Axicabtagene ciloleucel as first-line therapy in high-risk large B-cell lymphoma: the phase 2 ZUMA-12 trial

Successes and challenges in clinical gene therapy

Despite the ups and downs in the field over three decades, the science of gene therapy has continued to advance and provide enduring treatments for increasing number of diseases. There are active clinical trials approaching a variety of inherited and acquired disorders of different organ systems. Approaches include ex vivo modification of hematologic stem cells (HSC), T lymphocytes and other immune cells, as well as in vivo delivery of genes or gene editing reagents to the relevant target cells by either local or systemic administration. In this article, we highlight success and ongoing challenges in three areas of high activity in gene therapy: inherited blood cell diseases by targeting hematopoietic stem cells, malignant disorders using immune effector cells genetically modified with chimeric antigen receptors, and ophthalmologic, neurologic, and coagulation disorders using in vivo administration of adeno-associated virus (AAV) vectors. In recent years, there have been true cures for many of these diseases, with sustained clinical benefit that exceed those from other medical approaches. Each of these treatments faces ongoing challenges, namely their high one-time costs and the complexity of manufacturing the therapeutic agents, which are biological viruses and cell products, at pharmacologic standards of quality and consistency. New models of reimbursement are needed to make these innovative treatments widely available to patients in need.

2024 Update: Advances in the risk stratification and management of large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous disease with varying clinical outcomes. Our understanding of its molecular makeup continues to improve risk stratification, and artificial-intelligence and ctDNA-based analyses have the potential to enhance risk assessment and disease monitoring. R-CHOP and Pola-R-CHP are used in the frontline setting; chimeric antigen receptor therapy (CART) is now the new standard-of-care for most with primary refractory disease; both CART and autologous stem cell transplantation are utilized in the relapsed and refractory setting. In this review, we summarize the classification and management of DLBCL with an emphasis on recent advances in the field.

CAR-T Cell Therapy in Large B Cell Lymphoma

Large B-cell lymphomas (LBCLs) are among the most frequent (about 30%) non-Hodgkin's lymphoma. Despite the aggressive behavior of these lymphomas, more than 60% of patients can be cured with first-line chemoimmunotherapy using the R-CHOP regimen. Patients with refractory or relapsing disease show a poor outcome even when treated with second-line therapies. CD19-targeted chimeric antigen receptor (CAR) T-cells are emerging as an efficacious second-line treatment strategy for patients with LBCL. Three CD19-CAR-T-cell products received FDA and EMA approval. CAR-T cell therapy has also been explored for treating high-risk LBCL patients in the first-line setting and for patients with central nervous system involvement. Although CD19-CAR-T therapy has transformed the care of refractory/relapsed LBCL, about 60% of these patients will ultimately progress or relapse following CD19-CAR-T; therefore, it is fundamental to identify predictive criteria of response to CAR-T therapy and to develop salvage therapies for patients relapsing after CD19-CAR-T therapies. Moreover, ongoing clinical trials evaluate bispecific CAR-T cells targeting both CD19 and CD20 or CD19 and CD22 as a tool to improve the therapeutic efficacy and reduce the number of refractory/relapsing patients.

[Efficacy and safety analysis of the zanubrutinib-based bridging regimen in chimeric antigen receptor T-cell therapy for relapsed/refractory diffuse large B-cell lymphoma]

Objective: To further elucidate the clinical efficacy and safety of a combination regimen based on the BTK inhibitor zebutanil bridging CD19 Chimeric antigen receptor T cells (CAR-T cells) in the treatment of relapsed/refractory diffuse large B-cell lymphoma (r/r DLBCL) . Methods: Twenty-one patients with high-risk r/r DLBCL were treated with a zanubrutinib-based regimen bridging CAR-T between June 2020 and June 2023 at the Department of Hematology, Tongji Hospital, Tongji University and the Second Affiliated Hospital of Zhejiang University, and the efficacy and safety were retrospectively analyzed. Results: All 21 patients were enrolled, and the median age was 57 years (range: 38-76). Fourteen patients (66.7%) had an eastern cooperative oncology group performance status score (ECOG score) of ≥2. Eighteen patients (85.7%) had an international prognostic index (IPI) score of ≥3. Three patients (14.3%) had an IPI score of 2 but had extranodal infiltration. Fourteen patients (66.7%) had double-expression of DLBCL and seven (33.3%) had TP53 mutations. With a median follow-up of 24.8 (95% CI 17.0-31.6) months, the objective response rate was 81.0%, and 11 patients (52.4%) achieved complete remission. The median progression-free survival (PFS) was 12.8 months, and the median overall survival (OS) was not reached. The 1-year PFS rate was 52.4% (95% CI 29.8% -74.3%), and the 1-year OS rate was 80.1% (95% CI 58.1% -94.6%). Moreover, 18 patients (85.7%) had grade 1-2 cytokine-release syndrome, and two patients (9.5%) had grade 1 immune effector cell-associated neurotoxicity syndrome. Conclusion: Zanubrutinib-based combination bridging regimen of CAR-T therapy for r/r DLBCL has high efficacy and demonstrated a good safety profile.

Single-Cell RNA Analysis Reveals Cell-Intrinsic Functions of CAR T Cells Correlating with Response in a Phase II Study of Lymphoma Patients

PURPOSE

Although CD19 chimeric antigen receptor T cells (CAR-T) therapy has shown remarkable success in B-cell malignancies, a substantial fraction of patients do not obtain a long-term clinical response. This could be influenced by the quality of the individual CAR-T infusion product. To shed some light on this, clinical outcome was correlated to characteristics of CAR-T infusion products.

PATIENTS AND METHODS

In this phase II study, patients with B-cell lymphoma (n = 23) or leukemia (n = 1) received one or two infusions of third-generation CD19-directed CAR-Ts (2 × 108/m2). The clinical trial was registered at clinicaltrials.gov: NCT03068416. We investigated the transcriptional profile of individual CD19 CAR-T infusion products using targeted single-cell RNA sequencing and multicolor flow cytometry.

RESULTS

Two CAR-T infusions were not better than one in the settings used in this study. As for the CAR-T infusion products, we found that effector-like CD8+CAR-Ts with a high polyfunctionality, high cytotoxic and cytokine production profile, and low dysfunctional signature were associated with clinical response. An extended ex vivo expansion time during CAR-T manufacturing negatively influenced the proportion of effector CD8+CAR-Ts in the infusion product.

CONCLUSIONS

We identified cell-intrinsic characteristics of effector CD8+CAR-Ts correlating with response that could be used as an indicator for clinical outcome. The results in the study also serve as a guide to CAR-T manufacturing practices.

CAR-T cell therapy: Where are we now, and where are we heading?

Chimeric antigen receptor (CAR)-T-cell therapies have exhibited remarkable efficacy in the treatment of hematologic malignancies, with 9 CAR-T-cell products currently available. Furthermore, CAR-T cells have shown promising potential for expanding their therapeutic applications to diverse areas, including solid tumors, myocardial fibrosis, and autoimmune and infectious diseases. Despite these advancements, significant challenges pertaining to treatment-related toxic reactions and relapses persist. Consequently, current research efforts are focused on addressing these issues to enhance the safety and efficacy of CAR-T cells and reduce the relapse rate. This article provides a comprehensive overview of the present state of CAR-T-cell therapies, including their achievements, existing challenges, and potential future developments.

Challenges and solutions to superior chimeric antigen receptor-T design and deployment for B-cell lymphomas

Chimeric antigen receptor-T (CAR-T) therapies represent a major breakthrough in cancer medicine, given the ex vivo-based technology that harnesses the power of one's own immune system. These therapeutics have demonstrated remarkable success for relapsed/refractory B-cell lymphomas. Although more than a decade has passed since the initial introduction of CAR-T therapeutics for patients with leukaemia and lymphoma, there is still significant debate as to where CAR-T therapeutics fit into the management paradigm, as consensus guidelines are limited. Competing interventions deployed in subsequent lines of therapy for aggressive lymphoma include novel targeted agents, bispecific antibodies, and time-honoured stem cell transplant. In this focused review, we discuss the major obstacles to advancing the therapeutic reach for CAR-T products in early lines of therapy. Such barriers include antigen escape, "cold" tumour microenvironments, host inflammation and CAR-T cell exhaustion. We highlight solutions including point-of-care CAR-T manufacturing and early T lymphopheresis. We review the evidence basis for early CAR-T deployment for B-cell lymphomas in light of the recent Food and Drug Administration (FDA) approval of three first-in-class anti-CD3/CD20 bispecific antibodies-mosunetuzumab, epcoritamab and glofitamab. We propose practical recommendations for 2024.

Value for Money of CAR-T Cell Therapy for Patients with Diffuse Large B-cell Lymphoma in China: Evidence from a Cost-Effectiveness Analysis

OBJECTIVE

This research assesses the cost effectiveness of Axicabtagene ciloleucel (Axi-cel), Tisagenlecleucel (Tis-cel), Relmacabtagene autoleucel (Rel-cel) and Lisocabtagene maraleucel (Lis-cel) against standard of care (SOC) for patients with diffuse large B-cell lymphoma (DLBCL) in the first-line setting (1L), second-line setting (2L) and third-line or later setting (3L+).

METHODS

Markov modelling based on a flexible survival model was adopted to evaluate four chimeric antigen receptor T-cell (CAR-T) therapies compared with SOC for patients with diffuse large B-cell lymphoma (DLBCL). The clinical inputs and utility values of the model were derived from the most recent clinical trials and the health care costs from a Chinese provincial clinical center. Costs and quality-adjusted life years (QALYs) were used to derive incremental cost-effectiveness ratios (ICERs) from the Chinese health care system perspective.

RESULTS

The ICER of Axi-cel (1L) versus SOC was approximately Chinese Yuan (CNY) 2,125,311 per QALY. The ICER for Axi-cel (2L), Tis-cel (2L) and Liso-cel (2L)) versus SOC in transplant-eligible patients were approximately CNY363,977, CNY32,066,781 and CNY347,746 per quality-adjusted life year (QALY), respectively. The ICER for Liso-cel (2L) versus SOC in transplant-ineligible patients was approximately CNY1,233,972 per QALY. The ICERs for Axi-cel (3L+), Tis-cel (3L+), Rel-cel (3L+) and Liso-cel (3L+) versus SOC were approximately CNY346,009, CNY654,344, CNY280,964 and CNY436,858 per QALY, respectively. In the scenario analysis using mixture cure models, the long-term survival benefit for CAR-T and SOC groups was found higher, and only Rel-cel (3L+) was found to be cost effective.

CONCLUSION

Our results demonstrated that CAR-T treatments are not cost effective in any-line settings for DLBCL patients at the WHO-recommended willingness-to-pay threshold (CNY257,241 per QALY) in the base-case analysis. Price reduction of CAR-T therapies is the main approach for lowering ICERs and ensuring that the drug costs are proportional to patient health benefits.

The Dutch CAR-T Tumorboard Experience: Population-Based Real-World Data on Patients with Relapsed or Refractory Large B-Cell Lymphoma Referred for CD19-Directed CAR T-Cell Therapy in The Netherlands

The real-world results of chimeric antigen receptor T-cell (CAR-T) therapy for patients with relapsed/refractory (R/R) large B-cell lymphoma (LBCL) substantially differ across countries. In the Netherlands, the CAR-T tumorboard facilitates a unique nationwide infrastructure for referral, eligibility assessment and data collection. The aim of this study was to evaluate real-world outcomes of axicabtagene ciloleucel (axi-cel) in the Dutch population, including the thus-far underreported effects on health-related quality of life (HR-QoL). All patients with R/R LBCL after ≥2 lines of systemic therapy referred for axi-cel treatment between May 2020-May 2022 were included (N = 250). Of the 160 apheresed patients, 145 patients received an axi-cel infusion. The main reason for ineligibility was rapidly progressive disease. The outcomes are better or at least comparable to other studies (best overall response rate: 84% (complete response: 66%); 12-month progression-free-survival rate and overall survival rate: 48% and 62%, respectively). The 12-month NRM was 5%, mainly caused by infections. Clinically meaningful improvement in several HR-QoL domains was observed from Month 9 onwards. Expert-directed patient selection can support effective and sustainable application of CAR-T treatment. Matched comparisons between cohorts will help to understand the differences in outcomes across countries and select best practices. Despite the favorable results, for a considerable proportion of patients with R/R LBCL there still is an unmet medical need.

Immunotherapy in hematologic malignancies: achievements, challenges and future prospects

The immune-cell origin of hematologic malignancies provides a unique avenue for the understanding of both the mechanisms of immune responsiveness and immune escape, which has accelerated the progress of immunotherapy. Several categories of immunotherapies have been developed and are being further evaluated in clinical trials for the treatment of blood cancers, including stem cell transplantation, immune checkpoint inhibitors, antigen-targeted antibodies, antibody-drug conjugates, tumor vaccines, and adoptive cell therapies. These immunotherapies have shown the potential to induce long-term remission in refractory or relapsed patients and have led to a paradigm shift in cancer treatment with great clinical success. Different immunotherapeutic approaches have their advantages but also shortcomings that need to be addressed. To provide clinicians with timely information on these revolutionary therapeutic approaches, the comprehensive review provides historical perspectives on the applications and clinical considerations of the immunotherapy. Here, we first outline the recent advances that have been made in the understanding of the various categories of immunotherapies in the treatment of hematologic malignancies. We further discuss the specific mechanisms of action, summarize the clinical trials and outcomes of immunotherapies in hematologic malignancies, as well as the adverse effects and toxicity management and then provide novel insights into challenges and future directions.

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.

Chimeric antigen receptor T-cell therapy

Chimeric antigen receptor T-cell therapies are promising new options for patients with relapsed or refractory diffuse large B-cell lymphoma or acute lymphoblastic leukaemia. They increase complete response rates and the chances of achieving prolonged remission. Chimeric antigen receptor T cells are specially modified lymphocytes designed to stimulate the body's own immune system to target malignant cells. The process involves an initial harvest of the patient's own T cells, genetic modification, T-cell expansion and then reinfusion. Cytokine release syndrome is a major short-term complication of chimeric antigen receptor T-cell therapy. The presentation typically resembles septic shock and can be fatal. Immune effector cell-associated neurotoxicity syndrome is another major short-term complication. It presents with a spectrum of neurological deficits ranging from headache, delirium and anxiety to seizures and coma. There are early promising results with chimeric antigen receptor T-cell therapies in other cancers. These include mantle cell lymphoma, multiple myeloma and some solid organ tumours such as glioblastoma multiforme.

Inferior Outcomes of EU Versus US Patients Treated With CD19 CAR-T for Relapsed/Refractory Large B-cell Lymphoma: Association With Differences in Tumor Burden, Systemic Inflammation, Bridging Therapy Utilization, and CAR-T Product Use

Real-world evidence suggests a trend toward inferior survival of patients receiving CD19 chimeric antigen receptor (CAR) T-cell therapy in Europe (EU) and with tisagenlecleucel. The underlying logistic, patient- and disease-related reasons for these discrepancies remain poorly understood. In this multicenter retrospective observational study, we studied the patient-individual journey from CAR-T indication to infusion, baseline features, and survival outcomes in 374 patients treated with tisagenlecleucel (tisa-cel) or axicabtagene-ciloleucel (axi-cel) in EU and the United States (US). Compared with US patients, EU patients had prolonged indication-to-infusion intervals (66 versus 50 d; P < 0.001) and more commonly received intermediary therapies (holding and/or bridging therapy, 94% in EU versus 74% in US; P < 0.001). Baseline lactate dehydrogenase (LDH) (median 321 versus 271 U/L; P = 0.02) and ferritin levels (675 versus 425 ng/mL; P = 0.004) were significantly elevated in the EU cohort. Overall, we observed inferior survival in EU patients (median progression-free survival [PFS] 3.1 versus 9.2 months in US; P < 0.001) and with tisa-cel (3.2 versus 9.2 months with axi-cel; P < 0.001). On multivariate Lasso modeling, nonresponse to bridging, elevated ferritin, and increased C-reactive protein represented independent risks for treatment failure. Weighing these variables into a patient-individual risk balancer (high risk [HR] balancer), we found higher levels in EU versus US and tisa-cel versus axi-cel cohorts. Notably, superior PFS with axi-cel was exclusively evident in patients at low risk for progression (according to the HR balancer), but not in high-risk patients. These data demonstrate that inferior survival outcomes in EU patients are associated with longer time-to-infusion intervals, higher tumor burden/LDH levels, increased systemic inflammatory markers, and CAR-T product use.

A nomogram for predicting the rapid progression of diffuse large B-cell lymphoma established by combining baseline PET/CT total metabolic tumor volume, lesion diffusion, and TP53 mutations

OBJECTIVES

This study aimed to integrate positron emission tomography/computed tomography (PET/CT) metrics and genetic mutations to optimize the risk stratification for diffuse large B-cell lymphoma (DLBCL) patients.

METHODS

The data of 94 primary DLBCL patients with baseline PET/CT examination completed in the Shandong Cancer Hospital and Institute (Jinan, China) were analyzed to establish a training cohort. An independent cohort of 45 DLBCL patients with baseline PET/CT examination from other hospitals was established for external validation. The baseline total metabolic tumor volume (TMTV) and the largest distance between two lesions (Dmax) standardized by patient body surface area (SDmax) were calculated. The pretreatment pathological tissues of all patients were sequenced by a lymphopanel including 43 genes.

RESULTS

The optimal TMTV cutoff was 285.3 cm3 and the optimal SDmax cutoff was 0.135 m-1 . TP53 status was found as an independent predictive factor significantly affecting complete remission (p = 0.001). TMTV, SDmax, and TP53 status were the main factors of the nomogram and could stratify the patients into four distinct subgroups based on their predicted progression-free survival (PFS). The calibration curve demonstrated satisfactory agreement between the predicted and actual 1-year PFS of the patients. The receiver operating characteristic curves showed this nomogram based on PET/CT metrics and TP53 mutations had a better predictive ability than the clinic risk scores. Similar results were identified upon external validation.

CONCLUSIONS

The nomogram based on imaging factors and TP53 mutations could lead to a more accurate selection of DLBCL patients with rapid progression, to increase tailor therapy.

Chimeric antigen receptor T-cell therapy for adult B-cell acute lymphoblastic leukemia: state-of-the-(C)ART and the road ahead

Autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy has recently been added to the armamentarium in the battle against B-cell acute lymphoblastic leukemia (B-ALL). In this review, we discuss the trials that led to US Food and Drug Administration approval of CAR T-cell therapies in patients with B-ALL. We evaluate the evolving role of allogeneic hematopoietic stem cell transplant in the CAR T-cell era and discuss lessons learned from the first steps with CAR T-cell therapy in ALL. Upcoming innovations in CAR technology, including combined and alternative targets and off-the-shelf allogeneic CAR T-cell strategies are presented. Finally, we envision the role that CAR T cells could take in the management of adult patients with B-ALL in the near future.

Induction treatment in high-grade B-cell lymphoma with a concurrent MYC and BCL2 and/or BCL6 rearrangement: a systematic review and meta-analysis

Background and aim

High-grade B cell lymphomas with concomitant MYC and BCL2 and/or BCL6 rearrangements (HGBCL-DH/TH) have a poor prognosis when treated with the standard R-CHOP-like chemoimmunotherapy protocol. Whether this can be improved using intensified regimens is still under debate. However, due to the rarity of HGBCL-DH/TH there are no prospective, randomized controlled trials (RCT) available. Thus, with this systematic review and meta-analysis we attempted to compare survival in HGBCL-DH/TH patients receiving intensified vs. R-CHOP(-like) regimens.

Methods

The PubMed and Web of Science databases were searched for original studies reporting on first-line treatment in HGBCL-DH/TH patients from 08/2014 until 04/2022. Studies with only localized stage disease, ≤10 patients, single-arm, non-full peer-reviewed publications, and preclinical studies were excluded. The quality of literature and the risk of bias was assessed using the Methodological Index for Non-Randomized Studies (MINORS) and National Heart, Lung, and Blood Institute (NHLBI) Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. Random-effect models were used to compare R-CHOP-(like) and intensified regimens regarding 2-year overall survival (2y-OS) and 2-year progression-free survival (2y-PFS).

Results

Altogether, 11 retrospective studies, but no RCT, with 891 patients were included. Only four studies were of good quality based on aforementioned criteria. Intensified treatment could improve 2y-OS (hazard ratio [HR]=0.78 [95% confidence interval [CI] 0.63-0.96]; p=0.02) as well as 2y-PFS (HR=0.66 [95% CI 0.44-0.99]; p=0.045).

Conclusions

This meta-analysis indicates that intensified regimens could possibly improve 2y-OS and 2y-PFS in HGBCL-DH/TH patients. However, the significance of these results is mainly limited by data quality, data robustness, and its retrospective nature. There is still a need for innovative controlled clinical trials in this difficult to treat patient population.

Systematic review registration

https://www.crd.york.ac.uk/prospero, identifier CRD42022313234.

Survival with Axicabtagene Ciloleucel in Large B-Cell Lymphoma

BACKGROUND

In an analysis of the primary outcome of this phase 3 trial, patients with early relapsed or refractory large B-cell lymphoma who received axicabtagene ciloleucel (axi-cel), an autologous anti-CD19 chimeric antigen receptor T-cell therapy, as second-line treatment had significantly longer event-free survival than those who received standard care. Data were needed on longer-term outcomes.

METHODS

In this trial, we randomly assigned patients with early relapsed or refractory large B-cell lymphoma in a 1:1 ratio to receive either axi-cel or standard care (two to three cycles of chemoimmunotherapy followed by high-dose chemotherapy with autologous stem-cell transplantation in patients who had a response). The primary outcome was event-free survival, and key secondary outcomes were response and overall survival. Here, we report the results of the prespecified overall survival analysis at 5 years after the first patient underwent randomization.

RESULTS

A total of 359 patients underwent randomization to receive axi-cel (180 patients) or standard care (179 patients). At a median follow-up of 47.2 months, death had been reported in 82 patients in the axi-cel group and in 95 patients in the standard-care group. The median overall survival was not reached in the axi-cel group and was 31.1 months in the standard-care group; the estimated 4-year overall survival was 54.6% and 46.0%, respectively (hazard ratio for death, 0.73; 95% confidence interval [CI], 0.54 to 0.98; P = 0.03 by stratified two-sided log-rank test). This increased survival with axi-cel was observed in the intention-to-treat population, which included 74% of patients with primary refractory disease and other high-risk features. The median investigator-assessed progression-free survival was 14.7 months in the axi-cel group and 3.7 months in the standard-care group, with estimated 4-year percentages of 41.8% and 24.4%, respectively (hazard ratio, 0.51; 95% CI, 0.38 to 0.67). No new treatment-related deaths had occurred since the primary analysis of event-free survival.

CONCLUSIONS

At a median follow-up of 47.2 months, axi-cel as second-line treatment for patients with early relapsed or refractory large B-cell lymphoma resulted in significantly longer overall survival than standard care. (Funded by Kite; ZUMA-7 ClinicalTrials.gov number, NCT03391466.).

Integrating CAR-T cell therapy into the management of DLBCL: what we are learning

INTRODUCTION

Chimeric Antigen Receptor ;(CAR) T cells therapies have become part of the standard of care for patients with relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL). The weakness of CAR-T therapies is that there are no comparative clinical trials, although many publications based on real-life data have confirmed the results obtained in pivotal studies. After several years of the commercialization of CAR-T, some points still need to be fully clarified. Healthcare professionals have questions about identifying patients who may benefit from therapy. There are aspects inherent in the accessibility of care related to improved relationships between CAR-T-delivering and referral centers.

AREAS COVERED

Open questions are inherent in the salvage and bridge therapy, predictive criteria for response and persistence of CAR-T after infusion. Managing toxicities remain a top priority and one of the points on which further knowledge is needed.

EXPERT OPINION

This review aims to describe the current landscape of CAR-T cells in DLBCL, outline their outcomes and toxicities, and explain the outstanding questions that remain to be addressed.

Mechanisms of Resistance and Treatment of Relapse after CAR T-cell Therapy for Large B-cell Lymphoma and Multiple Myeloma

Although chimeric antigen receptor (CAR) T cell therapy (CAR-T) has altered the treatment landscape for relapsed/refractory B cell malignancies and multiple myeloma, only a minority of patients attain long-term disease remission. The underlying reasons for CAR-T resistance are multifaceted and can be broadly divided into host-related, tumor-intrinsic, microenvironmental and macroenvironmental, and CAR-T-related factors. Emerging host-related determinants of response to CAR-T relate to gut microbiome composition, intact hematopoietic function, body composition, and physical reserve. Emerging tumor-intrinsic resistance mechanisms include complex genomic alterations and mutations to immunomodulatory genes. Furthermore, the extent of systemic inflammation prior to CAR-T is a potent biomarker of response and reflects a proinflammatory tumor micromilieu characterized by infiltration of myeloid-derived suppressor cells and regulatory T cell populations. The tumor and its surrounding micromilieu also can shape the response of the host to CAR-T infusion and the subsequent expansion and persistence of CAR T cells, a prerequisite for efficient eradication of tumor cells. Here, focusing on both large B cell lymphoma and multiple myeloma, we review resistance mechanisms, explore therapeutic avenues to overcome resistance to CAR-T, and discuss the management of patients who relapse after CAR-T.

Cord blood-derived CD19-specific chimeric antigen receptor T cells: an off-the-shelf promising therapeutic option for treatment of diffuse large B-cell lymphoma

Purpose

Autologous chimeric antigen receptor (CAR) T cell therapy is one of the most significant breakthroughs in hematological malignancies. However, a three-week manufacturing cycle and ineffective T cell dysfunction in some patients hinder the widespread application of auto-CAR T cell therapy. Studies suggest that cord blood (CB), with its unique biological properties, could be an optimal source for CAR T cells, providing a product with 'off-the-shelf' availability. Therefore, exploring the potential of CB as an immunotherapeutic agent is essential for understanding and promoting the further use of CAR T cell therapy.

Experimental design

We used CB to generate CB-derived CD19-targeting CAR T (CB CD19-CAR T) cells. We assessed the anti-tumor capacity of CB CD19-CAR T cells to kill diffuse large B cell lymphoma (DLBCL) in vitro and in vivo.

Results

CB CD19-CAR T cells showed the target-specific killing of CD19+ T cell lymphoma cell line BV173 and CD19+ DLBCL cell line SUDHL-4, activated various effector functions, and inhibited tumor progression in a mouse (BALB/c nude) model. However, some exhaustion-associated genes were involved in off-tumor cytotoxicity towards activated lymphocytes. Gene expression profiles confirmed increased chemokines/chemokine receptors and exhaustion genes in CB CD19-CAR T cells upon tumor stimulation compared to CB T cells. They indicated inherent changes in the associated signaling pathways in the constructed CB CAR T cells and targeted tumor processes.

Conclusion

CB CD19-CAR T cells represent a promising therapeutic strategy for treating DLBCL. The unique biological properties and high availability of CB CD19-CAR T cells make this approach feasible.

A novel comorbidity score for older adults with non-Hodgkin lymphoma: the 3-factor risk estimate scale

For patients with non-Hodgkin lymphoma (NHL), formal comorbidity assessment is recommended but is rarely conducted in routine practice. A simple, validated measure of comorbidities that standardizes their assessment could improve adherence to guidelines. We previously constructed the 3-factor risk estimate scale (TRES) among patients with chronic lymphocytic leukemia (CLL). Here, we investigated TRES in multiple NHL subtypes. In the surveillance, epidemiology, and end results-Medicare database, patients with NHL diagnosed from 2008 to 2017 were included. Upper gastrointestinal, endocrine, and vascular comorbidities were identified using ICD-9/ICD-10 codes to assign TRES scores. Patient characteristic distributions were compared using χ2 or t test. Association of mortality and TRES score was assessed using Kaplan-Meier and multivariable Cox regression model for competing risk. A total of 40 486 patients were included in the study. Median age was 77 years (interquartile range [IQR], 71-83 years). The most frequent NHL subtypes were CLL (28.2%), diffuse large B-cell (27.6%), and follicular lymphoma (12.6%). Median follow-up was 33 months (IQR, 13-60 months). TRES was low, intermediate, and high in 40.8%, 37.0%, and 22.2% of patients, corresponding to median overall survival (OS) of 8.2, 5.3, and 2.9 years (P < .001), respectively. TRES was associated with OS in all NHL subtypes. In multivariable models, TRES was associated with inferior OS and NHL-specific survival. TRES is clinically translatable and associated with OS and lymphoma-specific survival in older adults with NHL.

Radiation for hematologic malignancies: from cell killing to immune cell priming

Over the past half-century, the role of radiotherapy has been revolutionized, in part, by a shift from intent to directly kill cancer cells to the goal of priming anti-tumor immune responses that attack both irradiated and non-irradiated tumors. Stimulation of anti-tumor immunity depends on the interplay between radiation, the tumor microenvironment, and the host immune system, which is a burgeoning concept in cancer immunology. While the interplay of radiotherapy and the immune system has been primarily studied in solid tumors, we are beginning to understand this interplay in hematological malignancies. The intent of this review is to lead readers through some of the important recent advances in immunotherapy and adoptive cell therapy, highlighting the best available evidence in support of incorporating radiation therapy and immunotherapy into the treatment of hematological malignancies. Evidence is presented regarding how radiation therapy 'converses' with the immune system to stimulate and enhance anti-tumor immune responses. This pro-immunogenic role of radiotherapy can be combined with monoclonal antibodies, cytokines and/or other immunostimulatory agents to enhance the regression of hematological malignancies. Furthermore, we will discuss how radiotherapy facilitates the effectiveness of cellular immunotherapies by acting as a "bridge" that facilitated CAR T cell engraftment and activity. These initial studies suggest radiotherapy may help catalyze a shift from using chemotherapy-intensive treatment to treatment that is "chemo-free" by combining with immunotherapy to target both the radiated and non-irradiated disease sites. This "journey" has opened the door for novel uses of radiotherapy in hematological malignancies due to its ability to prime anti-tumor immune responses which can augment immunotherapy and adoptive cell-based therapy.

CAR T-cell therapy in large B cell lymphoma

CD19-targeted chimeric antigen receptor (CAR) T-cells have revolutionized the treatment of lymphoid malignancies, including large B cell lymphoma (LBCL). Following seminal early phase multicenter clinical trials published between 2017 and 2020, three CD19-CAR T-cell products received FDA and EMA approval designations in lymphoma in the third-line setting, paving the way for follow-up studies in the second-line. Meanwhile, investigations into the applications of CAR T-cell therapy have further broadened to treating high-risk patients even prior to completion of first-line conventional chemo-immunotherapy. Furthermore, as early trials excluded patients with central nervous system involvement with lymphoma, several studies have recently shown promising efficacy of CD19-CAR T-cells in primary and secondary CNS lymphoma. Here we provide a detailed overview on clinical data supporting the use of CAR T-cells in patients with LBCL.

Five-year follow-up of ZUMA-1 supports the curative potential of axicabtagene ciloleucel in refractory large B-cell lymphoma

In phase 2 of ZUMA-1, a single-arm, multicenter, registrational trial, axicabtagene ciloleucel (axi-cel) autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy demonstrated durable responses at 2 years in patients with refractory large B-cell lymphoma (LBCL). Here, we assessed outcomes in ZUMA-1 after 5 years of follow-up. Eligible adults received lymphodepleting chemotherapy followed by axi-cel (2 × 106 cells per kg). Investigator-assessed response, survival, safety, and pharmacokinetics were assessed in patients who had received treatment. The objective response rate in these 101 patients was 83% (58% complete response rate); with a median follow-up of 63.1 months, responses were ongoing in 31% of patients at data cutoff. Median overall survival (OS) was 25.8 months, and the estimated 5-year OS rate was 42.6%. Disease-specific survival (excluding deaths unrelated to disease progression) estimated at 5 years was 51.0%. No new serious adverse events or deaths related to axi-cel were observed after additional follow-up. Peripheral blood B cells were detectable in all evaluable patients at 3 years with polyclonal B-cell recovery in 91% of patients. Ongoing responses at 60 months were associated with early CAR T-cell expansion. In conclusion, this 5-year follow-up analysis of ZUMA-1 demonstrates sustained overall and disease-specific survival, with no new safety signals in patients with refractory LBCL. Protracted B-cell aplasia was not required for durable responses. These findings support the curative potential of axi-cel in a subset of patients with aggressive B-cell lymphomas. This trial was registered at ClinicalTrials.gov, as #NCT02348216.

Interim FDG-PET/CT for Response Assessment of Lymphoma

The clinical use and prognostic value of interim FDG-PET/CT (iPET/CT), which is performed after treatment initiation but prior to its completion, varies by lymphoma subtype. Evidence supporting the prognostic value of iPET/CT is more robust for classical Hodgkin lymphoma (cHL), and in this lymphoma subtype, response-adapted treatment approaches guided by iPET/CT are a widely used standard of care for first-line therapy. The data supporting use of iPET/CT among patients with non-Hodgkin lymphoma (NHL) is less well-established, but failure to achieve complete metabolic response on iPET/CT is generally considered a poor prognostic factor with likely consequences for progression free survival. This review will present the available evidence supporting use of iPET/CT in lymphoma patients, particularly as it relates to prognostication and the ability to inform response-adapted treatment strategies. The latter will be addressed through a discussion on the major iPET-response adapted clinical trials with mention of ongoing trials. Special attention will be given to cHL and a few subtypes of NHL, including diffuse large B cell lymphoma (DLBCL), follicular lymphoma (FL), and peripheral T cell lymphoma (PTCL).

Long-term outcomes following CAR T cell therapy: what we know so far

Chimeric antigen receptors (CAR) are engineered fusion proteins designed to target T cells to antigens expressed on cancer cells. CAR T cells are now an established treatment for patients with relapsed and/or refractory B cell lymphomas, B cell acute lymphoblastic leukaemia and multiple myeloma. At the time of this writing, over a decade of follow-up data are available from the initial patients who received CD19-targeted CAR T cells for B cell malignancies. Data on the outcomes of patients who received B cell maturation antigen (BCMA)-targeted CAR T cells for multiple myeloma are more limited owing to the more recent development of these constructs. In this Review, we summarize long-term follow-up data on efficacy and toxicities from patients treated with CAR T cells targeting CD19 or BCMA. Overall, the data demonstrate that CD19-targeted CAR T cells can induce prolonged remissions in patients with B cell malignancies, often with minimal long-term toxicities, and are probably curative for a subset of patients. By contrast, remissions induced by BCMA-targeted CAR T cells are typically more short-lived but also generally have only limited long-term toxicities. We discuss factors associated with long-term remissions, including the depth of initial response, malignancy characteristics predictive of response, peak circulating CAR levels and the role of lymphodepleting chemotherapy. We also discuss ongoing investigational strategies designed to improve the length of remission following CAR T cell therapy.

Prognostic Value of 18F-FDG PET/CT in Diffuse Large B-Cell Lymphoma Treated with a Risk-Adapted Immunochemotherapy Regimen

Early identification of patients with diffuse large B-cell lymphoma (DLBCL) who are likely to experience disease recurrence or refractory disease after rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) would be useful for improving risk-adapted treatment strategies. We aimed to assess the prognostic value of 18F-FDG PET/CT parameters at baseline, interim, and end of treatment (EOT). Methods: We analyzed the prognostic impact of 18F-FDG PET/CT in 166 patients with DLBCL treated with a risk-adapted immunochemotherapy regimen. Scans were obtained at baseline, after 4 cycles of R-CHOP or 3 cycles of RR-CHOP (double dose of R) and 1 cycle of CHOP alone (interim) and 6 wk after completing therapy (EOT). Progression-free survival (PFS) and overall survival (OS) were estimated using Kaplan-Meier and the impact of clinical/PET factors assessed with Cox models. We also assessed the predictive ability of the recently proposed International Metabolic Prognostic Index (IMPI). Results: The median follow-up was 7.9 y. International Prognostic Index (IPI), baseline metabolic tumor volume (MTV), and change in maximum SUV (ΔSUVmax) at interim scans were statistically significant predictors for OS. Baseline MTV, interim ΔSUVmax, and EOT Deauville score were statistically significant predictors of PFS. Combining interim PET parameters demonstrated that patients with Deauville 4-5 and positive ΔSUVmax ≤ 70% at restaging (∼10% of the cohort) had extremely poor prognosis. The IMPI had limited discrimination and slightly overestimated the event rate in our cohort. Conclusion: Baseline MTV and interim ΔSUVmax predicted both PFS and OS with this sequential immunochemotherapy program. Combining interim Deauville score with interim ΔSUVmax may identify an extremely high-risk DLBCL population.

Prognostic value of the International Metabolic Prognostic Index for lymphoma patients receiving chimeric antigen receptor T-cell therapy

PURPOSE

Chimeric antigen receptor T-cell therapy (CART) prolongs survival for patients with relapsed/refractory B-cell non-Hodgkin's lymphoma. The recently introduced International Metabolic Prognostic Index (IMPI) was shown to improve prognostication in the first-line treatment of large B-cell lymphoma. Here, we investigate the prognostic value of the IMPI for progression-free (PFS) and overall survival (OS) in the setting of CD19 CART.

METHODS

Consecutively treated patients with baseline ¹⁸F-FDG PET/CT imaging and follow-up imaging at 30 days after CART were included. IMPI is composed of age, stage, and metabolic tumor volume (MTV) at baseline and was compared with the International Prognostic Index (IPI). Both indices were grouped into quartiles, as previously described for IPI. In addition, the continuous IMPI was subdivided into tertiaries for better separation of risk groups. Overall response rate (ORR), depth of response (DoR), and PFS were determined based on Lugano criteria. Proportional Cox regression analysis studied association of IMPI and IPI with PFS and OS.

RESULTS

Thirty-nine patients were included. The IPI was 1 in 23%, 2 in 21%, 3 in 26%, 4 in 21%, and 5 in 10% of the patients. IMPI^{low risk}, IMPI^{intermediate risk}, and IMPI^{high risk} patients had 30-day ORR of 69%, 62%, and 62% and 30-day DoR of - 67%, - 66%, and - 54% with a PFS of 187 days, 97 days, and 87 days, respectively. ORR and DoR showed no correlation with lower IMPI (r = 0.065, p = 0.697). Dividing patients into three risk groups showed a significant trend for PFS stratification (p = 0.030), while IPI did not (p = 0.133). Neither IPI nor IMPI yielded a significant association with OS after CART (both p > 0.05).

CONCLUSION

In the context of CART, the IMPI yielded prognostic value regarding PFS estimation. In contrast with IMPI in the first-line DLBCL setting, we did not observe a significant association of IMPI at baseline with OS after CART.

Late relapse after CAR-T cell therapy for adult patients with hematologic malignancies: a definite evidence from Systematic Review and Meta-Analysis on individual data

Chimeric Antigen Receptor (CAR)-modified T lymphocytes represent one of the most innovative and promising approaches to treating hematologic malignancies. CAR-T cell therapy is currently being used for the treatment of relapsed/refractory (r/r) B-cell malignancies including Acute Lymphoblastic Leukemia, Large B-Cell Lymphoma, Follicular Lymphoma, Multiple Myeloma and Mantle Cell Lymphoma. Despite the unprecedented clinical success, one of the major issues of the approved CAR-T cell therapy - tisagenlecleucel, axicabtagene, lisocabtagene, idecabtagene, ciltacabtagene and brexucabtagene - is the uncertainty about its persistence which in turn could lead to weak or no response to therapy with malignancy recurrence. Here we show that the prognosis of patients who do not respond to CAR-T cell therapy is still an unmet medical need. We performed a systematic review and meta-analysis collecting individual data on Duration of Response from at least 12-month follow-up studies. We found that the pooled prevalence of relapse within the first 12 months after CAR-T infusion was 61% (95% CI, 43%-78%); moreover, one year after the infusion, the analysis highlighted a pooled prevalence of relapse of 24% (95% CI, 11%-42%). Our results suggest that identifying potential predictive biomarkers of response to CAR-T therapy, especially for patients affected by the advanced stage of blood malignancies, could lead to stratification of the eligible population to that therapy, recognizing which patients will benefit and which will not, helping regulators to make decision in that way.

Genome-edited allogeneic donor "universal" chimeric antigen receptor T cells

αβ T cell receptor (TCRαβ) T cells modified to express chimeric antigen receptors (CAR), are now available as authorized therapies for certain B-cell malignancies. However the process of autologous harvest and generation of patient-specific products is costly, with complex logistics and infrastructure requirements. Premanufactured banks of allogeneic donor-derived CAR T cells could help widen applicability if the challenges of HLA-mismatched T-cell therapy can be addressed. Genome editing is being applied to overcome allogeneic barriers, most notably, by disrupting TCRαβ to prevent graft-versus-host disease, and multiple competing editing technologies, including CRISPR/Cas9 and base editing, have reached clinical phase testing. Improvements in accuracy and efficiency have unlocked applications for a wider range of blood malignancies, with multiplexed editing incorporated to target HLA molecules, shared antigens and checkpoint pathways. Clinical trials will help establish safety profiles and determine the durability of responses as well as the role of consolidation with allogeneic transplantation.

CAR immune cells: design principles, resistance and the next generation

The remarkable clinical activity of chimeric antigen receptor (CAR) therapies in B cell and plasma cell malignancies has validated the use of this therapeutic class for liquid cancers, but resistance and limited access remain as barriers to broader application. Here we review the immunobiology and design principles of current prototype CARs and present emerging platforms that are anticipated to drive future clinical advances. The field is witnessing a rapid expansion of next-generation CAR immune cell technologies designed to enhance efficacy, safety and access. Substantial progress has been made in augmenting immune cell fitness, activating endogenous immunity, arming cells to resist suppression via the tumour microenvironment and developing approaches to modulate antigen density thresholds. Increasingly sophisticated multispecific, logic-gated and regulatable CARs display the potential to overcome resistance and increase safety. Early signs of progress with stealth, virus-free and in vivo gene delivery platforms provide potential paths for reduced costs and increased access of cell therapies in the future. The continuing clinical success of CAR T cells in liquid cancers is driving the development of increasingly sophisticated immune cell therapies that are poised to translate to treatments for solid cancers and non-malignant diseases in the coming years.

Navigating the Evolving Treatment Landscape of Diffuse Large B-Cell Lymphoma

Diffuse large B-cell lymphoma, the most common subtype of non-Hodgkin lymphoma, comprises a heterogenous group of morphologically, genetically, and clinically distinct diseases. Several recent advances have affected the treatment landscape, which had been mostly stagnant for the past few decades. We will review the practice-changing studies in frontline (POLARIX), early relapse (ZUMA-7 and TRANSFORM), and multiple recurrent (ZUMA-1, JULIET, TRANSCEND, L-MIND, and LOTIS-2) stages and discuss how the treatment landscape may evolve with the emergence of bispecific antibodies.

CARs and Drugs: Pharmacological Ways of Boosting CAR-T-Cell Therapy

The development of chimeric antigen receptor T cells (CAR-T cells) has marked a new era in cancer immunotherapy. Based on a multitude of durable complete remissions in patients with hematological malignancies, FDA and EMA approval was issued to several CAR products targeting lymphoid leukemias and lymphomas. Nevertheless, about 50% of patients treated with these approved CAR products experience relapse or refractory disease necessitating salvage strategies. Moreover, in the vast majority of patients suffering from solid tumors, CAR-T-cell infusions could not induce durable complete remissions so far. Crucial obstacles to CAR-T-cell therapy resulting in a priori CAR-T-cell refractory disease or relapse after initially successful CAR-T-cell therapy encompass antigen shutdown and CAR-T-cell dysfunctionality. Antigen shutdown predominately rationalizes disease relapse in hematological malignancies, and CAR-T-cell dysfunctionality is characterized by insufficient CAR-T-cell proliferation and cytotoxicity frequently observed in patients with solid tumors. Thus, strategies to surmount those obstacles are being developed with high urgency. In this review, we want to highlight different approaches to combine CAR-T cells with drugs, such as small molecules and antibodies, to pharmacologically boost CAR-T-cell therapy. In particular, we discuss how certain drugs may help to counteract antigen shutdown and CAR-T-cell dysfunctionality in both hematological malignancies and solid tumors.

Molecular and therapeutic effect of CRISPR in treating cancer

Cancer has become one of the common causes of mortality around the globe due to mutations in the genome which allows rapid growth of cells uncontrollably without repairing DNA errors. Cancers could arise due alterations in DNA repair mechanisms (errors in mismatch repair genes), activation of oncogenes and inactivation of tumor suppressor genes. Each cancer type is different and each individual has a unique genetic change which leads them to cancer. Studying genetic and epigenetic alterations in the genome leads to understanding the underlying features. CAR T therapy over other immunotherapies such as monoclonal antibodies, immune checkpoint inhibitors, cancer vaccines and adoptive cell therapies has been widely used to treat cancer in recent days and gene editing has now become one of the promising treatments for many genetic diseases. This tool allows scientists to change the genome by adding, removing or altering genetic material of an organism. Due to advance in genetics and novel molecular techniques such as CRISPR, TALEN these genes can be edited in such a way that their original function could be replaced which in turn improved the treatment possibilities and can be used against malignancies and even cure cancer in future along with CAR T cell therapy due to the specific recognition and attacking of tumor.

A prognostic model based on gene expression parameters predicts a better response to bortezomib-containing immunochemotherapy in diffuse large B-cell lymphoma

Diffuse Large B-cell Lymphoma (DLBCL) is the most common type of aggressive lymphoma. Approximately 60% of fit patients achieve curation with immunochemotherapy, but the remaining patients relapse or have refractory disease, which predicts a short survival. Traditionally, risk stratification in DLBCL has been based on scores that combine clinical variables. Other methodologies have been developed based on the identification of novel molecular features, such as mutational profiles and gene expression signatures. Recently, we developed the LymForest-25 profile, which provides a personalized survival risk prediction based on the integration of transcriptomic and clinical features using an artificial intelligence system. In the present report, we studied the relationship between the molecular variables included in LymForest-25 in the context of the data released by the REMoDL-B trial, which evaluated the addition of bortezomib to the standard treatment (R-CHOP) in the upfront setting of DLBCL. For this, we retrained the machine learning model of survival on the group of patients treated with R-CHOP (N=469) and then made survival predictions for those patients treated with bortezomib plus R-CHOP (N=459). According to these results, the RB-CHOP scheme achieved a 30% reduction in the risk of progression or death for the 50% of DLBCL patients at higher molecular risk (p-value 0.03), potentially expanding the effectiveness of this treatment to a wider patient population as compared with other previously defined risk groups.

Drug-Resistance Mechanism and New Targeted Drugs and Treatments of Relapse and Refractory DLBCL

Diffuse large B-cell lymphoma (DLBCL) is the most common aggressive non-Hodgkin's lymphoma (NHL). 30 ~ 40% of DLBCL patients were resistant to the standard R-CHOP regimen or recurrence after remission. It is currently believed that drug resistance is the main cause of the recurrence and refractory of DLBCL (R/R DLBCL). With the increased understanding of DLBCL biology, tumor microenvironment and epigenetics, some new therapies and drugs like molecular and signal pathway target therapy, chimeric antigen receptor (CAR) T-cell therapy, immune checkpoint inhibitors, antibody drug-conjugate and tafasitamab have been used for R/R DLBCL. This article will review the drug resistance mechanism and novel targeted drugs and therapies of DLBCL.

Immune-based therapies in diffuse large B-cell lymphoma

INTRODUCTION

Diffuse large B-cell lymphoma (DLBCL) is an aggressive and clinically heterogeneous malignancy originating from B-cells with up to 40% of patients experiencing primary refractory disease or relapse after first-line treatment. However, the past 5 years have seen a flurry of new drug approvals for DLBCL anchored upon new immune therapies, including chimeric antigen receptor (CAR) T-cells and antibody-based therapies.

AREAS COVERED

This article summarizes recent advances in the treatment of DLBCL, including in the first line and relapsed and refractory setting (second-line and beyond). A literature search was conducted for publications relevant to the immunotherapeutic approach to DLBCL from 2000 through March 2023 within PubMed and articles were reviewed. The search terms were immunotherapy, monoclonal antibodies, chimeric antigen receptor modified T-cell (CAR-T), and classification of DLBCL. Relevant clinical trials and pre-clinical studies exploring the strengths and weaknesses of current immune therapies against DLBCL were chosen. We additionally explored how intrinsic differences amongst DLBCL subtype biology and endogenous host immune recruitment contribute to variable therapeutic efficacy.

EXPERT OPINION

Future treatments will minimize chemotherapy exposure and be chosen by underlying tumor biology, paving the way for the promise of chemotherapeutic free regimens and improved outcomes for poor-risk subgroups.

Outcomes of first therapy after CD19-CAR-T treatment failure in large B-cell lymphoma

Persistence or recurrence of large B-cell lymphoma after CD19-CAR-T is common, yet data guiding management are limited. We describe outcomes and features following CAR-T treatment failure. Of 305 adults who received CD19-CAR-T, 182 experienced disease recurrence or progression (1-year cumulative incidence 63% [95%CI: 57-69]). Of 52 post-CAR-T biopsies evaluated by flow cytometry, 49 (94%) expressed CD19. Subsequent anti-cancer treatment was administered in 135/182 (74%) patients with CAR-T treatment failure. Median OS from the first post-CAR-T treatment was 8 months (95%CI 5.6-11.0). Polatuzumab-, standard chemotherapy-, and lenalidomide-based treatments were the most common approaches after CAR-T. No complete responses (CRs) were observed with conventional chemotherapy, while CR rates exceeding 30% were seen following polatuzumab- or lenalidomide-based therapies. Factors associated with poor OS among patients treated post-CAR-T were pre-CAR-T bulky disease (HR 2.27 [1.10-4.72]), lack of response to CAR-T (2.33 [1.02-5.29]), age >65 years (HR 2.65 [1.49-4.73]) and elevated LDH at post-CAR-T treatment (HR 2.95 [1.61-5.38]). The presence of ≥2 of these factors was associated with inferior OS compared to ≤1 (56% vs. 19%). In this largest analysis to date of patients who progressed or relapsed after CD19-CAR-T, survival is poor, though novel agents such as polatuzumab and lenalidomide may have hold promise.

Impact of Precision Medicine in Oncology: Immuno-oncology

ABSTRACT

Cancer treatment has dramatically changed over the last decade with the development of immunotherapy. Therapies including immune cytokines, immune checkpoint inhibition, intratumoral therapies, and cellular therapies are already widely used in the oncology clinic. Active development continues in these areas and in the development of vaccines, bispecific therapies, and more refined cellular therapies. In this review, we will examine the role that immune therapy has in cancer treatment and explore areas of future development.

Safety and Efficacy of Humanized Versus Murinized CD19 and CD22 CAR T-Cell Cocktail Therapy for Refractory/Relapsed B-Cell Lymphoma

CD19 chimeric antigen receptor T-cell (CAR-T) therapy is efficacious for refractory/relapsed (R/R) B-cell hematological malignancies, yet relapse due to CD19 antigen escape remains a challenge. Our trial explored simultaneous targeting of multiple B-cell antigens as a therapeutic approach that may reduce the risk of relapse. We tested the safety and efficacy of CAR19/22 T-cell cocktail therapy including murinized and humanized products among patients with R/R aggressive B-cell lymphoma. In the group that received the humanized product, 11/12 (91.7%) patients achieved an objective response, including 9/12 (75%) complete responses (CRs) by day 28. The overall response rate and CR rate in the murinized group was 92.9% (13/14) and 42.9% (6/14), respectively. Nine of 12 (75%) patients in the humanized group maintained CR at month 3 following infusion, compared to 5/14 patients (35.7%) in the murinized group. Progression-free survival (PFS) was more favorable in the humanized compared to the murinized group. Most patients had mild cytokine release syndrome (CRS) (grade 1-2) in both groups. This study demonstrates that CAR19/22 T-cell cocktail therapy is safe and effective for R/R B-cell lymphoma and that patients treated with a humanized CAR-T exhibited better efficacy compared to patients treated with a murinized CAR-T therapy.

Diffuse Large B-Cell Lymphoma (DLBCL): Early Patient Management and Emerging Treatment Options

Diffuse large B-cell lymphoma (DLBCL) represents a curable disease with a 60-70% chance of cure with current R-CHOP chemoimmunotherapy. However, 30-40% of patients are refractory or relapsing. Many attempts failed to improve the outcome of DLBCL patients, including the intensification of R-CHOP regimen, consolidation, or maintenance therapy since the introduction of R-CHOP in 2000. Better understanding of both molecular biology of lymphoma cells and the tumor microenvironment raised the hope for future improvement of DLBCL patients' survival. Novel molecular findings have initiated clinical trials exploring targeted therapy based on driver genetic alterations with an intent to improve survival of high-risk subsets of patients. But the preliminary results remain ambiguous. The approach "agnostic" to specific molecular alterations of lymphoma cell includes antibody-drug conjugates (especially polatuzumab vedotin), immunotherapy comprising different antibodies with immunomodulatory effect (tafasitamab, lenalidomide), and T-cell engaging therapy (bispecific antibodies, early use of CAR T-cell). This approach could increase the cure rates and change the current therapeutic paradigm. However, better prognostic stratification, smarter designs of clinical trials, modification of endpoints including the use of ctDNA are needed. This review covers the complexity of DLBCL management.

The role of CAR-T cell therapy as second line in diffuse large B-cell lymphoma

For approximately three decades, autologous hematopoietic cell transplantation (auto-HCT) has been the standard of care for patients with relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL) after frontline therapy. This approach is limited due to the intensity of chemotherapy and the proportion of patients who relapse after auto-HCT. Since the approval of anti-CD19 chimeric antigen receptor T-cell (CAR-T) therapy and novel agents, the treatment paradigm for DLBCL has changed remarkably. Anti-CD19 CAR-T therapy was first approved for relapsed DLBCL after two or more previous lines of therapy with long-lasting responses, with over 50% of patients still alive at 5-year follow-up. Here, we discuss recent randomized phase 3 clinical trials using axicabtagene ciloleucel, tisagenlecleucel, and lisocabtagene maraleucel in the second-line therapy setting compared with the standard of care in transplant-eligible patients who have DLBCL R/R within 12 months of completing chemo-immunotherapy, potentially changing the treatment algorithm for DLBCL.

Radiation therapy prior to CAR T-cell therapy in lymphoma: impact on patient outcomes

INTRODUCTION

Anti-CD19 chimeric antigen receptor (CAR) T-cell therapy has revolutionized the treatment paradigm for patients with refractory or recurrent (R/R) diffuse large B-cell lymphomas (DLBCL). Nonetheless, most patients ultimately progress. The use of bridging or salvage radiotherapy (RT) in combination with CAR T-cell therapy has been proposed as potential strategies to improve patient outcomes, but consensus is currently lacking as to which, if either, approach is effective.

AREAS COVERED

We reviewed the immunologic and molecular mechanisms of resistance and the current retrospective data on patterns-of-failure, clinical risk factors, and treatment outcomes in patients undergoing CAR T-cell therapy, with and without bridging or salvage RT.

EXPERT OPINION

We believe that current basic and clinical evidence supports the use of comprehensive, ablative bridging irradiation (CABI), as opposed to low-dose bridging or salvage radiotherapy, as a promising strategy to improve CAR T-cell therapy outcomes in patients with R/R DLBCL. This potential benefit is likely greatest in patients with high tumor burden and/or localized disease, who are both at elevated risk of local recurrence and can often be safely and comprehensively treated with ablative radiation doses (EQD2 > 39 Gy). Hypothesis-driven clinical trials are needed prospectively assess the impact of radiation on outcomes in patients undergoing CAR T-cell therapy.

Cytopenias following anti-CD19 chimeric antigen receptor (CAR) T cell therapy: a systematic analysis for contributing factors

BACKGROUND

Cytopenia is one of the most common adverse events following the CAR-T cell infusion, affecting the quality of life and potentially leading to life-threatening bleeding and infection. This study aimed to systematically review the cytopenias following anti-CD19 CAR-T therapy and further analyse the contributing factors.

METHODS

Databases including PubMed, MEDLINE, Embase and Cochrane were systematically searched on 8 May 2022. A random-effect meta-analysis was used to estimate the incidence of cytopenia, and subgroup analyses were applied to explore heterogeneity.

RESULTS

A total of 68 studies involving 2950 patients were included in this study. The overall incidence of all grade anaemia, thrombocytopenia, neutropenia, leukopoenia, lymphocytopenia and febrile neutropenia was 65%, 55%, 78%, 62%, 70% and 27%, respectively, and the corresponding cytopenias of grade 3 or worse were 33%, 31%, 61%, 45%, 46%, and 21%, respectively. Subgroup analysis showed increased incidence of cytopenias in subgroups with lower median age, proportion of males (<65%) and proportion of bridging therapy (<80%) and in the subgroup with a median line of prior therapy ≥3. In terms of disease and therapeutic target, cytopenias were more frequent in ALL patients and in dual-target CAR-T therapies (targeting CD19 in combination with other targets). Furthermore, CAR-T products manufactured by lentiviral vectors and those with the costimulatory domain of CD28 were more likely to cause haematological toxicity. No significant differences were observed in cytopenia between patients treated with CAR-T products with murine and humanized scFv.

CONCLUSION

In conclusion, neutropenia is the most frequent cytopenia after CAR-T therapy, both in all grades or grade ≥3. The incidence of cytopenias following CAR-T therapy is influenced by the age, sex, disease and number of prior therapy lines of the patients, as well as the target and costimulatory domain of CAR-T cells, and viral vectors used for manufacturing.KEY MESSAGESNeutropenia is the most frequent cytopenia after CAR-T therapy.The clinical characteristics of the patients, the design of CAR-T cells and the protocol of CAR-T treatment can influence the occurrence of cytopenias following the CAR-T therapy.

Impact of Cytomegalovirus Replication in Patients with Aggressive B Cell Lymphoma Treated with Chimeric Antigen Receptor T Cell Therapy

Data are scarce on cytomegalovirus (CMV) replication in patients receiving CD19-directed chimeric antigen receptor (CAR) T cell treatment. Here we describe the incidence, severity, and management of CMV infection in patients with aggressive B cell lymphoma treated with CAR T cell therapy. In this retrospective observational study, we analyzed CMV viral load and its clinical impact in patients with aggressive B cell lymphoma receiving CAR T cell therapy between July 2018 and December 2021 at a single center. Patients with a negative baseline CMV IgG or a previous allogeneic stem cell transplantation were excluded. CMV replication was determined in whole blood. Overall, 105 patients met the study's inclusion criteria. Ten patients presented with CMV replication before CAR T cell infusion and were analyzed separately. Forty-two of the remaining 95 patients (44%) had at least 1 positive CMV determination, with a viral load ≥1000 IU/mL in 21 patients (22%). Four patients in the main cohort (N = 95) and 4 patients in the preinfusion replication group (N = 10) achieved a viral load >10,000 IU/mL. Only 7 patients received preemptive antiviral treatment. No CMV end-organ disease was reported. The sole independent risk factor associated with CMV viremia ≥1000 IU/mL was dexamethasone treatment (odds ratio, 8.4; 95% confidence interval, 2.4 to 36.6; P = .002). Based on our findings, we designed an algorithm for CMV management in this setting. CMV replication is relatively frequent in patients with aggressive B cell lymphoma receiving CAR T cell therapy. It is usually self-limited and not associated with end-organ disease. Patients receiving dexamethasone or harboring CMV replication before infusion might benefit from active surveillance and preemptive treatment strategies.

Current updates on generations, approvals, and clinical trials of CAR T-cell therapy

Chimeric antigen receptor (CAR) T-cell therapy is a novel, customized immunotherapy that is considered a 'living' and self-replicating drug to treat cancer, sometimes resulting in a complete cure. CAR T-cells are manufactured through genetic engineering of T-cells by equipping them with CARs to detect and target antigen-expressing cancer cells. CAR is designed to have an ectodomain extracellularly, a transmembrane domain spanning the cell membrane, and an endodomain intracellularly. Since its first discovery, the CAR structure has evolved greatly, from the first generation to the fifth generation, to offer new therapeutic alternatives for cancer patients. This treatment has achieved long-term and curative therapeutic efficacy in multiple blood malignancies that nowadays profoundly change the treatment landscape of lymphoma, leukemia, and multiple myeloma. But CART-cell therapy is associated with several hurdles, such as limited therapeutic efficacy, little effect on solid tumors, adverse effects, expensive cost, and feasibility issues, hindering its broader implications.

Barriers and Opportunities for CAR T-Cell Targeting of Solid Tumors

CAR T-cell therapy has transformed the treatment of hematological malignancies of the B cell lineage. However, the quest to fulfil the same promise for solid tumors is still in its infancy. This review summarizes some of the challenges that the field is trying to overcome for effective treatment of human carcinomas, including tumor heterogeneity, the paucity of truly tumor-specific targets, immunosuppression and metabolic restrictions at solid tumor beds, and defective T-cell trafficking. All these barriers are being currently investigated and, in some cases, targeted, by multiple independent groups. With clinical interventions against multiple human malignancies and different platforms under accelerated clinical development, the next few years will see an array of cellular therapies, including CAR T-cells, progressively becoming routine interventions to eliminate currently incurable diseases, as it happened with some hematological malignancies.