Breast CancerPhase 2DEMETERNCT07786051
DiEtary Mimicry by Glucocorticoid Modulation Evaluation in ER+ Metastatic Breast Cancer Treatment: Efficacy and Response (DEMETER Trial)
A Phase 2 study testing Dexamethasone (Oral) in people with Breast Cancer, run by The Netherlands Cancer Institute.
Trial 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… Read more about this study
- Who is it for?
- Ages 18 years and older, women only
- Conditions the study is for
- Breast Cancer
- What is being tested?
- Dexamethasone (Oral)
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 80 participants
- Where
- No sites listed yet
- Study dates
- 1 Nov 2026to 1 Nov 2028
- Phase
- Phase 2
- 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 years and older
- Women only
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Have provided written informed consent and are willing to comply to study procedures and treatment plan.
- 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.
- 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.
- Participants must meet one of the following criteria:
- Pre-menopausal women are required to have ovarian function suppression by means of bilateral oophorectomy or continued LHRH/GnRH agonists treatment.
- 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.
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- Have metastatic disease.
- 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.
- ECOG performance status 0-2.
- Have adequate organ function defined as follows:
- Hb: >5.7 mmol/L.
- ANC: >1.0 mmol/L
- Platelets: ≥ 75 x109/L
- Transaminases: ASAT and ALAT ≤3 x ULN (≤5.0 x ULN if liver metastases present);
- T. Bilirubin: ≤1.5 x ULN (≤3.0 x ULN if Gilbert's disease);
- eGFR: >30 ml/min/1,73 m2 (CKD-EPI)
- Has negative HIV (Ag+Ab), Hepatitis B surface antigen (HBsAg), or Hepatitis C antibody (anti-HCV) test.
- For participants opting to provide an on-treatment and/or EOT biopsy:
- Lesion to be biopsied for this study is deemed accessible and clinically feasible according to the (sub) investigator.
Who cannot join
- 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.
- 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.
- Known Central Nervous System (CNS) metastases.
- 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.
- History of hypersensitivity and/or other adverse effects to corticosteroids.
- Known Diabetes mellitus (type 1 or type 2) or Random Blood Sugar (RBS) of ≥11.1 mmol/L.
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- Clinically significant osteoporosis unless treated with denosumab or bisphosphonates.
- Have (history of) clinically significant ocular conditions such as glaucoma, papilledema and retinopathy.
- Presence of clinically significant or uncontrolled cardiovascular disease such as:
- Congestive Heart Failure: > New York Heart Association (NYHA) class II.
- 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.
- Clinically significant cardiac arrhythmias.
- Therapy resistant hypertension in the opinion of investigator.
- For participants receiving Ribociclib: QTcF > 480 ms.
- 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.
- Known history of psychosis or suicidal ideation.
- Are taking a prohibited medication (as defined in section 9.1.2) that cannot be discontinued for the duration of the study.
- 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.
- Participation in any other interventional study or receiving any other anti-cancer therapy other than endocrine therapy.
Trial locations and contacts
No sites are listed yet. Contact the study team or a site near you to ask about taking part.
About this study
Official title: 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.
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.
- Conditions
- Breast Cancer
- Being tested
- Dexamethasone (Oral)
- Keywords
- ER positive, HER2 negative, Metastatic breast cancer, Dexamethasone, Endocrine treatment
- Medical subject headings
- Breast Neoplasms
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Dexamethasone (Oral)Drug
Commercially available Dexamethasone in tablet form 1.5mg or 4mg
| Study group | Role | What they receive |
|---|---|---|
| Part 1: Dose 1 Dexamethasone + prior ET | Experimental | Dose 1 = Dexamethasone 3mg once daily, 1 week on, 3 weeks off schedule Receives: Drug: Dexamethasone (Oral) |
| Part 2: Dose 2 Dexamethasone + prior ET | Experimental | Dose 2 = Dexamethasone either 1.5mg or 4mg once daily, 1 week on, 3 weeks off schedule. Depending on the results of Part 1. Receives: Drug: Dexamethasone (Oral) |
What is being measured
The primary outcome is the main question the study is designed to answer.
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.
Measured: At the 16th week tumour evaluation.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 Aug 2026
- Study start1 Nov 2026 (estimated)
- Primary completion1 Nov 2028 (estimated)
- Study completion1 Nov 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Breast CancerStudies of the same condition, open and under way.
- More trials run by The Netherlands Cancer InstituteThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
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 2
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Sequential
- 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.
- Masking
- None (open label)
- Enrolment
- 80 participants (estimated)
Sponsor and investigators
- Lead sponsor
- The Netherlands Cancer Institute
- Sponsor type
- University, hospital or other
- Collaborators
- Oncode Institute
- Responsible party
- Sponsor
- Investigators
- Vincent Dezentjé, MD PhD, Principal investigator, The Netherlands Cancer Institute
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07786051
- Sponsor's protocol ID
- N26DMT
- Other IDs
- 2026-526816-35-00
- Acronym
- DEMETER
- Status last verified
- Jul 2026
- First submitted
- 21 Aug 2026
- Last updated
- 25 Aug 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided: To be determined
Study at a glance
From the registry record, last updated by the sponsor on 25 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- 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.
- ClinicalTrials.gov ID
- NCT07786051
- Acronym / sponsor ID
- DEMETER / N26DMT
- Conditions
- Breast Cancer
- Keywords
- ER positive, HER2 negative, Metastatic breast cancer, Dexamethasone, Endocrine treatment
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 80 participants (estimated)
- Lead sponsor
- The Netherlands Cancer InstituteUniversity, hospital or other
- Collaborators
- Oncode Institute
- Study start
- 1 Nov 2026 (estimated)
- Primary completion
- 1 Nov 2028 (estimated)
- Study completion
- 1 Nov 2028 (estimated)
- First posted
- 25 Aug 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Study design
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Sequential
- Masking
- None (open label)
- Number of arms
- 2
- 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.
| Arm | Type | Receives |
|---|---|---|
| Part 1: Dose 1 Dexamethasone + prior ET | Experimental | Drug: Dexamethasone (Oral)Dose 1 = Dexamethasone 3mg once daily, 1 week on, 3 weeks off schedule |
| Part 2: Dose 2 Dexamethasone + prior ET | Experimental | Drug: Dexamethasone (Oral)Dose 2 = Dexamethasone either 1.5mg or 4mg once daily, 1 week on, 3 weeks off schedule. Depending on the results of Part 1. |
Who may qualify
- Ages
- 18 years and older
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (19 listed)
- Have provided written informed consent and are willing to comply to study procedures and treatment plan.
- 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.
- 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.
- Participants must meet one of the following criteria:
- Have metastatic disease.
Key exclusion criteria (19 listed)
- 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.
- 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.
- Known Central Nervous System (CNS) metastases.
- 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.
- History of hypersensitivity and/or other adverse effects to corticosteroids.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Dexamethasone (Oral)Commercially available Dexamethasone in tablet form 1.5mg or 4mg | Drug | Part 1: Dose 1 Dexamethasone + prior ET, Part 2: Dose 2 Dexamethasone + prior ET |
Primary outcome
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.
Time frame: At the 16th week tumour evaluation.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 25 Aug 2026.
- Individual participant dataSharing planned: Undecided. To be determined
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Vincent Dezentjé, MD PhD principal investigator
The Netherlands Cancer Institute
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing Dexamethasone (Oral) in people with Breast Cancer, run by The Netherlands Cancer Institute.
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 19 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: opening soon, as of the sponsor's last update on 25 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
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.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
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 Wilbert Zwart, PhD (+31205129111, w.zwart@nki.nl), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
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. (time frame: At the 16th week tumour evaluation.). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 25 Aug 2026.