The Role of Autologous Stem Cell Transplantation in the Treatment of Newly Diagnosed Multiple Myeloma: Is It Time to Rethink the Paradigm in the Era of Targeted Therapy?

High-dose melphalan (HDM) plus autologous stem cell transplant (ASCT) remains a standard-of-care treatment approach for eligible patients with newly diagnosed multiple myeloma (NDMM) based on demonstrated superiority in terms of progression-free survival (PFS) versus nontransplant approaches. Very high rates of minimal residual disease (MRD)-negative responses are also being seen with novel triplet and quadruplet induction regimens plus HDM-ASCT. However, recent clinical trials have shown no overall survival benefit with transplant versus nontransplant approaches. Furthermore, HDM is associated with several important downsides, including acute and long-term toxicities, transient decreases in quality of life, the need for hospitalization, an increased mutational burden at relapse, and an elevated risk of second primary malignancies. In this context, given the highly heterogeneous nature of MM in the NDMM patient population, as well as the continued emergence of novel agents and treatment approaches, there is an increasing rationale for considering deferred HDM-ASCT approaches in selected patients. Approaches under investigation include MRD-adapted therapy and the use of novel immune-based therapies as alternatives to HDM-ASCT. Ongoing developments in understanding the pathobiology and prognostic factors in NDMM, plus immune profiling and routine MRD evaluation, will result in novel, HDM-sparing treatment paradigms, enabling further improvement in patient outcomes.