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AzTrials

Early and Locally Advanced Breast CancerTEODORNCT07084558

ABCSG 61 / TEODOR : Neoadjuvant TrEatment Optimization Driven by Circulating Tumor DNA and endOcrine Responsiveness

A study testing blood sample for Signatera (TM) test, biopsy for Ki-67 assessment and FFPE tumor sample for Signatera (TM) test (archived) in people with Early and Locally Advanced Breast Cancer, run by Austrian Breast & Colorectal Cancer Study Group at 14 sites in Austria.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
Search all trials

Trial summary

The goal of this performance study is to learn if treatment with neoadjuvant endocrine therapy compared to chemotherapy has comparable efficacy, but better quality of life outcomes in endocrine responsive participants with early and locally advanced ER+/HER2-negative breast cancer and no detectable ctDNA in peripheral… Read more about this study

Who is it for?
Ages 18 to 100 years
Conditions the study is for
Early and Locally Advanced Breast Cancer
What is being tested?
blood sample for Signatera (TM) test, biopsy for Ki-67 assessment and FFPE tumor sample for Signatera (TM) test (archived)
Could I receive a placebo?
No, everyone receives an active treatment
How many people
350 participants
Where
14 sitesAustria
Study dates
13 Aug 2025to 30 Jun 2033
Phase
Interventional
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 100 years
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Signed informed consent obtained prior to any study specific assessments and procedures
  • Women and men of age ≥18 years
  • Patients must have histologically confirmed invasive, unilateral and locally advanced breast cancer with the following characteristics:
  • Stage IIA-III per AJCC (American Joint Committee on Cancer) Breast Cancer Staging version 8
  • Histologically confirmed hormone receptor positive and HER2 negative tumor(s); HER2 measurement to be assessed locally according to the ASCO/CAP guidelines. In case the tumor is multicentric and/or multifocal, all histopathologically examined tumors must meet the pathologic criteria for hormone receptor positive and HER2 negative
  • ER positive tumors, i.e. >20% positive stained tumor cells
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  • PR positive or negative tumors
  • Systemic chemotherapy indicated by multidisciplinary tumor board
  • Absence of prior breast cancer specific treatment for the current malignancy when entering screening
  • Eastern Cooperative Oncology Group (ECOG) performance status of 0-2
  • Adequate bone marrow and organ function as defined by the following local laboratory values within 8 weeks before study treatment start:
  • Absolute neutrophil count (ANC) ≥ 1.5 × 109/L
  • Platelets ≥ 100 × 109/L
  • Hemoglobin ≥ 10.0 g/dL
  • Serum creatinine within normal institutional limits or creatinine clearance ≥ 60 mL/min/1.73 m² for patients with serum creatinine levels above institutional ULN.
  • Alanine amino transferase (ALT or SGPT) ≤ 1.5 × Upper Limit Normal (ULN); Aspartate amino transferase (AST or SGOT) ≤ 1.5 × ULN f. Total serum bilirubin ≤ ULN; or total bilirubin ≤ 3.0 × ULN with direct bilirubin within normal range in patients with well documented Gilbert's Syndrome
  • Patients must be able and willing to swallow and retain oral medication without a condition that would interfere with enteric absorption.
  • Patient must be willing and able to comply with scheduled visits, treatment plans, laboratory tests, and other study procedures.
  • In women of childbearing potential, urine or serum pregnancy test must be negative within 28 days prior to registration. In postmenopausal women or hysterectomized patients, pregnancy tests do not need to be performed

Who cannot join

  • Ineligible for appropriate locoregional treatment (breast surgery and or radiotherapy when indicated)
  • Bilateral invasive breast cancer or synchronous DCIS in contralateral breast
  • Patients receiving concurrent systemic exogenous sexual hormone therapy during the study (hormone replacement therapy, oral or any other hormonal contraceptives such as hormonal contraceptive coil, etc.) are not eligible but topical vaginal estrogen therapy is allowable.
  • Any chronic medication contraindicated for antineoplastic treatment
  • Participation in a prior or concurrent interventional study and receiving study treatment (concurrent or within 30 days prior to treatment start) 6) Patients receiving any prior systemic cancer therapy for invasive breast cancer
  • 7) Patients with a history of any malignancy are ineligible except for the following circumstances:
Show all 9Show fewer
  • Patients with a malignancy history other than adequately treated invasive breast cancer are eligible if they have been disease-free for at least 2 years and are deemed by the investigator to be at very low risk for recurrence of that malignancy (e.g. stage I gastric cancer or skin cancer)
  • Patients with the following cancers are eligible, even if diagnosed and adequately treated within the past 2 years: ductal carcinoma in situ of the breast, cervical cancer in situ, and non-metastatic nonmelanomatous skin cancers 8) Patient has medical or psychiatric disorders that would, in the investigator's judgement, interfere with the patient's safety or informed consent (e.g. known uncontrolled HIV infection, chronic/active viral or other known hepatitis and/or chronic liver disease, cirrhosis etc.).
  • 9) Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, diabetes, or psychiatric illness/social situations that would limit compliance with study requirements. Ability to comply with study requirements is to be assessed by each investigator at the time of screening for study participation 10) Patient has current impairment of gastrointestinal (GI) function or GI disease that may significantly alter the absorption of the oral study treatments (e.g., uncontrolled ulcerative diseases, uncontrolled nausea, vomiting or diarrhea, malabsorption syndrome, or small bowel resection) 11) Patient has any other concurrent severe and/or uncontrolled medical condition that would, in the Investigator´s judgment, cause unacceptable safety risks, contraindicate patient participation in the clinical study or compromise compliance with the protocol or limit life expectancy to ≤5 years 12) Pregnant or breast-feeding (lactating) women or women who plan to become pregnant or breast-feed during study treatment and 6 months thereafter

Trial locations and contacts

14 sites in 1 country. Contact the study team or a site near you to ask about taking part.

Katharina Jarolim, PhD contact

+43 1 4089230

katharina.jarolim@abcsg.at

14 sites in 1 country

Austria14 sites, 12 recruiting

  • Landesklinikum Baden BGZ; Abt. f. Allgemein- u. Viszeralchirurgie

    Baden

    Martin Bodingbauer, +4322529004, martin.bodingbauer@baden.lknoe.at

    Martin Bodingbauer, MD

    Recruiting

  • Dornbirn BGZ; Frauenheilkunde u. Geburtshilfe

    Dornbirn

    Active, not recruiting

  • Landeskrankenhaus Feldkirch Interne E

    Feldkirch

    Margit Sandholzer, +435522303, margit.sandholzer@lkhf.at

    Margit Sandholzer, MD

    Recruiting

  • MUG - LKH Graz Klin. Abt. f. Onkologie

    Graz

    Gabriel Rinnerthaler, +433163850, gabriel.rinnerthaler@medunigraz.at

    Gabriel Rinnerthaler, MD

    Recruiting

  • MUG - Univ. Frauenklinik Graz, Gyn. Abteilung

    Graz

    Vassiliki Kolovetsiou-Kreiner, +4331638580, vassiliki.kolovetsiou@medunigraz.at

    Vassiliki Kolovetsiou-Kreiner, MD

    Recruiting

  • MUI - Univ. Klinik f. Frauenheilkunde Innsbruck Klin. Abteilung f. Gynäkologie u. Geburtshilfe

    Innsbruck

    Daniel Egle, +4350504230, daniel.egle@tirol-kliniken.at

    Daniel Egle, MD

    Recruiting

  • TumorZentrum Kepler Universitätsklinikum Linz

    Linz

    Heike Kathleen Schwarz, +435768083, h.schwarz@kepleruniklinikum.at

    Heike Kathleen Schwarz, MD

    Recruiting

  • LKH Salzburg - PMU, Univ.Klinik f. Innere Medizin III / SCRI CCCIT

    Salzburg

    Simon Peter Gampenrieder, +43572550, s.gampenrieder@salk.at

    Simon Peter Gampenrieder, MD

    Recruiting

  • Universitätsklinikum St. Pölten, Klin. Abteilung f. Innere Medizin 1

    Sankt Pölten

    Maria Gold, +43274290040, maria.gold@stpoelten.lknoe.at

    Maria Gold, MD

    Recruiting

  • KH BHB St. Veit/Glan Brustzentrum Kärnten

    Sankt Veit an der Glan

    Active, not recruiting

  • Allg. Gynäkologie u. gyn. Onkologie/Senologie

    Vienna, Austria, 1190

    Sabine Danzinger, +43140400, sabine.danzinger@meduniwien.ac.at

    Sabine Danzinger, MD

    Recruiting

  • Hanusch Krankenhaus, 3. Medizinische Abteilung

    Vienna

    Jan Miechowiecki, +43191021, jan.miechowiecki@oegk.at

    Jan Miechowiecki, MD

    Recruiting

  • Klinik Hietzing, Gyn. Abteilung; Karl Landsteiner Institut f. gyn. Onkologie u. Senologie

    Vienna

    Christian Peters-Engl, +43180110, christian.petersengl@gesundheitsverbund.at

    Christian Peters-Engl, MD

    Recruiting

  • Universitätsklinikum Wiener Neustadt, Abteilung für Innere Medizin, Hämatologie und int. Onkologie

    Wiener Neustadt

    Mira Witek, +43262290040, mirasofie.witek@wienerneustadt.lknoe.at

    MIra Witek, MD

    Recruiting

Other trials in Austria

About this study

Official title: ABCSG 61 / TEODOR (Neoadjuvant TrEatment Optimization Driven by ctDNA and endOcrine Responsiveness): A Prospective, Randomized, Controlled, Openlabel Multicenter Phase II Study Investigating Neoadjuvant Endocrine Therapy Versus Chemotherapy in HR-positive, HER2negative, ctDNA-negative and Endocrine Responsive Early and Locally Advanced Breast Cancer

The goal of this performance study is to learn if treatment with neoadjuvant endocrine therapy compared to chemotherapy has comparable efficacy, but better quality of life outcomes in endocrine responsive participants with early and locally advanced ER+/HER2-negative breast cancer and no detectable ctDNA in peripheral blood.

The main question it aims to answer is:

Read more

Is neoadjuvant endocrine therapy at least equivalent to neoadjuvant chemotherapy for treatment of patients with ER-positive, HER2-negative breast cancer with no detectable ctDNA (as assessed with the SignateraTM test) prior to treatment start and a Ki-67-value smaller or equal to 10% after 3 weeks of initial aromatase inhibitor treatment (=endocrine responsive).

Researchers will compare neoadjuvant Standard of Care aromatase inhibitors (AI) or tamoxifen, if AI is not tolerated, with neoadjuvant Standard of Care chemotherapy to see if treatment efficacy is at least comparable between the treatment arms, when measured with the modified preoperative endocrine prognostic index (PEPI) score at surgery.

Participants will:

  • Provide blood and tumor samples for ctDNA-assessment with the SignateraTM test by Natera prior to treatment starts
  • Take AI therapy for 4 weeks in the initial Run-in phase
  • Undergo tumor biopsy after 3 weeks of AI for local evaluation of Ki-67
  • Receive either 8 months of neoadjuvant Standard of Care AI/ tamoxifen or 6-8 months of neoadjuvant Standard of Care chemotherapy in one of the three treatment arms of the Main Treatment Phase, depending on SignateraTM test result and Ki-67 value after 3 weeks of AI therapy (see "detailed description" for details).
  • Visit the clinic for checkups and tests at timepoints:
  • Prior to starting trial treatment
  • 3 weeks after start of endocrine treatment in the Run-in phase
  • Approx. 1 week later, prior to start of Main Treatment
  • After half of the therapy in the Main Therapy Phase has been completed
  • Once Main Treatment Phase treatment is complete (after 7-9 months overall)
  • For surgery and post-surgery checkup
  • Annually during the 5 years follow-up phase after surgery.
  • A subset of patients, who receive adjuvant chemotherapy after surgery, are asked to come to site for an additional visit after completion of chemotherapy.
  • Provide blood samples for ctDNA-assessment and future research when visiting the clinic
  • Answer patient-reported questionnaires about their quality of life, symptoms and sexual health
Read the detailed description

This is a prospective, randomized, controlled, open-label phase II performance study for participants with ER+/ HER2- early or locally advanced breast cancer. At the start of the trial, ctDNA is assessed for all participants with the SignateraTM test by Natera, using (archived) tumor tissue and blood samples. Eligible patients start AI therapy per Standard of Care in the Run-in Phase and after 3 weeks of treatment, Ki-67 levels are measured locally, to determine endocrine response. Following the Run-in Phase, participants, whose SignateraTM test result shows no detectable ctDNA and whose Ki-67 value is ≤ 10% are randomized 2:1 to receive either neoadjuvant AI or, if AI is not tolerated, tamoxifen in arm A or neoadjuvant chemotherapy in arm B. Participants with a Ki-67 value of >10% or detectable ctDNA, according to the SignateraTM test, receive chemotherapy in the third treatment arm C. All study treatment is applied as per standard of care. The planned duration of treatment is 4 weeks in the Run-in phase and 6-8 months in either arm of the Main Treatment Phase. The primary endpoint is the modified PEPI score. Patients will be followed for 5 years from surgery.

Being tested
blood sample for Signatera (TM) test, biopsy for Ki-67 assessment, FFPE tumor sample for Signatera (TM) test (archived)
Keywords
early breast cancer, locally advanced breast cancer, neoadjuvant endocrine therapy, chemotherapy, HR-positive, HER2-negative, ABCSG 61, TEODOR, endocrine responsive, Natera, in-vitro diagnostic, Signatera Test, Signatera, ctDNA
Medical subject headings
Breast Neoplasms

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • blood sample for Signatera (TM) testDiagnostic test

    ctDNA: Evaluation of ctDNA-status prior to treatment start (ctDNA not detected or ctDNA-positive) until the last of five follow-up visit

  • biopsy for Ki-67 assessmentDiagnostic test

    Ki67: Evaluation of Ki-67-value after 3 weeks of aromatase inhibitor

  • FFPE tumor sample for Signatera (TM) test (archived)Diagnostic test

    Evaluation of ctDNA status prior to treatment start

Study groups in NCT07084558
Study groupRoleWhat they receive
Endocrine treatment for responders to treatment with aromatase inhibitorExperimentalPatients are considered responders if they are ctDNA-negative prior treatment and if Ki-67 is less than or equal to 10% after 3 weeks of treatment with aromatase inhibitor
Receives: Diagnostic Test: blood sample for Signatera (TM) test; Diagnostic Test: biopsy for Ki-67 assessment; Diagnostic Test: FFPE tumor sample for Signatera (TM) test (archived)
Chemotherapy for responders to treatment with aromatase inhibitorExperimentalPatients are considered responders if they are ctDNA-negative prior treatment and if Ki-67 is less than or equal to 10% after 3 weeks of treatment with aromatase inhibitor
Receives: Diagnostic Test: blood sample for Signatera (TM) test; Diagnostic Test: biopsy for Ki-67 assessment; Diagnostic Test: FFPE tumor sample for Signatera (TM) test (archived)
Chemotherapy for non-responders to treatment with aromatase inhibitorExperimentalPatients are considered non-responders if they are ctDNA-positive prior treatment and if Ki-67 is greater than 10% after 3 weeks of treatment with aromatase inhibitor
Receives: Diagnostic Test: blood sample for Signatera (TM) test; Diagnostic Test: biopsy for Ki-67 assessment; Diagnostic Test: FFPE tumor sample for Signatera (TM) test (archived)

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Modified PEPI (Preoperative Endocrine Prognostic Index) score

    The proportions of patients with a modified PEPI score of 0 are compared between treatment arm A and treatment arm B. The score ranges between 0 and 12 with 0 indicating the lowest risk of relapse.

    Measured: From randomization to the timepoint of surgery

Secondary outcomes (7)

  1. RCB (Residual Cancer Burden) score

    The continuous RCB scores are compared between treatment arm A and treatment arm B. The score ranges from 0 to 100.

    Measured: From randomization to the timepoint of surgery

  2. BCTOR (Breast Conservation Turn-Over Rate)

    The proportion of patients with actual breast conservation surgery as planned are compared between treatment arm A and treatment arm B.

    Measured: From randomization to the timepoint of surgery

  3. EFS (Event-Free Survival)

    Time from randomization to the date of first event: local-regional progression prior surgery, distant progression prior surgery, invasive ipsilateral breast tumor recurrence, local-regional invasive recurrence, invasive contralateral breast cancer, distant recurrence, second primary invasive cancer of non-breast origin or death from any cause.

    Measured: From randomization until the end of the 5-year follow-up post-surgery period

  4. iDFS (Invasive Disease-Free Survival )

    Time from primary surgery to the date of the first event: invasive ipsilateral breast tumor recurrence, local-regional invasive recurrence, invasive contralateral breast cancer, distant recurrence, second primary invasive cancer of non-breast origin or death from any cause.

    Measured: From primary surgery until the end of the 5-year follow-up post-surgery period

  5. iBCFS (Invasive Breast Cancer-Free Survival )

    Time from primary surgery to the date of the first event: invasive ipsilateral breast tumor recurrence, local-regional invasive recurrence, invasive contralateral breast cancer, distant recurrence, or death from any cause.

    Measured: From primary surgery until the end of the 5-year follow-up post-surgery period

  6. DRFS (Distant Recurrence-Free Survival)

    Time from primary surgery to the date of the first event: distant recurrence or death from any cause.

    Measured: From primary surgery until the end of the 5-year follow-up post-surgery period

  7. OS (Overall Survival)

    Time from randomization to death.

    Measured: From randomization until the end of the 5-year follow-up post-surgery period

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted24 Jul 2025
  2. Study start13 Aug 2025
  3. Primary completion30 Jun 2028 (estimated)
  4. Study completion30 Jun 2033 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Diagnosis
Allocation
Randomised
Intervention model
Parallel groups
Masking
None (open label)
Enrolment
350 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07084558
Sponsor's protocol ID
ABCSG 61 / TEODOR
Acronym
TEODOR
Status last verified
Aug 2026
First submitted
17 Jul 2025
Last updated
19 Aug 2026
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
Yes
Individual data sharing
Yes: Key-coded personal information from this study may also be used for future ((non-)commercial, (inter-)national) scientific research projects \& statistics, provided the respective project is conducted in compliance with accepted standards of ethical principles; the responsible researcher(s)/statistician(s) has/have no legal means to de-identify any key-coded personal information. Data will be shared with other collaborating academic groups/people \& companies who work with the Sponsors, including but not limited to ECs and (inter-)national RA/HA, ABCSG (holder of clin. database), IVD/medication manufacturer and will be used for study purposes mentioned in protocol \& future scientific research projects, if agreed by the participant. Any data transfer will comply with respective applicable data law/regulations. The use of data must be defined in advance in a project description \& SAP, approved by ABCSG Board/Committee and will be transferred acc. with resp. Data Transfer Agreement.

Questions about this trial

What is this clinical trial studying?

A study testing blood sample for Signatera (TM) test, biopsy for Ki-67 assessment and FFPE tumor sample for Signatera (TM) test (archived) in people with Early and Locally Advanced Breast Cancer, run by Austrian Breast & Colorectal Cancer Study Group at 14 sites in Austria.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 19 inclusion and 9 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: looking for participants now, as of the sponsor's last update on 19 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 14 sites in Austria. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Katharina Jarolim, PhD (+43 1 4089230, katharina.jarolim@abcsg.at), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Modified PEPI (Preoperative Endocrine Prognostic Index) score (time frame: From randomization to the timepoint of surgery). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT07084558.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 19 Aug 2026.

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