Divergent Effects of Novel Immunomodulatory Agents and Cyclophosphamide on the Risk of Engraftment Syndrome after Autologous Peripheral Blood Stem Cell Transplantation for Multiple Myeloma

Engraftment syndrome (ES) is an increasingly observed and occasionally fatal complication after autologous peripheral blood stem cell transplantation (PBSCT). In this study, we demonstrate that the incidence of ES is significantly increased in patients undergoing autologous PBSCT for multiple myeloma in comparison to patients with non-Hodgkin lymphoma or Hodgkin lymphoma. Multivariate analysis revealed that age > 60 (hazard ratio [HR], 1.71; 95% confidence interval [CI], 1.12 to 2.62; P = .013) and transplantation for multiple myeloma (HR, 2.80; 95% CI, 1.60 to 4.90; P = .0003) were associated with an increased risk of this complication. When stratified for myeloma patients only, age > 60 (HR, 1.80; 95% CI, 1.13 to 2.87; P = .013) and prior treatment with both lenalidomide and bortezomib (HR, 1.83; 95% CI, 1.11 to 3.04; P = .0001) were associated with an increased incidence of ES. Conversely, lack of exposure to cyclophosphamide from either chemomobilization or as a component of the pretransplantation therapeutic regimen increased the risk of this complication (HR, 3.05; 95% CI, 1.91 to 4.87; P <.0001). These studies demonstrate that the pretransplantation exposure of multiple myeloma patients to novel immunomodulatory agents and cyclophosphamide significantly affects the subsequent risk of developing ES.