Inclusion Criteria

DISEASE CHARACTERISTICS:

- Diagnosis of multiple myeloma

- Must have received induction therapy within the past 3 months

- Chemoresponsive disease

- Greater than 50% reduction of monoclonal paraprotein with reduction in marrow
plasma cell infiltrate or greater than 50% reduction in marrow plasma cell
infiltrate if disease is non-secretory

- No symptomatic pleural effusions

- Eligible for stem cell transplantation

PATIENT CHARACTERISTICS:

Age:

- 18 and over

Performance status:

- ECOG 0-3 (ECOG 3 allowed only if due to bone disease or neuropathy)

Life expectancy:

- Not specified

Hematopoietic:

- Platelet count at least 150,000/mm^3

Hepatic:

- Bilirubin no greater than 2.5 mg/dL

Renal:

- Creatinine no greater than 2.5 mg/dL OR

- Creatinine clearance greater than 51 mL/min

Cardiovascular:

- No symptomatic cardiomyopathy

- No medically documented symptomatic cardiac arrhythmias within the past 60 days

- No New York Heart Association class III congestive heart failure

- No myocardial infarction within the past 6 months

Other:

- No other concurrent medical conditions that would preclude study

- No uncontrolled infections

- No other active malignancy within the past 5 years except for non-melanoma skin
cancer

- Not pregnant

- Negative pregnancy test

- Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY:

Biologic therapy:

- No prior stem cell mobilization or transplantation

Chemotherapy:

- See Disease Characteristics

- No more than 200 mg prior oral melphalan

Endocrine therapy:

- Not specified

Radiotherapy:

- No more than 3000 cGy of prior radiotherapy for myeloma

Surgery:

- Not specified