An International, Non-Comparative, Open-Label Study of PS-341 Administered to Patients With Multiple Myeloma Who Experienced Relapsed or Progressive Disease After Receiving at Least Four Previous Treatment Regimens or Experienced Progressive Disease After Receiving Dexamethasone in FHCRC Protocol 1746.00

Inclusion Criteria

DISEASE CHARACTERISTICS:

- Diagnosis of multiple myeloma (MM) and meeting 1 of the following criteria:

- Progressive disease during or after treatment with high-dose dexamethasone on
MPI Study M34101-039 (FHCRC-1746.00), with no other antineoplastic treatment for
MM initiated

- Relapsed or progressive disease after receiving at least 4 prior treatment
regimens for MM (non-MPI patients)

PATIENT CHARACTERISTICS:

Age

- Adult

Performance status

- Karnofsky 60-100% (non-MPI patients)

Life expectancy

- Not specified

Hematopoietic

- Absolute neutrophil count at least 500/mm^3 (no growth factor support)

- Platelet count at least 20,000/mm^3 (transfusions allowed)

- Hemoglobin at least 7.0 g/dL (transfusions allowed)

Hepatic

- Bilirubin no greater than 1.5 times upper limit of normal (ULN)

- AST and ALT no greater than 2.5 times ULN

- Hepatitis B surface antigen negative

- No known active hepatitis C infection

Renal

- Calcium less than 14 mg/dL

- Creatinine clearance at least 20 mL/min

Cardiovascular

- Non-MPI patients:

- No myocardial infarction within the past 6 months

- No New York Heart Association class III or IV heart failure

- No uncontrolled angina

- No severe uncontrolled ventricular arrhythmias

- No acute ischemia or active conduction system abnormalities by EKG

- No cardiac amyloidosis

- No poorly controlled hypertension

Other

- All patients:

- Not pregnant or nursing

- Negative pregnancy test

- Fertile patients must use effective contraception

- HIV negative

- Non-MPI patients:

- No other serious medical or psychiatric illness that would preclude study

- No prior allergic reaction attributable to compounds containing boron or
mannitol

- No peripheral neuropathy grade 2 or greater

- No diabetes mellitus

- No active systemic infection requiring treatment

- MPI patients:

- Recovered from dexamethasone-related toxicity

- No other new or worsening existing illness that would preclude study

PRIOR CONCURRENT THERAPY:

Biologic therapy

- At least 4 weeks since prior immunotherapy or antibody therapy (non-MPI patients)

- No concurrent thalidomide

Chemotherapy

- At least 3 weeks since prior chemotherapy (6 weeks for nitrosoureas) (non-MPI
patients)

Endocrine therapy

- See Disease Characteristics

- At least 3 weeks since prior corticosteroids (greater than 10 mg/day of prednisone or
equivalent) (non-MPI patients)

- No other concurrent corticosteroids (e.g., greater than 10 mg/day of prednisone or
equivalent)

Radiotherapy

- Concurrent local short-duration radiotherapy allowed

Surgery

- At least 4 weeks since prior major surgery (except kyphoplasty) (non-MPI patients)

- Concurrent kyphoplasty allowed

- Concurrent emergency orthopedic procedures allowed

Other

- No other concurrent antineoplastic treatment for MM

- No other concurrent investigational agents, including commercial agents approved for
other indications but investigational for MM

- No concurrent clarithromycin

- Concurrent bisphosphonates allowed