Abstract
Historically, the management of relapsed or refractory (R/R) diffuse large B-cell lymphoma (DLBCL) following first-line chemoimmunotherapy has been second-line chemotherapy, followed by high-dose chemotherapy and consolidative autologous hematopoietic stem cell transplantation (HSCT), resulting in durable remissions in approximately 40% of patients. In 2017, chimeric antigen receptor (CAR) T-cell therapy changed the landscape of treatment for patients with R/R DLBCL, with complete response rates ranging from 40-58% and long-term disease-free survival of >40% in the highest risk subgroups, including patients who relapsed after autologous HSCT. Since that time further studies have demonstrated improved overall response rates and survival outcomes in patients with primary refractory or early-relapsed (relapse within 1 year) DLBCL treated with CAR T-cell therapy compared with autologous HSCT, advancing CAR T-cell therapy into the second-line setting. However, >50% of patients will relapse in the post-CAR T-cell setting. In the past 2 years, two CD20 x CD3 bispecific antibodies were approved by the Food and Drug Administration for the treatment of R/R DLBCL after two or more lines of systemic therapy. These bispecific antibodies have demonstrated overall response rates exceeding 50% and durable remissions at >2 years of follow-up. Additionally, a notable treatment advantage of bispecific antibodies is their ability to be administered in the community setting, making treatment more accessible for patients. The development and advancement of these novel therapies raise questions regarding the ongoing role of HSCT in the management of R/R DLBCL and the best sequence of cellular and bispecific therapies to optimize patients' outcomes.