Efficacy and Safety of Lenalidomide in the Treatment of Multiple Myeloma: A Systematic Review and Meta-analysis of Randomized Controlled Trials

BACKGROUND: Lenalidomide has emerged as an important treatment for patients with multiple myeloma (MM). However, its role in the management of MM is still controversial and requires further clarification. The aim of this study was to evaluate efficacy and safety of lenalidomide for MM using a meta-analysis. METHODS: We searched the electronic databases including: PubMed, EMBASE and the Cochrane Center Register of Controlled Trials. Seven randomized clinical trials were identified, which included a total of 2357 patients with MM who received lenalidomide-containing, noncontaining lenalidomide regimens or placebo as induction therapy or maintenance therapy. The outcomes included overall response (OR) rate, complete response (CR) rate, 3-year progression-free survival (PFS) rate, 3-year overall survival (OS) rate, and different types of treatment-related adverse events. We calculated the risk ratios (RRs) as well as their 95% confidence intervals of these outcomes and pooled the results using RevMan 5.2 software. RESULTS: For patients with previously untreated MM, OR rate and CR rate was significantly higher in lenalidomide-containing group than the control group. For relapsed or refractory MM patients, lenalidomide-containing regimens significantly improved the OR rate, CR rate, 3-year PFS rate and 3-year OS rate. With regard to MM patients after autologous stem cell transplantation, lenalidomide maintenance therapy significantly improved 3-year PFS rate but did not result in improved 3-year OS rate. In terms of toxicities, lenalidomide therapy has a higher rate of Grade 3–4 grade cytopenias, infection, deep-vein thrombosis, and diarrhea. Furthermore, the incidence of second primary malignancies was significantly higher in the lenalidomide group. CONCLUSIONS: The lenalidomide-containing regimens as induction therapy clearly increased response rates and improved intervals of survival with acceptable toxicity rates for patients with MM. However, when physicians choose to use the lenalidomide as maintenance therapy, whether the benefits outweigh the risks should be taken into account.