AbstractBackgroundCurrent guidelines recommend using filgrastim or tbo‐filgrastim to mobilize hematopoietic progenitor cells in an autologous setting. However, previous studies have suggested other forms of granulocyte colony‐stimulating factor (G‐CSF) are equally efficacious, possibly with fewer leukaphereses required. Thus, we prospectively studied the efficacy of lenograstim, a glycosylated recombinant form of G‐CSF, in multiple myeloma (MM) patients.MethodsFrom November 2011 to January 2020, 98 MM patients undergoing autologous stem cell transplant (ASCT) from five academic centers in Korea were enrolled. Patients were mobilized with subcutaneous lenograstim (Neutrogin®) with fixed doses of 10 μg/kg for 4 days.ResultsMost of the patients (N= 90, 91.8%) achieved at least the targets of 2 × 106CD34+ cells/kg body weight, and more than half of MM patients (N= 57, 58.2%) reached a target of 5 × 106CD34+ cells/kg body weight. The mobilization failure rate was 8.2% (N= 8). The median number of CD34 + cell/kg using G‐CSF only was 5.25 × 106/kg (range 0.49–13.47). Adverse events included transfusion (TF,N= 53, 54.1%), bone pain (N= 6, 6.1%), fever (N= 2, 2.0%), and gastrointestinal troubles (N= 2, 2.0%). There were no grade 3 or 4 adverse events during mobilization. Body surface area (BSA) at mobilization and platelet TF were factors associated with CD34+ collection. Most patients achieved neutrophil (N= 93, 98.9%) and platelet (N= 89, 95.7%) engraftment.ConclusionLenograstim can safely and effectively mobilize stem cells in MM autologous settings.