There’s no “magic bullet” for cancer. Or is there?



In the U.S., it is expected that approximately 1.5 million people will be diagnosed with cancer each year, and one third of those will die of the disease. To combat such a complex and multifactorial disease SEER Stat Fact Sheets, doctors need more efficient and targeted treatments to destroy cancers cells without harming healthy tissues.


IRP researcher Ira Pastan, M.D., and colleagues created recombinant immunotoxins that specifically target cancer cells. The “magic bullets” are made by genetically engineering a potent bacterial toxin, Pseudomonas exotoxin A, with an antibody fragment that selectively binds to receptors on the cancer cell surface.


Delivering a toxic payload to the inside of a cancer cell while leaving healthy tissue unscathed is a major step forward in the battle against cancer. Research continues to determine which tumors might respond best to this type of targeted approach, but clinical trials are already underway, with some immunotoxins producing partial or complete remissions.


Onda M, Olafsen T, Tsutsumi Y, Bruland ØS, Pastan I. (2001). Cytotoxicity of Antiosteosarcoma Recombinant Immunotoxins Composed of TP-3 Fv Fragments and a Truncated Pseudomonas Exotoxin A. J Immunother 1991. 24(2), 144-150.

Kreitman RJ, Tallman MS, Robak T, Coutre S, Wilson WH, Stetler-Stevenson M, Fitzgerald DJ, Lechleider R, Pastan I. (2012). Phase I trial of anti-CD22 recombinant immunotoxin moxetumomab pasudotox (CAT-8015 or HA22) in patients with hairy cell leukemia. J Clin Oncol. 30(15), 1822-8.