A preferred biologically active agent is a compound of the following formula: This compound, an anti-proliferative agent known generally as CVT 313, is named 2-{(2-hydroxyethyl)-[9-isopropyl-6-(4-methoxybenzylamino)-9H-purin-2-yl]-amino}-ethanol or also known as 2-diethanolamino-6-(4-methoxybenzylamino)-9-isopropylpurine.