Patent ID: 8034808

Claim:
A method of treating a patient who has chronic lymphoid leukemia comprising administering a combination of a compound of formula (I): in which the dotted lines represent an optional second bond, and R is absent and X represents hydrogen when the second bond is present between the carbon to which X is attached and the nitrogen atom to which R is attached, or R represents hydrogen and X represents—OH when there is no second bond between the carbon to which X is attached and the nitrogen atom to which R is attached; and R 1 is absent and X 1 represents hydrogen when the second bond is present between the carbon to which X 1 is attached and the nitrogen atom to which R 1 is attached, or R 1 represents hydrogen and X 1 represents—OH when there is no second bond between the carbon to which X 1 is attached and the nitrogen atom to which R 1 is attached, or an addition salt thereof, with fludarabine to a patient in need thereof, in a therapeutically synergistic amount exhibiting a combination index of less than one, wherein the combination index is calculated from dose-response curves for the compound of formula (I) and fludarabine on chronic lymphoid leukemia cells.