U3-1784 is a human monoclonal antibody specifically raised against the Fibroblast Growth Factor Receptor 4 (FGFR4). The purpose of this study is to assess safety and tolerability of U3-1784, an FGFR4 human monoclonal antibody, in advanced tumour and HCC patients. The study is designed to identify a safe and tolerated dose in advanced tumour patients using a 3+3 dosing. The selected dose will then be used to assess safety and tolerability in HCC patients.