Clinical trial will evaluate safety, tolerability and antitumor activity of Repertoire’s novel off-the-shelf T cell receptor (TCR) bispecific therapy as monotherapy and in combination with an anti-PD-1 therapy

First asset derived from Repertoire’s DECODE^TM platform to enter human trials

CAMBRIDGE, Mass., April 23, 2026 /PRNewswire/ — Repertoire® Immune Medicines, a biotechnology company pioneering the discovery and development of programmable T cell-targeted immune medicines, today announced that the first participant has been dosed in a Phase 1/2 clinical trial of RPTR-1-201, a novel TCR bispecific therapy designed to treat advanced solid tumors. The trial is being conducted at multiple clinical sites in the United States and Europe following clearance of Repertoire’s Investigational New Drug (IND) application by the U.S. Food and Drug Administration and authorization via the Clinical Trials Information System (CTIS) in Europe.

“T cell-targeted immune medicines have shown they can drive deep and durable responses in some cancers, yet many patients with advanced solid tumors still have limited treatment options,” said Robert Andtbacka, MD, CM, Chief Medical Officer of Repertoire. “RPTR-1-201 is designed to direct a patient’s own T cells toward a shared, tumor-selective target. Dosing the first participant is a major milestone for Repertoire and the start of evaluating RPTR-1-201’s safety and potential benefit in the clinic.”

RPTR-1-201 is a TCR bispecific molecule comprised of an engineered TCR that binds with high affinity and precision to a tumor-selective epitope and an anti-CD3 moiety that engages and redirects T cells to kill tumor cells. In preclinical studies, RPTR-1-201 has demonstrated potent killing of both immunologically “hot” and “cold” tumors and a favorable preclinical safety profile. Unlike many other T cell-targeted approaches that focus on well-known antigens specific to a single tumor type, RPTR-1-201 binds to a novel epitope discovered using Repertoire’s DECODE^TM platform that is shared across multiple solid tumors and may be relevant for as many as 200,000 patients with metastatic or unresectable cancer each year in the U.S. and Europe.

The Phase 1/2 trial is designed to evaluate the safety, tolerability, and preliminary antitumor activity of RPTR-1-201 in adults with advanced solid tumors. The trial includes dose-escalation and dose-expansion phases and will evaluate RPTR-1-201 as monotherapy and in combination with an anti-PD-1 monoclonal antibody. Enrollment is ongoing at sites in the United States and Europe.

“The development of RPTR-1-201 was enabled by our platform, which identified unique TCRs against a pan-tumor, tumor-selective epitope. Subsequent TCR engineering by the Repertoire team generated an optimized TCR bispecific immune medicine that harnesses the immune system against difficult-to-treat solid tumors,” said Anthony J. Coyle, PhD, President, Research and Development at Repertoire. “The initiation of this trial marks an important milestone, as RPTR-1-201 is the first validation of our ability to convert immune codes into potential immune medicines for cancer. We are both excited and humbled by the opportunity to test this drug candidate in participants with advanced cancers.”

For more information about the trial, visit clinicaltrials.gov and use study identifier NCT07293754.

About Repertoire^® Immune Medicines

Repertoire^® Immune Medicines is a clinical-stage biotechnology company that harnesses the power of the human immune system to develop novel and potentially transformative therapies for cancer and autoimmune diseases. Using its proprietary DECODE^TM platform, which comprehensively maps the immune synapse between TCRs and their cognate antigenic epitopes, Repertoire translates these unique immune system insights into potent and targeted off-the-shelf immune medicines. The company integrates deep protein engineering expertise with artificial intelligence, powered by its proprietary DECODE database, to accelerate discovery and translation of drug candidates into clinical development. In addition to Repertoire’s wholly owned pipeline of immune medicines, the company has ongoing strategic partnerships with Bristol Myers Squibb, Genentech, Pfizer and Eli Lilly.

Repertoire^® was founded in 2019 by Flagship Pioneering. Its team operates from sites in Cambridge, Massachusetts and Zurich, Switzerland. To learn more about Repertoire^®, please visit our website at www.repertoire.com and follow us on LinkedIn and X.

Media Contact:

press@flagshippioneering.com

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