The Food and Drug Administration says the Invader UGT1A1 Molecular Assay has so far only been shown to work with Pfizer Inc's colon cancer drug Camptosar, but future data could link it to other drugs.
The test works by picking up differences in the UGT1A gene, which produces an enzyme that helps drugs metabolize. Differences in the gene affect how much medicine enters the blood stream. Higher levels of the drug in the blood may lead to increased side effects.
The FDA says Third Wave conducted an outside study of 66 colon cancer patients taking Campostar and found those with a certain variation in the UGT1A1 gene had a higher risk of toxicity.
