Adjuvant Dynamic marker - Adjusted Personalized Therapy comparing adjuvant Elacestrant with standard endocrine treatment in genomically and/or clinically high-risk ER+/HER2- early breast cancer (ADAPTela)

Overview

Sponsor-declared trial summary

Key facts

Sponsor

WSG Westdeutsche Studiengruppe GmbH

Participant type

Patients

Age range

18-64 years, 65+ years

Gender

Male and Female

Therapeutic area

Diseases [C] - Neoplasms [C04]

Trial duration

27 Apr 2026 → ongoing

Decision date (initial)

2026-03-22

Transition trial

No

Low-intervention

No

Rare-disease indication

No

Vulnerable population

Yes

Funding sources

Menarini-Stemline

Trial design

CTIS Part I — objectives, methods, condition coding

Main objective

Scope: Therapy, Efficacy, Safety

To show efficacy in terms of improved survival (iDFS) in patients receiving adjuvant elacestrant-containing therapy (+/- CDK4/6i) compared to SoC (+/- CDK4/6i) only

Secondary objectives 3

1. To assess distant disease-free survival (dDFS), relapse-free survival (RFS), DCIS disease-free survival (DFS-DCIS), invasive breast cancer-free survival (IBCFS), locoregional relapse-free survival (LRFS), and OS
2. To assess health-related quality of life (HRQoL via questionnaires EORTC- QLQ-C30, version 3.0, EORTC QLQ-BR42, version 1.0, CANKADOactive)
3. To assess toxicity in both arms

Conditions and MedDRA coding

ER+/HER2- early breast cancer

Study design 3 periods

Eligibility criteria

Principal inclusion / exclusion criteria as submitted by sponsor

Inclusion criteria 22

1. All patients, independent from gender
2. Patient must be ≥18 years at diagnosis
3. 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
4. Sign informed consent prior to any study-specific procedures.
5. Histologically confirmed unilateral, primary invasive carcinoma of the breast. Note: bilateral, multicentric, or multifocal carcinoma may only be included after consultation of Sponsor.
6. 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+.
7. 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).
8. 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).
9. 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.)
10. 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.
11. Completed (neo)adjuvant chemotherapy, if applicable
12. Completed radiotherapy, if applicable
13. 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
14. No contraindication for adjuvant SoC endocrine treatment
15. No contraindication for elacestrant treatment
16. No contraindication for ribociclib treatment, if medically indicated, and adequate washout time for CYP3A4 inducers/inhibitors or QT time- prolonging drugs
17. Tumour block available for central pathology review (core biopsy of initial diagnosis and biopsy/surgery sample of definite surgery, if available)
18. Performance Status ECOG ≤ 1 or Karnofsky Index ≥ 80%
19. 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.
20. 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)
21. Ability to swallow tablets
22. Contraception: see protocol for details

Exclusion criteria 22

1. Known hypersensitivity to any of the compounds or incorporated substances of the IMPs
2. Prior malignancy with a disease-free survival of <5 years, except curatively treated basalioma of the skin or pTis of the cervix uteri
3. Any history of invasive cancer within the last 10 years Note: adequately treated, basal or squamous-cell skin carcinoma, non- melanomatous skin cancer, curatively resected cervical cancer, and contralateral DCIS treated by mastectomy (contralateral in relation to current invasive breast cancer diagnosis) are excepted. Previous ipsilateral DCIS, irrespective of treatment, is excluded!
4. Patient with distant metastases of breast cancer beyond regional lymph nodes.
5. Concurrent treatment with cytotoxic agents for any non-oncological reason unless clarified with sponsor
6. Concurrent treatment with other experimental drugs
7. 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.
8. Previous treatment (>4 weeks) with any SERD
9. 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
10. Breast feeding woman
11. Use of oral, transdermal, injected, or implanted hormonal methods of contraception as well as hormonal replacement therapy (oestrogen or progesterone).
12. Reasons indicating risk of poor compliance
13. Patient not able to consent
14. Patient has not recovered from clinical and laboratory acute toxicities related to prior anticancer therapies to NCI CTCAE version 5.0 Grade ≤ 1.
15. Severe and relevant co-morbidity that would interact with the application of endocrine treatment of any kind or the participation in the study
16. 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
17. 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).
18. Uncontrolled infection requiring i.v. antibiotics, antivirals, or antifungals
19. 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.
20. 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.
21. Patient has received live vaccines within 30 days prior to randomization.
22. 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 and secondary outcome measures (English text)

Primary endpoints 1

1. iDFS, compared between patients randomized to adjuvant elacestrant (+/-CDK4/6i) or SOC ET (+/- CDK4/6i)

Secondary endpoints 10

1. OS defined as time from first diagnosis to death
2. dDFS
3. RFS
4. DFS-DCIS
5. IBCFS
6. LRFS, each as defined in STEEP 2.0
7. 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.
8. Long-term survival endpoints
9. 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
10. 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.

Investigational products

Investigational medicinal products (IMPs), comparators, placebo, auxiliary

Test 6

Sponsors and contacts

Sponsor organisations, regulatory contacts, third parties

WSG Westdeutsche Studiengruppe GmbH

Sponsor organisation

WSG Westdeutsche Studiengruppe GmbH

Address

Fliethstrasse 112-114, Stadtmitte Stadtmitte

City

Moenchengladbach

Postcode

41061

Country

Germany

Scientific contact point

Organisation

WSG Westdeutsche Studiengruppe GmbH

Contact name

Medical Board

Public contact point

Organisation

WSG Westdeutsche Studiengruppe GmbH

Contact name

Project Management

Third parties 11

Locations

3 EU/EEA countries · 38 investigational sites

By country

Investigational sites

Country notifications

Trial-start, recruitment-start, end and early-termination notifications submitted per Member State

Results and documents

Annex IV summary of results, Annex V layperson summary, and all documents registered in CTIS for this trial

Documents 25 files

Public protocol annexes, IB summaries, regulatory submissions and post-authorisation documents registered in CTIS.

Application history

3 submissions — initial application plus substantial / non-substantial modifications