- Primary therapy for multiple myeloma must start within three days after entry to this study. For purposes of eligibility for this study, myelosuppressive chemotherapy or high-dose dexamethasone based regimens are acceptable as primary therapy. The high-dose dexamethasone regimen must include, at a minimum, dexamethasone 40 mg per day days 1-4, 9-12, 17-20 for the first cycle and 40 mg per day on days 1-4 of the second cycle.