High-Dose Chemotherapy and Autologous or Allogeneic Transplantation in Aggressive B-Cell Lymphoma-Is There Still a Role?

Novel therapies such as CAR-T, BTK inhibitors and PD-1 inhibitors have changed the management of aggressive B-cell lymphomas. Nonetheless, these novel therapies have their own risk of late toxicities including second malignancies. They also create a subgroup of patients with relapse, treatment failure, or indefinite maintenance. We discuss the current role of autologous and allogeneic stem cell transplantation in this context. In patients with recurrent diffuse large B-cell lymphoma, CAR-T cell treatment has largely replaced autologous transplant. Autologous transplant should be considered in patients with late relapses and in selected patients with T-cell-rich B-cell lymphoma, where CAR-T cell therapy may be less effective. It also remains the treatment of choice for consolidation of patients with primary CNS lymphoma. In mantle cell lymphoma, intensive chemotherapy combined with BTK inhibitors and rituximab results in excellent outcomes, and the role of autologous transplantation is declining. In Hodgkin's lymphoma, autologous transplant consolidation remains the standard of care for patients who failed initial chemotherapy. Allogeneic transplantation has lower relapse rates but more complications and higher non-relapse mortality than autologous transplantation. It is usually reserved for patients who fail autologous transplantation or in whom autologous stem cells cannot be collected. It may also have an important role in patients who fail CAR-T therapies. The increasing complexity of care and evolving sequencing of therapies for patients with aggressive B-cell lymphomas only emphasizes the importance of appropriate patient selection and optimal timing of stem cell transplantation.