Bendamustine Hydrochloride in Treating Patients With Previously Treated Multiple Myeloma

Inclusion Criteria: 1. Patients with multiple myeloma who have not achieved a CR following at least 4 cycles of induction therapy 2. Age up to 80 years 3. ECOG Performance Status of 0 or 1 4. Left ventricular ejection fraction =/\> 40%. No uncontrolled arrhythmias or symptomatic cardiac disease 5. FEV1, FVC and DLCO =/\> 40%. No symptomatic pulmonary disease. 6. Serum bilirubin \<2 x upper limit of normal, alkaline phosphatase \<3 x upper limit of normal. No evidence of chronic active hepatitis or cirrhosis. No effusion or ascites \> 1 L prior to drainage. 7. HIV negative 8. Negative beta HCG test in woman with child bearing potential, defined as not post-menopausal for 12 months or no previous sterilization 9. Patients or guardian able to sign informed consent 10. Availability of previously collected autologous stem cells (at least 3.0 x 106 CD34 cells/kg) 11. Calculated GFR \> 50 ml/minute Exclusion Criteria: 1. Patients with uncontrolled hypertension (systolic \> 140, diastolic \> 90 despite antihypertensive therapy 2. Patients with uncontrolled bacteria, viral or fungal infections (currently taking medication and progression of clinical symptoms) 3. New York Heart Association (NYHA) Class III or IV heart failure, uncontrolled angina, severe uncontrolled ventricular arrhythmias, or electrocardiographic evidence of acute ischemia or active conduction system abnormalities 4. Relapsed/refractory myeloma