Adverse events

Carfilzomib 20 mg/m2 on day 1, 2 then 56 mg/m2 days 8, 9 and 15, 16 over 30 minutes every 28 days. Dexamethasone 4 mg (8 mg if \> 45 mg/m2) orally each day of carfilzomib therapy. If less than a partial remission (PR) after 4 cycles, add rituximab 375 mg/m2 on day 16 of each cycle. Patients who meet the criteria for progression prior to 4 cycles of therapy will have rituximab added to their treatment. For patients receiving rituximab, the carfilzomib dose will be decreased to 27 mg/m2. Patients will be treated to maximal response plus 2 additional cycles to a maximum of 12 cycles. Carfilzomib: Carfilzomib on Days 1, 2, 8, 9, 15, and 16 every 28 days for a minimum of 2 cycles (approximately 2 months). You may receive additional cycles for as long as your disease remains stable or improved or until your study doctor determines that you should stop receiving the study drug or you decide to stop participating in the study. Rituximab: If less than a partial remission (PR) after 4 cycles is achieved, rituximab 375 mg/m2 on day 16 of each subsequent cycle will be added to the treatment. Subjects who meet the criteria for progression prior to 4 cycles of therapy will have rituximab 375 mg/m2 weekly for 4 consecutive weeks every 3 cycles added to the treatment. Subjects will be treated to maximal response plus 2 additional cycles to a maximum of 12 cycles. Dexamethasone: weekly on Days 1, 2, 8, 9, 15 and 16 starting with cycle 1 and continuing every cycle thereafter.