Simvastatin + Cetuximab/Irinotecan in K-ras Mutant Colorectal Cancer (CRC)

Simvastatin is a 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor leading to inhibition of post-translational modification of small G proteins. Mevalonate-derived prenyl groups, farnesyl pyrophosphate (FPP) and geranylgeranyl pyrophosphate (GGPP), facilitate essential intracellular functions of various proteins such as Ras and Rho. Owing to its effect on post-transcriptional modifications of Ras and Rho, the anti-tumor effect of statins has been suggested in various cancer cell lines. However, more recent studies utilizing cancer gene signatures have systematically screened an array of drugs for potential anti-tumor effect and have discovered statins as potential novel targeted agent against cancer. Given the cardiovascular therapeutic dose is 1 mg/kg/day which translates into serum level of 0.1 uM in patients, the investigators have previously tested and reported that low dose lovastatin ranging from nanomolar to 0.3- 1 uM statin induced cell senescence or cytostatic effect of prostate cancer cells in vitro. In addition, the investigators previously reported on well tolerability and promising anti-tumor effect of combination of simvastatin 40 mg daily and standard FOLFIRI (irinotecan, infusional 5-fluorouracil, leucovorin) in metastatic colorectal cancer.