Combination Chemotherapy With or Without PSC 833 in Treating Patients With Relapsed or Refractory Multiple Myeloma

DISEASE CHARACTERISTICS: * Multiple myeloma of any stage confirmed by: * Bone marrow plasmacytosis with at least 10% plasma cells, sheets of plasma cells, or biopsy proven plasmacytosis * Myeloma (M) protein in serum and/or urine * Measurable disease by at least one of the following: * Serum M-component at least 1.0 g/dL by electrophoresis * Baseline measurement by nephelometry also, if used to follow response * Urine M-protein excretion greater than 200 mg/24 hours by electrophoresis * The following are not considered measurable but are followed for response: * Lytic bone lesions * Bone marrow plasmacytosis * Anemia * Serum beta 2-microglobulin * Objective evidence of progression by at least one of the following: * Increased serum M-protein (by electrophoresis unless M-spike less than 1.5 g/dL) * At least 50% above lowest remission level or by at least 2 g/dL * To more than 1.0 g/dL if sole protein indication of relapse * Nephelometry may be used instead of electrophoresis * Increased urine M-protein * To 50% above lowest level OR by 2 g/24 hours * To greater than 200 mg/24 hours * Definite new lytic bone lesions or at least a 50% increase in size of existing lesions (discussion with ECOG Study Chairman required if sole indication of progression) * Increase in serum or urine M-protein by 25% to under 50% (as above) plus one of the following: * Serum calcium greater than 12 mg/dL without other cause * Hemoglobin decreased by more than 2.0 g/dL not attributed to chemotherapy, interferon therapy, or a myelodysplastic syndrome * Less than 11 g/dL in men * Less than 10 g/dL in women * At least a 50% increase in bone marrow plasmacytosis * Failure of prior cytotoxic therapy defined by one of the following: * Never responded * Relapsed within 2 months of last treatment * Relapsed 2-12 months after last treatment following initial response * Adequate prior chemotherapy required, e.g.: * At least 2 courses of combination chemotherapy (e.g., VBMCP, VBAP, MP) * Prior vincristine, doxorubicin, and dexamethasone (VAD) allowed * No demonstrated resistance to VAD * At least 3 months since prior VAD * Cumulative doxorubicin dose no more than 250 mg/m2 * Prior autologous peripheral blood stem cell transplant allowed if performed prior to development of drug resistance * No prior allogeneic transplant * No smoldering myeloma, localized plasmacytoma, or monoclonal gammopathy of undetermined significance (MGUS) PATIENT CHARACTERISTICS: Age: * 18 and over Performance status: * ECOG 0-3 Life expectancy: * At least 2 months Hematopoietic: * Absolute neutrophil count at least 1,000/mm\^3 * Platelet count at least 50,000/mm\^3 Hepatic: * Bilirubin less than 1.5 times upper limit of normal (ULN) * AST less than 1.5 times ULN * No chronic or active hepatitis or cirrhosis Renal: * Creatinine less than 3.0 mg/dL Cardiovascular: * Ejection fraction at least 50% * No history of congestive heart failure * No overt angina despite medication * No myocardial infarction within 2 months * No poorly controlled hypertension (i.e., pressure 200/110 or higher despite medication) * No arrhythmia requiring therapy (i.e., sustained atrial or ventricular arrhythmia or multifocal premature ventricular contraction) * Digoxin to control ventricular rate of atrial fibrillation that has been chronic for more than 1 month allowed Neurologic: * No peripheral neuropathy with weakness * No cerebellar disease with ataxia Gastrointestinal: * Adequate gastrointestinal function to allow absorption of PSC 833 * No active peptic ulcer Other: * No hypersensitivity to PSC 833 or cyclosporine * No active infection * HIV negative * No uncontrolled diabetes mellitus * No second malignancy within the past 5 years except curatively treated nonmelanomatous skin cancer, carcinoma in situ of the cervix, or other localized cancer treated with surgery alone * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception * No other serious medical problem unless sufficiently stabilized PRIOR CONCURRENT THERAPY: Biologic therapy: * Prior biologic therapy (e.g., interferon) allowed Chemotherapy: * See Disease Characteristics * At least 3 weeks since other prior chemotherapy (including plicamycin) Endocrine therapy: * At least 2 weeks since high dose steroids (at least 100 mg/m2/day of prednisone or at least 40 mg/day of dexamethasone (including steroids for hypercalcemia) Radiotherapy: * At least 2 weeks since prior radiotherapy except limited radiotherapy to a single bone lesion Surgery: * At least 4 weeks since prior major surgery Other: * No concurrent anticoagulants * No concurrent drugs known to modulate cyclosporine blood concentrations