A Phase 3 interventional study of Elacestrant and Anastrozole in Breast Cancer, sponsored by Stemline Therapeutics, Inc.. Active, not recruiting at 555 sites in 28 countries. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-11-04.
Sponsored by Stemline Therapeutics, Inc. (part of Menarini Group) · Phase 3, Interventional, and Treatment
The primary goal of this study is to evaluate the effectiveness of elacestrant versus standard endocrine therapy in participants with node-positive, Estrogen Receptor-positive (ER+), Human Epidermal Growth Factor-2 negative (HER2-) early breast cancer with high risk of recurrence.
14,825 studies on the registry are indexed under Breast Neoplasms; 3,319 are open to participants now.
This study's enrollment of 4,556 is above the median of 72 across 10,896 interventional studies indexed under Breast Neoplasms.
Browse Breast Neoplasms studies →Stemline Therapeutics, Inc. is the lead sponsor of 23 studies on the registry; 7 are open to participants now.
First submitted after Stemline Therapeutics, Inc. became part of Menarini Group.
Counted across the registry records on this site, refreshed daily.
Key Inclusion Criteria:
Participants must be node positive (microscopic and macroscopic tumor involvement are allowed) and fulfill one of the following criteria:
1-3 positive axillary lymph nodes and
Key Exclusion Criteria:
Note: Other protocol defined Inclusion/Exclusion criteria may apply.
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The diagnosis was confirmed by looking at a sample under a microscope: tissue from a biopsy or surgery (histology), or cells from a fluid or needle sample (cytology).
Your pathology report is the document that shows this.
HER2 is a protein, made from the ERBB2 gene, that drives the growth of some cancers. A study may look for a level of the protein, extra copies of the gene, or a particular change in it.
In breast cancer, protein tests are read as HER2-positive, HER2-low or HER2-negative; other cancers use their own rules. Check which test result the study requires.
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Neoadjuvant treatment is given before the main treatment (usually surgery), often to shrink a tumour. Adjuvant treatment is given after it, to lower the chance of the cancer coming back.
Histologically or cytologically confirmed
The diagnosis was confirmed by looking at a sample under a microscope: tissue from a biopsy or surgery (histology), or cells from a fluid or needle sample (cytology).
Your pathology report is the document that shows this.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HER2
HER2 is a protein, made from the ERBB2 gene, that drives the growth of some cancers. A study may look for a level of the protein, extra copies of the gene, or a particular change in it.
In breast cancer, protein tests are read as HER2-positive, HER2-low or HER2-negative; other cancers use their own rules. Check which test result the study requires.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Biopsy and archival tissue
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Metastases
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Adjuvant and neoadjuvant
Neoadjuvant treatment is given before the main treatment (usually surgery), often to shrink a tumour. Adjuvant treatment is given after it, to lower the chance of the cancer coming back.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants will receive 345 milligrams (mg) elacestrant once daily (QD) for 5 years.
Drug: Elacestrant
Participants will receive the SoC endocrine therapy that was used prior to randomization: * AI (anastrozole 1 mg QD, letrozole 2.5 mg QD, or exemestane 25 mg QD); or * Tamoxifen 20 mg QD
Drug: Anastrozole · Drug: Letrozole · Drug: Exemestane · Drug: Tamoxifen
Administered as oral tablets
Administered as oral tablets
Administered as oral tablets
Administered as oral tablets
Administered as oral tablets
Invasive Breast Cancer-Free Survival (IBCFS)
Assessed by the time from date of randomization to the date of first occurrence of: * Ipsilateral invasive breast tumor recurrence * Local/regional invasive breast cancer recurrence * Distant recurrence * Contralateral invasive breast cancer, or * Death attributable to any cause
Time frame: Up to 5 years
Distant Relapse-Free Survival (DRFS)
Assessed by the time from date of randomization to the date of first occurrence of: * Distant recurrence, or * Death attributable to any cause
Time frame: Up to 5 years
Overall Survival (OS)
Time frame: Up to 5 years
Invasive Disease-Free Survival (IDFS)
Assessed by the time from date of randomization to the date of first occurrence of: * Local/regional recurrence * Contralateral recurrence * Second primary non-breast invasive cancer * Distant recurrence, or * Death attributable to any cause
Time frame: Up to 5 years
Number of Participants With Adverse Events (AEs)
Time frame: Up to 5 years plus 28 days
Change from Baseline in Global Health Status Quality of Life Scale score, as Assessed by the European Organization for the Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30)
Time frame: Baseline, Month 6, Annually at Years 1, 2, 3, 4, 5
Change from Baseline in the Physical Functioning Sub-Scale Score as Assessed by EORTC QLQ-C30
Time frame: Baseline, Month 6, Annually at Years 1, 2, 3, 4, 5
Change From Baseline in the Breast Cancer Endocrine Therapy Symptoms Sub-Scale Score, as Assessed by the EORTC Quality of Life Breast Cancer Questionnaire module (EORTC QLQ-BR42)
Time frame: Baseline, Month 6, Annually at Years 1, 2, 3, 4, 5
Change From Baseline in Side Effects, as Assessed by the Question 168 of the European Organization for the Research and Treatment of Cancer Question Library (EORTC Q168)
Time frame: Baseline, Month 6, Annually at Years 1, 2, 3, 4, 5
Area Under the Plasma Concentration Versus Time Curve at Steady State (AUCss) of Elacestrant
Time frame: Predose up to 4 hours postdose
Maximum Plasma Concentration at Steady State (Cmaxss) of Elacestrant
Time frame: Predose up to 4 hours postdose
Showing the first 100 of 555 sites across 28 countries. Choose a country and city above to see the rest.
Started Sep 2024 (actual). Primary completion is estimated for Aug 2029, 59 months after the start.
Of 272 industry-sponsored phase 3 interventional studies under Breast Neoplasms, half reached primary completion within 40 months of starting (the median), counting those still running; a quarter within 28 and three quarters within 63. This study's planned 59 months is above that.
Counting every sponsor, half of 600 studies reached it within 59 months; a quarter within 36 and three quarters within 96.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is active, not recruiting, as verified in Nov 2026. You cannot join it, but the record below documents what was studied.
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Studies of the drugs tested here: Elacestrant · Letrozole · Tamoxifen