LOTIS 2 FOLLOW‐UP ANALYSIS: UPDATED RESULTS FROM A PHASE 2 STUDY OF LONCASTUXIMAB TESIRINE IN RELAPSED OR REFRACTORY DIFFUSE LARGE B‐CELL LYMPHOMA

Targeting CD19 in diffuse large B-cell lymphoma: An expert opinion paper

The ubiquitous, early-stage expression, efficient internalization, limited off-target effects, and high disease specificity of CD19 make it an attractive therapeutic target. Currently available anti-CD19 therapies have demonstrated particular promise in patients with relapsed or refractory B-cell non-Hodgkin lymphoma. Selection of the most appropriate treatment strategy should be based on individual patient characteristics and the goal of therapy. However, evidence and knowledge about the sequencing of anti-CD19 therapies are limited. Here, we review the current evidence for CD19 as a target in diffuse large B-cell lymphoma and consider approaches to the use of anti-CD19 therapy.

Loncastuximab tesirine in relapsed or refractory diffuse large B-cell lymphoma: a review of clinical data

Loncastuximab tesirine-lpyl (ADC Therapeutics) is an anti-CD19 antibody-drug conjugate which consists of anti-CD19 antibody and cytotoxic alkylating agent, SG3199. Data from preclinical in vitro and animal studies demonstrated its selectivity and efficacy. The phase I LOTIS-1 study for relapsed, refractory B-cell non-Hodgkin lymphoma (NHL) demonstrated efficacy and a tolerable safety profile, with major adverse effects being neutropenia, thrombocytopenia, elevated liver enzymes, and fluid accumulation. Based on pharmacokinetics analysis in this study, a dose of 150 μg/kg every 3 weeks for cycles 1 and 2 followed by 75 μg/kg every 3 weeks until disease progression or intolerability was chosen for the phase II LOTIS-2 study. This study recruited relapsed, refractory diffuse large B-cell lymphoma and confirmed similar safety profile. Overall response rate was 48.6% (24.1% complete response), and overall survival was 9.9 months. Due to its safety and efficacy reported in the above trials, loncastuximab tesirine was recently approved by the US Food and Drug Administration for the treatment of relapsed, refractory diffuse large B-cell lymphoma. Several clinical trials are ongoing to assess its safety and efficacy in NHL in various clinical settings.

Promising Immunotherapeutic Modalities for B-Cell Lymphoproliferative Disorders

Over the last few years, treatment principles have been changed towards more targeted therapy for many B-cell lymphoma subtypes and in chronic lymphocytic leukemia (CLL). Immunotherapeutic modalities, namely monoclonal antibodies (mAbs), bispecific antibodies (bsAbs), antibody-drug conjugates (ADCs), and chimeric antigen receptor T (CAR-T) cell therapy, commonly use B-cell-associated antigens (CD19, CD20, CD22, and CD79b) as one of their targets. T-cell engagers (TCEs), a subclass of bsAbs, work on a similar mechanism as CAR-T cell therapy without the need of previous T-cell manipulation. Currently, several anti-CD20xCD3 TCEs have demonstrated promising efficacy across different lymphoma subtypes with slightly better outcomes in the indolent subset. Anti-CD19xCD3 TCEs are being developed as well but only blinatumomab has been evaluated in clinical trials yet. The results are not so impressive as those with anti-CD19 CAR-T cell therapy. Antibody-drug conjugates targeting different B-cell antigens (CD30, CD79b, CD19) seem to be effective in combination with mAbs, standard chemoimmunotherapy, or immune checkpoint inhibitors. Further investigation will show whether immunotherapy alone or in combinatory regimens has potential to replace chemotherapeutic agents from the first line treatment.