Outcomes of Standard-Risk Multiple Myeloma Patients Who Undergo Upfront Autologous Hematopoietic Stem Cell Transplantation

•Retrospective analysis of 1000 patients with standard-risk multiple myeloma who received upfront A autologous hematopoietic stem cell transplantation (autoHCT)•The median progression-free survival for the entire cohort was 68.3 months, and the median overall survival was not reached•These results highlight the favorable outcomes that are achieved with the use of modern therapies and upfront autoHCT in patients with SRMM. Patients with multiple myeloma (MM) without high-risk cytogenetic abnormalities are classified as having standard-risk MM (SRMM), and data focusing on their outcomes after autologous hematopoietic stem cell transplantation (autoHCT) are limited. To evaluate survival outcomes for patients with SRMM receiving autoHCT, and to elucidate factors that impact these outcomes. Single-center retrospective analysis that included consecutive MM patients who received upfront autoHCT between 2013 and 2021, had available cytogenetic information and had no high-risk chromosomal abnormalities on fluorescence in situ hybridization, defined as t(4;14), t(14;16), del(17p) or 1q21 gain or amplification. A total of 1000 SRMM patients were included, with a median age of 61 years (range 25 to 83), and 61% were male (n = 612). The most common induction regimens were bortezomib/lenalidomide/dexamethasone (VRD; n = 398, 40%) and carfilzomib/lenalidomide/dexamethasone (KRD; n = 212, 21%), and the majority (87%) received single-agent melphalan as conditioning. After induction and before autoHCT, 16% and 57% achieved ≥ complete response (CR) and ≥very good partial response (VGPR), respectively. At day 100 post autoHCT, 37% and 77% achieved ≥ CR and ≥VGPR, respectively. Sixty-two percent and 89% of patients achieved ≥ CR and ≥VGPR as best response post-transplant. A measurable residual disease (MRD) negative response pre- and post-transplantation was achieved in 43% (401/936) and 64% (199/311) of patients, respectively. After a median follow-up of 42.1 months, the median progression-free survival (PFS) for the entire cohort was 68.3 months (95% CI 60.1 to 72.1), and the median overall survival (OS) was not reached (95% CI 102.3-not reached). The 5-year PFS and OS rates were 55% and 83%, respectively. In multivariable analysis, achieving MRD-negative CR prior to autoHCT (HR 0.65 [95% CI 0.44 to 0.97], P = .033) or as best response (0.52 [0.34 to 0.78], P = .002), and use of post-transplant maintenance (0.69 [0.52 to 0.93], P = .013) and lenalidomide-based combination ma