Skip to content

DiEtary Mimicry by Glucocorticoid Modulation Evaluation in ER+ Metastatic Breast Cancer Treatment: Efficacy and Response (DEMETER Trial)

DiEtary Mimicry by Glucocorticoid Modulation Evaluation in ER+ Metastatic Breast Cancer Treatment: Efficacy and Response - DEMETER Trial A Phase II Clinical Study to Investigate the Efficacy of Dexamethasone as an Adjunct to Endocrine Therapy in ER+, HER2- Metastatic Breast Cancer.

Status
Not yet recruiting
Phases
Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT07786051
Acronym
DEMETER
Enrollment
80
Registered
2026-08-25
Start date
2026-11-01
Completion date
2028-11-01
Last updated
2026-08-25

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Breast Cancer

Keywords

ER positive, HER2 negative, Metastatic breast cancer, Dexamethasone, Endocrine treatment

Brief summary

This is a single centre, open label, phase II clinical study consisting of two parts, each consisting of a different dose of the same intervention to investigate the efficacy of dexamethasone as an adjunct to endocrine therapy in the treatment of ER+ HER2- metastatic breast cancer after progression on the same endocrine therapy.

Interventions

Commercially available Dexamethasone in tablet form 1.5mg or 4mg

Sponsors

The Netherlands Cancer Institute
Lead SponsorOTHER
Oncode Institute
CollaboratorUNKNOWN

Study design

Allocation
NON_RANDOMIZED
Intervention model
SEQUENTIAL
Primary purpose
TREATMENT
Masking
NONE

Intervention model description

This trial will initiate Part 1 with dexamethasone 3mg. The dosage of dexamethasone in Part 2 will be 1.5mg unless conclusion from the interim analyses (i.e., tolerable at 3 mg, CBR \<30 and insufficient GR activation) warrants a higher dose of dexamethasone.

Eligibility

Sex/Gender
FEMALE
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

1. Have provided written informed consent and are willing to comply to study procedures and treatment plan. 2. Documentation of histologically confirmed diagnosis of oestrogen receptor (ER) expression \>10% breast cancer based on local laboratory results. Tumour must be HER2 negative as defined by American Society of Clinical Oncology - College of American Pathologists (ASCOCAP) guidelines. If HER2 status is unavailable, then testing must be performed/repeated. 3. Have relapsed/refractory to treatment with aromatase inhibitors or Fulvestrant as monotherapy or in combination with CDK4/6 inhibitors in the 1st or 2nd line in metastatic setting. Prior treatment discontinuation must not be \> 8 weeks ago. 4. Participants must meet one of the following criteria: 1. Pre-menopausal women are required to have ovarian function suppression by means of bilateral oophorectomy or continued LHRH/GnRH agonists treatment. 2. Are over the age of 60 years or are of postmenopausal status as defined by no menses for 12 months without an alternative medical cause. A high FSH level (\>35 mIU/mL) in the postmenopausal range may be used to confirm a postmenopausal state. 5. Have metastatic disease. 6. At least 1 measurable lesion that would qualify as target lesion by RECIST v1.1, (assessed by the investigator) that can be accurately measured at baseline with CT or MRI and that is suitable for accurate repeated measurements. Lesions previously irradiated or subjected to other locoregional therapy will only be deemed measurable if disease progression at the treated site after completion of therapy is clearly documented. 7. ECOG performance status 0-2. 8. Have adequate organ function defined as follows: 1. Hb: \>5.7 mmol/L. 2. ANC: \>1.0 mmol/L 3. Platelets: ≥ 75 x109/L 4. Transaminases: ASAT and ALAT ≤3 x ULN (≤5.0 x ULN if liver metastases present); 5. T. Bilirubin: ≤1.5 x ULN (≤3.0 x ULN if Gilbert's disease); 6. eGFR: \>30 ml/min/1,73 m2 (CKD-EPI) 9. Has negative HIV (Ag+Ab), Hepatitis B surface antigen (HBsAg), or Hepatitis C antibody (anti-HCV) test. 10. For participants opting to provide an on-treatment and/or EOT biopsy: 1. Lesion to be biopsied for this study is deemed accessible and clinically feasible according to the (sub) investigator.

Exclusion criteria

1. Primary endocrine resistance: Progressed on endocrine therapy within 6 months of initiating treatment in the 1st line for advanced or mBC, or relapsed within first 2 years of endocrine therapy in the adjuvant setting. 2. Metastases such as massive uncontrolled effusions (pleural, pericardial, peritoneal), pulmonary lymphangitis, and \>50% liver involvement which have risk of life-threatening complications in the short term. 3. Known Central Nervous System (CNS) metastases. 4. Current use of corticosteroids including local administration such as intranasal, intraocular, intra-articular, inhaled or topical application, and/or having ongoing conditions requiring long-term use of corticosteroids. 5. History of hypersensitivity and/or other adverse effects to corticosteroids. 6. Known Diabetes mellitus (type 1 or type 2) or Random Blood Sugar (RBS) of ≥11.1 mmol/L. 7. Clinically significant osteoporosis unless treated with denosumab or bisphosphonates. 8. Have (history of) clinically significant ocular conditions such as glaucoma, papilledema and retinopathy. 9. Presence of clinically significant or uncontrolled cardiovascular disease such as: 1. Congestive Heart Failure: \> New York Heart Association (NYHA) class II. 2. Coronary Artery Disease: Participants must not have unstable angina or angina de novo within the last 3 months and myocardial infarction in the last 6 months. 3. Clinically significant cardiac arrhythmias. 4. Therapy resistant hypertension in the opinion of investigator. 5. For participants receiving Ribociclib: QTcF \> 480 ms. 10. Diagnosis of any other malignancy prior to C1D1, except those that are not believed to influence the participant's prognosis and do not require any further treatment. This includes but is not limited to adequately treated basal cell or squamous cell skin cancer and carcinoma in situ of the cervix. 11. Known history of psychosis or suicidal ideation. 12. Are taking a prohibited medication (as defined in section 9.1.2) that cannot be discontinued for the duration of the study. 13. Any other severe acute or chronic medical or psychiatric condition or laboratory abnormality that may increase the risk associated with study participation or may interfere with the interpretation of study results and, in the judgment of the clinician or investigator, would make the participant inappropriate for entry into this study. 14. Participation in any other interventional study or receiving any other anti-cancer therapy other than endocrine therapy.

Design outcomes

Primary

MeasureTime frame
Clinical Benefit Rate, which is defined as the proportion of participants having stable disease, partial response or complete response at the 16th week tumour evaluation.At the 16th week tumour evaluation.

Contacts

CONTACTWilbert Zwart, PhD
w.zwart@nki.nl+31205129111
PRINCIPAL_INVESTIGATORVincent Dezentjé, MD PhD

The Netherlands Cancer Institute

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Aug 26, 2026