Calidi Biotherapeutics to Present New Data on In Situ T-Cell Engagers at AACR 2026

The biotech company will showcase its RedTail virotherapy platform and a new TROP-2 targeting candidate at the cancer research conference.

Apr. 2, 2026 at 5:21am

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Calidi Biotherapeutics, a San Diego-based biotech company, announced it will present new data on its RedTail virotherapy platform and a lead candidate targeting TROP-2 at the upcoming American Association of Cancer Research (AACR) annual meeting in April 2026. The RedTail platform is designed to selectively target tumors, remodel the tumor microenvironment, and enable high-level expression of therapeutic genetic payloads directly at the tumor site.

Why it matters

Calidi's approach aims to overcome limitations of current T-cell engager therapies, which have struggled to show clinical benefit in solid tumors due to the immunosuppressive tumor microenvironment. By remodeling the tumor microenvironment and driving T-cell activation concurrently with expression of a T-cell engager, the RedTail platform could unlock the potential of this promising cancer immunotherapy approach.

The details

The company will present data on RedTail viruses engineered to express both a functional T-cell engager and IL-15 SA, a T and NK-cell activator, at high concentrations in the tumor microenvironment. This allows for simultaneous T-cell activation and high expression of the T-cell engager directly at the tumor site. Calidi is developing a lead candidate targeting TROP-2, a difficult target for T-cell engagers due to its expression in normal tissue and potential for off-tumor toxicity. The RedTail approach confines expression of the T-cell engager to the tumor microenvironment.

  • Calidi expects to file an IND for its lead RedTail candidate, CLD-401, by the end of 2026.
  • The AACR annual meeting will take place from April 17-22, 2026 in San Diego, California.

The players

Calidi Biotherapeutics

A biotechnology company pioneering the development of targeted genetic medicines, including its proprietary RedTail virotherapy platform.

Eric Poma, PhD

Chief Executive Officer of Calidi Biotherapeutics.

Antonio F. Santidrian, PhD

Chief Scientific Officer and Head of Technical Operations at Calidi Biotherapeutics.

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What they’re saying

“We continue to advance the RedTail platform through our lead asset, CLD-401, and now through our work with T-cell engagers. We believe RedTail represents a major breakthrough in the ability to deliver genetic payloads in a targeted fashion to distal sites of disease through systemic administration.”

— Eric Poma, Chief Executive Officer

“The data we will present at AACR highlight the ability of the RedTail platform to functionally overexpress complex biologics likes cytokines and T-cell engagers and profoundly alter the tumor microenvironment. The ability of the RedTail platform to induce high levels of expression of its genetic payloads only at the tumor can potentially overcome many of the limitations currently seen with cytokine and T-cell engager therapies.”

— Antonio F. Santidrian, Chief Scientific Officer and Head of Technical Operations

What’s next

Calidi continues to expand the functionality of the RedTail platform and is actively pursuing strategic partnerships to accelerate clinical development and broaden the impact of its technology.

The takeaway

Calidi's innovative RedTail virotherapy platform aims to overcome key limitations of current T-cell engager therapies in solid tumors by remodeling the tumor microenvironment and enabling high, targeted expression of these complex biologics directly at the tumor site.