Postrelapse survival rate correlates with first-line treatment strategy with thalidomide in patients with newly diagnosed multiple myeloma: a meta-analysis

To define whether or not thalidomide exposure upfront to newly diagnosed patients with multiple myeloma would adversely impact postrelapse survival (PRS), we performed a meta-analysis of randomized controlled trials. Medline, Embase, the Cochrane controlled trials register and the Science Citation Index were searched. Thirteen trials were identified, covering a total of 6097 subjects, and PRS data were available from eight trials. The summary hazard ratio (thalidomide vs control) of all those trials for PRS was 1.23 [95% CI, 1.05-1.45]. The HRs of thalidomide maintenance subgroups were 0.90 [0.57-1.41] for PRS, 0.61 [0.44-0.83] for progression-free survival (PFS) and 0.54 [0.36-0.80] for overall survival, respectively. The corresponding ratios of thalidomide induction and maintenance subgroups were 1.41 [1.13-1.76] for PRS, 0.68 [0.59-0.79] for PFS and 0.87 [0.73-1.04] for overall survival, respectively. In conclusion, thalidomide exposed upfront correlated with shorter PRS that partially compensated for prolonged initially PFS and resulted in no survival benefit when it is given as both induction pre-autologous and maintenance post-autologous stem cell transplantation; shorter PRS was not observed, and survival was improved when it is given only during maintenance phase following autologous stem cell transplantation in the patients with myeloma and who are eligible for transplant.