Thalidomide and hematopoietic-cell transplantation for multiple myeloma.

BACKGROUND: High-dose therapy with melphalan can prolong survival among patients with multiple myeloma. We assessed whether the addition of thalidomide, which has activity against advanced and refractory myeloma, would further improve survival.

METHODS: Between October 1998 and February 2004, 668 patients with newly diagnosed multiple myeloma received two cycles of intensive melphalan-based chemotherapy, each supported by autologous hematopoietic stem-cell transplantation. A total of 323 were randomly assigned to receive thalidomide from the outset until disease progression or undue adverse effects, and 345 did not receive thalidomide. The primary end point was the five-year event-free survival rate. Secondary end points were complete response and overall survival.

RESULTS: After a median follow-up of 42 months among survivors, the thalidomide and control groups had rates of complete response of 62 percent and 43 percent, respectively (P<0.001), and five-year event-free survival rates of 56 percent and 44 percent (P=0.01). The five-year rate of overall survival was approximately 65 percent in both groups (P=0.90). Median survival after relapse was 1.1 years in the thalidomide group and 2.7 years in the control group (P=0.001). Severe peripheral neuropathy and deep-vein thrombosis occurred more frequently in the thalidomide group than in the control group.

CONCLUSIONS: When incorporated into high-dose therapy for myeloma, thalidomide increased the frequency of complete responses and extended event-free survival at the expense of added adverse effects without improving overall survival. (ClinicalTrials.gov number, NCT00083551.).