Relapsed/Refractory Diffuse Large B-Cell Lymphoma: A Look at the Approved and Emerging Therapies

Approximately 40% of patients with diffuse large B cell lymphoma (DLBCL) do not respond or develop relapsed disease after first-line chemoimmunotherapy. A minority of these patients can be cured with autologous hematopoietic stem cell transplantation (AHCT). Although chimeric antigen receptor (CAR) T cells have transformed the treatment paradigm of relapsed/refractory DLBCL, only 30-40% of patients achieve durable remissions. In addition, many patients with relapsed/refractory DLBCL are ineligible to receive treatment with CAR T cells due to comorbidities or logistical limitations. Since 2019, the following four non-CAR T-cell treatments have been approved in relapsed/refractory DLBCL: polatuzumab in combination with bendamustine and rituximab, selinexor, tafasitamab plus lenalidomide, and loncastuximab. In this article, I review the data behind these four approvals and discuss important considerations on their use in clinical practice. I also review emerging therapies that have shown promising early results in relapsed/refractory DLBCL including the bispecific antibodies, antibody-drug conjugates, Bruton tyrosine kinase inhibitors, BCL2 inhibitors, immune checkpoint inhibitors, and epigenetic modifiers.