Comparison of tandem and single autologous stem cell transplantation in multiple myeloma: a retrospective propensity score-matching study

Abstract

Abstract Background: Comparative data on the efficacy and safety of tandem or single autologous stem cell transplantation (ASCT) for patients with multiple myeloma (MM) in China are currently lacking. This study aimed to compare the clinical outcomes of tandem and single ASCT in real-world MM patients. Methods: By utilizing a propensity score, we retrospectively analyzed the clinical data of 80 newly diagnosed MM patients who underwent ASCT in our center between November 2014 and November 2021, with 40 patients in each group receiving either single or tandem ASCT. Results: The percentage of ≥ complete remission (CR) after the 1st and 2nd ASCT was 75% and 85% in the tandem ASCT group, compared to 77.5% in the single group. Since transplant, the median progression-free survival (PFS) was 33.2 months and 71.7 months for the single and tandem cohorts (p=0.0099). Median overall survival (OS) for the single and tandem groups was 39.3 months and 75.8 months (p=0.0515). The estimated 7-year PFS and OS since ASCT was 29.9% and 43.5% in the single group versus 47.5% and 54.4 % in the tandem group. Median PFS in patients with ISS II/III who underwent single ASCT was 29.8 months versus 66.4 months in the tandem group (p=0.008). Median OS since transplant was not reached in either group (p=0.1468). Among patients with high-risk cytogenetics, the median PFS was 23.2 months and 43.4 months for the single and tandem cohorts (p=0.0423), while the median OS was 37.1 months and not reached (p=0.0767). Among patients not achieving ≥ CR before ASCT, the median PFS was 24.3 months and not reached for the single and tandem cohorts (p=0.0187), while the median OS sincetransplant was not reached in either cohort (p=0.1631). No transplant-related mortality occurred in both cohorts. There were no significant differences between these two cohorts regarding both non-hematological and hematological toxicities. Conclusions: Up-front tandem ASCT can deepen the depth of response and prolong the PFS of patients with MM, with a trend toward longer OS, particularly for patients with advanced ISS stages, high-risk cytogenetics, and no CR before transplant. Tandem ASCT may be tolerable for patients with MM.