Molecular assessment of intratumoral immune cell subsets and potential mechanisms of resistance to odronextamab, a CD20×CD3 bispecific antibody, in patients with relapsed/refractory B-cell non-Hodgkin lymphoma.

BACKGROUND: Patients with relapsed/refractory B-cell non-Hodgkin lymphoma (R/R B-NHL) have a significant need for effective treatment options. Odronextamab is an Fc-silenced, human, CD20×CD3 bispecific antibody that targets CD20-expressing cells via T-cell-mediated cytotoxicity independent of T-cell/major histocompatibility complex interaction. Phase I results in patients with R/R B-NHL demonstrated that odronextamab monotherapy could achieve deep and durable responses with a generally manageable safety profile (ELM-1; NCT02290951). As part of a biomarker analysis of the same study, we investigated potential biomarkers and mechanisms of resistance to odronextamab. METHODS: Patients with R/R B-NHL enrolled in ELM-1 received one time per week doses of intravenous odronextamab for 4×21 day cycles, then doses every 2 weeks thereafter. Patient tumor biopsies were obtained at baseline, on-treatment, and at progression. Immune cell markers were analyzed by immunohistochemistry, flow cytometry, single-cell RNA sequencing, and whole genome sequencing. RESULTS: Baseline tumor biopsies showed that almost all patients had high proportions of B cells that expressed the CD20 target antigen, whereas expression of other B-cell surface antigens (CD19, CD22, CD79b) was more variable. Responses to odronextamab in patients with diffuse large B-cell lymphoma were not related to the relative level of baseline CD20 expression, cell of origin, or high-risk molecular subtype. A potential link was observed between greater tumor programmed cell death-ligand 1 expression and increased likelihood of response to odronextamab. Similarly, a trend was observed between clinical response and increased levels of CD8 T cells and regulatory T cells at baseline. We also identified an on-treatment pharmacodynamic shift in intratumoral immune cell subsets. Finally, loss of CD20 expression through inactivating gene mutations was identified as a potential mechanism of resistance in patients who were treated with odronextamab until progression, as highlighted in two detailed patient cases reported here. CONCLUSIONS: This biomarker analysis expands on clinical findings of odronextamab in patients with R/R B-NHL, providing verification of the suitability of CD20 as a therapeutic target, as well as evidence for potential mechanisms of action and resistance.

Real-World Treatment Patterns After CD19-Directed CAR T Cell Therapy Among Patients with Diffuse Large B Cell Lymphoma.

INTRODUCTION: CD19-directed chimeric antigen receptor T cells (CAR T) are approved for treatment of adults with relapsed/refractory diffuse large B cell lymphoma (DLBCL) following at least two lines of therapy. METHODS: This study describes real-world treatment patterns after CAR T in adults with DLBCL. It includes adults diagnosed with DLBCL in IBM MarketScan Commercial and Medicare Supplemental healthcare claims databases administered CAR T between 2017 and 2019 (index event) and at least 6 months of continuous health plan enrollment pre-index. Kaplan-Meier methods were used to estimate risk and time to first subsequent treatment after CAR T, as a proxy for CAR T failure. RESULTS: Among 129 patients meeting study criteria, most (123; 95.4%) were hospitalized during CAR T therapy. Median length of stay was 17 (25th-75th percentile, 13-22) days. Estimated 6-month risk of subsequent treatment was 36.2% (95% confidence interval [CI] 27.1-45.8%). During median follow-up of 195 (25th-75th percentile, 102-362) days, median time to the first line of therapy after CAR T, accounting for censoring, was 378 days (95% CI 226, not reached). Among 48 patients who received another therapy after CAR T, 58.3% received immunotherapy, 50.0% radiation therapy, 25.0% chemotherapy, 25.0% targeted therapy, and 12.5% hematopoietic stem cell transplant. CONCLUSIONS: Among real-world patients with DLBCL treated with CAR T, the risk of not achieving a durable response is considerable; additional, effective options for DLBCL salvage treatment are needed.