Bortezomib and Dexamethasone in Treating Patients With Multiple Myeloma That Has Relapsed or Has Not Responded to Treatment

DISEASE CHARACTERISTICS:

• Diagnosis of multiple myeloma

• Refractory or relapsed disease meeting the following criteria:

• Primary refractory disease and first-line relapsing disease

• Progressive disease after last therapy

PATIENT CHARACTERISTICS:

• ECOG performance status 0-2

• Life expectancy > 3 months

• Platelet count ≥ 50,000/mm³ (≥ 30,000/mm³ for patients with significant bone marrow involvement)

• Transfusions allowed

• Hemoglobin ≥ 7.5 g/dL

• Absolute neutrophil count ≥ 750/mm³

• Serum calcium < 14 mg/dL

• AST and ALT < 2.5 times upper limit of normal

• Creatinine clearance ≥ 30 mL/min

• Not pregnant or nursing

• Negative pregnancy test

• Fertile patients must use effective contraception

• No peripheral neuropathy ≥ grade 2 within the past 14 days

• No hypersensitivity to boron or mannitol

• No cardiovascular complications, including any of the following:

• Myocardial infarction within the past 6 months

• New York Heart Association class III-IV heart failure

• Uncontrolled angina

• Ventricular arrhythmias

• Electrocardiographic evidence of acute ischemia or active conduction system abnormalities

• Cardiac amyloidosis

• No other cancer or treatment for cancer other than basal cell cancer of the skin within the past 5 years

• No poorly controlled chronic diseases (e.g., diabetes mellitus or hypertension)

• No HIV positivity

• No hepatitis B surface antigen or active hepatitis C infection

• No active systemic infection requiring therapy

• No serious medical or psychiatric illness that would interfere with study participation

PRIOR CONCURRENT THERAPY:

• No plasmapheresis within the past 4 weeks

• No major surgery within the past 4 weeks

• No prior bortezomib

• No chemotherapy (e.g., clarithromycin) within the past 4 weeks

• No radiotherapy within the past 3 weeks

• No corticosteroids (> 10 mg/day of prednisone or equivalent) within the past 3 weeks

• No other immunotherapy within the past 8 weeks

• No other investigational drugs within the past 14 days

• No concurrent participation in other clinical research studies