Abstract
For patients (pts) with relapsed or refractory multiple myeloma (RRMM) after previous autologous hematopoietic cell transplantation (AHCT), novel agents, cellular and immunotherapies are increasingly available. Options for second-line treatment mostly include triplet regimens based on proteasome inhibitors, immunomodulatory drugs and anti-CD38 monoclonal antibodies and since recently also CAR T cells. The importance of autologous salvage transplantation (retransplantation, Re-AHCT) has significantly decreased in recent years due to the availability of many new treatment options. Therefore, we performed a retrospective analysis of 171 pts cases with RRMM who received Re-AHCT between 2002 and 2021. With a median follow-up of 74.7 months, the 5-year rates of progression-free survival (PFS) and overall survival (OS) were 18% (median 20.6 months) and 57% (median 65.0 months), respectively, the 100-day mortality rate was 4%. Multivariate analysis identified R-ISS stage and duration of previous response (DoR) as independent prognostic factors for PFS and OS. While the revealed high-risk population (R-ISS stage II/III, DoR ≤ 24 months) was associated with a significantly worse PFS (HR 2.728) and OS (HR 3.129), the low-risk group (R-ISS I, DoR > 24 months) achieved a median PFS and OS of 45.0 months and 80.2 months, respectively. Therefore, Re-AHCT could remain an option in such prognostically favorable pts with RRMM even in the era of novel therapies especially when more potent treatment modalities are not available.