Efficacy and Safety of Single Versus Tandem Autologous Stem Cell Transplantation in Multiple Myeloma: A Single-Center Retrospective Analysis in China

Background: Currently, there is a lack of comparative data on the efficacy and safety of single or tandem ASCT in China. This study aimed to review the efficacy and safety of single or tandem ASCT in MM patients without selection criteria for specific studies.

Methods: Utilizing matched case-control study, we retrospectively analyzed the clinical data of 80 newly diagnosed MM (NDMM) patients who underwent ASCT in our department between November 2014 and June 2021, with 40 patients in each group receiving either single or tandem ASCT.

Results: In single ASCT group, the percentage of ≥CR before or post ASCT was 50% and 70%, respectively. In tandem ASCT group, the percentage of ≥CR pre ASCT was 47.5%, while the percentage of ≥CR after 1 ^st and 2 ^nd ASCT was 65% and 85%, respectively. From 1 ^st transplantation, the median progression-free survival (PFS) was 33.2 and 71.1 months for the single and tandem arm, respectively (P=0.0099), and the median overall survival (OS) for the single and tandem arm was 38.3 and 75.8 months, respectively (P=0.0519). In the single and tandem group, 7-year PFS was 29.9% and 57.0%, while 7-year OS was 26.3% and 43.5%, respectively. The median PFS was 23.2 and 61.2 months for the single and tandem arm in patients with high risk (P=0.038), while the median OS was 32.4 months and 65.8 months, respectively (P=0.045). No transplant-related mortality occurred in both cohorts. The median times to neutrophil and platelet engraftment for single group were 11 days and 13 days, respectively. In the tandem group, the median times to neutrophil engraftment post 1 ^st and 2 ^nd transplantations were 11 days and 12 days, respectively, while the mean engraftment times for platelets were 12 days and 17 days. Mucositis, engraftment syndrome, and infection were common but manageable complications.

Conclusion: Upfront tandem ASCT could deepen the depth of response and prolong PFS in MM patients and could be performed feasibly and safely in patients with myeloma, especially when novel agents are not available in China.