The invention provides a method for the treatment of Ph+
leukemia in a patient comprising administering to the patient (i) a BCR-
ABL tyrosine kinase inhibitor, and (ii) an agent which selectively binds to a
cell surface
receptor expressed on Ph+ leukemic stem cells. The invention further provides for the use of (i) and (ii) in, or in the manufacture of a medicament for, the treatment of Ph+
leukemia in a patient; and a composition for the treatment of Ph+
leukemia in a patient comprising (i) and (ii); and kits comprising (i) and (ii). In some embodiments, the
tyrosine kinase inhibitor is or is not
imatinib; or is selected from the group consisting of
dasatinib,
nilotinib, bosutinib,
axitinib, cediranib,
crizotinib, damnacanthal,
gefitinib,
lapatinib, lestaurtinib,
neratinib, semaxanib,
sunitinib, toceranib, tyrphostins, vandetanib, vatalanib, INNO-406, AP24534, XL228, PHA-739358, MK-0457, SGX393 and DC2036; or is selected from the group consisting of
dasatinib and
nilotinib. In some embodiments, the agent binds to a
receptor involved in signalling by at least one of IL-3, G-CSF and GM-CSF. In some embodiments, the agent is a mutein selected from the group consisting of IL-3 muteins, G-CSF muteins and GM-CSF muteins. In some embodiments, the mutein is an IL-3 mutein. In some embodiments, the agent is a soluble
receptor which is capable of binding to IL-3.