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OncoMatch/Clinical Trials/NCT03804944

Converting HR+ Breast Cancer Into an Individualized Vaccine

Is NCT03804944 recruiting? Yes, currently enrolling (May 2026). This Phase 2 trial studies multiple treatments including CDX-301 and Pembrolizumab (200mg IV for 30 minutes for breast cancer.

Phase 2RecruitingWeill Medical College of Cornell UniversityNCT03804944Data as of May 2026

Treatment: Pembrolizumab (200mg IV for 30 minutes · CDX-301Newly 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.

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Extracted eligibility criteria

Cancer type

Breast Carcinoma

Biomarker criteria

Required: HER2 (ERBB2) negative

Required: ESR1 positive

Required: PR (PGR) positive or negative

Disease stage

Required: Stage I (>1.5CM, IF N0), II, III (AJCC 8th edition)

Clinical stage I(>1.5cm, if N0) - III breast cancer, as per AJCC staging 8th edition.

Performance status

ECOG 0–1(Restricted strenuous activity)

Prior therapy

Cannot have received: systemic chemotherapy

Current use of systemic chemotherapy

Cannot have received: endocrine therapy

Current use of endoctine therap

Cannot have received: HER2-targeted therapy

Current use of HER2-neu targeted therapy

Cannot have received: anti-PD-1/PD-L1/PD-L2 or co-inhibitory T-cell receptor therapy

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).

Cannot have received: radiation therapy

Previous radiotherapy of the same breast.

Cannot have received: live vaccine

Has received a live vaccine within 30 days prior to the first dose of study drug.

Lab requirements

Blood counts

WBC ≥ 2000/uL Absolute neutrophil count (ANC) ≥1500/μL Platelets ≥100 000/μL Hemoglobin ≥9.0 g/dL or ≥5.6 mmol/La

Kidney function

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

Liver function

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)

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

Structured fields extracted by AI. May contain errors — verify against the official protocol.

US trial sites

  • Cedars-Sinai Medical Center · Los Angeles, California
  • Icahn School of Medicine at Mt Sinai · New York, New York
  • New York Presbyterian Hospital - Queens · New York, New York
  • Weill Cornell Medicine New York Presbyterian Hospital · New York, New York
  • Brooklyn Methodist Hospital - NewYork Presbyterian · New York, New York

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