FDA Grants Fast Track Designation to RPTR-1-201 for Advanced Triple-Negative Breast Cancer

The U.S. Food and Drug Administration has granted Fast Track Designation to RPTR-1-201, Repertoire Immune Medicines’ investigational T cell receptor bispecific immune medicine, for a subset of patients with advanced triple-negative breast cancer. The designation applies to HLA-A*02:01-positive adult patients with unresectable or metastatic triple-negative breast cancer whose disease has progressed after available standard therapies or who are unable to tolerate them.

The decision highlights the need for new treatment approaches in TNBC, a biologically aggressive breast cancer subtype with limited options after standard therapy failure.

RPTR-1-201 is designed as a TCR bispecific molecule that links tumor recognition with T-cell redirection. The drug consists of an engineered T cell receptor that binds a tumor-selective epitope with high affinity and precision, paired with an anti-CD3 moiety intended to engage T cells and direct them toward tumor-cell killing. This mechanism is part of a broader therapeutic strategy aimed at expanding immune-based approaches beyond conventional checkpoint inhibition.

The candidate was developed using Repertoire’s DECODE™ platform, which maps immune synapse biology to identify TCR-epitope pairs. The company says these insights can be translated into programmable T cell-targeted immune medicines, including TCR bispecifics directed against tumor-selective epitopes.

“RPTR-1-201 reflects our ability to discover tumor-selective epitopes and intentionally engineer TCR bispecifics designed to engage them with high affinity and specificity,” said Anthony Coyle, PhD, President and Head of Research and Development at Repertoire Immune Medicines. “Derived from our DECODE™ platform, RPTR-1-201 couples an epitope-specific TCR with an anti-CD3 domain to engage and redirect T cells. Fast Track Designation supports closer dialogue with the FDA as we advance the program and continue its clinical evaluation.”

RPTR-1-201 is currently being evaluated in a Phase 1/2 clinical trial in participants with advanced solid tumors. The study is assessing the investigational therapy both as monotherapy and in combination with an anti-PD-1 therapy. The trial is registered on ClinicalTrials.gov under the identifier NCT07293754.