Polyamines having the formula:or a salt thereof with a pharmaceutically acceptable acid wherein: R1-R6 may be the same or different and are
alkyl,
aryl,
aryl alkyl, cycloalkyl, optionally having an
alkyl chain interrupted by at least one etheric
oxygen atom, or
hydrogen;N1, N2, N3 and N4 are
nitrogen atoms capable of
protonation at physiological pH's;a and b may be the same or different and are integers from 1 to 4;A, B and C may be the same or different and are bridging groups which effectively maintain the distance between the
nitrogen atoms such that the polyamines:(i) are capable of uptake by a target
cell upon administration thereof to a human or non-
human animal; and(ii) upon uptake by the target
cell, competitively bind via an
electrostatic interaction between the positively charged
nitrogen atoms to substantially the same biological counter-anions as the
intracellular natural polyamines in the target
cell;the polyamines, upon binding to the biological counter-anion in the cell, function in a manner biologically different than the
intracellular polyamines, the polyamines not occurring in nature; as well as pharmaceutical compositions embodying the polyamines and methods of treating patients requiring anti-neoplastic therapy.