Comparison of thalidomide and lenalidomide as therapy for myelofibrosis

With the use of the International Working Group for Myelofibrosis Treatment and Research consensus criteria, we reassessed the efficacy of thalidomide and lenalidomide in 125 patients with myelofibrosis treated in 3 consecutive phase 2 trials: 44 received single-agent thalidomide, 41 single-agent lenalidomide, and 40 a combination of lenalidomide plus prednisone. The thalidomide group included significantly more untreated patients and patients with performance status of 2. The Lenalidomide-based therapy produced higher efficacy (34%-38%) than thalidomide (16%; P = .06). Responses to thalidomide were seen within 3-15 weeks, whereas responses to the lenalidomide-based therapy were also seen after a prolonged course of therapy (range, 2-45 weeks). Lenalidomide plus prednisone therapy resulted in significantly longer response duration (median, 34 months) than single-agent lenalidomide or thalidomide (median, 7 and 13 months, respectively; P = .042). Fewer patients (P = .001) discontinued the lenalidomide plus prednisone therapy (13%) because of side effects then patients on single-agents therapy (32%-39%). In conclusion, the combination of lenalidomide plus prednisone appears to be more effective and safer than single-agent thalidomide or lenalidomide. (Blood. 2011;118(4):899-902)