GT Biopharma presents preclinical data for GTB-5550 for targeted prostate cancer

GT Biopharma announced positive preclinical data in highlighting GTB-5550’s potential in prostate cancer. Martin Felices, PhD, Associate Professor of Medicine at the University of Minnesota, presented these data on Saturday, November 4th at the Society for Immunotherapy of Cancer Annual Meeting 2023, which is being held in San Diego, California November 1-5. Natural killer cells are being increasingly explored in clinical trials due to their safety profile and ability to mediate tumor killing without prior priming. However, lack of antigen-specific targeting, decreased numbers, and suppressive signals from the tumor microenvironment of Prostate Cancer, can negatively impact NK cell efficacy. GTB-5550 was specifically designed as a novel tri-specific killer engager molecule with three components: an arm that engages with CD16, an activating receptor of NK cells, an arm that binds to tumor antigens expressed in prostate cancer (PSMA or B7H3), and an interleukin-15 moiety that is essential for NK cell survival, proliferation, priming and motility. Key findings demonstrated that normal donor and prostate cancer patient NK cells displayed better, specific, degranulation against prostate cancer cell lines in the presence of PSMA or B7H3 TriKEs. NK cell cytotoxicity was also improved, even in the presence of enzalutamide resistant lines, hypoxia, or MDSCs. The TriKE molecules displayed improved tumor control, compared to IL-15 control or no treatment, in xenogeneic models of prostate cancer.