Polatuzumab vedotin, venetoclax, and an anti-CD20 monoclonal antibody in relapsed/refractory B-cell non-Hodgkin lymphoma.

The Phase 2 portion of this study evaluated safety and efficacy of polatuzumab vedotin 1.8 mg/kg and venetoclax 800 mg, plus fixed-dose obinutuzumab 1000 mg or rituximab 375 mg/m2 in patients with relapsed/refractory (R/R) follicular lymphoma (FL) or diffuse large B-cell lymphoma (DLBCL), respectively. Patients with complete response (CR) or partial response (PR)/stable disease (FL) or CR/PR (DLBCL) at end of induction (EOI; six 21-day cycles) received post-induction therapy with venetoclax and obinutuzumab or rituximab, respectively. Primary endpoint was CR rate at EOI. Safety-evaluable populations included 74 patients (FL cohort; median age 64 years; progression of disease within 24 months on first-line treatment, 25.7%; FL International Prognostic Index 3-5, 54.1%; ≥2 previous therapies, 74.3%) and 57 patients (DLBCL cohort; median age 65 years; International Prognostic Index 3-5, 54.4%; ≥2 previous therapies, 77.2%). The most common non-hematologic adverse events (mostly Grades 1-2) in the FL and DLBCL cohorts were diarrhea (55.4% and 47.4%, respectively) and nausea (47.3% and 36.8%); neutropenia was the most common Grades 3-4 toxicity (39.2% and 52.6%). Efficacy-evaluable populations included patients treated at the recommended Phase 2 dose (FL, n = 49; DLBCL, n = 48). CR rates at EOI were 59.2% (FL) and 31.3% (DLBCL); median progression-free survival was 22.8 months (95% confidence interval [CI], 14.5-not evaluable) and 4.6 months (95% CI, 3.6-8.1), respectively. Polatuzumab vedotin plus venetoclax and obinutuzumab/rituximab had acceptable safety in patients with R/R FL or DLBCL, with promising response rates in R/R FL, including high-risk patients.

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.

Consensus recommendations on the management of toxicity associated with CD3×CD20 bispecific antibody therapy.

ABSTRACT: Bispecific antibodies (BsAb) that target CD3 and CD20 represent a new milestone in the treatment of patients with B-cell non-Hodgkin lymphoma. These drugs have demonstrated remarkable single-agent activity in patients with heavily pretreated disease, and 3 drugs have so far received regulatory approvals in various countries. However, BsAbs can potentially lead to severe toxicity associated with T-cell activation, particularly cytokine release syndrome (CRS). The anticipated widespread use of these off-the-shelf products poses challenges for implementation and highlights the need for guidance in anticipating, mitigating, and managing adverse events. In clinical trials, guidance for the evaluation and treatment of CRS and neurotoxicity associated with BsAb therapy has been modeled after algorithms originally created for chimeric antigen receptor (CAR) T-cell therapies and other immune effector therapies, yet notable differences in timing, quality, and severity exist between the toxicities of BsAbs and CAR T-cell therapies. We therefore convened an international panel of academic and community practice physicians, advanced practitioners, registered nurses, and pharmacists with experience using CD3×CD20 BsAbs in clinical trial and off-trial settings to provide comprehensive, consensus-based recommendations specific to the assessment and management of CD3×CD20 BsAb-related toxicities.