PD-1 / CTLA-4 / VEGF

Class

trispecific antibody

Pathway

dual immune checkpoint blockade + anti-angiogenesis

This mechanism combines three distinct biological targets into a single antibody molecule: PD-1, CTLA-4, and VEGF. PD-1 and CTLA-4 are immune checkpoint receptors that dampen T-cell activity, one of the ways tumors evade immune attack. Blocking both simultaneously removes two independent brakes on T-cell activation, one acting early in T-cell priming (CTLA-4) and one later during ongoing immune responses within tissue (PD-1). VEGF, vascular endothelial growth factor, drives formation of new blood vessels that tumors depend on for growth and also creates an immunosuppressive microenvironment by impairing immune cell infiltration. Adding anti-VEGF activity to dual checkpoint blockade is intended to normalize tumor vasculature and improve immune cell access to the tumor, while also directly restraining tumor blood supply. The rationale for building this into one trispecific molecule rather than combining separate drugs is to achieve coordinated engagement of all three pathways at the tumor site, potentially improving activity and simplifying administration compared to multi-drug regimens. This class of approach is relevant broadly across solid tumors, particularly those characterized by dense, aberrant vasculature and significant immune suppression within the tumor microenvironment.