CD19-Targeted Immunotherapies for Diffuse Large B-Cell Lymphoma

Efficacy and safety of CD19 combined with CD22 or CD20 chimeric antigen receptor T-cell therapy for hematological malignancies

Background

CD19 combined with CD22 or CD20 therapy is a promising immunotherapy approach for the treatment of hematological malignancies. Dual-targeted CD19/CD22 CAR T and CD19/CD22 CAR T-cell therapy are currently being evaluated in clinical trials, and the extent of improvement using CD19 in combination with dual-targeted therapy has not yet been determined. To compare the differences between the two in the treatment of hematological tumors, this study summarized the available evidence. To evaluate and compare the efficacy and safety of CD19-combined CD22 and CD19-combined CD20 CAR T-cell therapy.

Methods

Data from 13 clinical studies that included 628 patients with hematological malignancies were extracted and analyzed based on a set of inclusion and exclusion criteria. The primary efficacy outcomes were overall response rate (ORR), complete response (CR) rate, partial response (PR) rate, overall survival (OS) rate and minimal residual disease (MRD)-negative response rate. The safety outcomes were cytokine release syndrome (CRS) rate and immune effector cell-associated neurotoxicity syndrome (ICANS) rate.

Results

For CD19 combined with CD22 CAR T-cell therapy, the ORR was 83.7%; CR, 78.0%; PR, 20.7%, OS, 78.7%; MRD-negative response rate, 82.3%; incidence of CRS, 58.2%; ICANS, 7.7%. For CD19 combined with CD20 CAR T-cell therapy, the ORR was 80.3%; CR, 68.2%; PR, 10.9%; OS, 76.8%; incidence of CRS, 54.5%; ICANS, 21%. Subgroup analysis indicated that the PR of CD19 combined with CD22 was significantly greater than that of CD19 combined with CD20, and the incidence of ICANS was significantly lower with the CD19+CD22 CAR-T combination.

Conclusion

The data from this study suggest that CD19 combined with CD22 CAR T-cell therapy had a higher partial response rate in the treatment of hematologic malignancies and higher safety profile in the occurrence of ICANS than CD19 combined with CD20. These data provide an important clinical basis for the development of new therapeutic targets and the construction of therapeutic methods for the treatment of hematologic malignancies, and broaden our understanding of CD19 dual-targeted CAR T therapy.

LILRB1 enhances the progression of diffuse large B-cell lymphoma through the CREB-SORBS3 pathway

PURPOSE

Although 60-70% of diffuse large B-cell lymphoma (DLBCL) patients can be cured with the current standard of chemotherapy and immunotherapy, the remaining patients experience treatment resistance and have poor clinical outcomes. More effective strategies are needed for the DLBCL treatment.

METHODS

Databases of clinical patients were analyzed to investigate potential functions of leukocyte immunoglobulin-like receptor B1 (LILRB1) in DLBCL. Short hairpin RNAs were used for validation of in vitro and in vivo function of LILRB1 in DLBCL. RNA-seq was applied to explore potential mechanism, western blot and chromatin immunoprecipitation techniques were used to characterize the underlying signaling of CREB-SORBS3 pathway.

RESULTS

We found that LILRB1 was highly expressed in DLBCL cells and was adversely correlated with the overall survival of DLBCL patients. Knockdown of LILRB1 effectively inhibited the proliferation of DLBCL cells both in vitro and in vivo. Mechanistically, LILRB1 upregulated CREB/CREB phosphorylation and transactivated SORBS3 expression to maintain DLBCL cell proliferation and tumorigenicity.

CONCLUSION

In this work, we revealed that LILRB1 was highly expressed in DLBCL cells and was negatively correlated with patient survival. Furthermore, we found that the LILRB1-CREB-SORBS3 pathway played a role in maintaining the proliferation of DLBCL cells. These data suggest that LILRB1 might be a potential target for the treatment of DLBCL.

The bispecific antibody AZD0486: an overview of the clinical journey to date with a focus on follicular lymphoma

INTRODUCTION

Follicular lymphoma (FL) is the most common indolent lymphoma. Patients with advanced-stage FL typically respond to therapy, then follow a relapsing/remitting course, with shorter progression-free survival with each subsequent line of therapy. Whilst existing CD19-directed therapies such as CAR T-cell therapy have shown promising efficacy in the management of relapsed/refractory FL, immune-mediated adverse events, such as cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity (ICANS), are well described. AZD0486 is a fully human bispecific (CD19×CD3) T-cell engager (TCE) that induces T cell-mediated cytotoxicity but with low-affinity binding of CD3, resulting in a reduction in cytokine release.

AREAS COVERED

In this review, we describe the key preclinical data for AZD0486 and evaluate in detail the available clinical data from the ongoing phase 1 first-in-human study, including safety, efficacy, pharmacokinetics, and future development plans.

EXPERT OPINION

Bispecific TCEs are among the most promising novel therapies in use for the management of relapsed/refractory B-cell lymphomas. AZD0486 results in high complete response rates with low incidence of high-grade immune-mediated toxicity compared to alternative TCE therapies. Importantly, it remains active in patients with lymphomas that have lost CD20 expression, an important mechanism of treatment failure following CD20 targeting TCEs.

Multi-targeted, NOT gated CAR-T cells as a strategy to protect normal lineages for blood cancer therapy

Introduction

Despite advances in treatment of blood cancers, several-including acute myeloid leukemia (AML)-continue to be recalcitrant. Cell therapies based on chimeric antigen receptors (CARs) have emerged as promising approaches for blood cancers. However, current CAR-T treatments suffer from on-target, off-tumor toxicity, because most familiar blood cancer targets are also expressed in normal lineages. In addition, they face the common problem of relapse due to target-antigen loss. Cell therapeutics engineered to integrate more than one signal, often called logic-gated cells, can in principle achieve greater selectivity for tumors.

Methods

We applied such a technology, a NOT gated system called Tmod™ that is being developed to treat solid-tumor patients, to the problem of therapeutic selectivity for blood cancer cells.

Results

Here we show that Tmod cells can be designed to target 2-4 antigens to provide different practical and conceptual options for a blood cancer therapy: (i) mono- and bispecific activating receptors that target CD33, a well-known AML antigen expressed on the majority of AML tumors (as well as healthy myeloid cells) and CD43 (SPN), an antigen expressed on many hematopoietic cancers (and normal blood lineages); and (ii) mono- and bispecific inhibitory receptors that target CD16b (FCGR3B) and CLEC9A, antigens expressed on key normal blood cells but not on most blood cancers.

Discussion

These results further demonstrate the robust modularity of the Tmod system and generalize the Tmod approach beyond solid tumors.

CXCR4 Inhibition Enhances the Efficacy of CD19 Monoclonal Antibody-Mediated Extermination of B-Cell Lymphoma

CD19 and CXCR4 are pivotal regulators of B-cell activation and migration, respectively. Specifically, CXCR4 signaling critically influences the dissemination of various malignant B cells through constitutive activation and aberrant expression. This study explores the interaction between CD19 and CXCR4 signaling in the context of B-cell lymphomas, particularly focusing on diffuse large B-cell lymphoma (DLBCL) and Waldenström Macroglobulinemia (WM). We assessed the roles of CD19 in survival and CXCL12-induced migration by using knockout (KO) cells of DLBCL and WM origin alongside evaluating the impact of CD19 monoclonal antibodies (mAbs) on antibody-dependent cell-mediated cytotoxicity (ADCC). Our results highlight that CD19 is important for survival and CXCL12-induced migration, and mAbs variably increase CXCL12-induced migration and enhance ADCC. Additionally, we demonstrate that the endogenous peptide inhibitor of the CXCR4 (EPI-X4) derivative JM#21 effectively inhibits CD19-mediated migration enhancement and promotes ADCC, thereby augmenting the therapeutic efficacy of CD19 mAb-based immunotherapy in lymphoma models. Our study underscores the potential of targeting both CD19 and CXCR4 to refine therapeutic strategies for treating B-cell malignancies, suggesting a synergistic approach could improve clinical outcomes in WM treatment.

Identification of a Novel Immune-Gene Signature with Prognostic Value in Patients with Head and Neck Cancer: A Pilot Study

The tumor microenvironment has a significant input on prognosis and also for predicting clinical outcomes in various types of cancers. However, tumor tissue is not always available, thus, rendering peripheral blood a preferable alternative in the search for prognostic and predictive gene signatures. Head and neck squamous cell carcinoma (HNSCC) constitutes a quite heterogeneous disease characterized by poor prognosis. Therefore, the discovery of novel therapeutics based on prognostic gene signatures for effective disease governance is of paramount importance. In this study, we report for the first time an immune-gene signature identified in the peripheral blood of HNSCC patients comprising five genes (CLEC4C, IL23A, LCK, LY9, and CD19) which were more than threefold downregulated as compared to healthy individuals and were associated with poor prognosis. By performing analyses of HNSCC tumor samples from The Cancer Genome Atlas (TCGA) database, we discovered that decreased expression of these genes, both as single genes and as a 5-gene signature (5-GS), was significantly correlated with worse overall survival (OS). Our data show that the levels of expression of the 5-GS represent an immune profile predicting OS in patients with HNSCC.

Cysteine-binding adjuvant enhances survival and promotes immune function in a murine model of acute myeloid leukemia

ABSTRACT

Therapeutic vaccination has long been a promising avenue for cancer immunotherapy but is often limited by tumor heterogeneity. The genetic and molecular diversity between patients often results in variation in the antigens present on cancer cell surfaces. As a result, recent research has focused on personalized cancer vaccines. Although promising, this strategy suffers from time-consuming production, high cost, inaccessibility, and targeting of a limited number of tumor antigens. Instead, we explore an antigen-agnostic polymeric in situ cancer vaccination platform for treating blood malignancies, in our model here with acute myeloid leukemia (AML). Rather than immunizing against specific antigens or targeting adjuvant to specific cell-surface markers, this platform leverages a characteristic metabolic and enzymatic dysregulation in cancer cells that produces an excess of free cysteine thiols on their surfaces. These thiols increase in abundance after treatment with cytotoxic agents such as cytarabine, the current standard of care in AML. The resulting free thiols can undergo efficient disulfide exchange with pyridyl disulfide (PDS) moieties on our construct and allow for in situ covalent attachment to cancer cell surfaces and debris. PDS-functionalized monomers are incorporated into a statistical copolymer with pendant mannose groups and TLR7 agonists to target covalently linked antigen and adjuvant to antigen-presenting cells in the liver and spleen after IV administration. There, the compound initiates an anticancer immune response, including T-cell activation and antibody generation, ultimately prolonging survival in cancer-bearing mice.

Deciphering stage 0 hematogones by flow cytometry in follow-up bone marrow samples of pediatric B-Acute lymphoblastic leukemia cases: A potential mimicker of residual disease after anti CD19 therapy

CD19 is frequently targeted for immunotherapy in B cell malignancies, which may result in loss of CD19 expression in leukemic cells as an escape mechanism. Stage 0 hematogones (Hgs) are normal CD19-negative very early B cell precursors that can be potentially mistaken for CD19 negative residual leukemic cells by flow cytometry (FCM) in B cell acute lymphoblastic leukemia (BCP-ALL) cases treated with anti CD19 therapy. Our main objective was to characterize and study the incidence of stage 0 hematogones in follow-up bone marrow samples of pediatric BCP-ALL cases. We analyzed the flow cytometry standard files of 61 pediatric BCP-ALL cases treated with conventional chemotherapy and targeted anti-CD19 therapy, for identifying the residual disease and normal B cell precursors including stage 0 Hgs. A non-CD19 alternate gating strategy was used to isolate the B cells for detecting the residual disease and stage 0 Hgs. The stage 0 Hgs were seen in 95% of marrow samples containing CD19+ Hgs. When compared with controls and posttransplant marrow samples, the fraction of stage 0 Hgs was higher in patients receiving anti CD19 therapy (p = 0.0048), but it was not significant when compared with patients receiving chemotherapy (p = 0.1788). Isolated stage 0 Hgs are found in samples treated with anti-CD19 therapy simulating CD19 negative residual illness. Our findings aid in understanding the stage 0 Hgs and its association with CD19+ Hgs in anti CD19 therapy and conventional chemotherapy. This is crucial as it can be potentially mistaken for residual disease in patients treated with anti CD19 therapy.

The progress of novel strategies on immune-based therapy in relapsed or refractory diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) can be cured with standard front-line immunochemotherapy, whereas nearly 30-40% of patients experience refractory or relapse. For several decades, the standard treatment strategy for fit relapsed/refractory (R/R) DLBCL patients has been high-dose chemotherapy followed by autologous hematopoietic stem cell transplant (auto-SCT). However, the patients who failed in salvage treatment or those ineligible for subsequent auto-SCT have dismal outcomes. Several immune-based therapies have been developed, including monoclonal antibodies, antibody-drug conjugates, bispecific T-cell engaging antibodies, chimeric antigen receptor T-cells, immune checkpoint inhibitors, and novel small molecules. Meanwhile, allogeneic SCT and radiotherapy are still necessary for disease control for fit patients with certain conditions. In this review, to expand clinical treatment options, we summarize the recent progress of immune-related therapies and prospect the future indirections in patients with R/R DLBCL.

CD19/CD22 bispecific chimeric antigen receptor‑NK‑92 cells are developed and evaluated

Anti-CD19 chimeric antigen receptor (CAR)-T cells have improved the outcomes of patients with B cell leukemia and lymphoma. However, their applications and positive outcomes remain limited. CAR-T cells are currently restricted to autologous blood as their source and their use can lead to downregulation of CD19 expression along with complications such as graft-versus-host disease and cytokine release syndrome. The present study aimed to develop anti-CD19/CD22 bispecific CAR structures using an anti-CD22 monoclonal antibody clone from chickens and analyze them in natural killer (NK)-92 cells, a human NK cell line, in vitro and in vivo. Anti-CD19/CD22 CAR-NK-92 cell cytotoxicity was assessed by the survival of target cells and counted using flow cytometry. Anti-CD22/CD19 and loop-structured anti-CD19/CD22 bi-specific CAR-NK-92 cells showed improved efficacy against OCI-Ly7 cells, a human B cell lymphoma cell line, compared with other CAR structures. These results demonstrate the potential of anti-CD19/CD22 bispecific CAR-NK cells and suggested that optimizing CAR structures in NK cells can improve the efficacy of CAR therapy.

Current Status of Novel Agents for the Treatment of B Cell Malignancies: What's Coming Next?

Resistance to death is one of the hallmarks of human B cell malignancies and often contributes to the lack of a lasting response to today's commonly used treatments. Drug discovery approaches designed to activate the death machinery have generated a large number of inhibitors of anti-apoptotic proteins from the B-cell lymphoma/leukemia 2 family and the B-cell receptor (BCR) signaling pathway. Orally administered small-molecule inhibitors of Bcl-2 protein and BCR partners (e.g., Bruton's tyrosine kinase and phosphatidylinositol-3 kinase) have already been included (as monotherapies or combination therapies) in the standard of care for selected B cell malignancies. Agonistic monoclonal antibodies and their derivatives (antibody-drug conjugates, antibody-radioisotope conjugates, bispecific T cell engagers, and chimeric antigen receptor-modified T cells) targeting tumor-associated antigens (TAAs, such as CD19, CD20, CD22, and CD38) are indicated for treatment (as monotherapies or combination therapies) of patients with B cell tumors. However, given that some patients are either refractory to current therapies or relapse after treatment, novel therapeutic strategies are needed. Here, we review current strategies for managing B cell malignancies, with a focus on the ongoing clinical development of more effective, selective drugs targeting these molecules, as well as other TAAs and signaling proteins. The observed impact of metabolic reprogramming on B cell pathophysiology highlights the promise of targeting metabolic checkpoints in the treatment of these disorders.

Acquired B-cell deficiency secondary to B-cell-depleting therapies

The advantage of the newer biological therapies is that the immunosuppressive effect is targeted, in contrast, to the standard, traditional immunomodulatory agents, which have a more global effect. However, there are unintended targets and consequences, even to these "precise" therapeutics, leading to acquired or secondary immunodeficiencies. Besides depleting specific cellular immune subsets, these biological agents, which include monoclonal antibodies against biologically relevant molecules, often have broader functional immune consequences, which become apparent over time. This review focuses on acquired B-cell immunodeficiency, secondary to the use of B-cell depleting therapeutic agents. Among the many adverse consequences of B-cell depletion is the risk of hypogammaglobulinemia, failure of B-cell recovery, impaired B-cell differentiation, and risk of infections. Factors, which modulate the outcomes of B-cell depleting therapies, include the intrinsic nature of the underlying disease, the concomitant use of other immunomodulatory agents, and the clinical status of the patient and other co-existing morbidities. This article seeks to explore the mechanism of action of B-cell depleting agents, the clinical utility and adverse effects of these therapies, and the relevance of systematic and serial laboratory immune monitoring in identifying patients at risk for developing immunological complications, and who may benefit from early intervention to mitigate the secondary consequences. Though these biological drugs are gaining widespread use, a harmonized approach to immune evaluation pre-and post-treatment has not yet gained traction across multiple clinical specialties, because of which, the true prevalence of these adverse events cannot be determined in the treated population, and a systematic and evidence-based dosing schedule cannot be developed. The aim of this review is to bring these issues into focus, and initiate a multi-specialty, data-driven approach to immune monitoring.

NK Cell-Based Immunotherapy in Colorectal Cancer

Human Natural Killer (NK) cells are all round players in immunity thanks to their powerful and immediate response against transformed cells and the ability to modulate the subsequent adaptive immune response. The potential of immunotherapies based on NK cell involvement has been initially revealed in the hematological setting but has inspired the design of different immune tools to also be applied against solid tumors, including colorectal cancer (CRC). Indeed, despite cancer prevention screening plans, surgery, and chemotherapy strategies, CRC is one of the most widespread cancers and with the highest mortality rate. Therefore, further efficient and complementary immune-based therapies are in urgent need. In this review, we gathered the most recent advances in NK cell-based immunotherapies aimed at fighting CRC, in particular, the use of monoclonal antibodies targeting tumor-associated antigens (TAAs), immune checkpoint blockade, and adoptive NK cell therapy, including NK cells modified with chimeric antigen receptor (CAR-NK).