Bortezomib and Bendamustine to Treat Relapsed/Refractory Myeloma

Patients with relapsed and refractory myeloma who have a measurable paraprotein in the serum or urine or measurable protein by Freelite or measurable disease by plasmacytoma will be given a combination of bendamustine and bortezomib each cycle. Response rate (PR or better after 2 cycles) and duration of response will be assessed. Therapy will be continued until disease progression. The bendamustine would be used in a day 1, day 4 dosing schedule after each dose of bortezomib to take advantage of the chemosensitizing properties of bortezomib. This minimizes the days of treatment to just the first week and allows rebound of blood counts. This will be a phase II trial with dose reduction as necessary. Bendamustine is a drug which appears to be non-cross-resistant with other alkylating agents in vitro and in vivo. Thus, we hypothesize that the combination of bortezomib and bendamustine will have activity in relapsed/refractory myeloma.