Cryopreserved versus Fresh Stem Cell Grafts in Autologous Transplantation for Multiple Myeloma: Impact on Early...

Autologous hematopoietic stem cell transplantation (ASCT) remains a cornerstone therapy for eligible patients with multiple myeloma. Cryopreservation of hematopoietic grafts provides logistical flexibility but may increase procedure-related toxicity and resource utilization.

We conducted a two-phase, non-randomized binational study at tertiary centers in Santiago, Chile, and Seville, Spain, comparing cryopreserved and non-cryopreserved grafts in patients undergoing ASCT. In the retrospective phase (2018-2023), outcomes were analyzed in 284 recipients of cryopreserved grafts and 148 recipients of non-cryopreserved grafts. In the prospective phase (2023-2025), 16 patients receiving cryopreserved grafts and 25 receiving non-cryopreserved grafts were evaluated for clinical endpoints and inflammatory biomarkers.

Recipients of non-cryopreserved grafts achieved faster neutrophil engraftment (median 11 vs 14-15 days) and shorter hospital stays (median 13 vs 18 days), with reduced rates of febrile neutropenia (19% vs 50%) and grade ≥3 mucositis (19% vs 60%). No early mortality occurred in either group. Cryopreserved grafts were associated with higher levels of selected inflammatory and endothelial-associated biomarkers, including IL-8 and VEGF-D, whereas non-cryopreserved grafts showed a distinct inflammatory profile, including a non-statistically significant trend toward higher IFN-γ levels at the time of transplantation.

Overall, the use of non-cryopreserved grafts was associated with reduced early transplant-related toxicity and comparable engraftment outcomes. Given the non-randomized design and center-specific supportive care practices, these findings should be interpreted as real-world associations and support further prospective evaluation of graft preservation strategies in autologous transplantation for multiple myeloma.