CD19 antibody-drug conjugate therapy in DLBCL does not preclude subsequent responses to CD19-directed CAR T-cell therapy

In relapsed or refractory diffuse large B-cell lymphoma, CD19 expression by immunohistochemistry alone is not a predictor of response to loncastuximab tesirine

CD19-targeting treatments have shown promise in relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL). Loncastuximab tesirine (loncastuximab tesirine-lpyl [Lonca]) is a CD19-targeting antibody-drug conjugate indicated for R/R DLBCL after at least two systemic treatments. CD19 expression was evaluated in patients receiving Lonca in the LOTIS-2 clinical trial with available tissue samples obtained after last systemic therapy/before Lonca treatment. Lonca cytotoxicity was evaluated in a panel of six lymphoma cell lines with various CD19 expression levels. Quantitative systems pharmacology (QSP) modelling was used to predict Lonca responses. Lonca responses were seen in patients across all CD19 expression levels, including patients with low/no detectable CD19 expression and H-scores at baseline. Similarly, Lonca induced cytotoxicity in cell lines with different levels of CD19 expression, including one with very low expression. QSP modelling predicted that CD19 expression by immunohistochemistry alone does not predict Lonca response, whereas inclusion of CD19 surface density improved response prediction. Virtual patients responded to Lonca with estimated CD19 as low as 1000 molecules/cell of CD19, normally below the immunohistochemistry detection level. We found Lonca is an effective treatment for R/R DLBCL regardless of CD19 expression by immunohistochemistry. These results provide the basis for future studies addressing CD19-targeted agent sequencing.

Efficacy of CD19 directed therapies in patients with relapsed or refractory large b-cell lymphoma relapsing after CD19 directed chimeric antigen receptor T-cell therapy

Outcomes are poor for patients with relapsed and/or refractory (R/R) large B-cell lymphoma (LBCL) post chimeric antigen receptor T-cell (CAR-T) therapy. Two CD19-directed therapies, tafasitamab- cxix plus lenalidomide (tafa-len) and loncastuximab tesirine (loncaT) are approved in R/R LBCL. The efficacy of these CD19 directed therapies in patients who relapse after CD19 directed CAR-T (CD19-CART) therapy is not well understood. We conducted a multi-center study of patients with R/R LBCL that received either tafa-len or loncaT at any timepoint for R/R disease after CD19-CART therapy. Fifty-three patients were included in this study with the median follow up of 56 (9.1-199) weeks from CAR-T infusion. Median number of systemic therapies pre-CAR-T therapy was 3 (range: 1-6); axicabtagene ciloleucel was the most utilized CAR-T product (n = 32,60%). Median time from CAR-T therapy to tafa-len or loncaT was 7.3 (1.2-38.2) months with median number of lines of therapy between CAR-T therapy and these regimens of 1 (0-5). Combined overall response rate and complete response rates were 27% and 10%, respectively. Median duration of response was 13.3 (2.1-56.7) weeks. In this real-world study, the use of currently approved CD19-directed therapies to treat R/R LBCL after CD19-CAR-T therapy showed limited clinical activity and duration of responses.

CD19 occupancy with tafasitamab increases therapeutic index of CART19 cell therapy and diminishes severity of CRS

ABSTRACT

In the development of various strategies of anti-CD19 immunotherapy for the treatment of B-cell malignancies, it remains unclear whether CD19 monoclonal antibody therapy impairs subsequent CD19-targeted chimeric antigen receptor T-cell (CART19) therapy. We evaluated the potential interference between the CD19-targeting monoclonal antibody tafasitamab and CART19 treatment in preclinical models. Concomitant treatment with tafasitamab and CART19 showed major CD19 binding competition, which led to CART19 functional impairment. However, when CD19+ cell lines were pretreated with tafasitamab overnight and the unbound antibody was subsequently removed from the culture, CART19 function was not affected. In preclinical in vivo models, tafasitamab pretreatment demonstrated reduced incidence and severity of cytokine release syndrome and exhibited superior antitumor effects and overall survival compared with CART19 alone. This was associated with transient CD19 occupancy with tafasitamab, which in turn resulted in the inhibition of CART19 overactivation, leading to diminished CAR T apoptosis and pyroptosis of tumor cells.

A paradox of choice: Sequencing therapy in relapsed/refractory diffuse large B-cell lymphoma

The available treatments for relapsed or refractory (R/R) diffuse large B-cell lymphoma (DLBCL) have experienced a dramatic change since 2017. Incremental advances in basic and translational science over several decades have led to innovations in immune-oncology. These innovations have culminated in eight separate approvals by the US Food and Drug Administration for the treatment of patients with R/R DLBCL over the last 10 years. High-dose therapy and autologous stem cell transplant (HDT-ASCT) remains the standard of care for transplant-eligible patients who relapse after an initial remission. For transplant-ineligible patients or for those who relapse following HDT-ASCT, multiple options exist. Monoclonal antibodies targeting CD19, antibody-drug conjugates, bispecific antibodies, immune effector cell products, and other agents with novel mechanisms of action are now available for patients with R/R DLBCL. There is increasing use of chimeric antigen receptor (CAR) T-cells as second-line therapy for patients with early relapse of DLBCL or those who are refractory to initial chemoimmunotherapy. The clinical benefits of these strategies vary and are influenced by patient and disease characteristics, as well as the type of prior therapy administered. Therefore, there are multiple clinical scenarios that clinicians might encounter when treating R/R DLBCL. An optimal sequence of drugs has not been established, and there is no evidence-based consensus on how to best order these agents. This abundance of choices introduces a paradox: proliferating treatment options are initially a boon to patients and providers, but as choices grow further they no longer liberate. Rather, more choices make the management of R/R DLBCL more challenging due to lack of direct comparisons among agents and a desire to maximize patient outcomes. Here, we provide a review of recently-approved second- and subsequent-line agents, summarize real-world data detailing the use of these medicines, and provide a framework for sequencing therapy in R/R DLBCL.

How to integrate CD19 specific chimeric antigen receptor T cells with other CD19 targeting agents in diffuse large B-cell lymphoma?

About one third of patients with diffuse large B-cell lymphoma (DLBCL) have a relapsing/refractory (R/R) disease after first line chemo-immunotherapy, with particularly poor outcomes observed in patients with primary refractory disease and early relapse. CD19 specific chimeric antigen receptor (CAR) T cell therapy is a game changer that results in durable and complete response rates in almost half of the patients with R/R DLBCL. Other emerging CD19-targeting therapies include monoclonal antibodies, bispecific antibodies and targeting antibody-drug conjugates, which also show encouraging results. However, the timing and sequencing of different anti-CD19-targeting agents and how they might interfere with subsequent CAR T cell treatment is still unclear. In this review, we summarize the results of the pivotal clinical trials as well as evidence from real-world series of the use of different CD19-targeting approved agents. We discuss the effect of various therapies on CD19 expression and its implications for treatment sequencing.

Chimeric Antigen Receptor T-Cell Therapy in Aggressive B-Cell Lymphoma

Chimeric antigen receptor (CAR) T-cell therapy is a revolutionary therapy increasingly used in the treatment of non-Hodgkin B-cell lymphoma. This review focuses on the use of CAR T-cell therapy in aggressive B-cell lymphoma including clinical indications, known short- and long-term toxicity, mechanisms of CAR T-cell efficacy and tumor resistance, and future directions in the treatment of aggressive lymphoma with CAR T-cell therapy.

Chimeric Antigen Receptor T-Cell Therapy for Hematologic Malignancies: A Practical Review

Chimeric antigen receptor T-cell (CAR-T) therapy has become an established therapeutic approach for the treatment of hematologic malignancies. The field continues to evolve rapidly and newer-generation constructs are being designed to enhance proliferative capacity, and achieve long-term persistence and greater efficacy with an overall lower incidence of toxicity. Initial clinical application of CAR-T therapies has focused on relapsed and/or refractory hematologic malignancies, and Food and Drug Administration-approved CAR-T products targeting CD19 are available for B-cell acute lymphoblastic leukemia and low- and high-grade B-cell non-Hodgkin lymphoma, and targeting B-cell maturation antigen are available for multiple myeloma. Cytokine release syndrome and immune effector cell-associated neurotoxicity syndrome have been recognized as class specific toxicities associated with these novel therapies. In this review, we focus on the clinical application of CAR-T therapies in adult patients with hematologic malignancies, including access issues, outpatient administration, and appropriate timing for referring a patient to a CAR-T treatment center.

Targeted Treatment of Adults with Relapsed or Refractory Diffuse Large B-Cell Lymphoma (DLBCL): Tafasitamab in Context

The outcomes of Relapsed/Refractory (R/R) Diffuse Large B-cell lymphoma have been historically poor. The recent development of several novel therapies including CD19 directed agents has improved the prognosis of this disease significantly. Chimeric antigen receptor (CAR) T-cell therapy has drastically changed the treatment of R/R DLBCL, but it is still associated with significant barriers and limited access. Tafasitamab (an anti-CD19 engineered monoclonal antibody), in addition to lenalidomide, has shown significant efficacy with exceptionally durable responses in patients with R/R DLBCL who are ineligible for autologous stem cell transplantation (ASCT). Tafasitamab-lenalidomide and certain other therapies (ie, antibody-drug conjugates and bispecific antibodies) are important treatment options for patients who are ineligible for CAR-T due to co-morbidities or lack of access, and patients with rapid progression of disease who are unable to wait for manufacturing of CAR-T. This review will thus discuss currently approved and recently studied targeted treatment options for patients with R/R DLBCL with an emphasis on CAR-T alternative options, particularly Tafasitamab-lenalidomide.

Clinical Treatment Guidelines for Tafasitamab Plus Lenalidomide in Patients with Relapsed or Refractory Diffuse Large B-Cell Lymphoma

Diffuse large B-cell lymphoma (DLBCL) accounts for approximately 24% of new cases of B-cell non-Hodgkin lymphoma in the US each year. Up to 50% of patients relapse or are refractory (R/R) to the standard first-line treatment option, R-CHOP. The anti-CD19 monoclonal antibody tafasitamab, in combination with lenalidomide (LEN), is an NCCN preferred regimen for transplant-ineligible patients with R/R DLBCL and received accelerated approval in the US (July 2020) and conditional marketing authorization in Europe (August 2021) and other countries, based on data from the L-MIND study. The recommended dose of tafasitamab is 12 mg/kg by intravenous infusion, administered in combination with LEN 25 mg for 12 cycles, followed by tafasitamab monotherapy until disease progression or unacceptable toxicity. Tafasitamab + LEN is associated with durable responses in patients with R/R DLBCL. The majority of clinically significant treatment-associated adverse events are attributable to LEN and can be managed with dose modification and supportive therapy. We provide guidelines for the management of patients with R/R DLBCL treated with tafasitamab and LEN in routine clinical practice, including elderly patients and those with renal and hepatic impairment, and advice regarding patient education as part of a comprehensive patient engagement plan. Our recommendations include LEN administration at a reduced dose if required in patients unable to tolerate the recommended dose. No dose modification is required for tafasitamab in special patient populations.

How I treat refractory/relapsed diffuse large B-cell lymphomas with CD19-directed chimeric antigen receptor T cells

Chimeric antigen receptor (CAR) T cells targeting CD19 represent a promising salvage immunotherapy for relapsed/refractory diffuse large B-cell lymphoma (R/R DLBCL), offering ~40% of long-term responses. In everyday clinical practice, haematologists involved in CAR T cell treatment of patients with R/R DLBCL have to deal with diagnostically complex cases and difficult therapeutic choices. The availability of novel immunotherapeutic agents for R/R DLBCL and recent advances in understanding CAR T-cell failure mechanisms demand a rational approach to identify the best choice for bridging therapy and managing post-CAR T-cell therapy relapses. Moreover, positron emission tomography/computerised tomography may result in false-positive interpretation, highlighting the importance of post-treatment biopsy. In this review, we discuss all above issues, presenting four instructive cases, with the aim to provide criteria and new perspectives for CAR T-cell treatment of DLBCL.

Treatment approaches for nodular lymphocyte-predominant Hodgkin lymphoma

Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is a rare variant of Hodgkin lymphoma characterized by a persistent risk of relapse but an excellent overall survival. Historically, it was treated similarly to classic Hodgkin lymphoma, but efforts have been made to deintensify treatment due to risk of late toxicity associated with intensive therapy. For patients with completely resected stage IA NLPHL, no further treatment may be considered, particularly for pediatric patients. For those with stage I-II NLPHL without risk factors such as B symptoms, sites>2, or variant pattern histology, lower intensity treatment with radiotherapy or chemotherapy alone may be sufficient. However, combined modality therapy is a standard treatment for favorable and unfavorable risk stage I-II NLPHL associated with excellent progression-free and overall survival rates. For patients with advanced stage NLPHL, the optimal chemotherapy is not defined, but R-CHOP appears to be an effective treatment. Efforts to study NLPHL through multicenter collaborative efforts are crucial to develop evidence based and individualized treatments for patients with NLPHL.

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.

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.

Targeting CD19 for diffuse large B cell lymphoma in the era of CARs: Other modes of transportation

CD19 is nearly ubiquitously expressed on B-lymphocytes and in B-cell malignancies. Although CD19-directed CAR T cells have greatly improved outcomes in B-cell malignancies, there are significant limitations with this therapy. CD19 can also be effectively targeted by other drug classes, such as monoclonal antibodies, antibody-drug conjugates, and bispecific T cell engagers or antibodies. However, the optimal patient selection and sequencing of these novel therapies has not yet been established. In this review, we discuss the utilization of CD19 as a target for the treatment of DLBCL, focusing on tafasitamab, loncastuximab tesirine, and blinatumomab. We provide a comprehensive review of the pivotal clinical trials, discussing the strength and limitations of the data for each agent. We explore the emerging evidence that CD19 expression is retained following exposure to these agents and that patients can be successfully re-challenged with anti-CD19 therapies of a different drug class upon disease relapse post-CAR T cells. Finally, we discuss how these drugs potentially fit into the most current treatment paradigm for DLBCL.

Targeting CD19 in diffuse large B-cell lymphoma: An expert opinion paper

The ubiquitous, early-stage expression, efficient internalization, limited off-target effects, and high disease specificity of CD19 make it an attractive therapeutic target. Currently available anti-CD19 therapies have demonstrated particular promise in patients with relapsed or refractory B-cell non-Hodgkin lymphoma. Selection of the most appropriate treatment strategy should be based on individual patient characteristics and the goal of therapy. However, evidence and knowledge about the sequencing of anti-CD19 therapies are limited. Here, we review the current evidence for CD19 as a target in diffuse large B-cell lymphoma and consider approaches to the use of anti-CD19 therapy.

The antibody-drug conjugate loncastuximab tesirine for the treatment of diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is a heterogenous subtype of non-Hodgkin lymphoma. Relapsed/refractory disease represents remains an unmet medical need, despite the introduction of novel cellular and targeted therapies. Loncastuximab tesirine is a cluster of differentiation19-targeting antibody-drug conjugate approved by the US Food and Drug Administration for relapsed DLBCL after 2 lines of systemic therapy based on a trial showing a 48.3% overall response rate. The spectrum of its clinical applications is expanding and is now being tested in other B-cell malignancies.

The AntiCD19 Antibody Drug Immunoconjugate Loncastuximab Achieves Responses in DLBCL Relapsing After AntiCD19 CAR-T Cell Therapy

INTRODUCTION

Chimeric antigen receptor T (CAR-T) cells targeting CD19 result in durable responses in approximately 40% of DLBCL patients. Loncastuximab tesirine, an antibody drug conjugate targeting CD19 with a pyrrolobenzodiazepine payload, has activity against DLBCL.

PATIENTS AND METHODS

We evaluated the outcomes of 13 DLBCL patients relapsed after CAR-T cells treated with loncastuximab in the LOTIS-2 trial.

RESULTS

Six patients (46%) had responses to loncastuximab (CR, n = 2). Median OS, PFS and duration of response after loncastuximab were 8.2, 1.4 and 8 months, respectively.

CONCLUSION

Loncastuximab can achieve responses in patients progressing after CAR-T cells. Sequencing CD19-targeting therapies is possible in cases without CD19 loss.

Monoclonal Antibodies in the Treatment of Diffuse Large B-Cell Lymphoma: Moving beyond Rituximab

Although rituximab has revolutionized the treatment of diffuse large B-cell lymphoma (DLBCL), a significant proportion of patients experience refractory disease or relapse early after the end of treatment. The lack of effective treatment options in the relapsed/refractory (R/R) setting had made the prognosis of these patients dismal. The initial enthusiasm for novel anti-CD20 antibodies had been short-lived as they failed to prove their superiority to rituximab. Therefore, research has focused on developing novel agents with a unique mechanism of action. Among them, two antibody-drug conjugates, namely polatuzumab vedotin (PolaV) and loncastuximab tesirine, along with tafasitamab, an anti-CD19 bioengineered antibody, have been approved for the treatment of R/R DLBCL. Whereas PolaV has been FDA and EMA approved, EMA has not approved loncastuximab tesirine and tafasitamab yet. Results from randomized trials, as well as real-life data for PolaV have been promising. Novel agents as bispecific antibodies bridging CD3 on T-cells to CD20 have shown very promising results in clinical trials and are expected to gain approval for treatment of R/R DLBCL soon. As the therapeutic armamentarium against DLBCL is expanding, an improvement in survival of patients with R/R and higher cure rates might soon become evident.

Loncastuximab tesirine in relapsed or refractory diffuse large B-cell lymphoma: a review of clinical data

Loncastuximab tesirine-lpyl (ADC Therapeutics) is an anti-CD19 antibody-drug conjugate which consists of anti-CD19 antibody and cytotoxic alkylating agent, SG3199. Data from preclinical in vitro and animal studies demonstrated its selectivity and efficacy. The phase I LOTIS-1 study for relapsed, refractory B-cell non-Hodgkin lymphoma (NHL) demonstrated efficacy and a tolerable safety profile, with major adverse effects being neutropenia, thrombocytopenia, elevated liver enzymes, and fluid accumulation. Based on pharmacokinetics analysis in this study, a dose of 150 μg/kg every 3 weeks for cycles 1 and 2 followed by 75 μg/kg every 3 weeks until disease progression or intolerability was chosen for the phase II LOTIS-2 study. This study recruited relapsed, refractory diffuse large B-cell lymphoma and confirmed similar safety profile. Overall response rate was 48.6% (24.1% complete response), and overall survival was 9.9 months. Due to its safety and efficacy reported in the above trials, loncastuximab tesirine was recently approved by the US Food and Drug Administration for the treatment of relapsed, refractory diffuse large B-cell lymphoma. Several clinical trials are ongoing to assess its safety and efficacy in NHL in various clinical settings.

Preparing for CAR T cell therapy: patient selection, bridging therapies and lymphodepletion

Chimeric antigen receptor (CAR) T cells have emerged as a potent therapeutic approach for patients with certain haematological cancers, with multiple CAR T cell products currently approved by the FDA for those with relapsed and/or refractory B cell malignancies. However, in order to derive the desired level of effectiveness, patients need to successfully receive the CAR T cell infusion in a timely fashion. This process entails apheresis of the patient's T cells, followed by CAR T cell manufacture. While awaiting infusion at an authorized treatment centre, patients may receive interim disease-directed therapy. Most patients will also receive a course of pre-CAR T cell lymphodepletion, which has emerged as an important factor in enabling durable responses. The time between apheresis and CAR T cell infusion is often not a simple journey, with each milestone being a critical step that can have important downstream consequences for the ability to receive the infusion and the strength of clinical responses. In this Review, we provide a summary of the many considerations for preparing patients with B cell non-Hodgkin lymphoma or acute lymphoblastic leukaemia for CAR T cell therapy, and outline current limitations and areas for future research.

CD19-Targeted Immunotherapies for Diffuse Large B-Cell Lymphoma

Surgical resection, chemotherapy and radiotherapy were, for many years, the only available cancer treatments. Recently, the use of immune checkpoint inhibitors and adoptive cell therapies has emerged as promising alternative. These cancer immunotherapies are aimed to support or harness the patient's immune system to recognize and destroy cancer cells. Preclinical and clinical studies, based on the use of T cells and more recently NK cells genetically modified with chimeric antigen receptors retargeting the adoptive cell therapy towards tumor cells, have already shown remarkable results. In this review, we outline the latest highlights and progress in immunotherapies for the treatment of Diffuse Large B-cell Lymphoma (DLBCL) patients, focusing on CD19-targeted immunotherapies. We also discuss current clinical trials and opportunities of using immunotherapies to treat DLBCL patients.

Management of relapsed or refractory large B-cell lymphoma in patients ineligible for CAR-T cell therapy

INTRODUCTION

Chimeric antigen receptor T (CAR-T) therapy has revolutionized the treatment of relapsed/refractory large B-cell lymphoma (LBCL). However, patients who are excluded or have no access to CAR-T represent a challenge for clinicians and have generally a dismal outcome. The landscape for this category of patients is constantly evolving: new agents have been approved in the last 2-3 years, alone or in combination, and novel treatment modalities are under investigations.

AREAS COVERED

Thereafter, we reviewed the currently available therapeutic strategies: conventional chemotherapy, Antibody-drug conjugate ADC (mainly polatuzumab and loncastuxumab), bispecific antibodies (CD19/CD3 and focus on novel CD20/CD3 Abs), immunomodulatory drugs (covering tafasitamab and lenalidomide, checkpoint inhibitors mainly in PMBL), small molecules (selinexor, BTK and PI3K inhibitors), and the role of radiotherapy.

EXPERT OPINION

Navigating this scenario, will uncover new challenges, including identifying an ideal sequence for these therapies, the most effective combinations, and search for consistent predictive factors to help selecting the appropriate population of LBCL patients. At present, supporting clinical research for CAR-T ineligible patients, a new and challenging group, must remain a major focus that is complementary to advances in CAR T-cell therapy.

Novel biologic therapies in relapsed or refractory diffuse large B cell lymphoma: CAR-T is not the only answer

Patients with diffuse large B-cell lymphoma who have refractory or relapsed disease following first line treatment have a poor prognosis when treated with conventional therapies. Significant efforts have been made in recent years to bring a broad spectrum of novel targeted therapies, the most noteworthy of which is chimeric antigen receptor T-cell therapy (CAR-T). Not all patients are eligible for CAR-T given the relatively high risk of complications and limited availability. Here we discuss promising novel biologic therapies that have been introduced in the last few years and go over ongoing clinical trials in the field.

Relapsed/Refractory Diffuse Large B-Cell Lymphoma: A Look at the Approved and Emerging Therapies

Approximately 40% of patients with diffuse large B cell lymphoma (DLBCL) do not respond or develop relapsed disease after first-line chemoimmunotherapy. A minority of these patients can be cured with autologous hematopoietic stem cell transplantation (AHCT). Although chimeric antigen receptor (CAR) T cells have transformed the treatment paradigm of relapsed/refractory DLBCL, only 30–40% of patients achieve durable remissions. In addition, many patients with relapsed/refractory DLBCL are ineligible to receive treatment with CAR T cells due to comorbidities or logistical limitations. Since 2019, the following four non-CAR T-cell treatments have been approved in relapsed/refractory DLBCL: polatuzumab in combination with bendamustine and rituximab, selinexor, tafasitamab plus lenalidomide, and loncastuximab. In this article, I review the data behind these four approvals and discuss important considerations on their use in clinical practice. I also review emerging therapies that have shown promising early results in relapsed/refractory DLBCL including the bispecific antibodies, antibody–drug conjugates, Bruton tyrosine kinase inhibitors, BCL2 inhibitors, immune checkpoint inhibitors, and epigenetic modifiers.

Immunotherapy for Diffuse Large B-Cell Lymphoma: Current Landscape and Future Directions

Simple Summary

Immunotherapy has played a pivotal role in the management of relapsed DLBCL. Stem cell transplant and CAR T-cell therapy are curative treatment modalities for relapsed disease. Despite this, a subset of patients continues to progress, and their outcomes remain dismal. Newer therapeutic options to optimize outcomes as well as minimize toxicity are warranted.

Abstract

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous disease. B-cell receptor (BCR) pathway is essential for malignant B-cell growth, survival, and proliferation. Various immune cells, including T-cells and macrophages in the tumor microenvironment (TME) contribute to tumor cell survival and pathogenesis of chemo-resistance. The presence of many targets on the malignant B-cells and in the TME has led to emergence of novel therapeutic agents. Stem cell transplant is the oldest treatment modality leveraging immune system in DLBCL. Subsequently, CD20 targeting monoclonal antibody and chimeric antigen receptor (CAR) T-cell therapy changed the treatment landscape of DLBCL. Recently, multiple novel immunotherapeutic agents have been added in the armamentarium for the management of DLBCL, and many are under development. In this review article, we will review latest updates of immunotherapeutic agents in the management of DLBCL.

NCCN Guidelines® Insights: B-Cell Lymphomas, Version 5.2021

In the last decade, a better understanding of the molecular pathogenesis of B-cell non-Hodgkin lymphomas has resulted in the development of novel targeted therapies, such as small molecule inhibitors of select kinases in the B-cell receptor pathway, antibody-drug conjugates, and small molecules that target a variety of proteins (eg, CD-19, EZH2, and XPO-1-mediated nuclear export). Anti-CD19 CAR T-cell therapy, first approved for relapsed/refractory (R/R) diffuse large B-cell lymphoma, has also emerged as a novel treatment option for R/R follicular lymphoma and mantle cell lymphoma. These NCCN Guideline Insights highlight the new targeted therapy options included in the NCCN Guidelines for B-Cell Lymphomas for the treatment of R/R disease.

Evaluating efficacy and safety of loncastuximab tesirine injection for the treatment of adult patients with relapsed or refractory large B-cell lymphoma

INTRODUCTION

Relapsed or refractory diffuse large B cell lymphoma (DLBCL) has a poor prognosis. Several novel therapies have gained regulatory approval for treatment of DLBCL, however there is still a need for additional therapies to be added to the armamentarium. Loncastuximab tesirine-lpyl (ADC Therapeutics), an anti-CD19 antibody-drug conjugate (ADC), was recently approved for the treatment of relapsed, refractory diffuse large B-cell lymphoma (DLBCL).

AREAS COVERED

We review the design and pharmacologic characteristics of loncastuximab tesirine-lpyl, emphasizing on the significance of CD19 as an effective target as well as pyrrolobenzodiazepine (PBD) as an effective payload. We review the key findings of the phase 1 LOTIS-1 and Phase 2 LOTIS-2 trials of loncastuximab in DLBCL, including efficacy and toxicity profile.

EXPERT OPINION

Key findings in the early-phase trial support the efficacy of Loncastuximab in DLBCL, including in high-risk subgroups. The side effects have been tolerable even in elderly patients (≥75 years). Several ongoing clinical trials are currently evaluating the safety and efficacy of loncastuximab tesirine in a variety of NHL subtypes, as well as the study of combination strategies.

Loncastuximab tesirine for treatment of relapsed or refractory diffuse large B cell lymphoma

INTRODUCTION

Approximately, a third of patients with diffuse large B-cell lymphoma (DLBCL) have refractory or relapsed disease after initial treatment. Despite recent regulatory approval of several new agents, including CAR-T cell therapy, polatuzumab vedotin and tafasitamab, there is still a need for additional therapies that expand the therapeutic alternatives and improve outcomes for patients with DLBCL that progresses after first line therapy.

AREAS COVERED

Studies of recently approved agents for relapsed DLBCL are reviewed. The relevance of CD19 as an immunotherapeutic target. The pharmacologic composition of loncastuximab tesirine and its cytotoxic payload, a pyrrolobenzodiazepine dimer. Phase I and phase 2 data for loncastuximab tesirine in non-Hodgkin lymphoma, showing the safety profile of this drug and the emerging efficacy results in DLBCL.

EXPERT OPINION

Loncastuximab tesirine is an antiCD19 antibody drug conjugate with a novel cytotoxic payload. Early studies showed this drug is tolerable, with a safety profile that is different from other antibody drug conjugates approved for lymphoid malignancies. Efficacy data shows activity in different non-Hodgkin lymphoma entities, and a phase 2 study has been completed in DLBCL showing durable responses, including in high-risk subgroups. Loncastuximab tesirine will be an important addition to the treatment alternatives for DLBCL.

Interventions and outcomes of adult patients with B-ALL progressing after CD19 chimeric antigen receptor T-cell therapy

CD19-targeted chimeric antigen receptor (CAR) T-cell therapy has become a breakthrough treatment of patients with relapsed/refractory B-cell acute lymphoblastic leukemia (B-ALL). However, despite the high initial response rate, the majority of adult patients with B-ALL progress after CD19 CAR T-cell therapy. Data on the natural history, management, and outcome of adult B-ALL progressing after CD19 CAR T cells have not been described in detail. Herein, we report comprehensive data of 38 adult patients with B-ALL who progressed after CD19 CAR T therapy at our institution. The median time to progression after CAR T-cell therapy was 5.5 months. Median survival after post-CAR T progression was 7.5 months. A high disease burden at the time of CAR T-cell infusion was significantly associated with risk of post-CAR T progression. Thirty patients (79%) received salvage treatment of post-CAR T disease progression, and 13 patients (43%) achieved complete remission (CR), but remission duration was short. Notably, 7 (58.3%) of 12 patients achieved CR after blinatumomab and/or inotuzumab administered following post-CAR T failure. Multivariate analysis revealed that a longer remission duration from CAR T cells was associated with superior survival after progression following CAR T-cell therapy. In summary, overall prognosis of adult B-ALL patients progressing after CD19 CAR T cells was poor, although a subset of patients achieved sustained remissions to salvage treatments, including blinatumomab, inotuzumab, and reinfusion of CAR T cells. Novel therapeutic strategies are needed to reduce risk of progression after CAR T-cell therapy and improve outcomes of these patients.

Anti-CD19 CAR T-cell therapy remission despite prior anti-CD19 antibody Tafasitamab in relapsed/refractory DLBCL

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Disease progression following anti-CD19 monoclonal antibody Tafasitamab treatment should not preclude subsequent anti-CD19 CART-cell therapy.

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Previous studies have demonstrated sequential anti-CD19 to be effective.

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Larger studies among R/R DLBCL patients across anti-CD19 modalities are needed to guide sequencing of therapies following initial anti-CD19 therapy.

Tafasitamab (MOR208) is an Fc-enhanced, humanized, monoclonal antibody that targets CD19. The L-MIND (NCT02399085) trial, an open-label, single-arm, phase II study of Tafasitamab (TAFA) plus lenalidomide (LEN), reported progression-free survival of 16 months in R/R DLBCL patients ineligible for autologous stem cell transplantation. Despite recent advances in anti-CD19 therapy, no clinical evidence exists to direct the sequencing of CAR T cell therapy following relapse after prior anti-CD19 therapy. We present the first published case of TAFA/LEN treatment followed by CAR T therapy with sustained remission. Disease progression following treatment with Tafasitamab may not preclude patients from CAR T cell therapy.

The use of tafasitamab in diffuse large B-cell lymphoma

Patients who relapse or are refractory after first-line therapy for diffuse large B-cell lymphoma (DLBCL) frequently have poor prognoses, especially when they are not candidates for autologous stem cell transplant (ASCT). Tafasitamab is a humanized monoclonal anti-CD19 antibody that has recently been approved by the FDA in combination with lenalidomide for the treatment of relapsed/refractory (R/R) DLBCL in patients who are not eligible for ASCT. Tafasitamab has an Fc region which has been modified to have an increased affinity for Fcγ receptors, to potentiate antibody-dependent cellular cytotoxicity and antibody-dependent cell-mediated phagocytosis. Here, we review the development, mode of action and clinical data for tafasitamab in combination with lenalidomide in R/R DLBCL, and discuss the various ways in which this novel antibody could be utilized in the treatment sequence to improve clinical outcomes for patients with DLBCL.

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.

The evolving role of allogeneic haematopoietic cell transplantation in the era of chimaeric antigen receptor T-cell therapy

Chimaeric antigen receptor T-cell (CAR T) therapy has revolutionized the management of many haematological malignancies. It is associated with impressive disease responses in relapsed or refractory high-grade B-cell non-Hodgkin lymphoma (B-NHL) and acute lymphoblastic leukaemia (B-ALL) with durable remissions in a subset of patients. Historically, haematopoietic cell transplantation (HCT) has been the standard consolidation strategy for many of these patients who are now being treated with CAR T. Relapses are frequent after CD19 CAR T therapy in B-ALL and consolidation with allogeneic HCT (allo-HCT) may improve survival of patients with high-risk disease. There appears to be a clear difference in B-ALL outcomes between paediatric and adult patients, with the latter having a much higher risk of relapse after CAR T therapy. Late relapses are infrequent in patients with B-NHL and consolidation with allo-HCT may not be needed in patients who achieve a complete remission after CAR T therapy. Future registry-based and prospective studies will hopefully provide the needed data in the future to risk-stratify the recipients of CAR T therapy. Meanwhile, we provide guidance on patient selection and practical issues with performing allo-HCT after CAR T therapy.

Incorporating Novel Targeted and Immunotherapeutic Agents in Treatment of B-Cell Lymphomas

The introduction of novel targeted agents and immunotherapeutic modalities into the treatment of B-cell lymphomas has drastically shifted the treatment landscape. In diffuse large B-cell lymphoma, recent approvals of CAR T-cell therapy, the antibody-drug conjugate polatuzumab, and the anti-CD19 monoclonal antibody tafasitamab have provided efficacious options for patients with relapsed and refractory disease. These immunotherapies attempt to harness power from the patient's own immune system to eradicate lymphoma. In chronic lymphocytic leukemia, oral targeted kinase inhibitors such as ibrutinib and acalabrutinib (Bruton tyrosine kinase inhibitors) and venetoclax (BCL2 inhibitor) are now favored over chemoimmunotherapy for upfront treatment because of improved progression-free survival across all subgroups (including high-risk subgroups such as unmutated immunoglobulin variable heavy chain and chromosome 17p deletion). In indolent lymphomas, several PI3K inhibitors are approved for treatment of relapsed disease. However, uptake of these agents has been limited because of toxicity concerns. Combination of lenalidomide and rituximab has been a safe and effective immune modality for patients with refractory indolent lymphomas; it is currently being used as a backbone to bring other targeted agents such as tazemetostat (EZH2 inhibitor) into earlier lines of treatment. In this article, we will review novel commercially available agents in the treatment of relapsed/refractory diffuse large B-cell lymphoma, treatment-naïve chronic lymphocytic leukemia, and relapsed/refractory indolent lymphomas. We will evaluate clinical trials that led to their approval and will provide an outlook into the future novel agents currently under investigation in B-cell malignancies.