Breast CancerPhase 4INTERSTELLARNCT05333328
OFS in Premenopausal Node+ Breast Cancer With Low Genomic Risk
A Phase 4 study testing Ovarian function suppression with endocrine treatments in people with Breast Cancer and Estrogen Receptor Positive Tumor, run by Gangnam Severance Hospital at 2 sites in South Korea.
Trial summary
Among ER+HER2- premenopausal patients with N1 who undergoes primary breast surgery, we will identify the patients with a genomic low risk using the multigene-assay (OncoFREE®). In these, ovarian function suppression with endocrine therapies including either tamoxifen or aromatase-inhibitors will be administered for 5… Read more about this study
- Who is it for?
- Ages 20 to 50 years, women only
- Conditions the study is for
- Breast Cancer, Estrogen Receptor Positive Tumor, HER2-negative Breast Cancer
- What is being tested?
- Ovarian function suppression with endocrine treatments
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 418 participants
- Where
- 2 sitesSouth Korea
- Study dates
- 6 Feb 2023to Jan 2033
- Phase
- Phase 4
- 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 20 to 50 years
- Women only
- No healthy volunteers
- Adult
Who may be able to join
- ER+HER2- breast cancer
- Premenopausal and age <=50
- T1 or T2
- N1 including micrometastasis
- Genomic Low Risk by OncoFREE test® (1-20)
Who cannot join
- Postmenopausal women
- ER-negative breast cancer
Trial locations and contacts
2 sites in 1 country. Contact the study team or a site near you to ask about taking part.
South Korea2 sites, 2 recruiting
- Recruiting
Gangnam Severance Hospital
Seoul, Korea, 06229
Sung Gwe Ahn, MD, PhD, 0220193370, asg2004@yuhs.ac
asg2004@yuhs.ac
- Not yet recruiting
Seoul National University Hospital
Seoul
Hyeoung Gon Moon
About this study
Official title: Endocrine Therapies With Ovarian Function Suppression in Premenopausal Node+ Early Breast Cancer With Low Genomic Risk (INTERSTELLAR Trial, KBCSG-25)
Among ER+HER2- premenopausal patients with N1 who undergoes primary breast surgery, we will identify the patients with a genomic low risk using the multigene-assay (OncoFREE®).
In these, ovarian function suppression with endocrine therapies including either tamoxifen or aromatase-inhibitors will be administered for 5 years.
Read the detailed description
- Among ER+HER2- premenopausal patients with N1 who undergoes primary breast surgery, we will identify the patients with a genomic low risk using the multigene-assay (OncoFREE®).
- In these, ovarian function suppression (OFS) with endocrine therapies including either tamoxifen or aromatase-inhibitors will be administered for 5 years.
- Either goserelin acetate or leuprorelin Acetate is allowed.
- These patients are able to choose bilateral salpingo-oophorectomy instead of OFS.
- Chemotherapy is omitted in these patients.
- Conditions
- Breast Cancer, Estrogen Receptor Positive Tumor, HER2-negative Breast Cancer, Premenopausal Breast Cancer, Node-positive Breast Cancer
- Being tested
- Ovarian function suppression with endocrine treatments
- Keywords
- Breast Cancer, Estrogen Receptor Positive Tumor, HER2-negative Breast Cancer, Premenopausal Breast Cancer, Node-positive Breast Cancer, Multigene assay, Ovarian-function suppression
- Medical subject headings
- Breast Neoplasms
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Ovarian function suppression with endocrine treatmentsDrug
- Ovarian function suppression (OFS) with endocrine therapies including either tamoxifen or aromatase-inhibitors will be administered for 5 years.
- Either goserelin acetate or leuprorelin Acetate is allowed.
- These patients are able to choose bilateral salpingo-oophorectomy instead of OFS.
- Chemotherapy is omitted in these patients.
| Study group | Role | What they receive |
|---|---|---|
| OFS with endocrine | Experimental | Among ER+HER2- premenopausal patients with N1 who undergoes primary breast surgery, the patients with a genomic low risk using the multigene-assay (OncoFREE®) will be included in this arm. Receives: Drug: Ovarian function suppression with endocrine treatments |
What is being measured
The primary outcome is the main question the study is designed to answer.
Distant recurrence-free survival
The interval between the date of primary surgery and the date of last censored, or distant recurrence or death of any cause
Measured: 5-years distant recurrence-free survival
Secondary outcomes (2)
Recurrence-free survival (RFS)
The interval between the date of primary surgery and the date of last censored, or any type of recurrence or death of any cause
Measured: 5-years RFS
Invasive disease-free survival (iDFS)
The interval between the date of primary surgery and the date of last censored, or any type of invasive disease except thyroid cancer or death of any cause
Measured: 5-years iDFS
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted18 Apr 2022
- Study start6 Feb 2023
- Primary completionJan 2031 (estimated)
- Study completionJan 2033 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Breast CancerStudies 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 4
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Model description
- De-escalating treatment as ovarian-function suppression with endocrine treatments alone in ER+HER2- premenopausal women with N1
- Masking
- None (open label)
- Enrolment
- 418 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Gangnam Severance Hospital
- Sponsor type
- University, hospital or other
- Collaborators
- Seoul National University
- Responsible party
- Principal investigator, Sung Gwe Ahn, Gangnam Severance Hospital
- Investigators
- Sung Gwe Ahn, M.D.,Ph.D., Principal investigator, Gangnam Severance Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05333328
- Sponsor's protocol ID
- 2021-1151-002
- Acronym
- INTERSTELLAR
- Status last verified
- May 2025
- First submitted
- 11 Apr 2022
- Last updated
- 22 May 2025
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Ahn SG, Sim SH, Kang T, Kim EK, Lee JE, Moon HG, Ahn JH, Lim W, Youn HJ, Kim HA, Yoon CI, Kim J, Kang B, Park MH, Kang SH, Kim LS, Bae SJ, Kook Y, Lee KH, Lee HB, Han W, Park YH. Prospective Single-Arm Study of Endocrine Therapies With Ovarian Function Suppression in Premenopausal Node-Positive Early Breast Cancer Patients With Low Genomic Risk (INTERSTELLAR Trial, KBCSG-25). J Breast Cancer. 2026 Feb;29(1):81-89. doi: 10.4048/jbc.2025.0181. Epub 2026 Jan 30.
PubMed 41612658
Study at a glance
From the registry record, last updated by the sponsor on 22 May 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Endocrine Therapies With Ovarian Function Suppression in Premenopausal Node+ Early Breast Cancer With Low Genomic Risk (INTERSTELLAR Trial, KBCSG-25)
- ClinicalTrials.gov ID
- NCT05333328
- Acronym / sponsor ID
- INTERSTELLAR / 2021-1151-002
- Conditions
- Breast Cancer, Estrogen Receptor Positive Tumor, HER2-negative Breast Cancer, Premenopausal Breast Cancer, Node-positive Breast Cancer
- Keywords
- Breast Cancer, Estrogen Receptor Positive Tumor, HER2-negative Breast Cancer, Premenopausal Breast Cancer, Node-positive Breast Cancer, Multigene assay, Ovarian-function suppression
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 418 participants (estimated)
- Lead sponsor
- Gangnam Severance HospitalUniversity, hospital or other
- Collaborators
- Seoul National University
- Study start
- 6 Feb 2023 (actual)
- Primary completion
- Jan 2031 (estimated)
- Study completion
- Jan 2033 (estimated)
- First posted
- 18 Apr 2022 (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.
Among ER+HER2- premenopausal patients with N1 who undergoes primary breast surgery, we will identify the patients with a genomic low risk using the multigene-assay (OncoFREE®).
In these, ovarian function suppression with endocrine therapies including either tamoxifen or aromatase-inhibitors will be administered for 5 years.
Detailed description
- Among ER+HER2- premenopausal patients with N1 who undergoes primary breast surgery, we will identify the patients with a genomic low risk using the multigene-assay (OncoFREE®).
- In these, ovarian function suppression (OFS) with endocrine therapies including either tamoxifen or aromatase-inhibitors will be administered for 5 years.
- Either goserelin acetate or leuprorelin Acetate is allowed.
- These patients are able to choose bilateral salpingo-oophorectomy instead of OFS.
- Chemotherapy is omitted in these patients.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- De-escalating treatment as ovarian-function suppression with endocrine treatments alone in ER+HER2- premenopausal women with N1
| Arm | Type | Receives |
|---|---|---|
| OFS with endocrine | Experimental | Drug: Ovarian function suppression with endocrine treatmentsAmong ER+HER2- premenopausal patients with N1 who undergoes primary breast surgery, the patients with a genomic low risk using the multigene-assay (OncoFREE®) will be included in this arm. |
Who may qualify
- Ages
- 20 to 50 years
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (5 listed)
- ER+HER2- breast cancer
- Premenopausal and age <=50
- T1 or T2
- N1 including micrometastasis
- Genomic Low Risk by OncoFREE test® (1-20)
Key exclusion criteria (2 listed)
- Postmenopausal women
- ER-negative breast cancer
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 |
|---|---|---|
| Ovarian function suppression with endocrine treatments* Ovarian function suppression (OFS) with endocrine therapies including either tamoxifen or aromatase-inhibitors will be administered for 5 years. * Either goserelin acetate or leuprorelin Acetate is allowed. * These patients are able to choose bilateral salpingo-oophorectomy instead of OFS. * Chemotherapy is omitted in these patients. | Drug | OFS with endocrine |
Primary outcome
Distant recurrence-free survival
Time frame: 5-years distant recurrence-free survival
The interval between the date of primary surgery and the date of last censored, or distant recurrence or death of any cause
2 secondary outcomes
Recurrence-free survival (RFS)
Time frame: 5-years RFS
Invasive disease-free survival (iDFS)
Time frame: 5-years iDFS
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 22 May 2025.
- Derived from this study: PubMed 41612658Ahn SG, Sim SH, Kang T, Kim EK, Lee JE, Moon HG, Ahn JH, Lim W, Youn HJ, Kim HA, Yoon CI, Kim J, Kang B, Park MH, Kang SH, Kim LS, Bae SJ, Kook Y, Lee KH, Lee HB, Han W, Park YH. Prospective Single-Arm Study of Endocrine Therapies With Ovarian Function Suppression in Premenopausal Node-Positive Early Breast Cancer Patients With Low Genomic Risk (INTERSTELLAR Trial, KBCSG-25). J Breast Cancer. 2026 Feb;29(1):81-89. doi: 10.4048/jbc.2025.0181. Epub 2026 Jan 30.
- 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.
Sung Gwe Ahn, M.D.,Ph.D. principal investigator
Gangnam Severance Hospital
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing Ovarian function suppression with endocrine treatments in people with Breast Cancer and Estrogen Receptor Positive Tumor, run by Gangnam Severance Hospital at 2 sites in South Korea.
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 5 inclusion and 2 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 22 May 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in South Korea. 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.
What does this phase mean?
Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
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 Sung Gwe Ahn, M.D.,Ph.D. (0220193370, asg2004@yuhs.ac), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Distant recurrence-free survival (time frame: 5-years distant recurrence-free survival). 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 NCT05333328, which also lists 1 linked publication.
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 22 May 2025.