FIELD: medicine, oncology, immunology. SUBSTANCE: invention relates to new immunotoxins and methods of treatment of patients with neoplastic (tumor) sicknesses. These immunotoxins are formed by conjugation of antigen-binding range and showing specificity binding with respect to protein C33 and gelonine (growth cell modulating agent) and they are components of a pharmaceutical composition. Immunotoxins of these invention kill tumor cells that show expression of antigen C33 being specifically and selectively. Therefore, new immunotoxins can be used for treatment of patients with acute and chronic leukosis and other myelodisplastic syndromes. Method and composition provide tumor growth delay by administration of a pharmaceutical composition of this invention in tumor cells. EFFECT: enhanced effectiveness of treatment. 11 cl, 8 dwg, 8 ex
