Background: Thalidomide is an immunomodulatory and anti-angiogenic drug that has shown promise in patients with myeloma. Trials comparing efficacy of standard melphalan and prednisone (MP) therapy with MP plus thalidomide (MPT) in transplant-ineligible or elderly patients with multiple myeloma (MM) have provided conflicting evidence. This meta-analysis aimed to determine the efficacy and toxicity of thalidomide in previously untreated elderly patients with myeloma.
Methods: Medline, the Cochrane Controlled Trials register, conference proceedings of the American Society of Hematology (1995-2014), the American Society of Clinical Oncology (1995-2014), and CBM, VIP, and CNKI databases were searched for randomized control trials with the use of the medical subject headings "MM " and "thalidomide ". Trials were assessed by two reviewers for eligibility. Meta-analysis was conducted using a fixed effects model. Sensitivity analysis was performed to test the robustness of the findings.
Results: Overall, seven trials were identified, covering a total of 1821 subjects. The summary hazard ratio (thalidomide vs. control) was 0.82 (95% confidence interval [CI]: 0.72-0.94) for overall survival (OS), and 0.65 (95% CI: 0.58-0.73) for progression-free survival, in favor of thalidomide treated group. The risk ratio of complete response with induction thalidomide was 3.48 (95% CI: 2.24-5.41). A higher rate of III/IV adverse events were observed in MPT arm compared with the MP arm. However, analysis of sub-groups administering anticoagulation as venous thromboembolism prophylaxis suggested no difference in relative risk of thrombotic events between two arms (RR = 1.47, 95% CI: 0.43-5.07, P = 0.54). Further analysis of trials on the treatment effects of MPT versus MP on adverse events-related mortality showed no statistical difference between two arms (RR = 1.24, 95% CI: [0.95-1.63], P = 0.120).
Conclusion: Thalidomide appears to improve the OS of elderly and/or transplant-ineligible patients with MM when it is added to standard MP therapy.