Phase I Multicenter, Open-label, Clinical and Pharmacokinetic Study of Plitidepsin in Combination with Sorafenib or Gemcitabine in Patients with Advanced Solid Tumors or Lymphomas to determine the maximum tolerated dose (MTD) and the recommended dose (RD) of plitidepsin in combination with sorafenib or gemcitabine in patients with advanced solid tumors or lymphomas.