Sorafenib PK in Patients With Advanced HCC and Child-Pugh B

Patients will receive sorafenib at a starting dose of 200 mg twice daily. In the absence of toxicity dosage will be gradually escalated up to 400 mg BID.

Before start of treatment patients receive a single oral dose of midazolam to phenotype CYP3A4 activity. Blood samples will be taken at several time points to measure sorafenib and midazolam concentrations.

In a subgroup of 15 patients (in the Academic Medical Center Amsterdam), this test will be replaced by an oral cocktail of subclinical doses of caffeine, midazolam, omeprazole, warfarin and metoprolol and will be repeated after 4 weeks of treatment to assess the influence of sorafenib on cytochrome P450 (CYP) 1A2, 3A4, 2C19, 2C9 and 2D6 activity, respectively.