Clinical trial • Phase III • Oncology

ELACESTRANT for Estrogen receptor-positive HER2-negative early breast cancer

Phase III trial of ELACESTRANT for Estrogen receptor-positive HER2-negative early breast cancer.

Overview

Trial Therapeutic Area
Oncology
Trial Disease
Estrogen receptor-positive HER2-negative early breast cancer
Trial Stage
Phase III
Drug Modality
Small molecule|Small molecule

Key dates

Initial CTIS Submission Date
14-11-2025
First CTIS Authorization Date
11-03-2026

Trial design

Randomised, open-label, arm 1: adjuvant elacestrant (+/- ribociclib) for 5 years (+gnrh, if clinically indicated). arm 2: standard of care endocrine therapy (soc et) for 5 years (+/- ribociclib). doses/schedules not specified in arm descriptions.-controlled Phase III trial in Austria, Germany, Spain.

Randomised
Yes
Open Label
Yes
Comparator
Arm 1: adjuvant elacestrant (+/- ribociclib) for 5 years (+GnRH, if clinically indicated). Arm 2: standard of care endocrine therapy (SoC ET) for 5 years (+/- ribociclib). Doses/schedules not specified in arm descriptions.
Target Sample Size
1520
Trial Duration For Participant
1825

Eligibility

Recruits 1520 This trial has 'isVulnerablePopulationSelected': true in the registry. Consent requirements specify that 'The patient must be capable of giving informed consent' and that participants must 'Sign informed consent prior to any study-specific procedures.' No assent procedures for minors are provided and inclusion requires age ≥18, so vulnerable-subject handling focuses on capacity to consent and exclusion of those unable to consent..

Pregnancy Exclusion
Concurrent pregnancy; patients of childbearing potential or potentially childbearing partners of male patients must implement a highly effective (less than 1% failure rate) non-hormonal contraceptive measures during the study treatment
Vulnerable Population
This trial has 'isVulnerablePopulationSelected': true in the registry. Consent requirements specify that 'The patient must be capable of giving informed consent' and that participants must 'Sign informed consent prior to any study-specific procedures.' No assent procedures for minors are provided and inclusion requires age ≥18, so vulnerable-subject handling focuses on capacity to consent and exclusion of those unable to consent.

Inclusion criteria

  • {"criterion_text":"- All patients, independent from gender\n- Completed 2-6 weeks of endocrine induction treatment and Ki-67 response assessment Note: 2-4 weeks recommended, up to 6 weeks allowed. Endocrine induction is highly recommended, but if endocrine induction therapy could not be performed or ET response is not representative, clinical factors should be used.\n- Completed (neo)adjuvant chemotherapy, if applicable\n- Completed radiotherapy, if applicable\n- Patient meets any of the following three conditions at end of primary treatment (including endocrine induction treatment, biopsy/surgery, and if necessary, chemotherapy and radiotherapy and up to 12 months standard- of-care endocrine treatment, excluding previous treatment > 4 weeks with any SERD): see protocol for details\n- No contraindication for adjuvant SoC endocrine treatment\n- No contraindication for elacestrant treatment\n- No contraindication for ribociclib treatment, if medically indicated, and adequate washout time for CYP3A4 inducers/inhibitors or QT time- prolonging drugs\n- Tumour block available for central pathology review (core biopsy of initial diagnosis and biopsy/surgery sample of definite surgery, if available)\n- Performance Status ECOG ≤ 1 or Karnofsky Index ≥ 80%\n- Laboratory requirements (female and male patients, not older than 14 days prior to date of informed consent): absolute neutrophil count ≥ 1.5 × 109/L, platelets ≥ 100 × 109/L, haemoglobin ≥ 9.0 g/dL, INR ≤ 1.5, serum creatinine < 1.5 × ULN OR clearance ≥30 mL/min for participant with creatinine levels >1.5 × institutional ULN, total bilirubin < ULN, except for patients with Gilbert’s Syndrome who may only be included if the total bilirubin is ≤ 3.0 × ULN or direct bilirubin ≤ 1.5 × ULN, aspartate transaminase (AST) < 2.5 × ULN, alanine transaminase (ALT) < 2.5 × ULN, Screening lipid panel fasting levels: total cholesterol ≤400 mg/dL AND/OR triglycerides <500 mg/dL.\n- Patient must be ≥18 years at diagnosis\n- Clinical assessments: normal electrocardiogram within 6 weeks prior to randomization (QTcF interval at screening <450msec using Fridericia’s correction, mean resting heart rate 50-90 bpm)\n- Ability to swallow tablets\n- Contraception: see protocol for details\n- The patient must be capable of giving informed consent and be willing and able to comply with the requirements and restrictions in this protocol and accessible for treatment and follow-up\n- Sign informed consent prior to any study-specific procedures.\n- Histologically confirmed unilateral, primary invasive carcinoma of the breast. Note: bilateral, multicentric, or multifocal carcinoma may only be included after consultation of Sponsor.\n- Histologically confirmed diagnosis of primary hormone-receptor-positive (HR+) (i.e., oestrogen-receptor (ER) ≥ 10% and/or progesterone-receptor PR ≥ 10%) early breast cancer by local laboratory Note: ER positive according to ASCO / AGO Guidelines, ER 1-10% (low) is not defined as HR+.\n- Patient has HER2-negative breast cancer defined as a negative in-situ hybridization test or an IHC status of 0, 1+, or 2+, if IHC is 2+, a negative in-situ hybridization (FISH, CISH, or SISH) test is required (based on the most recently analysed tissue sample and all tested by a local laboratory).\n- No evidence of distant metastasis (confirmed by CT thorax / abdomen, X- ray chest, ultrasound liver, bone scan, or PET-CT, respectively, performed within clinical routine).\n- High genomic risk assessment within clinical routine (Oncotype DX® preferred; In those cases, where Oncotype Dx® is not possible in clinical routine, Oncotype Dx® should be assessed retrospectively after inclusion of the patient and as a study specific measure, provided sufficient tumour tissue from primary diagnosis is available.)"}

Exclusion criteria

  • {"criterion_text":"- Known hypersensitivity to any of the compounds or incorporated substances of the IMPs\n- Breast feeding woman\n- Use of oral, transdermal, injected, or implanted hormonal methods of contraception as well as hormonal replacement therapy (oestrogen or progesterone).\n- Reasons indicating risk of poor compliance\n- Patient not able to consent\n- Patient has not recovered from clinical and laboratory acute toxicities related to prior anticancer therapies to NCI CTCAE version 5.0 Grade ≤ 1.\n- Severe and relevant co-morbidity that would interact with the application of endocrine treatment of any kind or the participation in the study\n- For patients planned for ribociclib treatment: Clinically significant, uncontrolled heart disease and/or cardiac repolarization abnormality, including any of the following: see protocol for details\n- Patient has impairment of gastrointestinal (GI) function or GI disease that may significantly alter the absorption of the study drugs (e.g., uncontrolled ulcerative diseases, uncontrolled nausea, vomiting, diarrhoea, malabsorption syndrome, or small-bowel resection).\n- Uncontrolled infection requiring i.v. antibiotics, antivirals, or antifungals\n- Active primary immunodeficiency, known human immunodeficiency virus (HIV) infection. Patients should be tested for HIV prior to randomization if required by local regulations or ethics committee (EC). Patients who test positive for HIV-antibody are excluded.\n- Prior malignancy with a disease-free survival of <5 years, except curatively treated basalioma of the skin or pTis of the cervix uteri\n- Patient with distant metastases of breast cancer beyond regional lymph nodes.\n- Concurrent treatment with cytotoxic agents for any non-oncological reason unless clarified with sponsor\n- Concurrent treatment with other experimental drugs\n- Participation in another interventional clinical trial with or without any investigational, not marketed drug within 30 days or 5 half-lives of the respective drug, whichever is longer, prior to study entry. In case of other interventional trial contact Sponsor.\n- Previous treatment (>4 weeks) with any SERD\n- Concurrent pregnancy; patients of childbearing potential or potentially childbearing partners of male patients must implement a highly effective (less than 1% failure rate) non-hormonal contraceptive measures during the study treatment\n- Patient has known active hepatitis-B-virus (HBV) or hepatitis-C-virus (HCV) infection. Screening for HBV or HBC-infection and testing for hepatitis-B or -C is highly recommended according to current valid (local) clinical guidelines, but neither part of the interventional study procedures, nor required for enrolment.\n- Patient has received live vaccines within 30 days prior to randomization.\n- Patient was submitted to an institution by virtue of an order of a court or a governmental authority must be excluded from participation."}

Endpoints

Primary endpoints

  • {"endpoint_text":"- iDFS, compared between patients randomized to adjuvant elacestrant (+/-CDK4/6i) or SOC ET (+/- CDK4/6i)","definition_or_measurement_approach":""}

Secondary endpoints

  • {"endpoint_text":"- OS defined as time from first diagnosis to death\n- dDFS\n- RFS\n- DFS-DCIS\n- IBCFS\n- LRFS, each as defined in STEEP 2.0\n- Change of HRQoL between baseline, measured after completion of SoC primary treatment (including (neo)adjuvant chemotherapy, surgery, further local therapy), and on following defined timepoints: before start of treatment, 6-monthly during treatment until year 3 and yearly afterwards.\n- Long-term survival endpoints\n- Survival outcomes in premenopausal patients with N0 + RS 16-25 and N1 + RS 0-25 treated by ovarian function suppression (OFS) in combination with either aromatase inhibitor or tamoxifen (SoC) +/- ribociclib (in stage II) or elacestrant +/- ribociclib (in stage II) without chemotherapy use\n- Comparison of toxicity of regimen by evaluation of adverse events of special interest (AESI)-, adverse drug reaction (ADR)-, serious adverse drug reaction (SADR)-, and serious adverse event (SAE)-rates.","definition_or_measurement_approach":"- OS: defined as time from first diagnosis to death\n- LRFS: 'each as defined in STEEP 2.0' (as specified)\n- Change of HRQoL: measured via questionnaires EORTC-QLQ-C30 v3.0, EORTC QLQ-BR42 v1.0, CANKADOactive at specified timepoints (baseline after completion of SoC primary treatment, before start of treatment, every 6 months during treatment until year 3, then yearly)\n- Comparison of toxicity: by evaluation of AESI-, ADR-, SADR-, and SAE-rates (as specified)"}

Recruitment

Registry Or Advocacy Recruitment
True, WSGlong gGmbH (Registry Data Collection); site type includes a patient organisation/association (Stiftung Mathias-Spital Rheine) listed among sites.
Planned Sample Size
1520
Recruitment Window Months
90
Consent Approach
Informed consent must be signed by the participant prior to any study-specific procedures. Participants must be capable of giving informed consent. Study information and ICF documents are available per-member state (documents listed for Austria, Germany, Spain) in local languages; consent is obtained from the adult participant (no paediatric assent procedures provided).

Geography

Total Number Of Sites
38
Total Number Of Participants
1520

Austria

Earliest CTIS Part Ii Submission Date
27-02-2026
Latest Decision Or Authorization Date
22-03-2026
Processing Time Days
23
Number Of Sites
2
Number Of Participants
180

Sites

Site Name
Medical University Of Graz
Department Name
Klinische Abteilung für Onkologie
Contact Person Name
Gabriel Rinnerthaler
Contact Person Email
onkologie@uniklinikum.kages.at
Site Name
Medizinische Universitaet Innsbruck
Department Name
Klin. Abt. f. Gynäkologie u. Geburtshilfe
Contact Person Name
Daniel Egle

Germany

Earliest CTIS Part Ii Submission Date
19-02-2026
Latest Decision Or Authorization Date
11-03-2026
Processing Time Days
20
Number Of Sites
35
Number Of Participants
1050

Sites

Site Name
St. Barbara-Klinik Hamm GmbH
Department Name
Brustzentrum
Contact Person Name
Wlodzimierz Badur
Contact Person Email
wbadur@barbaraklinik.de
Site Name
Johanniter GmbH
Department Name
Onkologisches Zentrum
Contact Person Name
Yon-Dschun Ko
Contact Person Email
info@johanniter.de
Site Name
Haematologisch Onkologische Schwerpunktpraxis
Department Name
Haematologisch Onkologische Schwerpunktpraxis
Contact Person Name
Dominik Pretscher
Contact Person Email
info@onkopraxis-wuerzburg.de
Site Name
Gemeinschaftspraxis Frauenärzte am Bahnhofsplatz
Department Name
Gemeinschaftspraxis Frauenärzte am Bahnhofsplatz
Contact Person Name
Christoph Uleer
Contact Person Email
info@frauenarzt-hildesheim.de
Site Name
Staedtisches Klinikum Lueneburg gGmbH
Department Name
Brustkrebszentrum Lüneburg
Contact Person Name
Peter Dall
Contact Person Email
info@klinikum-lueneburg.de
Site Name
Elisabeth Krankenhaus GmbH
Department Name
Brustzentrum
Contact Person Name
Sabine Schmatloch
Contact Person Email
bz-studien@ekh-ks.de
Site Name
Klinikum Esslingen GmbH
Department Name
Klinik für Frauenheilkunde und Geburtshilfe
Contact Person Name
Alexander Hein
Site Name
Centrum für Hämatologie und Onkologie Bethanien
Department Name
Centrum für Hämatologie und Onkologie Bethanien
Contact Person Name
Hans Tesch
Contact Person Email
Onkologie-Frankfurt@telemed.de
Site Name
Klinik Dr. Hancken GmbH
Department Name
Klinik Dr. Hancken Stade
Contact Person Name
Wiebke Timm
Contact Person Email
info@hancken.de
Site Name
Medical University Of Lausitz Carl Thiem
Department Name
Frauenklinik
Contact Person Name
Nikola Bangemann
Contact Person Email
info@mul-ct.de
Site Name
Gesundheitszentrum Wetterau gGmbH
Department Name
Gynäkologische Ambulanz
Contact Person Name
Carolin Hammerle
Contact Person Email
info@gz-wetterau.de
Site Name
Klinikum Mutterhaus der Borromaeerinnen gGmbH
Department Name
Innere Medizin 1
Contact Person Name
Sebastian Jud
Site Name
MVZ Medical Center Duesseldorf GmbH
Department Name
GynOnco Düsseldorf
Contact Person Name
Athina Kostara
Contact Person Email
info@gynonco.de
Site Name
Universitaetsklinikum Tuebingen AöR
Department Name
Frauenklinik
Contact Person Name
Andreas Hartkopf
Site Name
Universitaetsklinikum Mannheim GmbH
Department Name
Frauenklinik
Contact Person Name
Mattea Reinisch
Contact Person Email
info@umm.de
Site Name
Universitaetsklinikum Duesseldorf AöR
Department Name
Klinik für Frauenheilkunde und Geburtshilfe
Contact Person Name
Tanja Fehm
Site Name
Brustzentrum Rhein-Ruhr Servicegesellschaft mbH
Department Name
Brustzentrum Rhein-Ruhr
Contact Person Name
Katja Krauß
Site Name
Marien-Hospital Witten
Department Name
Brustzentrum
Contact Person Name
Monika Graeser
Site Name
Klinikum St Marien Amberg
Department Name
Klinik für Frauenheilkunde und Geburtshilfe
Contact Person Name
Tanja Hauzenberger
Site Name
MKS St. Paulus GmbH
Department Name
Märkisches Brustzentrum
Contact Person Name
Sarah Wetzig
Contact Person Email
brustzentrum@marien-kh.de
Site Name
Praxis Fuer Interdisziplinaere Onkologie And Haematologie GbR
Department Name
Praxis Fuer Interdisziplinaere Onkologie And Haematologie GbR
Contact Person Name
Matthias Zaiss
Contact Person Email
info@onkologie-freiburg.de
Site Name
Klinikum Dortmund gGmbH
Department Name
Frauenklinik Dortmund
Contact Person Name
Claudia Biehl
Contact Person Email
claudia.biehl@klinikumdo.de
Site Name
LMU Klinikum Muenchen AöR
Department Name
Frauenheilkunde und Geburtshilfe
Contact Person Name
Nadia Harbeck
Site Name
St.-Antonius-Hospital gGmbH
Department Name
Klinik für Hämatologie und Onkologie
Contact Person Name
Peter Staib
Site Name
Hämatologische Onkologische Praxis im Medicum
Department Name
Hämatologische Onkologische Praxis im Medicum
Contact Person Name
Ralf Meyer
Contact Person Email
info@bremer-onkologen.de
Site Name
Mammazentrum Hamburg MVZ GbR
Department Name
Mammazentrum Hamburg MVZ GbR
Contact Person Name
Christian Schem
Contact Person Email
info@mammazentrum-hamburg.de
Site Name
Stiftung Mathias-Spital Rheine
Department Name
Brustzentrum
Contact Person Name
Mathias Füller
Site Name
Franziskus Hospital Harderberg
Department Name
MVZ II der Niels Stensen Kliniken - Onkologie u. Hämatologie
Contact Person Name
Kerstin Lüdtke-Heckenkamp
Contact Person Email
onkologie@nsk.de
Site Name
Haematologie-Onkologie im Zentrum MVZ GmbH
Department Name
Haematologie-Onkologie im Zentrum MVZ GmbH
Contact Person Name
Bernhard Heinrich
Contact Person Email
info@hop-augsburg.de
Site Name
Marienhospital Bottrop gGmbH
Department Name
Klinik für Gynäkologie und Geburtshilfe
Contact Person Name
Hans-Christian Kolberg
Contact Person Email
gynaekologie@mhb-bottrop.de
Site Name
Medizinische Hochschule Hannover
Department Name
Klinik für Frauenheilkunde und Geburtshilfe, Brustzentrum
Contact Person Name
Tjoung-Won Park-Simon
Contact Person Email
brustzentrum@mh-hannover.de
Site Name
Praxisnetz Hämatologie / internistische Onkologie
Department Name
Praxisnetz Hämatologie / internistische Onkologie
Contact Person Name
Ernst Rodermann
Contact Person Email
info@onkologie-rheinsieg.de
Site Name
Rotkreuzklinikum Muenchen gGmbH
Department Name
Interdisziplinäres Brustzentrum
Contact Person Name
Michael Braun
Contact Person Email
kontakt@gynonko.de
Site Name
Helios Universitaetsklinikum Wuppertal
Department Name
Landesfrauenklinik - Brustzentrum
Contact Person Name
Vesna Bjelic-Radisic
Site Name
HELIOS Klinikum Berlin-Buch GmbH
Department Name
Klinik für Gynäkologie und Geburtshilfe
Contact Person Name
Christine Mau

Spain

Earliest CTIS Part Ii Submission Date
11-03-2026
Latest Decision Or Authorization Date
19-03-2026
Processing Time Days
8
Number Of Sites
1
Number Of Participants
290

Sites

Site Name
Hospital Beata Maria Ana
Department Name
Unidad de Cáncer de Mama
Contact Person Name
Javier Cortés Castán
Contact Person Email
citas@iobmadrid.com

Sponsor

Primary sponsor

Full Name
WSG Westdeutsche Studiengruppe GmbH
Organisation Type
Pharmaceutical company
Country Of Registered Address
Germany

Third parties

  • {"country":"Austria","full_name":"ABCSG Research Services GmbH","duties_or_roles":"codes: 1,12,2,5","organisation_type":"Laboratory/Research/Testing facility"}
  • {"country":"Germany","full_name":"WSGlong gGmbH","duties_or_roles":"Registry Data Collection","organisation_type":"Health care"}
  • {"country":"Germany","full_name":"Hannover Unified Biobank","duties_or_roles":"Storage biological samples","organisation_type":"Health care"}
  • {"country":"Germany","full_name":"CANKADO Service GmbH","duties_or_roles":"code: 7","organisation_type":"Health care"}
  • {"country":"Germany","full_name":"Medizinische Hochschule Hannover","duties_or_roles":"Biological sample analyses","organisation_type":"Educational Institution"}
  • {"country":"Spain","full_name":"Medica Scientia Innovation Research SL","duties_or_roles":"codes: 1,12,2,5","organisation_type":"Health care"}
  • {"country":"Germany","full_name":"Universitaetsklinikum Heidelberg AöR","duties_or_roles":"Secondary Packaging RIBO, Labelling RIBO, Storage RIBO","organisation_type":"Hospital/Clinic/Other health care facility"}
  • {"country":"Germany","full_name":"KRIEGER Pharma GmbH & Co. KG","duties_or_roles":"RIBO + ELA - Storage and Distribution","organisation_type":"Pharmaceutical company"}
  • {"country":"Germany","full_name":"Universitätsklinikum Bonn, Studienzentrum Bonn","duties_or_roles":"code: 8","organisation_type":"Health care"}
  • {"country":"Germany","full_name":"Berlin-Chemie AG","duties_or_roles":"ELA - Primary and Secondary Packaging, Labelling, Storage, Distribution","organisation_type":"Pharmaceutical company"}
  • {"country":"Sweden","full_name":"Viedoc Technologies AB","duties_or_roles":"code: 7 (electronic data capture/support)","organisation_type":"Non-Pharmaceutical company"}

Investigational products

Investigational Product Name
ORSERDU 86 mg film-coated tablets
Active Substance
ELACESTRANT
Modality
Small molecule
Routes Of Administration
ORAL USE
Route
oral
Authorisation Status
Authorised
Maximum Dose
258 mg (maxDailyDoseAmount)
Investigational Product Name
ORSERDU 345 mg film-coated tablets
Active Substance
ELACESTRANT
Modality
Small molecule
Routes Of Administration
ORAL USE
Route
oral
Authorisation Status
Authorised
Maximum Dose
345 mg (maxDailyDoseAmount)
Investigational Product Name
Kisqali 200 mg film-coated tablets
Active Substance
RIBOCICLIB
Modality
Small molecule
Routes Of Administration
ORAL USE
Route
oral
Authorisation Status
Authorised
Maximum Dose
400 mg (maxDailyDoseAmount)
Combination Treatment
Yes

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