By Stephen Parmley, Senior Writer
The spate of biotechs announcing new targets, combinations or milestones in the PD-1 space in the last two months suggests pharmas may not have to wait long to add second-generation therapies to their pipelines of checkpoint inhibitors. While AnaptysBio Inc. and cCAM have preclinical targets that could complement PD-1 inhibition, OncoSec Medical Inc. is about to enter the clinic with a combination that uses PD-1 suppression to potentiate the immune activation of IL-12.
The push for new compounds is driven by the fact that many patients don't respond to PD-1 therapies because their tumors have either low or no expression of the receptor's ligand, PD-L1. By acting through complementary pathways, upregulating the expression of PD-L1 or increasing the ability of antigen-presenting cells to trigger immune pathways, the next generation of compounds is designed to potentiate the tumor-killing effect of PD-1 inhibitors (See Cover Story).