Purpose: Multiple myeloma is a malignancy of plasma cells and is characterized by increased marrow angiogenesis. Thalidomide, an agent with antiangiogenic properties, is effective in relapsed myeloma. We report the results of a study combining thalidomide and dexamethasone as initial therapy for myeloma.
Patients and methods: Fifty patients with newly diagnosed myeloma were studied. Thalidomide was given at a dose of 200 mg/d orally. Dexamethasone was given at a dose of 40 mg/d orally on days 1 to 4, 9 to 12, and 17 to 20 (odd cycles) and 40 mg/d on days 1 to 4 (even cycles), repeated monthly.
Results: Of all 50 patients, a confirmed response was seen in 32 patients yielding a response rate of 64% (95% confidence interval, 49% to 77%). Thirty-one patients (62%) proceeded to stem-cell collection after four cycles of therapy including 26 who underwent stem-cell transplantation and five who chose stem-cell cryopreservation. Major grade 3 or 4 toxicities were observed in 16 patients (32%), and the most frequent were deep vein thrombosis (six patients), constipation (four patients), rash (three patients), and dyspnea (two patients). Three deaths occurred during active therapy because of a pancreatitis, pulmonary embolism, and infection.
Conclusion: We conclude that the combination of thalidomide plus dexamethasone is a feasible and active regimen in the treatment of multiple myeloma. It merits further study as an oral alternative to infusional chemotherapy with vincristine, doxorubicin, and dexamethasone and other intravenous regimens currently used as pretransplantation induction therapy for myeloma.