Sequential VAD (Vincristine, Adriamycin, Dexamethasone) and VTD (Bortezomib, Thalidomide, Dexamethasone) Induction Followed by High-Dose Therapy with Autologous Stem Cell Transplantation and Maintenance Treatment with Bortezomib for Newly Diagnosed Multiple Myeloma: Final Analysis of Phase II Trial