Flavopiridol in Treating Patients With Relapsed or Refractory Multiple Myeloma

Inclusion Criteria: * Diagnosis of relapsed or refractory multiple myeloma (MM) requiring treatment * Durie-Salmon stage I or greater at diagnosis * Patients with non-secretory or oligo-secretory MM (defined as maximum urinary M-spike less than 200 mg/24 hours and a maximum serum M-spike less than 0.5 g/dL during entire disease course) must have at least 30% bone marrow plasma cells * Patients with secretory MM must have measurable disease defined as serum monoclonal protein of at least 1 g/dL or urinary M-spike of at least 200 mg/24 hours * Must have received at least 1, but no more than 5 prior therapy regimens * Patients who have had 4 or 5 regimens are allowed provided corticosteroids and/or thalidomide are part of the regimens * No more than 5 prior chemotherapy regimens (as long as 2 contained dexamethasone or thalidomide) * Prior autologous peripheral blood stem cell transplantation is considered 1 prior regimen * Performance status - ECOG 0-2 * Performance status - ECOG 0-3 if secondary to neuropathy or acute bone event (e.g., vertebral compression or rib fracture) * Absolute neutrophil count at least 750/mm\^3 * Bilirubin no greater than 1.5 times upper limit of normal (ULN) * Alkaline phosphatase no greater than 2.5 times ULN * AST no greater than 2.5 times ULN * Creatinine no greater than 3 mg/dL * No myocardial infarction within the past 6 months * Peripheral neuropathy secondary to prior drug therapy or myeloma-associated neuropathy allowed * No other uncontrolled serious medical condition * No uncontrolled infection * No other active malignancy * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception * See Disease Characteristics * No prior allogeneic stem cell transplantation * At least 10 days since prior thalidomide * No concurrent biologic therapy * See Disease Characteristics * At least 2 weeks since prior myelosuppressive chemotherapy * No other concurrent chemotherapy * See Disease Characteristics * No concurrent corticosteroids (including as antiemetics) except chronic corticosteroids for disorders other than myeloma (e.g., rheumatoid arthritis or adrenal insufficiency) * Maximum dose allowed for prednisone is no more than 10 mg/day or hydrocortisone no more than 40 mg/day * At least 10 days since prior bortezomib or tipifarnib * Concurrent bisphosphonates allowed if on stable dose before study entry