DISEASE CHARACTERISTICS:

• Diagnosis of multiple myeloma based on at least two of the following:

  • Paraprotein in serum and/or urine
  • Greater than 10% plasma cells in bone marrow
  • Lytic bone lesions
• Measurable serum and/or urine paraprotein
• Progression from first or second stable plateau phase
• No non-secretory myeloma or plasma cell leukemia (greater than 2,000/mm^3 circulating plasma cells)
• No primary refractory disease or second or later relapse

PATIENT CHARACTERISTICS:

Age:

• 18 and over

Performance status:

• 0-3

Life expectancy:

• Not specified

Hematopoietic:

• Neutrophil count at least 1,000/mm^3
• Platelet count at least 75,000/mm^3

Hepatic:

• Bilirubin no greater than 1.5 times upper limit of normal (ULN)
• ALT/AST no greater than 2.5 times ULN

Renal:

• Creatinine less than 3.4 mg/dL

Cardiovascular:

• No clinically significant cardiac insufficiency
• No uncontrolled hypertension

Other:

• No uncontrolled diabetes mellitus
• No recent history of peptic ulceration
• HIV-1 and HIV-2 negative
• Fertile patients must use effective contraception during and for 6 months after study participation

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• No prior allogeneic peripheral blood stem cell or bone marrow transplantation
• No planned future autologous transplantation unless sufficient stored stem cells available
• Prior interferon allowed if administered as maintenance of stable plateau phase
• No concurrent epoetin alfa

Chemotherapy:

• At least 3 months since prior chemotherapy

Endocrine therapy:

• Not specified

Radiotherapy:

• Concurrent radiotherapy for pain or to treat localized tumors allowed

Surgery:

• Not specified

Other:

• No prior participation in any clinical trial with an unlicensed product