Patients with responding or stable disease after chemotherapy receive maintenance therapy with interferon alfa beginning 14-20 weeks after day 0 of the second course of chemotherapy. Interferon alfa is administered SC 3 times a week for 3 years. Patients also receive pamidronate IV every 4 weeks until disease progression. Patients who are not in complete remission (CR) 6 months after completing the second course of chemotherapy receive oral thalidomide daily for a maximum of 1 year or for 3 months after achieving CR.