High-dose chemotherapy followed by autologous stem cell transplantation (ASCT) remains the standard of care for multiple myeloma (MM) patients. Although outpatient ASCT has been shown to be safe and feasible, the procedure is overall rare with most patients in the US undergoing inpatient ASCT. Furthermore, hospitalization rates for patients that undergo outpatient ASCT remain high. Adequate markers that predict hospitalization during outpatient ASCT are lacking, yet would be of great clinical value to select patients that are suited to outpatient ASCT. In this study we aimed to elucidate differences between planned outpatient and inpatient ASCT and further evaluated clinical characteristics that are significantly associated with hospitalization during planned outpatient hospitalization. Factors that were significantly associated with a planned inpatient ASCT included an advanced MM disease stage, worse performance status as well as non-Caucasian race, while low albumin levels and female gender were significantly associated with hospitalization during outpatient ASCT. The results of this analysis provide crucial knowledge of factors that are associated with planned inpatient ASCT and hospitalization during outpatient ASCT and could guide the treating physician in decision-making and further facilitate outpatient transplantation.

Daratumumab, a CD38-targeting monoclonal antibody, has significantly improved survival rates in multiple myeloma (MM), yet patients who progress on Daratumumab have dismal clinical outcomes with an overall median of less than 10 months. While emerging novel modalities have shown promising results, the current study explores the use of high-dose chemotherapy followed by autologous stem cell transplantation (ASCT) in heavily pretreated Daratumumab-refractory MM patients. We retrospectively investigated the outcome of 69 consecutive patients who received upfront ASCT. The median progression-free survival (PFS) for the entire patient cohort was 7.2 months with a median overall survival (OS) of 19.3 months. For patients with ≥very good partial response (VGPR), median PFS and OS improved to 9 months and 34 months, respectively. Achievement of MRD negativity in ≥VGPR did not further improve the outcome. A better performance status, younger age, longer time interval from initial MM diagnosis/initial ASCT to salvage ASCT and low-risk GEP70 were all associated with improved PFS and OS after salvage ASCT. Our results suggest a role for salvage ASCT in selected heavily pretreated and Daratumumab-refractory patients.

Autologous stem cell transplantation (ASCT) has been a mainstay in myeloma treatment for over three decades, but patient prognosis post-ASCT varies significantly. In a retrospective study of 5259 patients with multiple myeloma (MM) at the University of Arkansas for Medical Sciences undergoing ASCT with a median 57-month follow-up, we divided the dataset into training (70%) and validation (30%) subsets. Employing univariable and multivariable Cox analyses, we systematically assessed 29 clinical variables, identifying crucial adverse prognostic factors, such as extended duration between MM diagnosis and ASCT, elevated serum ferritin, and reduced transferrin levels. These factors could enhance existing prognostic models. Additionally, we pinpointed significant poor prognosis markers like high serum calcium and low platelet counts, though they are applicable to a smaller patient population. Utilizing seven easily accessible high-risk variables, we devised a four-stage system (ATM4S) with primary stage borders determined through K-adaptive partitioning. This staging system underwent validation in both the training dataset and an independent cohort of 514 ASCT-treated MM patients from the University of Iowa. We also explored cytogenetic risk factors within this staging system, emphasizing its potential clinical utility for refining prognostic assessments and guiding personalized treatment approaches.