PTX-912

PTX-912 is a first-in-class, bifunctional recombinant fusion protein that combines an anti-PD-1 monoclonal antibody with a conditionally masked interleukin-2 (IL-2) variant. It is designed to simultaneously block the PD-1 immune checkpoint and deliver IL-2 receptor agonism specifically within the tumor microenvironment, thereby stimulating T cell and natural killer (NK) cell activity while minimizing peripheral toxicities typically associated with systemic IL-2 therapy. The IL-2 component of PTX-912 is activated by tumor-associated proteases, ensuring localized immune activation. Preclinical studies have demonstrated potent anti-tumor efficacy in models resistant to PD‑1 blockade and a favorable safety profile without significant immune-related adverse events. Clinical development is ongoing for advanced solid tumors[1][3][9].