Methods of combatting infectious diseases using dicationic bis-benzimidazoles

A method of treating leukemia in a subject in need of said treatment, comprising administering to said subject a compound of Formula IA or a physiologically acceptable salt thereof:

• wherein:
• R1 and R2 are each independently selected from the group consisting of H, lower alkyl, alkoxyalkyl, cycloalkyl, aryl, alkylaryl, hydroxyalkyl, aminoalkyl, and alkylaminoalkyl, or R1 and R2 together represent C2 to C10 alkyl, hydroxyalkyl, or alkylene, or R1 and R2 together are:
• wherein n is a number from 1 to 3, and R10 is H or —CONHR11NR15R16, wherein R11 is lower alkyl and R15 and R16 are each independently selected from the group consisting of H and lower alkyl;
• and
• R3 is H, hydroxy, lower alkyl, cycloalkyl, aryl, alkylaryl, alkoxyalkyl, hydroxycycloalkyl, alkoxycycloalkoxy, hydroxyalkyl, aminoalkyl or alkylaminoalkyl;
• and
• R4 and R5 are each independently selected from the group consisting of H, lower alkyl, halogen, aryl, arylalkyl, aminoalkyl, aminoaryl, oxyalkyl, oxyaryl, and oxyarylalkyl;
• in an amount effective to treat leukemia.