NCT04683679 · Memorial Sloan Kettering Cancer Center
A Study of Radiation Therapy With Pembrolizumab and Olaparib or Other Radiosensitizers in Women Who Have Triple-Negative or Hormone-Receptor Positive/Her2 Negative Breast Cancer
What this study is about
The purpose of this study is to find out whether adding pembrolizumab, with or without olaparib, to standard radiation therapy is a safe and effective treatment for metastatic breast cancer, , and to see whether the study treatment is better than, the same as, or worse than the usual approach (radiation therapy alone).
View original scientific description
The purpose of this study is to find out whether adding pembrolizumab, with or without olaparib, to standard radiation therapy is a safe and effective treatment for metastatic breast cancer, , and to see whether the study treatment is better than, the same as, or worse than the usual approach (radiation therapy alone).
Interventions
DRUG
Pembrolizumab
Pembrolizumab 200 mg will be administered as a 30 minute IV infusion every 3 weeks for 3 doses
DRUG
Olaparib
Olaparib will be administered twice daily continuously without breaks on a 21-day (3 week) cycle length, for a total of 2 cycles. Olaparib tablets will be administered bid (2 x 150 mg tablets twice daily; total 600 mg daily) on continuous days without interruption for 2 cycles. Each 3 week period constitutes one cycle.
RADIATION
Radiation
The dose of radiation will be 8-9 Gy x 3 fractions. Radiation therapy will begin on C1D2-7. For tumors that are too large for this schedule, an accomodation of 30 Gy in 6 Gy per fraction is allowed, a schedule commonly used at MSK.
Primary outcome measures
Overall Response Rate
Time frame: 8 weeks from baseline
To assess overall response rate (ORR) to pembrolizumab + , SBRT + /-olaparib, in non-targeted unirradiated lesions at 8 weeks using RECIST v1.1 in patients with mTNBC who have progressed on ICI or are PD-L1 negative and mER+BC.
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 participants who are at least 18 years of age on the day of signing informed consent with histologically confirmed diagnosis of triple negative breast cancer or ER+/Her2 will be enrolled in this study.
- Have an Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 1. Evaluation of ECOG is to be performed within 30 days prior to the date of allocation/randomization
- Histologically or cytologically-confirmed TNBC (defined as ER \<5%, PR \<5%, HER- 2-neu 0-1+ by IHC or FISH-negative or per MD discretion).
- Histologically of cytologically-confirmed ER+ breast cancer, defined as ER 1-100% and HER-2/neu 0-1+ by IHC or FISH-negative
- Metastatic or recurrent TNBC.
- Metastatic or recurrent ER+ breast cancer
- For mTNBC patients, prior receipt of ICI with progression and/or PDL1-negative. PDL-1 status is not used to determine eligibility among mER+BC patients
- Note: PDL1-status may be determined on tissues from either primary or mTNBC. Determina
Where
- Basking Ridge, New Jersey
- Middletown, New Jersey
- Montvale, New Jersey
- Commack, New York
- Harrison, New York
- New York, New York
- Uniondale, 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 Feb 17, 2026 · Source of record for eligibility and locations