Sorafenib Activity and Disposition in Liver Cancer Does Not Depend on Organic Cation Transporter 1.

Systemic therapy of advanced hepatocellular carcinoma (HCC) with the small-molecule multikinase inhibitor sorafenib is associated with large interindividual pharmacokinetic variability and unpredictable side effects potentially requiring dose reduction or treatment termination. Organic cation transporter (OCT1; gene SLC22A1) has been proposed as a clinical biomarker of HCC response. Because proof is lacking that OCT1 transports sorafenib, we used a combinatorial approach to define how OCT1 contributes to sorafenib transport.