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Recruiting Phase 2 NCT03804944

NCT03804944 Converting HR+ Breast Cancer Into an Individualized Vaccine

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Clinical Trial Summary
NCT ID NCT03804944
Status Recruiting
Phase Phase 2
Sponsor Weill Medical College of Cornell University
Condition Breast Cancer
Study Type INTERVENTIONAL
Enrollment 100 participants
Start Date 2020-03-17
Primary Completion 2026-12-31

Eligibility & Interventions

Sex Female only
Min Age 18 Years
Max Age 90 Years
Study Type INTERVENTIONAL
Interventions
Focal Radiation therapyPembrolizumab (200mg IV for 30 minutesCDX-301

Eligibility Fast-Check

Enter your details for a quick preliminary check. This does not replace medical advice.

What to Expect as a Participant

You will actively receive the study intervention — which may be a drug, biologic, device, or procedure.

In Phase 2, researchers evaluate early signs of effectiveness. You may be randomized to receive the active treatment or a comparator. Monitoring continues closely.

This trial targets 100 participants in total. It began in 2020-03-17 with a primary completion date of 2026-12-31.

⚠ This information is for research awareness only. Always consult your physician before joining any clinical trial. Participation is voluntary and you may withdraw at any time.

Brief Summary

Newly diagnosed post-menopausal women with clinical stage II-III, HR+HER2- breast cancer are eligible to a randomized trial, concurrently open at five US academic institutions. Patients receiving 4 months of standard neoadjuvant hormonal therapy with letrozole are randomly assigned to one of 4 arms of a trial testing focal hypo-fractionated RT alone or with immunotherapy combinations.

Eligibility Criteria

Inclusion Criteria: * Post-menopausal female ≥ 18 years of age (Post-menopausal status defined as either 1) at least 2 years without menstrual period or 2) or patients older than 50 with serological evidence of post-menopausal status or 3) hysterectomized patients of any age with FSH confirmation of post-menopausal status. * Eastern Cooperative Oncology Group (ECOG) performance status 0-1 * Biopsy proven diagnosis of ER+ PR+ or PR- HER2- breast cancer. * Clinical stage I(\>1.5cm, if N0) - III breast cancer, as per AJCC staging 8th edition. * Patient needs to be able to understand and demonstrate willingness to sign a written informed consent document. Adequate bone marrow reserve and liver function: WBC ≥ 2000/uL Absolute neutrophil count (ANC) ≥1500/μL Platelets ≥100 000/μL Hemoglobin ≥9.0 g/dL or ≥5.6 mmol/La Creatinine OR Measured or calculated creatinine clearance (GFR can also be used in place of creatinine or CrCl) ≤1.5 × ULN OR ≥30 mL/min for participant with creatinine levels \>1.5 × institutional ULN Total bilirubin ≤1.5 ×ULN OR direct bilirubin ≤ULN for participants with total bilirubin levels \>1.5 × ULN AST (SGOT) and ALT (SGPT) ≤2.5 × ULN (≤5 × ULN for participants with liver metastases) International normalized ratio (INR) OR prothrombin time (PT) Activated partial thromboplastin time (aPTT) ≤1.5 × ULN unless participant is receiving anticoagulant therapy as long as PT or aPTT is within therapeutic range of intended use of anticoagulants Exclusion Criteria: * Active connective tissue disorders, such as lupus or scleroderma requiring flare therapy * Current use of systemic chemotherapy, endoctine therap or HER2-neu targeted therapy * Post surgical excision of breast cancer. * Previous radiotherapy of the same breast. * Has received prior therapy with an anti-PD-1, anti-PD-L1, or anti-PD-L2 agent or with an agent directed to another stimulatory or co-inhibitory T-cell receptor (eg, CTLA-4, OX-40, CD137). * Inability to obtain histologic proof of breast cancer * Has received a live vaccine within 30 days prior to the first dose of study drug. Examples of live vaccines include, but are not limited to, the following: measles, mumps, rubella, varicella/zoster (chicken pox), yellow fever, rabies, Bacillus Calmette-Guérin (BCG), and typhoid vaccine. Seasonal influenza vaccines for injection are generally killed virus vaccines and are allowed; however, intranasal influenza vaccines (eg, FluMist®) are live attenuated vaccines and are not allowed. * Is currently participating in or has participated in a study of an investigational agent or has used an investigational device within 4 weeks prior to the first dose of study treatment. Note: Participants who have entered the follow-up phase of an investigational study may participate as long as it has been 4 weeks after the last dose of the previous investigational agent. * 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 immunosuppressive therapy within 7 days prior to the first dose of study drug. * Has a known additional malignancy (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 hypersensitivity (≥Grade 3) to pembrolizumab and/or any of its excipients. * Has active autoimmune 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 that required steroids or has current pneumonitis. * Has an active infection requiring systemic therapy.Has a known history of Human Immunodeficiency Virus (HIV). Note: No HIV testing is required unless mandated by local health authority. * Has a known history of Hepatitis B (defined as Hepatitis B surface antigen \[HBsAg\] reactive) or known active Hepatitis C 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). Note: optional based on country. * Has known psychiatric or substance abuse disorders that would interfere with cooperation with the requirements of the trial.

Contact & Investigator

Central Contact

Fabiana Gregucci, M.D.

✉ fgr4002@med.cornell.edu

📞 646 962-3110

Principal Investigator

Silvia Formenti, M.D.

PRINCIPAL INVESTIGATOR

Weill Cornell Medicine - New York Presbyterian Hospital

Frequently Asked Questions

Who can join the NCT03804944 clinical trial?

This trial is open to female participants only, aged 18 Years or older, up to 90 Years, studying Breast Cancer. Full inclusion and exclusion criteria are listed in the Eligibility Criteria section. Always confirm your eligibility with the research team before applying.

What phase is the NCT03804944 trial and what does that mean for participants?

Phase 2 trials evaluate whether the treatment shows signs of effectiveness while continuing to monitor safety. More participants are enrolled than in Phase 1 to help refine the treatment protocol.

Is NCT03804944 currently recruiting?

Yes, NCT03804944 is actively recruiting participants. Contact the research team at fgr4002@med.cornell.edu for enrollment information.

Where is the NCT03804944 trial being conducted?

This trial is being conducted at Los Angeles, United States, New York, United States, New York, United States, New York, United States and 4 additional locations.

Who is sponsoring the NCT03804944 clinical trial?

NCT03804944 is sponsored by Weill Medical College of Cornell University. The principal investigator is Silvia Formenti, M.D. at Weill Cornell Medicine - New York Presbyterian Hospital. The trial plans to enroll 100 participants.

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ClinicalMetric — Independent clinical trial intelligence platform. Not affiliated with NIH, ClinicalTrials.gov, the U.S. FDA, or any pharmaceutical company, hospital, or clinical research organization. Trial data is sourced from ClinicalTrials.gov for informational purposes only and does not constitute medical advice. Do not make any treatment, enrollment, or health decisions based solely on information found here — always consult a qualified healthcare professional. Full Disclaimer  ·  Last Reviewed: April 2026  ·  Data Methodology