The orotate salt form of carboxyamidotriazole (CAI), an orally bioavailable small molecule with potential antiangiogenic and antiproliferative activities. Carboxyamidotriazole binds to and inhibits non-voltage-operated calcium channels, blocking both Ca2+ influx into cells and Ca2+ release from intracellular stores, resulting in the disruption of calcium channel-mediated signal transduction. CAI inhibits PI3 activity and vascular endothelial growth factor (VEGF) signaling. This may inhibit endothelial proliferation, tumor cell growth, invasion and metastasis.