The efficacy and safety of lenalidomide in the treatment of multiple myeloma patients after allo-hematopoietic stem-cell transplantation: a systematic review and meta-analysis

Background: There has been long-standing controversy regarding the effectiveness and safety of lenalidomide as a maintenance treatment for patients with multiple myeloma (MM) after allogeneic cell transplantation. This meta-analysis aimed to explore the effectiveness and safety of lenalidomide in the maintenance treatment of MM patients after allogeneic cell transplantation based on published data. Methods: A systematic review and meta-analysis was conducted in English and Chinese databases, covering all available publications until 1 December 2020. Statistical analysis was performed using the software STATA 14.0, and odds ratios (ORs) combined with 95% confidence intervals (CIs) were calculated to explore the efficacy and safety of lenalidomide in the treatment of MM patients after allogeneic cell transplantation. Results: A total of 173 MM cases in 8 independent studies from 2007 to 2014 were included. Through a single-arm meta-analysis of the disease status of MM patients after lenalidomide treatment, 3.6% of patients were in minimal response (MR, P=0.006), 39.0% were in complete remission (CR, P=0.169), 20.2% in partial remission (PR, P<0.001), 12.8% in very good partial remission (VGPR, P=0.049), and 9.7% in SD (P=0.023); the PD was 5.6% (P=0.010). Through meta-analysis of adverse reactions after taking lenalidomide, 35.3% (P=0.628) of participants developed acute graft-versus-host disease (GVHD); 22.6% (P=0.049) developed chronic GVHD; 20.3% (P=0.001) developed infection; 22.5% (P=0.352) had thrombocytopenia; 32.5% (P<0.000) had neutropenia; pain occurred in 17.8% (P=0.350) of patients, and peripheral neuropathy occurred in 17.8% (P=0.995) of participants. The overall survival (OS) of >= 2 years and progression-free survival (PFS) of >= 2 years of MM patients after allo-hematopoietic-stem-cell transplantation (HSCT) taking lenalidomide were analyzed, and the results were 64.9% (P=0.049) and 58.4% (P=0.890), respectively. Discussion: Lenalidomide is effective in the treatment of MM patients after allo-HSCT, and reducing the incidence of infection and peripheral neuropathy, but it is not effective in reducing GVHD and blood system adverse reactions.