The Utility Of Genomics And Functional Imaging To Predict Irinotecan Pharmacokinetics And Pharmacodynannics: The Predict Ir Study.

2564Background: BSA-based dosing of Irinotecan (IR), does not account for its pharmacokinetic (PK) and pharmacodynamic (PD) variability. Given IR’s unique metabolism, functional hepatic nuclear imaging (HNI) with probes for hepatic transporters correlated with its PK. This study further evaluated the utility of HNI combined with extensive excretory/metabolic/PD pharmacogenomics (PG) to predict IR PK and PD in patients (pts) treated with FOLFIRI to enable dose individualization. Methods: Eligible pts had advanced colorectal cancer, suitable for 1st/2nd-line FOLFIRI± Bevacizumab. Pts had blood analyzed by Affymetrix DMET™ Plus Array and additional SNPs were genotyped. For HNI, pts were given IV 250MBq 99mTc-IDA and imaging data analyzed for hepatic extraction/excretion parameters (clearance [CL], 1hour retention [1hRET], deconvulutional CL [DeCL], hepatic extraction fraction [HEF]). Pts treated with chemotherapy, q2-weekly, and restaged after 4 cycles. Blood taken for IR and metabolite (SN38, SN38G) analysi...