Treatment Yields Complete Regression of a Human Cancer in Mice

A simple modification in an anti-cancer treatment currently in clinical trials has been found to considerably improve the drug's effectiveness and decreases side effects in studies with laboratory mice.

Researchers reported their findings in the May 16, 2007, issue of the journal Bioconjugate Chemistry. Enzon Pharmaceuticals' (Bridgewater, NJ, USA) David Filpula and colleagues at the U.S. National Cancer Institute (NCI) worked on SS1P, a so-called immunotoxin that targets and destroys cells producing the surface protein mesothelin.

Ovarian, pancreatic, and malignant mesothelioma cells all produce abnormally large amounts of mesothelin and therefore are targets for SS1P. In the new study, researchers modified SS1P with PEGylation, which involves attaching chains of polyethylene glycol (PEG) to the molecule. PEGylation is a well-established process that is used in at least six protein-based pharmaceutical compounds currently commercially available.

PEGylated SS1Ps had fewer side effects and were more effective in mice bearing human tumors than standard SS1P, the report stated. One dose of the modified SS1P resulted in complete regression of the mouse tumors, the first time that such an effect had been observed, according to the investigators. PEGylation of SS1P and other immunotoxins may hold potential therapeutic application in cancer patients, as well, they added.


Related Links:
Enzon Pharmaceuticals
U.S. National Cancer Institute