NCT07300475

Cancer Immunotherapeutic (PCI) Strategy in Triple Negative Breast Cancer Patients

Phase 1 Clinical Trial of a Personalized Cancer Immunotherapeutic (PCI) Strategy +/- AB248 (CD8-selective IL-2 Mutein Fusion Protein) in Patients With a New Diagnosis of Triple Negative Breast Cancer Undergoing Neoadjuvant Chemoimmunotherapy

• Status: Not Yet Recruiting
• Phase: Phase 1
• Study type: Interventional
• Enrollment: 30 (estimated)
• Sponsor: Washington University School of Medicine · Academic / Other
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

This is a phase 1 clinical trial to evaluate the safety, feasibility and immunogenicity of a personalized cancer immunotherapeutic (PCI) strategy with or without CD8-selective IL-2 mutein fusion protein in patients with triple negative breast cancer undergoing neoadjuvant chemoimmunotherapy.

Conditions

• Triple Negative Breast Cancer

Interventions

Type	Name	Description
DRUG	Paclitaxel	As part of the KEYNOTE 522 Regimen, paclitaxel is given intravenously (IV) with a dose 80 mg/m2 on Days 1, 8, and 15 of a 21 day cycle after Step 0 enrollment. Paclitaxel will be given a total of 4 cycles (cycles 1-4).
DRUG	Carboplatin	As part of the KEYNOTE 522 Regimen, carboplatin is given intravenously (IV) with a dose of AUC 1.5 on Days 1, 8, and 15 of a 21 day cycle after Step 0 enrollment. Carboplatin will be given a total of 4 cycles (cycles 1-4).
DRUG	Pembrolizumab	As a part of the KEYNOTE 522 Regimen, pembrolizumab is given intravenously (IV) at a dose of 200 mg on Day 1 of a 21 day cycle after Step 0 enrollment. Pembrolizumab will be given for 8 cycles (cycles 1-8) Pembrolizumab will also be given intravenously (IV) at a dose of 200 mg on days 43, 64, and 85 (same as adjuvant PCI) and then 6 additional doses.
DRUG	Doxorubicin	As part of the KEYNOTE 522 Regimen, doxorubicin will be given intravenously (IV) at a dose of 60 mg/m2 on Day 1 of a 21 day cycle after Step 0 enrollment. Doxorubicin will be given a total of 4 cycles (cycles 5-8).
DRUG	Cyclophosphamide	As part of the KEYNOTE 522 Regimen, cyclophosphamide is given intravenously (IV) at a dose of 600 mg/m2 dose on Day 1 of a 21 day cycle after Step 0 enrollment. Cyclophosphamide will be given a total of 4 cycles (cycles 5-8).
BIOLOGICAL	Personalized cancer immunotherapeutic (PCI)	PCI is given intra-muscular (IM) at 1 mg dose. Each PCI will consists of up to 4 separate injections, with each syringe containing peptides from one of the up to four peptide pools combined with adjuvant poly-ICLC.
DRUG	AB248 (CD8-selective IL-2 mutein fusion protein)	AB248 is given intravenously (IV) over 30 minutes at the recommended dose.
OTHER	pVAC tools neoantigen prediction algorithm	The pVACtools suite of software tools will be used to identify and prioritize cancer neoantigens based on neoantigen identification algorithms.
DRUG	poly-ICLC	Poly-ICLC is mixed with the personalized cancer immunotherapeutic (PCI). The PCI is given intramuscularly (IM) at 1mg dose.

Timeline

• Start date: 2026-03-31
• Primary completion: 2030-01-08
• Completion: 2034-12-09
• First posted: 2025-12-23
• Last updated: 2026-02-13

Locations

1 site across 1 country: United States

Regulatory

• FDA-regulated drug study