Some cancer immunotherapy drugs turn off a signaling pathway; others turn on a signaling pathway (1). FDA-approved immunotherapy drugs that target the PD-L1/PD-1 or CTLA-4/B-7 immune checkpoints function as antagonists to block immune signaling pathways. Investigational immunotherapy drugs that target GITRL/GITR function as agonists to activate an immune signaling pathway. Investigational drugs that target OX40L/OX40 … Continue reading Immunotherapy Antagonists and Agonists