Allogeneic Hematopoietic Stem Cell Transplantation in Refractory Multiple Myeloma—A Retrospective Multicenter Analysis

A growing list of therapies available for patients with multiple myeloma (MM) results in deep response rates, but eventually almost all patients relapse. Allogeneic hematopoietic cell transplantation (allo-SCT) is a familiar approach for MM, but responses are often short and side effects burdensome. Simultaneously, allo-SCT provides a unique platform on which novel immune therapies can be employed to improve clinical outcomes. Our work describes the characteristics and outcomes of 128 refractory myeloma patients who underwent allo-SCT at five German centers between 2010 and 2021. The median number of therapies before the transplant was 6. With a median follow-up of 6, 4 years, the median progression-free survival and overall survival were 7 and 19 months, respectively. NRM was 28% after 6 years. OS and PFS were 61% and 45% at 1 year, 49% and 34% at 2 years, and 38% and 25% at 6 years. Achieving a CR before transplant was the single most significant variable before transplant. Allo-SCT yet remains an option for fit patient's refractory to all other treatments available. It is potentially curative for a subset of patients. Finding the characteristics of patients with durable remissions is key to sparing unnecessary toxicity for those unlikely to benefit.