Inclusion Criteria

DISEASE CHARACTERISTICS:

- Diagnosis of stage II or III multiple myeloma

- Refractory myeloma defined as progressive disease (more than 25% increase in M
protein or in radiographic findings of nonsecretory myeloma) despite up to 3 courses
of prior cytotoxic chemotherapy

- No more than 3 prior cytotoxic regimens

- No more than 1 prior high-dose cytotoxic regimen with stem cell transplantation

- History of disease progression after prior steroid antimyeloma therapy

- No smoldering myeloma

- Measurable disease based on presence of serum and urine M protein and/or measurable
plasmacytoma

PATIENT CHARACTERISTICS:

Age:

- Over 18

Performance status:

- Karnofsky 70-100%

Life expectancy:

- At least 3 months

Hematopoietic:

- Absolute granulocyte count greater than 1,200/mm^3*

- Platelet count greater than 75,000/mm^3*

- Hemoglobin greater than 10 g/dL* NOTE: *Unless due to multiple myeloma

Hepatic:

- Bilirubin no greater than 2 times upper limit of normal (ULN)

- SGOT and SGPT no greater than 2 times ULN

Renal:

- Creatinine no greater than 1.5 times ULN

Cardiovascular:

- Absolute QT interval less than 460 msec in the presence of normal potassium and
magnesium levels

- No significant underlying cardiac dysfunction

- No conduction defects

- No unstable angina

- No congestive heart failure

- No New York Heart Association class II-IV cardiac disease

- No myocardial infarction within the past 6 months

Other:

- No preexisting grade 2 or greater neurotoxicity/neuropathy

- No other malignancy within the past 5 years except curatively treated carcinoma in
situ of the cervix or nonmelanoma skin cancer

- No uncontrolled diabetes mellitus

- No active serious infection uncontrolled by antibiotics

- No history of grand mal seizures (other than infantile febrile seizures)

- Not pregnant or nursing

- Negative pregnancy test

- Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY:

Biologic therapy:

- See Disease Characteristics

- See Chemotherapy

- At least 28 days since prior biologic therapy

Chemotherapy:

- See Disease Characteristics

- At least 28 days since prior cytotoxic chemotherapy, including high-dose cytotoxic
regimen with stem cell transplantation

- No other concurrent cytotoxic chemotherapy

Endocrine therapy:

- See Disease Characteristics

Radiotherapy:

- At least 28 days since prior radiotherapy except for focal radiation for symptom
control

Surgery:

- Not specified