Thirteen patients with chronic granulocytic leukemia who had entered an accelerating phase ("blast crisis") of their illness were treated with a combination of agents known to be effective in both acute granulocytic and acute lymphocytic leukemia, (prednisone, mercaptopurine, and methotrexate; vincristine sulfate was added in five instances). Only one complete clinical remission was seen. One marrow remission in the face of increasing adenopathy was seen; there were two partial remissions. The toxicity was severe and included four drug-related deaths.
Foley HT, Bennett JM. Combination Chemotherapy of Chronic. Arch Intern Med. 1969;123(2):166–170. doi:10.1001/archinte.1969.00300120054010