Historical Perspective of High-Dose Therapy Followed by Autologous Stem Cell Transplantation in Multiple Myeloma.

Background: High-dose therapy (HDT) followed by autologous stem cell transplantation (ASCT) has become part of standard of care (SOC) in newly diagnosed multiple myeloma. In this review, we provide a historical perspective on ASCT since its introduction in the 1990s.

Summary: Overall survival (OS) benefit for HDT followed by ASCT was demonstrated in studies comparing HDT with ASCT to standard-dose therapy (SDT) before the era of novel agents. Conditioning is done with melphalan 200 mg/m2. Lower doses (MEL140, MEL150) for older patients with comorbidities are safe and have comparable results. The addition of busulfan to melphalan improves progression-free survival (PFS) but not OS. HDT with ASCT after induction with novel agents prolongs PFS but not OS compared to SDT alone. The benefit is more evident in patients with high-risk cytogenetics. Mobilization can be achieved with granulocyte colony-stimulating factor alone, but is improved with the addition of chemotherapy. Plerixafor reduces mobilization failure and enables sufficient stem cell collection after induction with novel agents. ASCT is safe with a low rate of mortality (1%), and selected patients can be managed as outpatients.

Key Messages: HDT followed by ASCT remains part of SOC due to its PFS benefit and relatively low toxicity.