OncQuest Laboratories Ltd, the pioneer in the Indian Oncology clinical testing, has launched UGT1A1 Genotyping for determining therapeutic response of Irinotecan, a chemotherapy drug which has been approved by the US FDA as a second line therapy to treat colorectal cancer that has metastasized (spread to other parts of the body) or has recurred or gotten worse after earlier chemotherapy.
OncQuest’s new technologically advanced clinical and research laboratory is fully equipped with molecular technologies allowing for rapid advancement in the complex field of theranostics, pharmacogenomics, companion diagnostics, proteomics, bioinformatics & biomarker studies.
Irinotecan, a prodrug, to exert its anticancerous effects requires conversion to an active drug SN-38 in the body. A carboxyl esterase-converting enzyme helps this conversion. i.e. uridine di -phosphate glucuronosyl transferase 1 A1 (UGT1A1).
UGT1A1 is responsible for the clearance of irinotecan by glucuronidation, thus preventing toxicity of Irinotecan. However,It has been seen that genetic variations in UGT1A1 enzyme are responsible for its decreased activity, accumulation of SN-38 in the body resulting in irinotecan- dose related toxic effects including grade (3/4) neutropenia, diarrhoea, and asthenia which at times are fatal.
Hence, determining the variations in the gene encoding for uridine diphosphate glucuronosyltransferase 1A1 (UGT1A1) may help predict which patients are most likely to develop these irinotecan-related toxic effects.
US FDA has approved UGT1A1 testing before starting Irinotecan on a patient, which could help in guiding the selection of appropriate starting dosages of Irinotecan, reducing the risk of severe drug accumulation toxic effects and improving the chances that therapy could be maintained.