Mestag Therapeutics to Present Targeted Cancer Therapy at AACR

Biotech company selected for late-breaking poster on FAP-targeted LTBR agonist MST-0312 at major oncology conference.

Apr. 14, 2026 at 7:49am

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An abstract, ghostly X-ray image revealing the intricate molecular structure of a bispecific antibody, conceptually representing a new approach to cancer immunotherapy.A novel bispecific antibody designed to harness the power of the immune system against solid tumors.San Diego Today

Mestag Therapeutics, a biotech company focused on fibroblast-based immunotherapies, announced it has been selected to present pre-clinical data on its FAP-targeted LTBR agonist antibody MST-0312 in a late-breaking poster session at the upcoming American Association for Cancer Research (AACR) Annual Meeting. MST-0312 is designed to induce the formation of tertiary lymphoid structures and high endothelial venules in solid tumors, which can enhance immune cell access and activity within the tumor microenvironment.

Why it matters

The presence of tertiary lymphoid structures and high endothelial venules in solid tumors has been associated with improved patient survival and better responses to cancer immunotherapies. Mestag's approach aims to leverage this fibroblast-immune biology to develop a new class of targeted cancer treatments.

The details

MST-0312 is a bispecific antibody that binds to fibroblast activation protein (FAP) on tumor-associated fibroblasts and activates the lymphotoxin beta receptor (LTBR) pathway. This activation is intended to induce the formation of tertiary lymphoid structures and high endothelial venules within the tumor, which can facilitate greater infiltration and activity of anti-tumor immune cells. Mestag plans to initiate a Phase 1 clinical trial of MST-0312, called the STARLYS trial, in mid-2026.

  • The AACR Annual Meeting will take place from April 17-22, 2026 in San Diego, California.
  • Mestag's late-breaking poster presentation on MST-0312 is scheduled for Tuesday, April 21, 2026 from 9:00am to 12:00pm.
  • Mestag plans to initiate the Phase 1 STARLYS trial for MST-0312 in mid-2026.

The players

Mestag Therapeutics

A biotech company harnessing fibroblast immunology to develop treatments for cancer and inflammatory diseases.

Pascal Merchiers

Chief Development Officer at Mestag Therapeutics, who will present the data on MST-0312 at the AACR Annual Meeting.

American Association for Cancer Research (AACR)

A major oncology conference where Mestag has been selected to present its late-breaking research.

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What they’re saying

“MST-0312 is a FAP-targeted LTBR agonist bispecific antibody designed to induce the formation of tertiary lymphoid structures (TLS) and high endothelial venules (HEV) in solid tumors.”

— Pascal Merchiers, Chief Development Officer, Mestag Therapeutics

What’s next

Mestag plans to initiate the Phase 1 STARLYS trial for MST-0312 in mid-2026 to further evaluate the safety and efficacy of the targeted LTBR agonist in solid tumor patients.

The takeaway

Mestag's approach to leveraging fibroblast-immune biology represents a novel therapeutic strategy in oncology, with the potential to enhance immune cell infiltration and activity within solid tumors. The upcoming AACR presentation will provide an important first look at the preclinical data supporting this targeted LTBR agonist program.