(UroToday.com) HPN424 is a prostate-specific membrane antigen (PSMA)-targeting T cell engager designed to redirect T cells to kill PSMA-expressing prostate cancer cells. It is engineered with three binding domains: anti-PSMA for tumor cell engagement, anti-albumin for half-life extension, and anti-CD3 for T cell engagement. Furthermore, HPN424 is optimized for small size and increased stability compared to other bispecific platforms. The following schematic highlights the mechanism of action of HPN424: