Everolimus in Treating Patients With Relapsed or Refractory Multiple Myeloma

DISEASE CHARACTERISTICS: * Diagnosis of multiple myeloma, meeting 1 of the following criteria: * Monoclonal protein in the serum of ≥ 1 g/dL * Monoclonal light chain in the urine protein electrophoresis of ≥ 200 mg/24 hours * Measurable light chains by free light chain assay of ≥ 10 mg/dL * Measurable plasmacytoma * Must have received prior therapy and have relapsed or refractory disease PATIENT CHARACTERISTICS: * ECOG performance status 0-2 * Life expectancy ≥ 12 weeks * ANC ≥ 1,000/mm³ * Platelet count ≥ 75,000/mm³ * Hemoglobin ≥ 8.0 g/dL * Total bilirubin ≤ 2.0 mg/dL (if total bilirubin is elevated, direct bilirubin must be normal) * AST ≤ 3 times upper limit of normal (ULN) * Creatinine ≤ 1.5 times ULN * Calcium \< 11 mg/dL * No uncontrolled infection * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception * No HIV positivity PRIOR CONCURRENT THERAPY: * See Disease Characteristics * At least 3 weeks since prior cytotoxic chemotherapy * At least 2 weeks since prior biologic therapy or radiotherapy * At least 2 weeks since prior corticosteroids * Concurrent chronic corticosteroids allowed for treatment of disorders other than myeloma * No other concurrent chemotherapy, immunotherapy, radiotherapy, or any ancillary therapy considered investigational