Abstract: Methods of treatment and pharmaceutical combinations are provided for the treatment of acute leukemia, such as acute myelogenous leukemia, and myelodysplastic syndrome. The methods of treatment and pharmaceutical combinations employ an anti-CD33 cytotoxic conjugate in combination with at least one compound selected from the group consisting of an anthracycline and a pyrimidine or purine nucleoside analog. Preferred methods of treatment and pharmaceutical combinations employ gemtuzumab ozogamicin, daunorubicin, and cytarabine.

Abstract: A novel multi-unit ribozyme is provided which is capable of selectively cleaving the mRNA transcript of a hybrid oncogene resulting from a chromosomal translocation. Specialized delivery vehicles such as liposomes, and growth factor conjugates for cellular uptake by receptor-mediated endocytosis, are also described. The multi-unit ribozyme is used for the treatment of neoplasms characterized by expression of the oncogene. In one embodiment, a multi-unit ribozyme is provided which cleaves the mRNA transcript of Philadelphia chromosome-positive cells, thereby blocking production of the tumorigenic p210.sup.bcr-abl fusion protein.