 - Maintenance therapy: Beginning 4 weeks after completion of consolidation therapy, patients receive arsenic trioxide IV over 1-4 hours and ascorbic acid IV over 15-30 minutes on days 1, 8, 15, and 22. Treatment with arsenic trioxide and ascorbic acid repeats every 90 days every 12 weeks. Patients also receive oral dexamethasone on days 1-4. Treatment with dexamethasone repeats every 28 days. Patients receive oral thalidomide once daily. Maintenance therapy continues in the absence of disease progression or unacceptable toxicity. 