Invitrogen Advances Drug Discovery Safety Testing

Launches first non-isotopic test kit for high throughput hERG channel blockage screening

Carlsbad, CA - Lethal off-target cardiotoxicity of several blockbuster therapeutics has led to the U. S. Food and Drug Administration's recommendation that all new small molecule drug compounds be tested for hERG channel blockage. Invitrogen Corporation, a provider of essential life sciences technologies for research, production and diagnostics, today announced the availability of a proprietary test kit that enables drug discovery researchers to better screen for cardiotoxicity traits of potential drug compounds earlier in the discovery process. The Predictor hERG Fluorescence Polarization Assay Kit is the first non-isotopic, homogenous test kit for performing hERG ion channel blockage screening.

Drug-induced long QT syndrome and adverse cardiotoxic affects have been linked with blockage of the human ether-a-go-go related gene (hERG) channel. The current gold standard for hERG ion channel blockage determination is electrophysiology patch-clamp analysis; however this technology is costly and time consuming to perform for the number of compounds entering the drug discovery process. The Predictor hERG assay allows researchers to triage compounds and identify potential liabilities prior to the investment in patch clamp techniques. This simple assay is at least a twice as fast to complete and lends itself to automation, while being less costly than alternative radioligand displacement assays.

"Pharmaceutical researchers are under tremendous pressure to better assess compound safety as early in the drug discovery process as possible," said Dr. Brian Pollack, chief scientific officer for Invitrogen Corp. "The Predictor hERG assay delivers a new cost-effective, efficient solution for assessing potential toxicity while also eliminating the issues associated with using radioisotopes for such assays."

The Predictor Fluorescence polarization assay is based upon the principle of fluorescence polarization (FP), in which a tracer is displaced from the hERG channel by compounds that bind to the channel. When the tracer is bound to the channel the FP value is high, and when displaced by hERG binding compounds the FP value is low. Results are highly predictive of patch-clamp data, with a Z' value of 0.86. The assay is also stable at DMSO, methanol, or ethanol concentrations up to five percent.

SOURCE: Invitrogen