Repertoire Immune Medicines Doses First Patient in Phase 1/2 Trial

Cambridge, Massachusetts, USA – April 23, 2026

Repertoire Immune Medicines announced a major clinical milestone with the first participant dosed in its Phase 1/2 clinical trial of RPTR-1-201, a novel T cell receptor (TCR) bispecific immune therapy designed to treat advanced solid tumors. The study, initiated following U.S. FDA IND clearance and European CTIS authorization, will evaluate the therapy’s safety, tolerability, and preliminary antitumor activity, marking the company’s transition from discovery to clinical-stage validation of its proprietary DECODE™ immune mapping platform.

First-in-Human Trial Targets Advanced Solid Tumors

The Phase 1/2 clinical trial represents a significant step forward in precision immuno-oncology, as RPTR-1-201 becomes the first therapeutic candidate derived from Repertoire’s DECODE™ platform to enter human studies. The trial is being conducted across multiple sites in the United States and Europe, enrolling patients with advanced or metastatic solid tumors who have limited treatment options.

The study design includes both dose-escalation and dose-expansion phases, allowing researchers to evaluate optimal dosing, safety profile, and early signals of efficacy. Importantly, RPTR-1-201 will be tested as both a monotherapy and in combination with anti-PD-1 immune checkpoint inhibitors, reflecting a strategy to enhance immune system activation and tumor targeting.

This milestone highlights the growing importance of first-in-human trials in advancing next-generation immunotherapies and provides an early indication of the therapy’s potential clinical impact.

Innovative TCR Bispecific Therapy Enables Targeted Immune Response

RPTR-1-201 is a first-in-class TCR bispecific molecule designed to redirect a patient’s own T cells toward tumor cells by binding to a tumor-selective epitope and engaging the CD3 receptor on T cells. This dual mechanism enables precise targeting and activation of immune responses, offering a promising approach for treating cancers that are traditionally difficult to manage.

Unlike conventional therapies that focus on tumor-specific antigens limited to certain cancer types, RPTR-1-201 targets a shared epitope identified through the DECODE™ platform, potentially expanding its applicability across multiple solid tumors. This innovation could address a large patient population, estimated at up to 200,000 individuals annually in the U.S. and Europe, who currently have limited therapeutic options.

Preclinical studies have demonstrated potent tumor cell killing in both “hot” and “cold” tumor environments, along with a favorable safety profile, supporting the rationale for clinical evaluation.

DECODE™ Platform Drives Next-Generation Immunotherapy Development

The initiation of this trial also validates Repertoire’s DECODE™ platform, a proprietary technology that maps the interaction between T cell receptors and antigenic epitopes to identify novel immune targets. By integrating artificial intelligence, protein engineering, and immune system mapping, the platform enables the development of off-the-shelf immune therapies with high precision and scalability.

This approach represents a shift toward programmable immune medicines, where therapies are designed to selectively engage the immune system against cancer cells while minimizing off-target effects. The ability to translate immune insights into clinically viable therapies positions Repertoire at the forefront of next-generation oncology innovation.

The successful initiation of the RPTR-1-201 trial marks a critical milestone in demonstrating the platform’s potential to accelerate drug discovery and bring transformative therapies to patients. As clinical data emerges, the therapy could pave the way for new treatment paradigms in solid tumor oncology, particularly in areas with high unmet medical need.

Source: Repertoire Immune Medicines press release