Safety and Pharmacokinetics of Regorafenib and Cetuximab in Combination

Inclusion Criteria: * Patients with histologically or cytologically confirmed, locally advanced or metastatic solid tumors who are not candidates for standard therapy or in whom regorafenib or cetuximab is considered a standard treatment. Patients with metastatic colorectal cancer (mCRC) must have a record of K-ras gene mutational analysis available and no K-ras mutation is present. * Male or female patients ≥ 18 years of age * Women of childbearing potential must have a blood or urine pregnancy test performed a maximum of 7 days before start of study treatment, and a negative result must be documented before start of study treatment * Life expectancy of at least 3 months * Adequate bone marrow, liver and renal function as assessed by the following laboratory requirements conducted within 7 days of starting the study treatment: * Platelet count ≥ 100,000/cubic millimeters (mm3), hemoglobin (Hb) ≥ 8.5 g/dl, leukocyte count \> 3,000/mm3, absolute neutrophil count (ANC) ≥ 1,000/mm3 * Total bilirubin ≤ 1.5 x the upper limit of normal (ULN). Mildly elevated total bilirubin (\< 6 mg/dL) is allowed if Gilbert's syndrome is documented. * Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤ 2.5 x ULN (≤ 5 x ULN for subjects with liver involvement of their cancer) * Alkaline phosphatase limit ≤ 2.5 x ULN (≤ 5 x ULN for subjects whose cancer involves their liver). * Amylase and lipase ≤ 1.5 x ULN * Serum creatinine ≤ 1.5 times ULN and creatinine clearance (CLcr) ≥ 30 mL/min according to the Cockroft-Gault formula * Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 or 1 Exclusion Criteria: * Prior treatment with Regorafenib * Prior discontinuation of cetuximab treatment due to toxicity or intolerance of cetuximab * Major surgical procedure, open biopsy, or significant traumatic injury within 28 days before start of study medication * Non-healing wound, ulcer, or bone fracture * Systemic anticancer therapy within 28 days * Patients unable to swallow and retain oral medications