Cryopreserved versus non-cryopreserved stem cell autografts in multiple myeloma a restrospective cohort study.

The use of non-cryopreserved hematopoietic stem cells (HSC) can be an alternative to the traditional cryopreserved infusions of HSCs in autologous stem cell transplantation (aHSCT). After high-dose melphalan conditioning (HDM), we sought to compare time to engraftment, overall survival, and safety in multiple myeloma (MM) patients undergoing a first aHSCT after high-dose melphalan conditioning (HDM). We conducted a cohort study from March 2018 to December 2019. Of all autologous transplants performed during this period, 105 were for MM as the first consolidation. Fifty-one patients received a cryopreserved graft; the remaining 54 patients received a fresh infusion. General clinical characteristics were similar between these two groups. Cell viability was higher in non-cryopreserved grafts (95% vs. 86% p < 0.01). Four deaths occurred during hospitalization in the cryopreserved group, one in the non-cryopreserved group. The cumulative incidence of neutrophil and platelet engraftment on D + 25 was higher in the non-cryopreserved compared to the cryopreserved group (98% vs 90% p < 0.01 and 96.2% vs 72.54% p < 0.01 respectively). Additionally, the hospital length of stay was reduced by 4 days for patients for the non-cryopreserved cohort. In summary, the use of non-cryopreserved HSCs after HDM is safe and effective compared to patients who received a cryopreserved graft.