 31151
        • Research Site
      • Daegu, South Korea, 42415
        • Research Site
      • Goyang-si, South Korea, 10408
        • Research Site
      • Hwasun-eup, South Korea, 58128
        • Research Site
      • Incheon, South Korea, 405-760
        • Research Site
      • Seongbuk-Gu, South Korea, 02841
        • Research Site
      • Seongnam-si, South Korea, 13620
        • Research Site
      • Seongnam-si, South Korea, 13520
        • Research Site
      • Seoul, South Korea, 03080
        • Research Site
      • Seoul, South Korea, 06273
        • Research Site
      • Seoul, South Korea, 06351
        • Research Site
      • Seoul, South Korea, 06591
        • Research Site
      • Seoul, South Korea, 3722
        • Research Site
      • Seoul, South Korea, 07985
        • Research Site
      • Songpa-gu, South Korea, 05505
        • Research Site
      • Suwon, South Korea, 16499
        • Research Site
  • Spain
      • Badajoz, Spain, 06080
        • Research Site
      • Badalona, Spain, 08916
        • Research Site
      • Barcelona, Spain, 08041
        • Research Site
      • Donostia / San Sebastian, Spain, 20014
        • Research Site
      • Huelva, Spain, 21005
        • Research Site
      • Jaén, Spain, 23007
        • Research Site
      • Las Palmas de Gran Canaria, Spain, 35016
        • Research Site
      • Majadahonda, Spain, 28222
        • Research Site
      • Murcia, Spain, 30008
        • Research Site
      • Málaga, Spain, 29010
        • Research Site
      • Pontevedra, Spain, 36312
        • Research Site
      • Pozuelo de Alarcón, Spain, 28223
        • Research Site
      • Santander, Spain, 39008
        • Research Site
      • Toledo, Spain, 45007
        • Research Site
      • Zaragoza, Spain, 50009
        • Research Site
  • Switzerland
      • Basel, Switzerland, 4031
        • Research Site
      • Liestal, Switzerland, CH-4410
        • Research Site
      • Rennaz, Switzerland, 1847
        • Research Site
  • United States
    • California
      • Duarte, California, United States, 91010
        • Research Site
      • Palo Alto, California, United States, 94304
        • Research Site
    • Georgia
      • Marietta, Georgia, United States, 30060
        • Research Site
    • Illinois
      • Evanston, Illinois, United States, 60201
        • Research Site
    • Kentucky
      • Edgewood, Kentucky, United States, 41017
        • Research Site
      • Louisville, Kentucky, United States, 40202
        • Research Site
    • Nevada
      • Reno, Nevada, United States, 89502
        • Research Site
    • South Dakota
      • Sioux Falls, South Dakota, United States, 57105
        • Research Site
    • Tennessee
      • Nashville, Tennessee, United States, 37204
        • Research Site
    • Texas
      • Fort Worth, Texas, United States, 76104
        • Research Site
      • Kingwood, Texas, United States, 77339
        • Research Site
    • Virginia
      • Midlothian, Virginia, United States, 23114
        • Research Site

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Capable of giving signed informed consent.

  2. Female or male, must be ≥ 18 years or as per locally allowed age limit for screening.

    Type of Participant and Disease Characteristics

  3. Histologically or cytologically documented diagnosis of ER+, HER2- BC based on local laboratory results and who are not amenable to resection or radiation therapy with curative intent.
  4. Previously untreated with any systemic anti-cancer therapy for their locoregionally recurrent or metastatic ER+ disease.
  5. De novo Stage 4 disease, or recurrence from early CD stage breast cancer after having received 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.
  6. ECOG performance status of 0 or 1.
  7. Adequate organ and marrow function. Sex and Contraceptive/Barrier Requirements
  8. For those female or male patients who are not abstinent (in line with their preferred and usual lifestyle choice), and intend to be heterosexually active with a partner:

Female patients must be using highly effective contraceptive measures from the time of screening until 4 weeks after discontinuation of study treatment, and must have a negative serum pregnancy test before first dose of any study treatment if they are of childbearing potential; or must have evidence of nonchild-bearing potential by fulfilling one of the following criteria at screening:

(a) Post-menopausal, defined as women with cessation of regular menses for at least 12 consecutive months with no alternative pathological or physiological cause: (i) Age ≥ 60 years (ii) Age < 60 years with serum estradiol and FSH level within the laboratory's reference range for post-menopausal females (iii) Previous bilateral surgical oophorectomy (iv) Medically confirmed ovarian failure OR (b) Pre/peri-menopausal, ie, not meeting the criteria for being post-menopausal.

(i) Pre-/peri-menopausal women can be enrolled if amenable to be treated with monthly LHRH agonists (goserelin or leuprorelin [also known as leuprolide]). Patients must have concomitant treatment with LHRH agonists (goserelin or leuprorelin [leuprolide]) before or on the same day as the first dose of study treatment - and must be willing to continue on it for the duration of the study.

Non sterilised male partners of a patient who is a woman of childbearing potential must use a male condom plus spermicide (condom alone in countries where spermicides are not approved) throughout this period.

Male participants who intend to be sexually active with a female partner of childbearing potential must be surgically sterile or using an acceptable method of contraception from the time of screening throughout the total duration of the programme and the drug washout period to prevent pregnancy in a partner. Male participants must not donate or bank sperm during this same time period.

Male patients can be enrolled if amenable to be treated with monthly LHRH agonists (goserelin or leuprorelin [also known as leuprolide]) unless the patients have clear orchiectomy medical history. Willingness to use 2 non-hormonal based methods of contraception throughout the study.

Exclusion Criteria:

  1. Participants who are not clinically indicated for endocrine therapy in combination with the CDK4/6 inhibitor ribociclib.
  2. No evidence of advanced inoperable disease, or bone only disease with sclerotic/osteoblastic bone lesions only per standard of care imaging.
  3. Have advanced, symptomatic, visceral spread, that are at risk of life-threatening complications in the short term, and/or pulmonary lymphangitis.
  4. Persistent treatment-induced non-haematological toxicities (CTCAE Grade > 2).
  5. Known active infection including tuberculosis HBV and HCV.
  6. Known to have tested positive for HIV. Participants with HIV may be enrolled if they fulfil the criteria recommended by FDA and ASCO guidelines.
  7. Any clinically important abnormalities in heart conduction patterns; participants with pacemakers or medically controlled atrial fibrillation are not excluded.
  8. Ongoing symptomatic hypotension.
  9. Pregnant or lactating women or patients not willing to use highly effective contraception as defined in the protocol.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Non-Randomized
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Camizestrant and Ribociclib
Patients will receive the standard dose of camizestrant and ribociclib once daily as oral tablets
Drug: Camizestrant
Patients will receive the standard dose of camizestrant once daily as oral tablets
Other Names:
  • AZD9833
Drug: Ribociclib
Patients will receive the standard dose of ribociclib once daily as oral tablets
Other Names:
  • KISQALI®

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Efficacy of camizestrant and ribociclib by time to next treatment (TTNT)
Time Frame: Following first dose of study treatment until earliest of subsequent therapy, death and 2 years after first dose of study treatment.

TTNT is defined as time from the date of the first administration of study treatment to the earliest start date of subsequent anti-cancer medication or death.

The primary measure of interest is the TTNT event-free rate at 2 years.
Following first dose of study treatment until earliest of subsequent therapy, death and 2 years after first dose of study treatment.

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Efficacy of camizestrant and ribociclib by time to discontinuation (TTD)
Time Frame: Following first dose of study treatment until earliest of discontinuation of camizestrant, death and 2 years after first dose of study treatment

TTD is defined as time from the date of the first administration of study treatment to the earliest date of camizestrant treatment discontinuation or death.

The primary measure of interest is the TTD event-free rate at 2 years.
Following first dose of study treatment until earliest of discontinuation of camizestrant, death and 2 years after first dose of study treatment
Efficacy of camizestrant and ribociclib by progression free survival (PFS)
Time Frame: Following first dose of study treatment until earliest of death, disease progression, and 2 years after first dose of study treatment.

PFS is defined as time from first dose of study treatment until progression per RECIST 1.1 as assessed by investigator or death due to any cause.

The primary measures of interest are the PFS event-free rates at 1 and 2 years.
Following first dose of study treatment until earliest of death, disease progression, and 2 years after first dose of study treatment.
CTCAE grade ≥ 3 associated with camizestrant and ribociclib within first 6 months of study treatment
Time Frame: Following first dose of study treatment until 6 months later
Incidence of Grade >=3 CTCAEs associated with Camizestrant and/or Ribo within first 6 months of receiving study treatment.
Following first dose of study treatment until 6 months later

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
AstraZeneca

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
ICON plc

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
May 26, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
April 20, 2028

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
April 10, 2034

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
May 12, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 9, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
June 15, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
June 15, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 9, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
May 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • D8532C00008

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD 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 requests will be evaluated as per the AZ disclosure commitment: https://astrazenecagrouptrials.pharmacm.com/ST/Submission/Disclosure

IPD Sharing 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.

IPD Sharing Access Criteria

When a request has been approved AstraZeneca will provide access to the de-identified 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.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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