Platelet-activating factor (PAF) is a biologically active phospholipid that activates platelets, polymorphonuclear leukocytes, monocytes, and macrophages. PAF also increases vascular permeability, decreases cardiac output, induces hypotension, stimulates uterine contraction, and has been implicated in pathological processes, such as inflammation and allergy. Apafant is a water soluble, selective PAF receptor antagonist that inhibits PAF binding to human PAF receptors with a Ki value of 9.9 nM. Apafant displays anti-inflammatory, antiangiogenic, and anticancer activity.