MM-196: Efficiency and Safety in Autologous Stem Cell Transplant Versus Tandem in Patients with Multiple Myeloma with New Diagnosis

Abstract

Context: Currently, the therapy of high doses of chemotherapy followed by autologous stem cell transplant (ASCT) is considered standard treatment for patients with newly diagnosed multiple myeloma (MM). However, recently it has been demonstrated that tandem transplant is useful in the subgroup of patients with high-risk myeloma. Objective: Evaluate the efficiency and safety of high-dose chemotherapy therapy followed by ASCT vs tandem in patients with high-risk multiple myeloma and plasma cell leukemia. Design: Retrospective cohort study Setting: Single-center study in a private referral hospital. Patients or other participants: Patients with a recent diagnosis of multiple myeloma according to the IMWG 2014 criteria and high-risk features or plasma cell leukemia that underwent a single or tandem ASCT at our center between 2009 and 2018 were included in the study. High-risk multiple myeloma was defined to patients who cytogenetic analysis of high risk and FISH with (17p); t(4;14); t(14;16) or alteration of chromosome 1 and/or extraosseous extramedullary disease. Main outcome measures: We analyzed the assessed overall survival (OS), event-free survival (EFS), event-free survival and treatment-related mortality (TRM). Results: We included a total of 54 patients, with a median follow-up of 48 months. Time from diagnosis of multiple myeloma to first transplant was 6.6 months and the time between one transplant and the other was 98 days in the tandem group. Patients treated with tandem did not have better OS; HR for mortality for patients treated with tandem transplant vs single transplant=0.8 or EFS (HR=0.76). Response rate was statistically significantly better with tandem (risk ratio=0.69), but with a statistically significant increase in TRM (risk ratio=1.71) Conclusions: The therapy of ASCT continues to be considered efficient and safe for patients with MM. The use of tandem did not result in improved OS or EFS and is associated with improved response rates but increased mortality; however, the tandem is a strategy in a group of patients with high-risk diseases.