Immune Checkpoint Blockade Mediated by a Small‐Molecule Nanoinhibitor Targeting the PD‐1/PD‐L1 Pathway Synergizes with Photodynamic Therapy to Elicit Antitumor Immunity and Antimetastatic Effects on Breast Cancer

Targeting programmed cell death protein 1 (PD-1)/programmed death ligand 1 (PD-L1) immunologic checkpoint blockade with monoclonal antibodies has achieved recent clinical success in antitumor therapy. However, therapeutic antibodies exhibit several issues such as limited tumor penetration, immunogenicity, and costly production. Here, Bristol-Myers Squibb nanoparticles (NPs) are prepared using a reprecipitation method. The NPs have advantages...