NCT04563507 · Weill Medical College of Cornell University
Combined Immunotherapies in Metastatic ER+ Breast Cancer
What this study is about
Women with Hormone Receptor (HR)+ Human Epidermal growth factor Receptor (HER)2- metastatic breast cancer are eligible to a randomly assigned trial. Patients receiving standard first line therapy for metastatic HR+ Breast cancer(BC) (letrozole+palbociclib) are randomly assigned to also receive Stereotactic Body Radiation Therapy(SBRT) to each metastatic lesion.
View original scientific description
Women with Hormone Receptor (HR)+ Human Epidermal growth factor Receptor (HER)2- metastatic breast cancer are eligible to a randomized trial. Patients receiving standard first line therapy for metastatic HR+ Breast cancer(BC) (letrozole+palbociclib) are randomly assigned to also receive Stereotactic Body Radiation Therapy(SBRT) to each metastatic lesion.
Interventions
RADIATION
Stereotactic Body Radiation Therapy (SBRT) (50GY in 5 fractions)
Patients randomized to arm 2 will start letrozole alone, and add palbociclib on day 21, after completion of I-SBRT. They will undergo tumor Immunogenic-SBRT(I-SBRT) days 1-12 (+/-2 days, to enable inclusion of holidays). During the week preceding day 1, they will undergo simulation and planning for radiotherapy. Each oligometastatic lesion will be treated with I-SBRT every 48 hours. Treatment may be given daily (to keep the total I-SBRT treatment time to ≤ 12 days) and lesions targeted with I-SBRT will thus be alternated each day to accommodate for the 48 hour interval between fractions
DRUG
Letrozole 2.5Mg Tab
All patients start standard therapy with oral letrozole (Femara), day 1 of the study.
DRUG
Palbociclib 125mg
Patients randomized to arm 2 will start letrozole alone, and add palbociclib on day 21, after completion of I-SBRT.
Primary outcome measures
Progression free survival (PFS) will be measured
Time frame: End of study, up to 36 months.
Progression free survival (PFS) is defined as the time from the start of study treatment until the disease progression or death.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Female ≥ 18 years of age pre and post-menopausal
- Metastatic disease (≤ 5 sites of measurable disease by RECIST)
- Eligible for treatment with CDK4/6 + aromatase inhibitors
- Premenopausal status is defined as either:
- Patient had last menstrual period within the last 12 months, OR
- If on tamoxifen or toremifene within the past 14 days, plasma estradiol and FSH must be in the premenopausal range per local normal range, OR
- In case of therapy-induced amenorrhea, plasma estradiol and/or FSH must be in t
Where
- New York, New York
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Dec 15, 2025 · Source of record for eligibility and locations