DISEASE CHARACTERISTICS: Diagnosis of relapsed or refractory multiple myeloma confirmed by the presence of the following: Bone marrow plasmacytosis with at least 10 percent plasma cells Sheets of plasma cells OR Biopsy-proven plasmacytoma Documentation of at least one of the following criteria: Serum myeloma (M)-protein component at least 1.0 g/dL by serum protein electrophoresis Urine M-protein excretion more than 200 mg/24 hours by urine protein electrophoresis Stage IIA or IIIA disease Measurable disease The following are not considered measurable disease: Lytic bone lesions Anemia Bone marrow plasmacytosis Beta-2 microglobulin in serum Previously treated with conventional chemotherapy Progressing or relapsing disease at time of study

PATIENT CHARACTERISTICS: Age: 18 and over Performance status: ECOG 0-3 Life expectancy: More than 8 weeks Hematopoietic: Absolute neutrophil count at least 1,000/mm3 Hepatic: AST or ALT no greater than 2 times upper limit of normal (ULN) Bilirubin no greater than 2 mg/dL Renal: Creatinine no greater than 1.5 times ULN Calcium no greater than 12 mg/dL Other: Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception Capable of swallowing intact study medication tablets No concurrent serious infection No grade 3 or greater peripheral neuropathy No life-threatening illness unrelated to tumor No other active or invasive cancer within the past 3 years except nonmelanoma skin cancer

PRIOR CONCURRENT THERAPY: Biologic therapy: Prior thalidomide allowed At least 14 days since prior immunologic agents No concurrent immunologic agents

Chemotherapy: See Disease Characteristics At least 3 weeks since prior cytotoxic chemotherapy No other concurrent cytotoxic therapy Endocrine therapy:

At least 14 days since prior high-dose corticosteroids No concurrent hormonal therapy No concurrent corticosteroids Radiotherapy: At least 3 weeks since prior radiotherapy and recovered No concurrent radiotherapy Surgery: Not specified Other: No other concurrent cancer therapy Concurrent pamidronate or other bisphosphonates allowed