ClinicalTrials.gg
RecruitingNCT03449238Updated Mar 30, 2026

Pembrolizumab And Stereotactic Radiosurgery (Srs) Of Selected Brain Metastases In Breast Cancer Patients

A Phase 1/2 interventional study of Pembrolizumab in Metastatic Breast Cancer and Brain Metastases, sponsored by Weill Medical College of Cornell University. Recruiting at 3 sites in United States. Open to female participants aged 19 Years to 90 Years. Per ClinicalTrials.gov, last updated 2026-03-30.

Sponsored by Weill Medical College of Cornell University · Phase 1/2, Interventional, and Treatment

From the registry’s dates

  • Started Nov 2018; still recruiting 7 years 11 months later.

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Phase
Phase 1/2
Study type
Interventional
Enrollment
41
Allocation
Not applicable
Ages
19 Years to 90 Years
Sex
Female
01

Where this study stands

Counted across the records on this site · 2026-11-14

Among 85 studies testing pembrolizumab in Breast Neoplasms — 22 open to participants now, 45 under way, 8 of them phase 3. pembrolizumab · Breast Neoplasms.

Planned enrollment
45th of 85
41 · median 44
Started
2018
with 9 others
Phase 1/2
13 of 85
2 open now
Primary completion
2028-12
later than 33 of 44 live
Registered
37th of 85
by date

Among the 85 studies testing pembrolizumab in Breast Neoplasms, this one is the 45th largest by planned enrollment, is one of 10 that started in 2018, is one of 13 in phase 1/2, reaches primary completion later than 33 of the 44 other live ones, and was the 37th registered.

Breast Neoplasms

14,832 studies on the registry are indexed under Breast Neoplasms; 3,320 are open to participants now.

Browse Breast Neoplasms studies →

Open to participants now

22 of the 85 studies testing pembrolizumab in Breast Neoplasms are open now, in 11 countries. Recruiting first, the newest first:

16 more — sign in →

By country, each count listing its studies:

All 22 open studies →

About pembrolizumab

pembrolizumab: first FDA approval 2014 (KEYTRUDA), first EMA approval 2015. What it is approved for, and how studies give it, is on its page →

Who these studies take

Of the 2,399 Breast Neoplasms studies recruiting now, 1,570 (65%) set no upper age limit and 592 (25%) stop at 75 or younger; 103 take children under 18; 215 take healthy volunteers.

This study: 19 Years to 90 Years · female · no healthy volunteers.

The full table on the hub →

This tab as a report to print or save as PDF → With an account.

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Watch this landscapeDownload CSVNarrow it in search →With an account: a weekly mail of what changed among 85 studies testing pembrolizumab in Breast Neoplasms, or all of them as a file.
02

Study summary

Patients with metastatic breast cancer with at least 2 brain metastases will receive pembrolizumab every 3 weeks. Patients will undergo stereotactic radiosurgery (SRS) to one of the brain lesions. Pembrolizumab infusion will be given on Day 4 (+/-1) after SRS treatment at the standard dose of 200mg IV over 30 minutes and repeated every 3 weeks until disease progression or unacceptable toxicity.

Read the detailed description

Patients with metastatic breast cancer with at least 2 brain metastases, eligible to receive SRS. Patients will complete radiation therapy within 1 week and Pembrolizumab may be continued every 3 weeks until evidence of brain progression or serious adverse toxicity. Patients will be followed until death.

Pembrolizumab infusion will be given on Day 4 (+/-1) after SRS treatment at the standard dose of 200mg IV over 30 minutes and repeated every 3 weeks until disease progression or unacceptable toxicity.

03

Conditions studied

  • Metastatic Breast Cancer
  • Brain Metastases
04

Who can participate

Ages eligible
19 Years to 90 Years
Sexes eligible
Female
Accepts healthy volunteers
No

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  • Age older than 18
  • (ECOG) performance status 0-1
  • Men and/or pre- or women with breast cancer with at least 2 intracranial untreated and measurable (≥ 3mm) metastases as visualized on brain MRI
  • A diagnostic contrast enhanced MRI demonstrating at least 2 lesions in the brain, (≥3mm in size), performed within two weeks prior to treatment
  • Maximum diameter of treated lesions should be \<4cm in size
  • Have based on 1.1. Lesions situated in a previously irradiated area are considered measurable if progression has been demonstrated in such lesions.
  • Patient needs to be able to understand and demonstrate willingness to sign a written document
  • Prior SRS is permitted, however the lesions targeted for treatment on trial need to be previously untreated by SRS
  • Patients who have undergone prior subtotal resection are eligible providing that residual disease is \<4cm in maximum diameter: the cavity will be treated as standard of care.
  • Continuing a concurrent use of hormonal therapy or anti-Her2 neu therapy is allowed, if the patient exhibits progression during these treatments
  • Enrolled patients should have a two-week from last systemic treatment
  • The participant (or legally acceptable representative if applicable) provides written informed consent for the trial.
  • duration of 120 days
  • Adequate bone marrow reserve and liver function

Exclusion criteria

Exclusion Criteria:

  • Active connective tissue disorders, such as lupus or scleroderma requiring flare therapy
  • Patients who have undergone complete resection of all known
  • Inability to obtain histologic proof of breast cancer
  • Target lesion within 5mm of the optic apparatus so that some portion of the optic nerve or chiasm would be included in the SRS field
  • Has received prior radiotherapy within 2 weeks of start of study treatment. Participants must have recovered from all radiation-related toxicities, not require , and not have had radiation pneumonitis. A 1-week is permitted for palliative radiation (≤2 weeks of radiotherapy) to non-CNS disease.
  • Has received a or live-attenuated vaccine within 30 days prior to the first dose of study drug. Administration of killed vaccines is allowed.
  • Is currently participating in or has participated in a study of an agent or has used an investigational device within 4 weeks prior to the first dose of study treatment.
  • Has a diagnosis of immunodeficiency or is receiving chronic systemic steroid therapy (in dosing exceeding 10 mg daily of prednisone equivalent) or any other form of therapy within 7 days prior to the first dose of study drug.
  • Has a known additional (second primary) that is progressing or has required active treatment within the past 3 years. Note: Participants with basal cell carcinoma of the skin, squamous cell carcinoma of the skin, or carcinoma in situ (e.g. cervical cancer in situ) that have undergone potentially curative therapy are not excluded.
  • Has severe (≥Grade 3) to pembrolizumab and/or any of its .
  • Has active disease that has required systemic treatment in the past 2 years (i.e. with use of disease modifying agents, corticosteroids or immunosuppressive drugs). Replacement therapy (eg., thyroxine, insulin, or physiologic corticosteroid replacement therapy for adrenal or pituitary insufficiency, etc.) is not considered a form of systemic treatment.
  • Has a history of (non-infectious) pneumonitis/interstitial lung disease that required steroids or has current pneumonitis.
  • Has an active infection requiring systemic therapy..Has a known history of (HIV).
  • Has a known history of (defined as Hepatitis B surface antigen [HBsAg] reactive) or known active virus (defined as HCV RNA [qualitative] is detected) infection. Note: no testing for Hepatitis B and Hepatitis C is required unless mandated by local health authority.
  • Has a known history of active TB (Bacillus Tuberculosis).
  • Has known psychiatric or substance abuse disorders that would interfere with cooperation with the requirements of the trial.
  • Is pregnant or breastfeeding, or expecting to conceive or father children within the projected duration of the study, starting with the screening visit through 120 days after the last dose of trial treatment.
Terms in these criteria, in plain language(20)

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.

ECOG performance status

A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.

0
Fully active, no restrictions.
1
Limited in strenuous activity, but walking and able to do light work, such as housework or office work.
2
Walking and able to look after yourself, but unable to work; up and about more than half of waking hours.
3
Able to look after yourself only in part; in bed or a chair more than half of waking hours.
4
Unable to look after yourself at all; in bed or a chair all day.

Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.

Postmenopausal

Periods have stopped for good: usually no period for 12 months in a row without another medical reason, sometimes confirmed by a blood test (FSH).

Metastases

Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.

Measurable disease

The amount of disease can be tracked with a defined measurement, so the study can see whether it shrinks or grows. It might be a tumour measured on a scan or, in some blood cancers such as myeloma, a marker measured in blood or urine.

The criteria or the study team say which measurement counts — having no tumour visible on a scan does not by itself rule you out.

RECIST

The standard rules for measuring tumours on CT or MRI scans, to tell whether a cancer is shrinking, stable or growing during treatment.

“Measurable disease per RECIST 1.1” usually means at least one tumour 10 mm or more at its longest on a CT scan, or a lymph node 15 mm or more across its short axis.

Informed consent

Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.

You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.

Brain metastases

Cancer deposits in the brain from a cancer that started elsewhere in the body (CNS metastases include the spinal cord).

Studies differ: some leave out any brain metastases, some accept ones treated and stable for some weeks. Check what this study allows.

Washout period

A planned gap after a treatment, so that its effects can lessen before the study treatment or a study assessment. Ask the study team and the doctor who prescribed it before changing any medicine.

Contraception

Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.

Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.

Corticosteroids (steroids)

Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.

Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.

Live vaccines

Vaccines made with a weakened form of the germ, such as measles–mumps–rubella (MMR), chickenpox and yellow fever. They can be risky when the immune system is weakened. Flu injections are not live; the nasal flu spray is.

Investigational drug or device

A drug or device being studied in a clinical trial.

It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.

Immunosuppression

A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.

Read whether the line is about a condition or about medicines, and which medicines and doses it means.

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.

Hypersensitivity

An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.

Excipients

The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.

Autoimmune disease

A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.

Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.

HIV

The human immunodeficiency virus, which weakens the immune system.

Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.

Hepatitis B tests

Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.

Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.

Hepatitis C tests

Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.

After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.

05

Study design

Phase
Phase 1 / Phase 2
Primary purpose
Treatment
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrollment
41 participants (estimated)

Study arms

  • Other
    Pembrolizumab and SRS

    Pembrolizumab infusion will be given on Day 4 (+/-1) after SRS treatment at the standard dose of 200mg IV over 30 minutes and repeated every 3 weeks until disease progression or unacceptable toxicity.

    Drug: Pembrolizumab

Interventions

  • Pembrolizumab infusion will be given on Day 4 (+/-1) after SRS treatment at the standard dose of 200mg IV over 30 minutes and repeated every 3 weeks until disease progression or unacceptable toxicity.

06

What researchers measure

Primary outcomes

  1. Tumor response for non-irradiated brain lesions at 8 weeks according to RECIST1.1

    detect abscopal responses in non-irradiated brain metastases, followed at routine post SRS brain MRI (evaluated at 8 weeks post-treatment, +/- one week) according to Response Evaluation criteria in Solid Tumors (RECIST1.1)

    Time frame: 8 weeks

  2. Correlation of abscopal responses with the radiation dose received

    Correlate potential abscopal responses with their radiation dose exposure

    Time frame: 1 year

  3. Overall survival - assessed from the start of study drug until death in non-irradiation metastases in the rest of the body by routine imaging.

    detect systemic objective responses in non-irradiated metastases in the rest of the body, by routine imaging

    Time frame: 3 years

Secondary outcomes

  1. Number of participants with abscopal response will be assessed.

    Evaluation of an abscopal effect elsewhere in the body. This will be assessed by serial CT based imaging performed every 3 months.

    Time frame: up to 12 weeks

07

Study locations

3 of 3 sites recruiting
08

References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

09

Timeline

Tracking since Sep 25, 2026
ElapsedEstimatedEstimated, not yet reachedSimilar studies: half by the dot; the band is the middle halfHalf of similar studies reached it by the dot; the band is the middle half, from a quarter to three quarters

Started Nov 2018 (actual). Primary completion is estimated for Dec 2028, 121 months after the start.

Of 166 non-industry phase 1/2 interventional studies under Breast Neoplasms, half reached primary completion within 67 months of starting (the median), counting those still running; a quarter within 45 and three quarters within 95. This study's planned 121 months is above that.

Counting every sponsor, half of 327 studies reached it within 61 months; a quarter within 45 and three quarters within 88.

How these figures are worked out, and which studies are left out of them.

Registered
Feb 14, 2018
First posted
Feb 28, 2018
StartActual
Nov 15, 2018
Primary completionEst.
Dec 31, 2028
CompletionEst.
Dec 31, 2030
Last update
Mar 30, 2026
What these dates mean
Start.
When the first participant enrolled; while estimated, when the study expects to open to recruitment.
Primary completion.
When the last participant was examined or treated to collect data for the study's main question, its primary outcome. A study that stopped early gives the date its data collection stopped.
Completion.
When the last participant's last visit took place, for every outcome, secondary ones and side effects included: the end of the study. Often later than primary completion, sometimes the same day.
Actual and Est.
Actual means the registry says the date has happened. Est. (estimated) is a date the sponsor plans or expects. It can still move, and the sponsor is expected to change it to actual once it has passed.
No changes since tracking began. The registry record was last updated on Mar 30, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT03449238
Responsible party
Sponsor
First posted
Feb 28, 2018
Start date
Nov 15, 2018
Primary completion
Dec 31, 2028 (estimated)
Completion
Dec 31, 2030 (estimated)
Last update
Mar 30, 2026

Study contacts

Fabiana Gregucci, M.D.
Contact
fgr4002@med.cornell.edu
646-962-3110
Silvia Formenti, M.D.
principal investigator · Weill Cornell Medicine - New York Presbyterian Hospital

Oversight

Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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Studies of the drug tested here: Pembrolizumab

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