BPT331

BPT331 is an investigational PD1-IL2 cis-signaling immunocytokine being developed by Bright Peak Therapeutics for the treatment of cancer. The molecule is a biologic therapeutic created through the site-specific chemical conjugation of a synthetically engineered Interleukin-2 (IL-2) cytokine to the Fc domain of a PD-1-targeting monoclonal antibody. BPT331 is designed to deliver coordinated PD-1 checkpoint blockade while selectively activating antigen-experienced PD-1+ T effector cells within the tumor microenvironment via cis-signaling. This approach aims to concentrate IL-2 activity on tumor-resident PD-1high effector T cells, thereby enhancing antitumor efficacy while limiting the systemic immune activation and toxicity typically associated with non-targeted IL-2 therapies.