Open-Label Study of Elacestrant Combinations for Metastatic Breast Cancer
This study is testing different combinations of a drug called elacestrant with other approved medications (alpelisib, everolimus, ribociclib, or palbociclib) for people with metastatic breast cancer that is estrogen receptor positive and HER2 negative (ER+/HER2-). The main goals are to find a safe dose for these combinations and to see how well they work. You may be eligible if you are 18 or older and have this type of breast cancer. The study is open-label, meaning both you and your doctors will know which treatment you are receiving. The study aims to enroll 435 participants.
- Study design
- This is an open-label, multi-center Phase 1b/2 study. It plans to enroll up to 435 participants to test elacestrant in combination with other drugs.
- What's involved
- Not specified in the trial record.
- Compensation
- Not stated in the trial record.
- Follow-up
- The study will measure how long participants live without their cancer getting worse (progression-free survival) at 6 months.
AI-generated from the public study record. Only the study team can confirm whether you're eligible — confirm details with them before making decisions.
NCT05563220
Open-Label Umbrella Study To Evaluate Safety And Efficacy Of Elacestrant In Various Combination In Participants With Metastatic Breast Cancer
Active, Not Recruiting
PHASE1Ages 18+InterventionalTreatmentStemline Therapeutics, Inc.
~435 participants
Updated 2026-06-12 on ClinicalTrials.gov
What's tested:ElacestrantAlpelisibEverolimusRibociclibPalbociclibCapivasertib
At a glance
Recruiting sites
0 of 83 listed sites are recruiting right now
RecruitingSuspended, closed, or not yet open
What they're measuring
Number of Participants with DLTs Observed During the First Cycle
Measured over 28 days
+1 more outcome measured
Conditions
Where it's being run
83 sites across 34 statesSpain13
California6
Brazil5
France5
Israel5
Italy4
United Kingdom4
New Jersey3
Who to contact
This trial hasn't published a contact. View it on ClinicalTrials.gov
Do you actually qualify for this trial?
Add a private profile and we'll compare every criterion below against your situation — and tell you which ones are met, uncertain, or excluding.
Eligibility criteria
Inclusion
Postmenopausal status is defined as follows or in accordance with local regulations:
Premenopausal and perimenopausal women (who do not fit postmenopausal criteria) and men must be receiving a luteinizing hormone-releasing hormone (LHRH) agonist and must be initiated at least 3 weeks (4 depending on local label) before the start of trial therapy and are planning to continue LHRH agonist treatment during the study treatment. 3. Histopathological or cytological confirmed ER+, HER2-, breast cancer, per local laboratory, as per the American Society of Clinical Oncology/College of American Pathologists guidelines. Note: In the context of this trial, ER status will be considered positive if ≥10% of tumor cells demonstrate positive nuclear staining by immunohistochemistry, with or without progesterone positivity. 4. Documented radiological disease progression during or after the most recent therapy. 5. At least 1 measurable lesion as per Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST v1.1). Tumor lesions previously irradiated or subjected to any locoregional treatment will only be considered measurable if there is clear, documented progression at the treated site. For participants with bone only disease, lesions: must be lytic or mixed (lytic + blastic / sclerotic), confirmed and accurately assessed by computed tomography or magnetic resonance imaging, and must have an identifiable soft tissue component meeting the definition of measurability per RECIST v1.1. Note: participants with blastic / sclerotic bone lesions only are not eligible. 6. Eastern Cooperative Oncology Group performance status of 0 or 1. 7. Participant has adequate bone marrow and organ function, as defined by the following laboratory values:
Creatinine clearance (male) = (\[140-age in years\] × weight in kilograms \[kg\])/ (\[serum creatinine in milligrams/deciliter (mg/dL)\] × 72)
Creatinine clearance (female) = (0.85 × \[140-age in years\] × weight in kg)/ (\[serum creatinine in mg/dL\] × 72)
Exclusion
Participants with hepatitis B virus and/or hepatitis C virus infection must have undetectable viral load during screening.
Participants known to be human immunodeficiency virus+ are allowed if they have undetectable viral load at baseline. 8. Documented pneumonitis/interstitial lung disease prior to Cycle 1 Day 1. 9. Major surgery within 28 days before starting trial therapy. 10. Inability to take oral medications, refractory or chronic nausea, gastrointestinal conditions (including significant gastric or bowel resection), history of malabsorption syndrome, or any other uncontrolled gastrointestinal condition that impact the absorption of the study drug. 11. Known intolerance to elacestrant or any of its excipients. 12. Pregnant and breast-feeding women are excluded from the study. In addition, women of childbearing potential are excluded who:
Within 28 days before starting trial therapy, did not use a highly effective method of contraception.
Do not agree to use a highly effective method of contraception (Appendix F) or abstain from heterosexual intercourse throughout the entire study period and for 120 days after trial therapy discontinuation. 13. Men or women who do not agree to abstain from donating sperm or ova, or to use a highly effective method of contraception, 28 days prior, during the course of the treatment period and for 120 days after the last dose of study treatment. 14. Participant is currently receiving or received any of the following medications prior to first dose of trial therapy:
Known strong or moderate inducers or inhibitors of cytochrome P450 (CYP) 3A4 within 14 days or 5 half-lives, whichever is shorter, (refer to https://drug-interactions.medicine.iu.edu/maintable.aspx or https://www.fda.gov/drugs/drug-interactions-labeling/drug-development-and-drug-interactions-table-substrates-inhibitors-and-inducers).
Herbal preparations/medications within 7 days. These include, but are not limited to, St. John's wort, kava, ephedra (ma huang), gingko biloba, dehydroepiandrosterone, yohimbe, saw palmetto, and ginseng.
Vaccination, including but not limited to vaccination against COVID-19, during the 7 days prior to starting trial therapy. 15. Evidence of ongoing alcohol or drug abuse as assessed by the investigator. 16. Any severe medical or psychiatric condition that, in the Investigator's opinion, would preclude the participant's participation in a clinical study.
Long QT syndrome
Uncontrolled or significant cardiac disease including recent (6 months) myocardial infarction, congestive heart failure, unstable angina, and brady-arrhythmias
Electrolyte abnormalities (K+, Ca++, Phos, Mg++) ≥Grade 1 5. Participant is currently receiving or received drugs known to prolong QT interval within 14 days or 5 half-lives, whichever is shorter, before the first dose of trial therapy.
Long QT syndrome
Uncontrolled or significant cardiac disease including recent (6 months) myocardial infarction, congestive heart failure, unstable angina, and brady-arrhythmias
Electrolyte abnormalities (K+, Ca++, Phos, Mg++) ≥Grade 1 5. Participant is currently receiving or received drugs known to prolong QT interval within 14 days or 5 half-lives, whichever is shorter, before the first dose of trial therapy.
What this trial measures
- Number of Participants with DLTs Observed During the First Cycle28 days
Number of dose-limiting toxicities during the first cycle
- Progression-free Survival6 months
The time from the date of the first dose to the date of the first radiological documentation of disease progression or death, whichever comes first.