Chimeric antigen receptor modified T cell therapy in B cell non-Hodgkin lymphomas

Mature B‐ and plasma‐cell flow cytometric analysis: A review of the impact of targeted therapy

Flow cytometry has been indispensable in diagnosing B cell lymphoma and plasma cell neoplasms. The advances in novel multicolor flow cytometry have also made this technology a robust tool for monitoring minimal/measurable residual disease in chronic lymphocytic leukemia and multiple myeloma. However, challenges using conventional gating strategies to isolate neoplastic B or plasma cells are emerging due to the rapidly increasing number of antibody therapeutics targeting single or multiple classic B/plasma cell-lineage markers, such as CD19, CD20, and CD22 in B cells and CD38 in plasma cells. This review is the first of a two-part series that summarizes the most current targeted therapies used in B and plasma cell neoplasms and proposes detailed alternative approaches to overcome post-targeted therapy analysis challenges by flow cytometry. The second review in this series (Chen et al.) focuses on challenges encountered in the use of targeted therapy in precursor B cell neoplasms.

Change of tumor-infiltrating lymphocyte of associating liver partition and portal vein ligation for staged hepatectomy for hepatocellular carcinoma

BACKGROUND

The role of tumor-infiltrating lymphocytes (TILs) in the growth and progression of hepatocellular carcinoma (HCC) has attracted widespread attention.

AIM

To evaluate the feasibility of associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) for massive HCC by exploring the role of TIL in the tumor microenvironment.

METHODS

Fifteen massive HCC patients who underwent ALPPS treatment and 46 who underwent hemi-hepatectomy were selected for this study. Propensity score matching was utilized to match patients in ALPPS and hemi-hepatectomy groups (1:1). Quantitative analysis of TILs in tumor and adjacent tissues between the two groups was performed by immunofluorescence staining and further analyses with oncological characteristics. In the meantime, trends of TILs in peripheral blood were compared between the two groups during the perioperative period.

RESULTS

Continuous measurement of tumor volume and necrosis volume showed that the proportion of tumor necrosis volume on the seventh day after stage-I ALPPS was significantly higher than the pre-operative value (P = 0.024). In the preoperative period of stage-I ALPPS, the proportion of tumor necrosis volume in the high CD8⁺ T cell infiltration group was significantly higher than that in the low group (P = 0.048).

CONCLUSION

TIL infiltration level maintained a dynamic balance during the preoperative period of ALPPS. Compared with right hemi-hepatectomy, the ALPPS procedure does not cause severe immunosuppression with the decrease in TIL infiltration and pathological changes in immune components of peripheral blood. Our results suggested that ALPPS is safe and feasible for treating massive HCC from the perspective of immunology. In addition, high CD8⁺ T cell infiltration is associated with increasing tumor necrosis in the perioperative period of ALPPS.

CD20-specific chimeric antigen receptor-expressing T cells as salvage therapy in rituximab-refractory/relapsed B-cell non-Hodgkin lymphoma

BACKGROUND AIMS

The infusion of chimeric antigen receptor (CAR) T cells that target specific tumor-associated antigens is a promising strategy that has exhibited encouraging results in clinical trials. However, few studies have focused on the effectiveness and safety of CD20 CAR T cells in rituximab-refractory/relapsed (R/R) B-cell non-Hodgkin lymphoma (B-NHL) patients, particularly those treated with rituximab for a short time. This prospective study aimed to assess the effectiveness and toxicity of CD20 CAR T cells in R/R B-NHL patients previously treated with rituximab.

METHODS

The authors conducted a prospective, single-center phase I study on the effectiveness and toxicity of CD20 CAR T cells in rituximab-treated R/R B-NHL patients (no. ChiCTR2000036350). A total of 15 patients with R/R B-NHL were enrolled between November 21, 2017, and December 1, 2021.

RESULTS

An overall response rate of 100% was shown in enrolled patients, with 12 (80%) achieving complete remission and three (20%) achieving partial remission for the best response. The median follow-up time was 12.4 months. Progression-free survival and overall survival were not yet reached by the data cutoff day. No patient developed grade 4 cytokine release syndrome, and only one patient had immune effector cell-associated neurotoxicity syndrome.

CONCLUSIONS

All enrolled B-NHL patients who were previously R/R to rituximab achieved different degrees of clinical response with tolerable toxicities. Notably, patients who had received rituximab within 3 months had a poorer prognosis.

Overview of the pre-clinical and clinical studies about the use of CAR-T cell therapy of cancer combined with oncolytic viruses

Background

Cancer is one of the critical issues of the global health system with a high mortality rate even with the available therapies, so using novel therapeutic approaches to reduce the mortality rate and increase the quality of life is sensed more than ever.

Main body

CAR-T cell therapy and oncolytic viruses are innovative cancer therapeutic approaches with fewer complications than common treatments such as chemotherapy and radiotherapy and significantly improve the quality of life. Oncolytic viruses can selectively proliferate in the cancer cells and destroy them. The specificity of oncolytic viruses potentially maintains the normal cells and tissues intact. T-cells are genetically manipulated and armed against the specific antigens of the tumor cells in CAR-T cell therapy. Eventually, they are returned to the body and act against the tumor cells. Nowadays, virology and oncology researchers intend to improve the efficacy of immunotherapy by utilizing CAR-T cells in combination with oncolytic viruses.

Conclusion

Using CAR-T cells along with oncolytic viruses can enhance the efficacy of CAR-T cell therapy in destroying the solid tumors, increasing the permeability of the tumor cells for T-cells, reducing the disturbing effects of the immune system, and increasing the success chance in the treatment of this hazardous disease.

In recent years, significant progress has been achieved in using oncolytic viruses alone and in combination with other therapeutic approaches such as CAR-T cell therapy in pre-clinical and clinical investigations. This principle necessitates a deeper consideration of these treatment strategies. This review intends to curtly investigate each of these therapeutic methods, lonely and in combination form. We will also point to the pre-clinical and clinical studies about the use of CAR-T cell therapy combined with oncolytic viruses.

Therapeutic potential of CAR T cell in malignancies: A scoping review

Although tremendous advancements in cancer therapy over the last several years, cancer still is a complex illness to cure. Traditional cancer treatments, including chemotherapy, radiotherapy, and surgery, have a poor therapeutic effect, emphasizing the significance of employing innovative treatments like activated cell therapy. Chimeric antigen receptor T cell is one of the most prevalent types of activated cell therapy have been developed to direct T lymphocytes toward cancers (CAR-T cells). CAR-T cells therapy has illustrated poor impact versus solid tumors despite the remarkable success in patients suffering from hematological malignancies. CAR-T cells must overcome various hurdles to obtain full responses to solid tumors, including growth, stability, trafficking, and destiny inside tumors. As a result, novel treatment methods will entail overcoming the challenges that CAR-T cells face in solid tumors. The use of CAR-T cells in combination with other therapeutic approaches such as chemotherapy, radiotherapy, immuno-checkpoint inhibitors, and oncolytic viruses can promote the effectiveness of CAR-T cell therapy for the treatment of solid tumors. However, more research is needed to determine the safety and effectiveness of these therapies. CAR-T cell treatment success rates vary by type of disease, but are predicted to reach up to 90% in patients with leukemia. However, since this kind of immunotherapy is still in its infancy, there is much to learn about its efficacy. This review provided an in-depth examination of CAR-T cell therapy and its success and failure as a cancer treatment approach. We also discuss combination therapies with CAR-T Cell.

Case Report: Successful Chimeric Antigen Receptor T Cell Therapy in Haploidentical-Allogeneic Stem Cell Transplant Patients With Post-Transplant Lymphoproliferative Disorder

Background

Epstein–Barr virus-associated post-transplant lymphoproliferative disorder (EBV-PTLD) is a potentially fatal complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Rituximab has been proven to dramatically improve the prognosis of patients with EBV reactivation and PTLD. However, reports on the curative management of refractory PTLD are scarce.

Case Presentation

In this report, we describe the successful management of two patients with EBV-PTLD with chimeric antigen receptor T-cell (CAR-T) therapy.

Conclusion

The present results demonstrated that patients with EBV-PTLD may benefit from CAR-T therapy and that the toxicity is manageable. Further studies are needed to verify these findings.

Final results of a phase 1 study of loncastuximab tesirine in relapsed/refractory B-cell non-Hodgkin lymphoma

The prognosis for patients with relapsed or refractory (R/R) B-cell non-Hodgkin lymphoma (B-NHL) remains poor, with a need for alternatives to current salvage therapies. Loncastuximab tesirine (ADCT-402) is an antibody-drug conjugate comprising a humanized anti-CD19 monoclonal antibody conjugated to a pyrrolobenzodiazepine dimer toxin. Presented here are final results of a phase 1 dose-escalation and dose-expansion study in patients with R/R B-NHL. Objectives were to determine the maximum tolerated dose (MTD) and recommended dose(s) for expansion and evaluate safety, clinical activity, pharmacokinetics, and immunogenicity of loncastuximab tesirine. Overall, 183 patients received loncastuximab tesirine, with 3 + 3 dose escalation at 15 to 200 µg/kg and dose expansion at 120 and 150 µg/kg. Dose-limiting toxicities (all hematologic) were reported in 4 patients. The MTD was not reached, although cumulative toxicity was higher at 200 µg/kg. Hematologic treatment-emergent adverse events were most common, followed by fatigue, nausea, edema, and liver enzyme abnormalities. Overall response rate (ORR) in evaluable patients was 45.6%, including 26.7% complete responses (CRs). ORRs in patients with diffuse large B-cell lymphoma (DLBCL), mantle cell lymphoma, and follicular lymphoma were 42.3%, 46.7%, and 78.6%, respectively. Median duration of response in all patients was 5.4 months and not reached in patients with DLBCL (doses ≥120 µg/kg) who achieved a CR. Loncastuximab tesirine had good stability in serum, notable antitumor activity, and an acceptable safety profile, warranting continued study in B-NHL. The recommended dose for phase 2 was determined as 150 µg/kg every 3 weeks for 2 doses followed by 75 µg/kg every 3 weeks. This trial was registered at www.clinicaltrials.gov as #NCT02669017.

Loncastuximab tesirine in relapsed or refractory diffuse large B-cell lymphoma (LOTIS-2): a multicentre, open-label, single-arm, phase 2 trial

BACKGROUND

Patients with relapsed or refractory diffuse large B-cell lymphoma (DLBCL) who do not respond to or who have progressive disease after salvage therapies have a poor prognosis. Loncastuximab tesirine is a CD19-directed antibody-drug conjugate with encouraging phase 1 single-agent antitumour activity and acceptable safety in non-Hodgkin lymphoma. We aimed to evaluate the antitumour activity and safety of loncastuximab tesirine in patients with relapsed or refractory DLBCL.

METHODS

We did a multicentre (28 hospital sites in the USA, UK, Italy, and Switzerland), open-label, single-arm, phase 2 trial (LOTIS-2) in patients aged 18 years or older with relapsed or refractory DLBCL after two or more multiagent systemic treatments, who had measurable disease and Eastern Cooperative Oncology Group performance status 0-2. Eligible patients received loncastuximab tesirine intravenously on day 1 of each 21-day cycle, at 150 μg/kg for two cycles, then 75 μg/kg thereafter, for up to 1 year or until disease relapse or progression, unacceptable toxicity, death, major protocol deviation, pregnancy, or patient, investigator, or sponsor decision. The primary endpoint was overall response rate assessed by central review. Primary antitumour activity and safety analyses were done in the as-treated population (patients who received at least one dose of loncastuximab tesirine), when all responding patients had at least 6 months of follow-up after initial documented response. Enrolment is complete. This trial is registered with ClinicalTrials.gov, NCT03589469.

FINDINGS

Between Aug 1, 2018, and Sept 24, 2019, 184 patients were assessed for eligibility and 145 (79%) were enrolled and received at least one dose of loncastuximab tesirine, including patients with high-risk characteristics for poor prognosis, such as double-hit, triple-hit, transformed, or primary refractory DLBCL. 70 of 145 patients had complete or partial response (overall response rate 48·3% [95% CI 39·9-56·7]); 35 had complete response and 35 had partial response. The most common grade 3 or higher treatment-emergent adverse events were neutropenia (37 [26%] of 145 patients), thrombocytopenia (26 [18%]), and increased gamma-glutamyltransferase (24 [17%]). Serious adverse events were reported in 57 (39%) of 145 patients. Treatment-emergent adverse events with a fatal outcome occurred in eight (6%) of 145 patients; none were considered related to loncastuximab tesirine.

INTERPRETATION

Loncastuximab tesirine has substantial single-agent antitumour activity and produces durable responses with an acceptable safety profile, potentially offering a new therapeutic option for heavily pretreated patients with relapsed or refractory DLBCL.

FUNDING

ADC Therapeutics.

CART Cell Toxicities: New Insight into Mechanisms and Management

T cells genetically engineered with chimeric antigen receptors (CART) have become a potent class of cancer immunotherapeutics. Numerous clinical trials of CART cells have revealed remarkable remission rates in patients with relapsed or refractory hematologic malignancies. Despite recent clinical success, CART cell therapy has also led to significant morbidity and occasional mortality from associated toxicities. Cytokine release syndrome (CRS) and Immune effector cell-associated neurotoxicity syndrome (ICANS) present barriers to the extensive use of CART cell therapy in the clinic. CRS can lead to fever, hypoxia, hypotension, coagulopathies, and multiorgan failure, and ICANS can result in cognitive dysfunction, seizures, and cerebral edema. The mechanisms of CRS and ICANS are becoming clearer, but many aspects remain unknown. Disease type and burden, peak serum CART cell levels, CART cell dose, CAR structure, elevated pro-inflammatory cytokines, and activated myeloid and endothelial cells all contribute to CART cell toxicity. Current guidelines for the management of toxicities associated with CART cell therapy vary between clinics, but are typically comprised of supportive care and treatment with corticosteroids or tocilizumab, depending on the severity of the symptoms. Acquiring a deeper understanding of CART cell toxicities and developing new management and prevention strategies are ongoing. In this review, we present findings in the mechanisms and management of CART cell toxicities.

Effectiveness and Safety of Pixantrone for the Treatment of Relapsed or Refractory Diffuse Large B-Cell Lymphoma in Every-Day Clinical Practice: The Italian Cohort of the PIXA Registry

INTRODUCTION

Treatment of relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL) represents a challenge for clinicians due to the lack of therapeutic options. DLBCL is not a rare disease in Italy. Pixantrone is an aza-anthracenedione, which, when compared to anthracyclines and anthracenediones, has a significantly reduced cardiotoxicity while maintaining good anti-tumor activity. However, the evidence on the use of pixantrone in the context of daily clinical practice is scarce.

METHODS

We focused on the Italian patient subset of a larger European retrospective study (the PIXA Registry) to assess the efficacy and safety of pixantrone in a real-life DLBCL population. The molecular profile of the disease and its impact on drug efficacy were also assessed.

RESULTS

Fifteen heavily pretreated DLBCL patients (13 males and 2 females) underwent treatment with pixantrone for a median of 2 cycles (range 1-6). Eight patients were bcl2 positive, 7 bcl6 positive, and 4 myc positive; 4 patients were diagnosed as double-hit, and 2 as triple-hit DLBCL. The overall response rate was 26.7% with a best response rate of 46.7%. Three patients had grade IV adverse events, which caused drug discontinuation. Four patients had 5 cases of grade III toxicities (1 thrombocytopenia, 1 stomatitis, and 3 neutropenia). One mild cardiac toxicity (sinus tachycardia for which no action was required) was possibly related to the study drug.

CONCLUSION

Our data documented drug efficacy that is satisfactory for this high-risk subset of patients with an acceptable toxicity profile. Results indicate that pixantrone could be a significant treatment option in patients with R/R aggressive DLBCL treated in everyday clinical practice.

T Cells Expressing NKG2D CAR with a DAP12 Signaling Domain Stimulate Lower Cytokine Production While Effective in Tumor Eradication

Cytokine-related toxicity associated with the use of highly active chimeric antigen receptor T cells (CAR-T cells) is a significant clinical problem. By fusing the natural killer group 2D (NKG2D) ectodomain to 4-1BB and the DAP12 cytoplasmic domain containing only one immunoreceptor tyrosine-based activation motif, we have developed a 2nd-generation (2nd-Gen) NKG2D CAR for stable expression in human T cells. When compared to T cells modified with NKG2D CAR containing the commonly used CD3ζ activation domain, T cells expressing the NKG2D-DAP12 CAR stimulated lower level release of interferon gamma (IFN-γ), tumor necrosis factor alpha (TNF-α), and interleukin (IL)-2 during tumor cell lysis and their proliferative activity was lower upon repeated antigen stimulation, although no difference between the two CARs was observed in mediating in vitro tumor cell lysis. In tumor-bearing NSG mice, both types of CAR-T cells displayed similar anti-tumor activity, being able to completely eradicate established solid tumor xenografts. However, treatment with the NKG2D-CD3ζ CAR-T cells led to the death of most mice from xenogeneic graft versus host disease starting 30 days post-CAR-T cell injection, which was associated with a higher level of cytokine release, whereas all the mice treated with the NKG2D-DAP12 CAR-T cells survived well. Thus, the incorporation of the DAP12 activation domain in a CAR design may possibly provide a potential clinical advantage in mitigating the risk of cytokine release syndrome (CRS).

Bispecific Chimeric Antigen Receptor T Cell Therapy for B Cell Malignancies and Multiple Myeloma

Simple Summary

In relapsed, refractory B cell malignancies and multiple myeloma, chimeric antigen receptor (CAR) T cell therapy has represented a major scientific advancement with high response rates and durable responses for many. Nonetheless, target antigen downregulation in tumor cells can lead to poor responses and relapsed disease. Current FDA approved CAR T cell therapies only target a single B-cell specific cell marker. While effective, single targeted CAR T cell therapy can lead selective pressure against the target antigen leading to loss of expression and tumor cell escape. Simultaneous dual antigen targeting CAR therapy has been evaluated in multiple early phase clinical trials in response to these clinical challenges in hopes of improving response rates and preventing relapse. This article discusses the limitations of single targeted CAR T cell therapy, approaches to dual antigen targeting, and the results of early phase trials utilizing dual antigen targeting CAR T cell therapy.

Abstract

Chimeric antigen receptor (CAR) modified T cell therapy offers a targeted immunotherapeutic approach to patients with refractory hematological malignancies. This technology is most advanced in B cell malignancies and multiple myeloma and is rapidly evolving as more data become available regarding clinical efficacy and response durability. Despite excellent initial response rates with single antigen targeting CARs, failure to respond to therapy and relapse due to target antigen downregulation remain clinical challenges. To mitigate immunophenotypic selective pressures, simultaneous dual antigen targeting with bispecific CAR T cells or multiple administration of different populations of CAR T cells may prevent relapse by addressing one resistance mechanism attributed to antigenic loss. This article will review recently published data on the use of dual targeting with CAR T cells from early phase clinical trials aimed at treating B cell malignancies and multiple myeloma.

Activation of CAR and non-CAR T cells within the tumor microenvironment following CAR T cell therapy

Mechanisms of chimeric antigen receptor (CAR) T cell-mediated antitumor immunity and toxicity remain poorly characterized because few studies examine the intact tumor microenvironment (TME) following CAR T cell infusion. Axicabtagene ciloleucel is an autologous anti-CD19 CAR T cell therapy approved for patients with large B cell lymphoma. We devised multiplex immunostaining and ISH assays to interrogate CAR T cells and other immune cell infiltrates in biopsies of diffuse large B cell lymphoma following axicabtagene ciloleucel infusion. We found that a majority of intratumoral CAR T cells expressed markers of T cell activation but, unexpectedly, constituted ≤5% of all T cells within the TME 5 days or more after therapy. Large numbers of T cells without CAR were also activated within the TME after axicabtagene ciloleucel infusion; these cells were positive for Ki-67, IFN-γ, granzyme B (GzmB), and/or PD-1 and were found at the highest levels in biopsies with CAR T cells. Additionally, non-CAR immune cells were the exclusive source of IL-6, a cytokine associated with cytokine release syndrome, and were found at their highest numbers in biopsies with CAR T cells. These data suggest that intratumoral CAR T cells are associated with non-CAR immune cell activation within the TME with both beneficial and pathological effects.

Allogeneic transplantation in elderly patients ≥65 years with non-Hodgkin lymphoma: a time-trend analysis

Allogeneic hematopoietic cell transplantation (allo-HCT) is a curative therapy for relapsed/refractory and high-risk non-Hodgkin lymphoma (NHL). However, no large studies have evaluated allo-HCT utilization in elderly NHL patients (≥65 years). Using the CIBMTR registry, we report a time-trend analysis of 727 NHL patients (≥65 years) undergoing the first allo-HCT from 2000 to 2015 in the United States (US). Study cohorts were divided by time period: 2000-2005 (N = 76) vs. 2006-2010 (N = 238) vs. 2011-2015 (N = 413). Primary outcome was overall survival (OS). Secondary outcomes included progression-free survival (PFS), relapse/progression (R/P), and non-relapse mortality (NRM). Median age at transplant, use of reduced-intensity conditioning, and graft source remained stable, while use of unrelated donors increased in the most current era. The 1-year probabilities of NRM from 2000 to 2005 vs. 2006-2010 vs. 2011-2015 were 24% vs. 19% vs. 21%, respectively (p = 0.67). Four-year probability of R/P was similar among the three cohorts: 48% (2000-2005), 40% (2006-2010), and 40% (2011-2015) (p = 0.39). The 4-year probabilities of PFS and OS (2000-2005 vs. 2006-2010 vs. 2011-2015) showed significantly improved outcomes in more recent time periods: 17% vs. 31% vs. 30% (p = 0.02) and 21% vs. 42% vs. 44% (p < 0.001), respectively. Utilization of allo-HCT increased in elderly NHL patients in the US since 2000 with improving survival outcomes.

Advances in Molecular Biology and Targeted Therapy of Mantle Cell Lymphoma

Mantle cell lymphoma (MCL) is a heterogeneous malignancy with a broad spectrum of clinical behavior from indolent to highly aggressive cases. Despite the fact that MCL remains in most cases incurable by currently applied immunochemotherapy, our increasing knowledge on the biology of MCL in the last two decades has led to the design, testing, and approval of several innovative agents that dramatically changed the treatment landscape for MCL patients. Most importantly, the implementation of new drugs and novel treatment algorithms into clinical practice has successfully translated into improved outcomes of MCL patients not only in the clinical trials, but also in real life. This review focuses on recent advances in our understanding of the pathogenesis of MCL, and provides a brief survey of currently used treatment options with special focus on mode of action of selected innovative anti-lymphoma molecules. Finally, it outlines future perspectives of patient management with progressive shift from generally applied immunotherapy toward risk-stratified, patient-tailored protocols that would implement innovative agents and/or procedures with the ultimate goal to eradicate the lymphoma and cure the patient.