Mustbio announced preclinical results of a novel αPD-1/αVEGF/IL-2v tri-specific fusion protein (MB4090) at the 2025 American Association for Cancer Research (AACR) Annual Meeting.
The study highlights MB4090’s superior anti-tumor efficacy and significant increase in tumor-infiltrating lymphocytes (TILs) in immune checkpoint inhibitor (ICI)-resistant tumor models, compared to αPD-1 monoclonal antibodies or αPD-1/αVEGF bispecific antibodies.

Key Findings:

   • MB4090 is a tri-specific fusion protein that combines:

      ∙ T cell activation through an anti-PD-1 antibody,

      ∙ enhanced lymphocyte infiltration via VEGF blockade, and

      ∙  tumor-selective T cell activation and proliferation induced by an attenuated IL-2 variant (IL-2v)

   • MB4090 selectively kills tumor cells with minimal impact on normal tissues, demonstrating excellent tolerability in animal models.

   •  In ICI-resistant tumor models, MB4090 outperformed both αPD-1 monoclonal antibodies and αPD-1/αVEGF bispecific antibodies in anti-tumor efficacy and TIL induction.

   • These results support the potential of αPD-1/αVEGF/IL-2v tri-specific fusion protein as a next-generation therapeutic candidate for patients unresponsive to conventional immune checkpoint therapies.