Sorafenib Phase II Study for Japanese Anaplastic or Medullary Thyroid Carcinoma Patients

Inclusion Criteria: * Japanese patients with ATC (Anaplastic thyroid carcinoma) or locally advanced or metastatic MTC (medullary thyroid carcinoma) * Not a candidate for surgery or radiotherapy with curative intent * Histologically or cytologically confirmed ATC or MTC * Measurable or non-measurable disease (but clinically evaluable) according to RECIST 1.1. * Age \>= 18 years * Adequate bone marrow, liver and renal function to be conducted within 14 days prior to treatment * Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 0 or 1 * Life expectancy of at least 12 weeks Exclusion Criteria: * Histologic subtypes of thyroid cancer other than anaplastic or medullary carcinoma * Prior anti-cancer treatment with tyrosine kinase inhibitors, monoclonal antibodies (licensed or investigational) that target VEGF or VEGF (vascular endothelial growth factor) receptors or other targeted agents * Prior chemotherapy for thyroid cancer (only one regimen is allowed) * Major surgery, open biopsy, or significant traumatic injury within 30 days prior to enrollment in the study. * Subjects with tracheal, bronchial or esophageal infiltration with significant risk of bleeding but without having received local treatment prior to enrollment in the study