Therapeutic application of thalidomide in multiple myeloma.

Treatment with thalidomide and dexamethasone was given to 26 patients with active, previously untreated multiple myeloma (MM). Thalidomide was administered in an initial dosage of 200 mg/d for 2 weeks and then increased as tolerated (in 200-mg increments at 2-week intervals) to a maximum daily dose of 800 mg. Dexamethasone was given orally in a dosage of 40 mg/d on days 1 through 4, 9 through 12, and 17 through 20 in odd cycles and 40 mg/d on days 1 through 4 in even cycles at monthly intervals. Response was defined as a decrease in serum and urine monoclonal (M)-protein by 50% or greater. Twenty (77%) of 26 patients with active MM exhibited a therapeutic response. Among the first seven patients treated with a thalidomide dose of 400 mg, grade III to IV skin toxicity developed in two. Drug titration was then stopped and the thalidomide dose maintained at 200 mg/d. Six (86%) of seven patients showed a response after thalidomide dose escalation, whereas 14 (74%) of 19 patients demonstrated a response with a constant thalidomide dose of 200 mg/d. Thalidomide alone produced a response in six (38%) of 16 patients with smoldering or indolent myeloma. The angiogenesis grade was elevated in only 8% of these patients. Thirty-two patients with relapsed myeloma were treated with thalidomide dosed at 200 mg/d, with 200-mg escalations every 2 weeks to a maximum daily dose of 800 mg. Prior chemotherapy had failed and five (16%) patients had experienced relapse following stem cell transplantation. Ten (38%) of the 26 patients who had received at least two cycles of therapy obtained a response.