AE-941 in Treating Patients With Relapsed or Refractory Multiple Myeloma

DISEASE CHARACTERISTICS: Diagnosis of multiple myeloma (MM) according to the Durie and Salmon criteria Refractory to or in early relapse after standard chemotherapy with or without stem cell transplantation Measurable disease Quantifiable IgM, IgG, or IgA paraprotein in serum AND/OR Bence-Jones protein in urine No plasma cell leukemia (more than 20% plasma cells in peripheral blood and an absolute plasma cell count of at least 2,000/mm3) No nonsecretory MM No spinal cord compression PATIENT CHARACTERISTICS: Age: 18 and over Performance status: ECOG 0-2 Life expectancy: More than 6 months Hematopoietic: No clinical symptoms of hyperviscosity Hepatic: Not specified Renal: Creatinine no greater than 2 times upper limit of normal Calcium no greater than 11 mg/dL Other: No other prior malignancy within the past 5 years except basal cell carcinoma of the skin or carcinoma in situ of the cervix No severe allergy to fish or seafood No medical condition that would interfere with intake and/or absorption of study medication (e.g., gastrectomy or major intestinal resection) No significant medical or psychiatric condition that would preclude study participation Not pregnant Negative pregnancy test Fertile patients must use adequate contraception PRIOR CONCURRENT THERAPY: Biologic therapy: See Disease Characteristics No prior history of treatment with thalidomide for more than 14 days duration At least 4 weeks since prior biological therapy for MM Concurrent epoetin alfa allowed Chemotherapy: See Disease Characteristics At least 4 weeks since prior chemotherapy for MM Endocrine therapy: At least 4 weeks since prior steroid therapy for MM No prednisone maintenance therapy Radiotherapy: At least 4 weeks since prior radiotherapy No concurrent palliative or curative radiotherapy Surgery: Not specified Other: At least 28 days since other prior shark cartilage products At least 28 days since other prior experimental therapeutic agents Concurrent monthly bisphosphonate (pamidronates) infusions allowed No other concurrent anticancer treatment No other concurrent shark cartilage products No other concurrent therapies for MM