If you do not respond to the third cycle of bortezomib/rituximab, you will be given a chemotherapy regimen containing the drugs rituximab, cyclophosphamide, vincristine, and doxorubicin, together with dexamethasone. This combination is known as modified R-Hyper-CVAD. Rituximab will be given through a vein over about 4 hours on Day 1 only. Cyclophosphamide will be given through a vein every 12 hours on Days 1-4. Doxorubicin and vincristine will be given through a vein continuously over 24 hours on Days 1-4. Dexamethasone is taken by mouth daily on Days 1-4, 9-12, and 17-20.