OligoProgressive Metastatic DiseaseNCT06925984
Stereotactic Radiotherapy for Oligoprogressive ER+/HER- Metastatic Breast Cancer, a Prospective Phase 2 Study (Oligopro-Breast)
A study testing SBRT in people with OligoProgressive Metastatic Disease, run by Jules Bordet Institute at 5 sites in Belgium.
Trial summary
The Oligopro-Breast trial is a Phase II study targeting women with ER+/HER2- metastatic breast cancer who have been on endocrine therapy and/or CDK4/6 inhibitors for at least 6 months, and show progressive disease at 1-3 extracranial metastases, which are treatable locally. Read more about this study
- Who is it for?
- Ages 18 years and older, women only
- Conditions the study is for
- OligoProgressive Metastatic Disease
- What is being tested?
- SBRT
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 48 participants
- Where
- 5 sitesBelgium
- Study dates
- 30 Oct 2025to 1 May 2030
- 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 years and older
- Women only
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- ECOG performance status 0-2.
- Histologically confirmed ER+/HER2- MBC.
- History of polymetastatic disease. Patients with genuine oligometastatic disease and 1-3 oligoprogressive lesions are only allowed if ablative therapy of all metastases is deemed impossible.
- Under 1st to 2nd systemic treatment line with hormonotherapy and/or CDK4/6 inhibitors for at least 6 months before progression.
- Progressive disease at 1-3 extracranial sites.
- Ability to treat all progressive lesions locally according to the treating radiation oncologist.
Who cannot join
- Second malignancy if it is not in complete remission.
- Previous local treatment for oligoprogression under the current systemic treatment line
- Current progression in a lesion that has been treated with SBRT before and is not amendable for surgery or radiofrequency ablation (RFA).
- Progressive or newly diagnosed brain metastases. Known brain metastases that have been nonprogressive for at least 6 months, are not an exclusion criterion.
- Inability to continue the same ST line after local therapy (for example because of toxicity or patient refusal).
- Pregnancy.
- Inability to sign the informed consent.
Trial locations and contacts
5 sites in 1 country. Contact the study team or a site near you to ask about taking part.
5 sites in 1 country
Belgium5 sites, 5 recruiting
- Recruiting
Jules Bordet Institute
Brussels
Alex De Caluwé, MD, +32 2 541 38 28, alex.decaluwe@hubruxelles.be
- Recruiting
UZ Gent
Ghent
Liv Veldeman, MD PhD, +32 9 332 30 15
- Recruiting
AZ Groeninge
Kortrijk
Isabelle Kindts, MD PhD, +32 56 63 39 03, radiotherapie@azgroeninge.be
- Recruiting
AZ Sint-Maarten
Mechelen
Alex De Caluwé, MD, +32 15 89 29 80, azsintmaarten@emmaus.be
- Recruiting
CHU UCL Namur - Site Saint Elisabeth
Namur
Vincent Remouchamps, MD PhD, +32 81 72 05 25, sormn.se@chuuclnamur.uclouvain.be
About this study
Official title: The Oligopro-Breast Study: Stereotactic Radiotherapy for Oligoprogressive ER+/HER- Metastatic Breast Cancer, a Prospective Phase 2 Study
The Oligopro-Breast trial is a Phase II study targeting women with ER+/HER2- metastatic breast cancer who have been on endocrine therapy and/or CDK4/6 inhibitors for at least 6 months, and show progressive disease at 1-3 extracranial metastases, which are treatable locally. The trial aims to investigate if treating these resistant metastases with SBRT (or other local treatments if SBRT is not possible) can extend the use of the current systemic therapy.
Patients will continue their existing systemic treatment while receiving SBRT on all progressive lesions. If new oligoprogression occurs, SBRT will be performed again. A new systemic treatment line will start if there is polyprogression (more than 3 lesions at once), progression of more than 6 lesions over 12 months, intracranial progression, or lesions that cannot be treated locally.
Read more
The scientific question is whether local treatment of resistant metastases can prolong the effectiveness of ongoing systemic therapy, which is particularly beneficial if the treatment is well-tolerated. The primary objective is to measure the proportion of patients surviving without changing their systemic treatment line at 6 months after SBRT.
This trial is significant for patients as it explores a method to potentially extend the duration of effective and well-tolerated treatments, offering hope for better management of metastatic breast cancer.
- Conditions
- OligoProgressive Metastatic Disease
- Being tested
- SBRT
- Keywords
- Oligoprogression, metastatic breast cancer, CDK4/6 inhibitors, SBRT, SABR, radiotherapy
- Medical subject headings
- Breast Neoplasms
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
SBRTRadiation
SBRT of all oligoprogressive metastases (or other local therapy if SBRT not advisable), followed by continuation of the same systemic therapy.
| Study group | Role | What they receive |
|---|---|---|
| SBRT on the oligoprogressive metastases. Continuation of same systemic therapy. | Experimental | Not described Receives: Radiation: SBRT |
What is being measured
The primary outcome is the main question the study is designed to answer.
NExt Systemic Treatment-Free Survival (NEST-FS)
Measured: At 6 months
Secondary outcomes (9)
Time to next line of systemic therapy (NEST)
Measured: 3 years
Progression-free survival (PFS)
Measured: 3 years
Modified Progression-free survival (mPFS)
Defined as the survival in the absence of any of the following : (1) polyprogression (progressive disease of more than 3 lesions at the same time), (2) progression of more than 6 lesions over a 12-month rolling period, (3) intracranial progression, (4) progressing lesion that cannot be treated locally, or (5) death.
Measured: 3 years
Chemotherapy-free survival
Measured: 3 years
Progression-free survival after start of the subsequent line of systemic treatment (PFS2)
Measured: 3 year
Patterns of metastatic progression
We defined four patterns of progression: stable disease, progression on untreated pre-existing lesions, progression on treated lesions, or development of new lesions. In case of progression, it will also be determined whether it is oligoprogression (progression of 3 lesions or less) or polyprogression (progression of more than 3 lesions).
Measured: 3 years
Overall survival (OS)
Measured: 3 years
Acute and late physician-scored toxicity of the local intervention
Acute and late physician-scored toxicity of the local intervention (CTCAE 5.0, Early: within 90 days; late: 90 or more days after SBRT);
Measured: 3 years
Quality of life (QoL)
Evolution of QoL measured with the EORTC QLQ-C30
Measured: 3 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted13 Apr 2025
- Study start30 Oct 2025
- Primary completion1 May 2028 (estimated)
- Study completion1 May 2030 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for OligoProgressive Metastatic DiseaseStudies of the same condition, open and under way.
- 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 N/A
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 48 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Jules Bordet Institute
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06925984
- Sponsor's protocol ID
- CE4005
- Status last verified
- Oct 2025
- First submitted
- 26 Mar 2025
- Last updated
- 2 Feb 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 2 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Oligopro-Breast Study: Stereotactic Radiotherapy for Oligoprogressive ER+/HER- Metastatic Breast Cancer, a Prospective Phase 2 Study
- ClinicalTrials.gov ID
- NCT06925984
- Acronym / sponsor ID
- CE4005
- Conditions
- OligoProgressive Metastatic Disease
- Keywords
- Oligoprogression, metastatic breast cancer, CDK4/6 inhibitors, SBRT, SABR, radiotherapy
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 48 participants (estimated)
- Lead sponsor
- Jules Bordet InstituteUniversity, hospital or other
- Study start
- 30 Oct 2025 (actual)
- Primary completion
- 1 May 2028 (estimated)
- Study completion
- 1 May 2030 (estimated)
- First posted
- 13 Apr 2025 (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.
The Oligopro-Breast trial is a Phase II study targeting women with ER+/HER2- metastatic breast cancer who have been on endocrine therapy and/or CDK4/6 inhibitors for at least 6 months, and show progressive disease at 1-3 extracranial metastases, which are treatable locally. The trial aims to investigate if treating these resistant metastases with SBRT (or other local treatments if SBRT is not possible) can extend the use of the current systemic therapy.
Patients will continue their existing systemic treatment while receiving SBRT on all progressive lesions. If new oligoprogression occurs, SBRT will be performed again. A new systemic treatment line will start if there is polyprogression (more than 3 lesions at once), progression of more than 6 lesions over 12 months, intracranial progression, or lesions that cannot be treated locally.
The scientific question is whether local treatment of resistant metastases can prolong the effectiveness of ongoing systemic therapy, which is particularly beneficial if the treatment is well-tolerated. The primary objective is to measure the proportion of patients surviving without changing their systemic treatment line at 6 months after SBRT.
This trial is significant for patients as it explores a method to potentially extend the duration of effective and well-tolerated treatments, offering hope for better management of metastatic breast cancer.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| SBRT on the oligoprogressive metastases. Continuation of same systemic therapy. | Experimental | Radiation: SBRT |
Who may qualify
- Ages
- 18 years and older
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- ECOG performance status 0-2.
- Histologically confirmed ER+/HER2- MBC.
- History of polymetastatic disease. Patients with genuine oligometastatic disease and 1-3 oligoprogressive lesions are only allowed if ablative therapy of all metastases is deemed impossible.
- Under 1st to 2nd systemic treatment line with hormonotherapy and/or CDK4/6 inhibitors for at least 6 months before progression.
- Progressive disease at 1-3 extracranial sites.
Key exclusion criteria (7 listed)
- Second malignancy if it is not in complete remission.
- Previous local treatment for oligoprogression under the current systemic treatment line
- Current progression in a lesion that has been treated with SBRT before and is not amendable for surgery or radiofrequency ablation (RFA).
- Progressive or newly diagnosed brain metastases. Known brain metastases that have been nonprogressive for at least 6 months, are not an exclusion criterion.
- Inability to continue the same ST line after local therapy (for example because of toxicity or patient refusal).
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 |
|---|---|---|
| SBRTSBRT of all oligoprogressive metastases (or other local therapy if SBRT not advisable), followed by continuation of the same systemic therapy. | Radiation | SBRT on the oligoprogressive metastases. Continuation of same systemic therapy. |
Primary outcome
NExt Systemic Treatment-Free Survival (NEST-FS)
Time frame: At 6 months
9 secondary outcomes
Time to next line of systemic therapy (NEST)
Time frame: 3 years
Progression-free survival (PFS)
Time frame: 3 years
Modified Progression-free survival (mPFS)
Time frame: 3 years
Chemotherapy-free survival
Time frame: 3 years
Progression-free survival after start of the subsequent line of systemic treatment (PFS2)
Time frame: 3 year
Patterns of metastatic progression
Time frame: 3 years
Overall survival (OS)
Time frame: 3 years
Acute and late physician-scored toxicity of the local intervention
Time frame: 3 years
Quality of life (QoL)
Time frame: 3 years
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 2 Feb 2026.
- Individual participant dataSharing planned: No
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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.
5 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing SBRT in people with OligoProgressive Metastatic Disease, run by Jules Bordet Institute at 5 sites in Belgium.
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 6 inclusion and 7 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 2 Feb 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 5 sites in Belgium. 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 Robbe Van den Begin, MD PhD (+32 2 541 38 28, robbe.vandenbegin@hubruxelles.be), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
NExt Systemic Treatment-Free Survival (NEST-FS) (time frame: At 6 months). 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 2 Feb 2026.