High-Dose Melphalan, Total-Body Irradiation, and Peripheral Stem Cell Transplantation in Treating Patients With Multiple Myeloma in First Relapse

OBJECTIVES: I. Assess bone marrow reconstitution and peripheral blood cell counts of patients with multiple myeloma treated with high-dose melphalan (L-PAM) and total-body irradiation (TBI) followed by peripheral blood stem cell (PBSC) rescue. II. Assess the efficacy of intravenous L-PAM and TBI for treatment of relapsing/refractory myeloma. III. Assess the tolerability and toxicity of this regimen in patients with relapsing multiple myeloma. IV. Assess response rate and survival of relapsing/refractory patients treated with this regimen.

OUTLINE: Prior to entry, patients will have received 3 monthly courses of standard VAD followed by PBSC collection on Regimen A; those who responded to VAD continue standard VAD to best response and upon relapse (on or off therapy) proceed to Regimen B. Patients with no response to 3 courses of VAD and those with no response to an alkylating-based regimen proceed immediately to Regimen B following PBSC collection. The following acronyms are used: CTX Cyclophosphamide, NSC-26271 G-CSF Granulocyte Colony Stimulating Factor (Amgen), NSC-614629 L-PAM Melphalan, NSC-8806 PBSC Peripheral Blood Stem Cells VAD Vincristine/Doxorubicin/Dexamethasone TBI Total Body Irradiation Regimen A: Stem Cell Mobilization/Harvest. CTX; G-CSF. Regimen B: Single-Agent Myeloablative Chemoradiotherapy with Stem Cell Rescue. L-PAM; TBI (Co60 or linear accelerators of 4 MV or greater); with PBSC.

PROJECTED ACCRUAL: If 9 or fewer or 20 or more responses are seen in the first 50 patients treated, the study will be discontinued.

DISEASE CHARACTERISTICS: Multiple myeloma confirmed by bone marrow plasmacytosis and with measurable M-component in the serum or urine by immunoelectrophoresis or immunofixation No Stage I myeloma No smoldering multiple myeloma Refractory to or in first relapse following an initial response to VAD (vincristine/doxorubicin/dexamethasone), with relapse defined as any of the following: 50% increase above the lowest remission level of serum or urine M-protein while on therapy 25-50% increase above the lowest remission level of serum or urine M-protein associated with either: Hypercalcemia (greater than 11 mg/dl) Hb decrease of 2 g/dl attributable to increasing marrow plasmacytosis Appearance of new lytic lesions Calcium no greater than 11 mg/dl No myeloma meningitis No plasma cell leukemia

PATIENT CHARACTERISTICS: Age: 18 to 65 Performance status: ECOG 0-2 Hematopoietic: WBC greater than 500 (after G-CSF) Platelets greater than 25,000 Hepatic: Bilirubin no greater than 2.0 mg/dl Renal: Creatinine no greater than 2.0 mg/dl Cardiovascular: No NYHA class II-IV disease Pulmonary: DLCO at least 50% of predicted FVC at least 75% of predicted FEV1 at least 60% of predicted Other: No uncontrolled infection No active fungal infection No fever No prior malignancy within 5 years except: Basal cell skin cancer In situ carcinoma of the cervix No pregnant or nursing women

PRIOR CONCURRENT THERAPY: Biologic therapy: Prior biological response modifiers allowed Chemotherapy: No time limit between cytotoxic therapy and protocol treatment Prior cumulative melphalan dose less than 300 mg Endocrine therapy: Corticosteroids for hypercalcemia allowed Radiotherapy: Prior radiotherapy allowed Prior pelvic radiotherapy allowed, but patients with such therapy are unlikely to have adequate PBSC harvested Surgery: Not specified