Single‐dose etoposide is an effective and safe protocol for stem cell mobilization in patients with multiple myeloma

Background Single‐dose etoposide was used an outpatient‐based protocol for mobilization in patients with multiple myeloma (MM) for autologous stem cell transplantation (ASCT). Thus, we retrospectively analyzed the efficacy and safety of our one‐day protocol in comparison with that of previous methods. Methods We retrospectively analyzed 168 patients with MM who underwent peripheral blood stem cell collection for upfront ASCT between 2008 and 2018. The mobilization protocols included G‐CSF alone (G‐mobilization), one‐day 375 mg/m2 of etoposide (E375), two‐days of 375 mg/m2 of etoposide (E750), or one‐day high‐dose (3.5 g/m2) cyclophosphamide (HD CY). For comparison of efficacy of each protocol, collected CD34+ cells over 4 × 106/kg and under 2 × 106/kg were defined as “adequate harvest” and “harvest failure,” respectively. Results The median number of collected CD34+ cells was 5.58 × 106/kg in patients receiving single‐dose etoposide, and the percentage of uncomplicated optimal harvest of E375 (65.6%, 21/32) was significantly higher than that of E750 (41.9%, 13/31) and HD CY (31.3%, 15/48). The E375 showed the highest rate of adequate harvest (96.9%, 31/32) compared to that of E750 (87.1%), HD CY (75.0%), and G‐mobilization (59.6%). Most E375 patients achieved adequate harvest without complication (29/32, 90.6%), the CD34+ cell collection yield on apheresis days one and two of E375 was not significantly different from that of E750, and no harvest failures occurred for E375. Neutrophil and platelet engraftments were significantly faster in E375 than other groups (P