CD33-specific single-chain immunotoxin and method of use

摘要

A single-chain immunotoxin composition and method of treatment with the composition is disclosed. Preferably, the immunotoxin is comprised of a CD33-specific single chain Fv antibody fragment and a genetically engineered variant of Pseudomonas Exotoxin A (ETA). A preferred engineered Exotoxin A is referred to ETA' and may includes a KDEL peptide at its C-terminus, a cellular peptide mediating improved retrograde transport to the endoplasmic reticulum (ER). The immunotoxin compound may be formulated with a carrier and administered into patients where the antibody portion binds to CD33-positive cells and kills those cells to provide an effective treatment for diseases such as human myeloid leukemia.