Relapsed disease: off-the-shelf immunotherapies vs customized engineered products

Innovations in immuno-oncology for lymphomas have outpaced therapeutic developments in any other cancer histology. In the 1990s, rituximab, a CD20 monoclonal antibody, drastically changed treatment paradigms for B-cell non-Hodgkin lymphomas (B-NHLs). In parallel, the concept that T cells could be genetically reprogrammed and regulated to address tumor cell evasion was developed. Twenty years later, this concept has materialized—3 customized engineered CD19 chimeric antigen receptor T-cell (CART) constructs have been embraced as third-line therapies and beyond for aggressive B-NHL. Responses with CARTs are durable in 30% to 40% of patients, with consistent results in older patients, primary refractory disease, high-grade B-cell lymphoma, and patients with concurrent secondary central nervous system disease, all features historically associated with poorer outcomes. Challenges associated with the administration of CARTs include cumbersome and time-consuming manufacturing processes, toxicities, and cost, not to mention a substantial risk of relapse. Fortunately, as our understanding of how to manipulate the immune system to achieve full antitumor potential has grown, so has the rapid development of off-the-shelf immunotherapies, with CD20/CD3 bispecific antibodies standing out above all others. These agents have shown promising activity in aggressive B-NHL and have the potential to circumvent some of the challenges encountered with customized engineered products. However, toxicities remain substantial, dosing schedules intensive, and experience limited with these agents. Novel customized and off-the-shelf therapeutics as well as rational combinations of these agents are underway. Ultimately, growing experience with both customized engineered and off-the-shelf immunotherapies will provide guidance on optimal methods of delivery and sequencing.