No free rides: management of toxicities of novel immunotherapies in ALL, including financial

Bispecific T cell engager-armed T cells targeting integrin ανβ6 exhibit enhanced T cell redirection and antitumor activity in cholangiocarcinoma

Advanced cholangiocarcinoma (CCA) presents a clinical challenge due to limited treatment options, necessitating exploration of innovative therapeutic approaches. Bispecific T cell engager (BTE)-armed T cell therapy shows promise in hematological and solid malignancies, offering potential advantages in safety over continuous BTE infusion. In this context, we developed a novel BTE, targeting CD3 on T cells and integrin αvβ6, an antigen elevated in various epithelial malignancies, on cancer cells. The novel BTE was generated by fusing an integrin αvβ6-binding peptide (A20) to an anti-CD3 (OKT3) single-chain variable fragment (scFv) through a G4S peptide linker (A20/αCD3 BTE). T cells were then armed with A20/αCD3 BTE (A20/αCD3-armed T cells) and assessed for antitumor activity. Our results highlight the specific binding of A20/αCD3 BTE to CD3 on T cells and integrin αvβ6 on target cells, effectively redirecting T cells towards these targets. After co-culture, A20/αCD3-armed T cells exhibited significantly heightened cytotoxicity against integrin αvβ6-expressing target cells compared to unarmed T cells in both KKU-213A cells and A375.β6 cells. Moreover, in a five-day co-culture, A20/αCD3-armed T cells demonstrated superior cytotoxicity against KKU-213A spheroids compared to unarmed T cells. Importantly, A20/αCD3-armed T cells exhibited an increased proportion of the effector memory T cell (Tem) subset, upregulation of T cell activation markers, enhanced T cell proliferation, and increased cytolytic molecule/cytokine production, when compared to unarmed T cells in an integrin αvβ6-dependent manner. These findings support the potential of A20/αCD3-armed T cells as a novel therapeutic approach for integrin αvβ6-expressing cancers.

All about blinatumomab: the bispecific T cell engager immunotherapy for B cell acute lymphoblastic leukemia

INTRODUCTION

B cell acute lymphoblastic leukemia-lymphoma (B-ALL) accounts for approximately 75% of ALL cases and is observed in children and adults. Recent advances in disease diagnosis, stratification and prognostication have led to a better characterization of different subgroups of ALL. Notwithstanding the significant improvement in the complete remission rate of B-ALL, patients with minimal residual disease (MRD) and relapsed/refractory (R/R) settings suffer from poor outcomes.

HYPOTHESIS

However, novel therapies, such as agents targeting tyrosine kinases or the CD20 molecule, combination therapies and improved supportive care, have changed the treatment landscape of B-ALL.

METHOD AND RESULTS

Meanwhile, blinatumomab has been FDA-approved for MRD-positive or R/R B-ALL patients. Blinatumomab is a bispecific T cell engager containing the CD3 and CD19 that recognize domains redirecting cytotoxic T cells to lyse B cells. Promising outcomes, including long-term overall survival and improved MRD-negative response rates, have been reported in patients who received this drug. Adding blinatumomab to new ALL regimens seems promising for achieving better outcomes in poor prognosis B-ALL patients. Nevertheless, the neurotoxicity and cytokine release syndrome are the two major adverse events following the blinatumomab therapy.

CONCLUSION

This review summarizes the function and effectiveness of blinatumomab in R/R and MRD positive B-ALL patients. Furthermore, blinatumomab's positive and negative aspects as a novel therapy for B-ALL patients have been briefly discussed.

Immune therapies of B-cell acute lymphoblastic leukaemia in children and adults

B-cell acute lymphoblastic leukaemia (B-cell ALL) is a common haematologic cancer in children and adults. About 10 percent of children and 50 percent of adults fail to achieve a histological complete remission or subsequently relapse despite current anti-leukaemia drug therapies and/or haematopoietic cell transplants. Several new immune therapies including monoclonal antibodies and chimeric antigen receptor (CAR)-T-cells are proved safe and effective in this setting. We review data on US Food and Drug Administration (FDA)-approved immune therapies for B-cell ALL in children and adults including blinatumomab, inotuzumab ozogamicin, tisagenlecleucel, and brexucabtagene autoleucel. We also summarize pharmaco-dynamics, pharmaco-kinetics, and pharmaco-economics of these interventions.

Immunotherapeutic potential of blinatumomab-secreting γ9δ2 T Cells

Previous studies have explored the use of engineered blinatumomab-secreting autologous αβ T cells for CD19-targeted cancer therapy. To create a more flexible allogeneic delivery system, we utilized γ9δ2 T cells rather than αβ T cells in a similar application. First, we showed that γ9δ2 T cells could serve as effector cells for blinatumomab, and these effector memory cells could survive for at least 7 days after infusion. The genetically modified blinatumomab-secreting γ9δ2 T cells induced significant cytotoxicity in CD19⁺ tumor cell lines and primary cells from chronic lymphocytic leukemia patients. Of note, blinatumomab-secreting γ9δ2 T cells might also exhibit dual-targeting of CD19 and isopentenyl pyrophosphate, a universal tumor-associated antigen. Furthermore, blinatumomab-secreting γ9δ2 T cells killed CD19-transfected adherent cells, suggesting that the γ9δ2 T cells might be effective for treating solid tumors with appropriate cancer antigens. Together, these results demonstrate the promise of blinatumomab-secreting γ9δ2 T cells as a cancer therapy.

Decentralized manufacturing of anti CD19 CAR-T cells using CliniMACS Prodigy®: real-world experience and cost analysis in India

Chimeric Antigen Receptor (CAR) T cell therapy is an accepted standard of care for relapsed/refractory B cell malignancies. However, the high cost of existing industry-driven centralized production makes this therapy unaffordable in low and middle-income countries. Decentralized or point of care manufacturing has the potential to overcome some of these challenges. Here we demonstrate a decentralized manufacturing process for anti-CD19-CAR-T cells using a fully automated closed system (Miltenyi CliniMACS Prodigy®) is feasible in a developing country setting. Validation run data, as part of a pre-clinical trial safety evaluation, demonstrates the successful and robust manufacturing of anti-CD19 CAR-T cells with T cell expansion of 25 to 47-fold. The median transduction efficiency was 48.8%, with a median viability of 98% and fulfillment of all standard release criteria assays for clinical application. Evaluation of production costs in an academic, not for profit setting in India provide a benchmark for low and middle-income pricing which could greatly increase access to this therapy. Based on our analysis, the cost per product would be approximately $35,107 US dollars. Our data highlights the safety, efficacy, and reproducibility of the process for use in planned future clinical trials.

Switching from salvage chemotherapy to immunotherapy in adult B-cell acute lymphoblastic leukemia

About one-half of adults with acute B-cell lymphoblastic leukemia (B-ALL) who do not achieve molecular complete remission or who subsequently relapse are not cured by current chemo- or targeted therapies. Previously, the sole therapeutic option for such persons was a hematopoietic stem cell transplant. Recently, several immune therapies including monoclonal antibodies, bispecific T-cell engagers (BiTEs), antibody-drug conjugates (ADCs), and chimeric antigen receptor T-cells (CARs) have been shown safe and effective in this setting. In this manuscript, we summarize data on US FDA-approved immune therapies of advanced adult B-ALL including rituximab, blinatumomab, inotuzumab ozogamicin, tisagenlecleucel and brexucabtagene autoleucel. We consider the results of clinical trials focusing on efficacy, safety, and quality of life (QoL). Real-world evidence is presented as well. We also briefly discuss pharmacodynamics, pharmacokinetics, and pharmacoeconomics followed by risk-benefit analyses. Lastly, we present future directions of immune therapies for advanced B-ALL in adults.

Practical aspects of chimeric antigen receptor T-cell administration: From commercial to point-of-care manufacturing

Chimeric antigen receptor T-cells targeting the CD19 antigen have achieved impressive results in patients with relapsed/refractory (R/R) B-cell malignancies, leading to their approval in the European Union and other jurisdictions. In Spain, the 100% academic anti-CD19 CART-cell product varnimcabtagene autoleucel (var-cel, ARI-0001 cells) has been extraordinarily approved under the Hospital Exemption clause for the treatment of patients older than 25 years of age with R/R acute lymphoblastic leukaemia. Var-cel has also been granted PRIority MEdicines designation by the European Medicines Agency for the same indication. In this review we reveal some practical aspects related to the preparation and administration of academic point-of-care CART-cell products, using var-cel as an example, and put them into the context of commercial products.

Direct CNS administration of rituximab and epratuzumab in a pediatric patient with relapsed refractory CNS B-cell acute lymphoblastic leukemia

Relapsed central nervous system (CNS) leukemia presents a therapeutic challenge to pediatric oncologists. Systemic monoclonal antibody therapy has shown recent promise in patients with relapsed acute lymphoblastic leukemia, however its effect on CNS disease in this population is not well established. We describe a case of multiply relapsed and refractory CNS leukemia in an adolescent patient who responded to the intra-CNS delivery of rituximab (anti-CD20) and epratuzumab (anti-CD22) therapy, demonstrating the practical use and potential efficacy of a novel route of monoclonal antibody administration in difficult-to-treat CNS leukemia.

A Case Report on Dysgraphia in a Patient Receiving Blinatumomab: Complex Characters Are Easy to Find in a Handwriting Test

Recent advances in chemotherapy have led to the emergence of new types of anticancer agents. With these advances, cases of side effects that have not been witnessed in the past have emerged. The systems of side effect evaluation and their grading have been based on the existing knowledge, such as the CTCAE (Common Terminology Standard for Adverse Events) for evaluating adverse drug reactions in cancer chemotherapy clinical trials. Therefore, new types of side effects may be overlooked or underestimated. Blinatumomab is a bispecific T-cell–engager (BiTE) antibody with specificity for CD19 on B cells and CD3 on T cells. Neurological events, such as neuropathy and encephalopathy, are serious side effects of BiTE antibodies. We encountered a case of a 62-year-old woman who experienced short-term memory impairment and dysgraphia after the first blinatumomab administration for Philadelphia chromosome negative (Ph−) B-cell acute lymphoblastic leukemia (ALL). The CTCAE does not include dysgraphia as a classifier for antibody therapies, such as blinatumomab, and immune effector cell-associated neurotoxicity syndrome, which is defined as a Chimeric antigen receptor T cell therapy-related toxicity; dysgraphia is included in the list of symptoms but is not graded. In this case, the severity of dysgraphia differed depending on the complexity of the letters examined. There is no report that the severity of dysgraphia depends on the letters’ complexity, and therefore, it may be overlooked when using simple letters. We have reported the characteristics of dysgraphia in this case and the differences observed when judging different letters.

Neurotoxicity Associated with Treatment of Acute Lymphoblastic Leukemia Chemotherapy and Immunotherapy

Immunotherapy is a milestone in the treatment of poor-prognosis pediatric acute lymphoblastic leukemia (ALL) and is expected to improve treatment outcomes and reduce doses of conventional chemotherapy without compromising the effectiveness of the therapy. However, both chemotherapy and immunotherapy cause side effects, including neurological ones. Acute neurological complications occur in 3.6–11% of children treated for ALL. The most neurotoxical chemotherapeutics are L-asparaginase (L-ASP), methotrexate (MTX), vincristine (VCR), and nelarabine (Ara-G). Neurotoxicity associated with methotrexate (MTX-NT) occurs in 3–7% of children treated for ALL and is characterized by seizures, stroke-like symptoms, speech disturbances, and encephalopathy. Recent studies indicate that specific polymorphisms in genes related to neurogenesis may have a predisposition to MTX toxicity. One of the most common complications associated with CAR T-cell therapy is immune effector cell-associated neurotoxicity syndrome (ICANS). Mechanisms of neurotoxicity in CAR T-cell therapy are still unknown and may be due to disruption of the blood–brain barrier and the effects of elevated cytokine levels on the central nervous system (CNS). In this review, we present an analysis of the current knowledge on the mechanisms of neurotoxicity of standard chemotherapy and the targeted therapy in children with ALL.

Clinical Development and Therapeutic Applications of Bispecific Antibodies for Hematologic Malignancies

Bispecific antibodies are composed of two monoclonal antibodies that engage T cells with tumor cell antigens and lead to tumor cell lysis. The most common types fall into the category of bispecific T cell engagers, or BiTEs, that have the canonical CD3-CD19 bispecific construct. Blinatumomab is the first bispecific antibody that received FDA approval for relapsed refractory B cell precursor acute lymphoblastic leukemia. Blinatumomab has been shown to have robust clinical outcomes and is associated with adverse events such as cytokine release syndrome and neurotoxicity. Other bispecific antibodies are under clinical investigation for multiple myeloma and acute myeloid leukemia. Along with immune checkpoint inhibitors and chimeric antigen T cell receptor therapies, bispecific antibodies are considered a mainstay as a therapeutic option for cancer immunotherapies for Hematologic malignancies.

The Contribution of Liver Sinusoidal Endothelial Cells to Clearance of Therapeutic Antibody

Many chronic inflammatory diseases are treated by administration of “biological” therapies in terms of fully human and humanized monoclonal antibodies or Fc fusion proteins. These tools have widespread efficacy and are favored because they generally exhibit high specificity for target with a low toxicity. However, the design of clinically applicable humanized antibodies is complicated by the need to circumvent normal antibody clearance mechanisms to maintain therapeutic dosing, whilst avoiding development of off target antibody dependent cellular toxicity. Classically, professional phagocytic immune cells are responsible for scavenging and clearance of antibody via interactions with the Fc portion. Immune cells such as macrophages, monocytes, and neutrophils express Fc receptor subsets, such as the FcγR that can then clear immune complexes. Another, the neonatal Fc receptor (FcRn) is key to clearance of IgG in vivo and serum half-life of antibody is explicitly linked to function of this receptor. The liver is a site of significant expression of FcRn and indeed several hepatic cell populations including Kupffer cells and liver sinusoidal endothelial cells (LSEC), play key roles in antibody clearance. This combined with the fact that the liver is a highly perfused organ with a relatively permissive microcirculation means that hepatic binding of antibody has a significant effect on pharmacokinetics of clearance. Liver disease can alter systemic distribution or pharmacokinetics of antibody-based therapies and impact on clinical effectiveness, however, few studies document the changes in key membrane receptors involved in antibody clearance across the spectrum of liver disease. Similarly, the individual contribution of LSEC scavenger receptors to antibody clearance in a healthy or chronically diseased organ is not well characterized. This is an important omission since pharmacokinetic studies of antibody distribution are often based on studies in healthy individuals and thus may not reflect the picture in an aging or chronically diseased population. Therefore, in this review we consider the expression and function of key antibody-binding receptors on LSEC, and the features of therapeutic antibodies which may accentuate clearance by the liver. We then discuss the implications of this for the design and utility of monoclonal antibody-based therapies.

The treatment landscape for Relapsed Refractory B Acute Lymphoblastic Leukaemia (ALL)

The last eight years have seen a rapid expansion of salvage options for patients with relapsed refractory (RR) acute lymphoblastic leukemia (ALL). The efficacy of targeted approaches with blinatumomab and Inotuzumab ozogamicin (InO), outweigh that of conventional chemotherapeutic regimens, and the reduced toxicity profile has also translated into higher transplant realization rates. Factors influencing the sequential use of these two antibodies include the preference for InO in those with high disease burden, while blinatumomab is a superior agent for attaining MRD responses in low disease burden groups. InO should not be used first in those with significant liver disease. Most impressive is the advent of chimeric antigen receptor cell therapy (CAR-T), a curative therapy in a significant proportion of younger patients with RR-ALL. Careful consideration is now required in the selection of relapse therapies; this review summarizes current available strategies and how to navigate the treatment landscape for RR ALL.

CAR-T-OPENIA: Chimeric antigen receptor T-cell therapy-associated cytopenias

Chimeric antigen receptor (CAR) T-cell is the most recent version in the evolution of cellular therapy with promising responses, which has revolutionized the management of some hematological malignancies in the current times. As the clinical use has progressed rather rapidly since the first approval in 2017, toxicities beyond cytokine release syndrome and immune effector cell-associated neurological syndrome have surfaced. Cytopenias are common in <30 days ("early"), 30-90 days ("short-term") as well as >90 days ("prolonged"); and have clinical implications to patient care as well as resource utilization. We review the details of etiology, factors associated with cytopenias, and management considerations for patients with cytopenias for each of these time-frames. This would potentially serve as a clinical guide for hematological toxicity or CAR-T-OPENIA, which is commonly encountered with the use of CAR T-cell therapy.

Financial toxicity in cancer care: origins, impact, and solutions

Financial toxicity describes the financial burden and distress that can arise for patients, and their family members, as a result of cancer treatment. It includes direct out-of-pocket costs for treatment and indirect costs such as travel, time, and changes to employment that can increase the burden of cancer. While high costs of cancer care have threatened the sustainability of access to care for decades, it is only in the past 10 years that the term "financial toxicity" has been popularized to recognize that the financial burdens of care can be just as important as the physical toxicities traditionally associated with cancer therapy. The past decade has seen a rapid growth in research identifying the prevalence and impact of financial toxicity. Research is now beginning to focus on innovations in screening and care delivery that can mitigate this risk. There is a need to determine the optimal strategy for clinicians and cancer centers to address costs of care in order to minimize financial toxicity, promote access to high value care, and reduce health disparities. We review the evolution of concerns over costs of cancer care, the impact of financial burdens on patients, methods to screen for financial toxicity, proposed solutions, and priorities for future research to identify and address costs that threaten the health and quality of life for many patients with cancer.

Economic Evidence on Potentially Curative Gene Therapy Products: A Systematic Literature Review

OBJECTIVE

The aim of this review was to summarize all available evidence on the cost effectiveness of potentially curative gene therapies and identify challenges that economic evaluations face in this area.

METHODS

We conducted a systematic review of four databases (PubMed/MEDLINE, Embase, CINAHL, EconLit) and grey literature sources. We conducted the search on August 23, 2019 and updated it on November 26, 2020. We included all English, French and Spanish language studies that addressed a gene therapy that had received regulatory approval or had entered a phase III trial, and also reported on costs related to the therapy. Critical appraisal was conducted to assess quality of reporting in included studies.

RESULTS

Fifty-six studies were identified. Of the 42 full economic evaluations, 71% (n = 30) evaluated chimeric antigen receptor T-cell therapies, most used either a Markov model (n = 17, 40%) and/or a partitioned survival model (n = 17, 40%), and 76% (n = 32) adopted a public or private payer perspective. The model characteristics with the greatest impact on cost effectiveness included assumptions about the efficacy of the treatment and the comparators used.

CONCLUSION

All gene therapies in this review were shown to be more effective than their comparators, although due to high costs not all were considered cost effective at standard cost-effectiveness thresholds. Despite their high cost, some gene therapies have the potential to dominate the alternatives in conditions with high mortality/disability. The choice of comparator and assumptions regarding long-term effectiveness had substantial impacts on cost-effectiveness estimates and need to be carefully considered. Both the quality of inputs and the quality of reporting were highly variable.

Hematopoietic recovery in patients receiving chimeric antigen receptor T-cell therapy for hematologic malignancies

Factors contributing to hematopoietic recovery following chimeric antigen receptor (CAR) T-cell therapy have not been well studied. In an analysis of 83 patients with hematologic malignancies treated with CAR T-cell therapy, we describe patterns of hematopoietic recovery and evaluate potentially associated factors. We included patients who received axicabtagene ciloleucel (n = 30) or tisagenlecleucel (n = 10) for B-cell lymphoma, CD19-28z CAR T therapy for B-cell acute lymphoblastic leukemia (NCT01044069; n = 37), or B-cell maturation antigen targeting CAR T cells for multiple myeloma (NCT03070327; n = 6). Patients treated with CAR T cells who had not progressed, died, or received additional chemotherapy had "recovered" (per definition in Materials and methods section) hemoglobin, platelet, neutrophil, and white blood cell counts at rates of 61%, 51%, 33%, and 28% at month 1 postinfusion and 93%, 90%, 80%, and 59% at month 3 postinfusion, respectively. Univariate analysis showed that increasing grade of immune effector cell-associated neurological syndrome (ICANS), baseline cytopenias, CAR construct, and higher peak C-reactive protein or ferritin levels were statistically significantly associated with a lower likelihood of complete count recovery at 1 month; a similar trend was seen for cytokine release syndrome (CRS). After adjustment for baseline cytopenia and CAR construct, grade ≥3 CRS or ICANS remained significantly associated with the absence of complete count recovery at 1 month. Higher levels of vascular endothelial growth factor and macrophage-derived chemokines, although not statistically significant, were seen patients without complete count recovery at 1 month. This remains to be studied further in larger prospective studies.

Bispecific Antibodies: A Review of Development, Clinical Efficacy and Toxicity in B-Cell Lymphomas

The treatment landscape of B-cell lymphomas is evolving with the advent of novel agents including immune and cellular therapies. Bispecific antibodies (bsAbs) are molecules that recognise two different antigens and are used to engage effector cells, such as T-cells, to kill malignant B-cells. Several bispecific antibodies have entered early phase clinical development since the approval of the CD19/CD3 bispecific antibody, blinatumomab, for relapsed/refractory acute lymphoblastic leukaemia. Novel bsAbs include CD20/CD3 antibodies that are being investigated in both aggressive and indolent non-Hodgkin lymphoma with encouraging overall response rates including complete remissions. These results are seen even in heavily pre-treated patient populations such as those who have relapsed after chimeric antigen receptor T-cell therapy. Potential toxicities include cytokine release syndrome, neurotoxicity and tumour flare, with a number of strategies existing to mitigate these risks. Here, we review the development of bsAbs, their mechanism of action and the different types of bsAbs and how they differ in structure. We will present the currently available data from clinical trials regarding response rates, progression free survival and outcomes across a range of non-Hodgkin lymphoma subtypes. Finally, we will discuss the key toxicities of bsAbs, their rates and management of these adverse events.

Neurological complications of cancer immunotherapy

Immunotherapy has emerged as a powerful therapeutic approach in many areas of clinical oncology and hematology. The approval of ipilimumab, a monoclonal antibody targeting the immune cell receptor CTLA-4, has marked the beginning of the era of immune checkpoint inhibitors. In the meantime, numerous antibodies targeting the PD-1 pathway have expanded the class of clinically approved immune checkpoint inhibitors. Furthermore, novel antibodies directed against other immune checkpoints are currently in clinical evaluation. More recently, bispecific antibodies, which link T cells directly to tumor cells as well as adoptive T cell transfer with immune cells engineered to express a chimeric antigen receptor, have been approved in certain indications. Neurological complications associated with the use of these novel immunotherapeutic concepts have been recognized more and more frequently. Immune checkpoint inhibitors may cause various neurological deficits mainly by alterations of the peripheral nervous system's integrity. These include radiculopathies, neuropathies, myopathies as well as myasthenic syndromes. Side effects involving the central nervous system are less frequent but may result in severe clinical symptoms and syndromes. The administration of chimeric antigen receptor (CAR) T cell is subject to rigorous patient selection and their use is frequently associated with neurological complications including encephalopathy and seizures, which require immediate action and appropriate therapeutic measures. Close clinical monitoring for neurological symptoms is key for early recognition of immunotherapy-related side effects. Comprehensive diagnostic work-up and adequate therapeutic measures are essential to avoid further clinical deterioration and residual neurological deficits.

Toxicities of Chimeric Antigen Receptor T Cell Therapy in Multiple Myeloma: An Overview of Experience From Clinical Trials, Pathophysiology, and Management Strategies

In the last few years, monoclonal antibodies (mAbs) such as elotuzumab and daratutumab have brought the treatment of multiple myeloma (MM) into the new era of immunotherapy. More recently, chimeric antigen receptor (CAR) modified T cell, a novel cellular immunotherapy, has been developed for treatment of relapsed/refractory (RR) MM, and early phase clinical trials have shown promising efficacy of CAR T cell therapy. Many patients with end stage RRMM regard CAR T cell therapy as their “last chance” and a “hope of cure”. However, severe adverse events (AEs) and even toxic death related to CAR T cell therapy have been observed. The management of AEs related to CAR T cell therapy represents a new challenge, as the pathophysiology is not fully understood and there is still no well-established standard of management. With regard to CAR T cell associated toxicities in MM, in this review, we will provide an overview of experience from clinical trials, pathophysiology, and management strategies.

Novel Therapies in the Treatment of Adult Acute Lymphoblastic Leukemia

PURPOSE OF REVIEW

Acute lymphoblastic leukemia (ALL) is a rare hematologic malignancy. Advances in multi-agent chemotherapy have resulted in dramatic improvements in the number of pediatric cases that result in a cure; however, until recently, treatment options for older adults or patients with relapsed and refractory disease were extremely limited. This review seeks to describe in greater detail a number of emerging novel treatment modalities recently approved for this cancer.

RECENT FINDINGS

In this review, we discuss a number of recently approved novel therapies for ALL, including new approaches with targeted tyrosine kinase inhibitors, novel immune-based therapies including the bispecific antibody blinatumomab and the antibody-drug conjugate inotuzumab ozogamicin, and the role of cellular therapeutics such as chimeric antigen receptor (CAR) T cells. We also discuss the impact that advances in diagnostics and disease classification and monitoring have had on treatment. A number of advances in ALL have resulted in dramatic changes to the treatment landscape and therapeutic options both at the time of diagnosis and in salvage. These findings are reshaping our treatment paradigms throughout the course of disease.

Market access of gene therapies across Europe, USA, and Canada: challenges, trends, and solutions

This review can inform gene therapy developers on challenges that can be encountered when seeking market access. Moreover, it provides an overview of trends among challenges and potential solutions.

Antibody based therapy in relapsed acute lymphoblastic leukemia

Outcomes for relapsed and refractory acute lymphoblastic leukemia (ALL) remain poor. With the advent of targeted monoclonal antibodies and antibody constructs, these outcomes have been significantly improved both in the frontline and salvage setting. These targets include a bispecific antibody that targets both CD3 and CD19, known as blinatumomab, as well as a conjugated antibody that targets CD22, known as inotuzumab ozogamicin. These agents have been thoroughly studied and successively approved for use as monotherapy, however, more recently they have been incorporated in combination or sequentially with cytotoxic chemotherapy. In this chapter, we will discuss the role that these monoclonal antibodies play as monotherapy and in combination in the treatment of ALL in the salvage setting, and how they continue to transform the treatment management of relapsed and refractory ALL.

Management of adverse effects of new monoclonal antibody treatments in acute lymphoblastic leukemia

Therapeutic options for relapsed/refractory B-cell acute lymphoblastic leukemia have evolved in the past few years. The FDA has approved three novel therapies for this disease: inotuzumab ozogamicin (an anti-CD22 antibody–drug conjugate), blinatumomab (a bispecific T-cell engager), and chimeric antigen receptor T-cell therapy. Although these novel immunotherapies have revolutionized the therapeutic landscape, it is important to understand the crucial aspects of administration, especially toxicity. In this article, we review the unique toxicities and adverse effects of blinatumomab and inotuzumab ozogamicin and provide recommendations for prevention of adverse effects as well as the management options for each medication.

Navigating Ethical Practices in the Era of High Cost Hematology

PURPOSE OF REVIEW

In this review article, we will highlight ethical issues faced by hematologists due to a growing constellation of expensive diagnostics and therapeutics in hematology. We outline the important issues surrounding this topic including stakeholders, cost considerations, and various ethical challenges surrounding access to care, communication about costs, and individual vs. societal responsibilities. We review available tools to navigate these ethical themes and offer potential solutions.

RECENT FINDINGS

We identified several gaps in the literature on the topic of ethical issues in hematology treatment and supplement by non-hematological cancer and general medical literature. We propose proactive solutions to address these problems to include cost transparency, utilization of evidence-based decision making tools, application of the four quadrant approach to ethical care, and advanced systems-based practice curriculum for physician trainees.

Concepts in immuno-oncology: tackling B cell malignancies with CD19-directed bispecific T cell engager therapies

The B cell surface antigen CD19 is a target for treating B cell malignancies, such as B cell precursor acute lymphoblastic leukemia and B cell non-Hodgkin lymphoma. The BiTE® immuno-oncology platform includes blinatumomab, which is approved for relapsed/refractory B cell precursor acute lymphoblastic leukemia and B cell precursor acute lymphoblastic leukemia with minimal residual disease. Blinatumomab is also being evaluated in combination with other agents (tyrosine kinase inhibitors, checkpoint inhibitors, and chemotherapy) in various treatment settings, including frontline protocols. An extended half-life BiTE molecule is also under investigation. Patients receiving blinatumomab may experience cytokine release syndrome and neurotoxicity; however, these events may be less frequent and severe than in patients receiving other CD19-targeted immunotherapies, such as chimeric antigen receptor T cell therapy. We review BiTE technology for treating malignancies that express CD19, analyzing the benefits and limitations of this bispecific T cell engager platform from clinical experience with blinatumomab.

Engineering Immune Cells for in vivo Secretion of Tumor-Specific T Cell-Redirecting Bispecific Antibodies

Immunotherapeutic approaches based on the redirection of T cell activity toward tumor cells are actively being investigated. The impressive clinical success of the continuously intravenously infused T cell-redirecting bispecific antibody (T-bsAb) blinatumomab (anti-CD19 x anti-CD3), and of engineered T cells expressing anti-CD19 chimeric antigen receptors (CAR-T cells) in hematological malignancies, has led to renewed interest in a novel cancer immunotherapy strategy that combines features of antibody- and cell-based therapies. This emerging approach is based on the endogenous secretion of T-bsAbs by engineered T cells (STAb-T cells). Adoptive transfer of genetically modified STAb-T cells has demonstrated potent anti-tumor activity in both solid tumor and hematologic preclinical xenograft models. We review here the potential benefits of the STAb-T strategy over similar approaches currently being used in clinic, and we discuss the potential combination of this promising strategy with the well-established CAR-T cell approach.

The Society for Immunotherapy of Cancer consensus statement on immunotherapy for the treatment of multiple myeloma

Outcomes in multiple myeloma (MM) have improved dramatically in the last two decades with the advent of novel therapies including immunomodulatory agents (IMiDs), proteasome inhibitors and monoclonal antibodies. In recent years, immunotherapy for the treatment of MM has advanced rapidly, with the approval of new targeted agents and monoclonal antibodies directed against myeloma cell-surface antigens, as well as maturing data from late stage trials of chimeric antigen receptor CAR T cells. Therapies that engage the immune system to treat myeloma offer significant clinical benefits with durable responses and manageable toxicity profiles, however, the appropriate use of these immunotherapy agents can present unique challenges for practicing physicians. Therefore, the Society for Immunotherapy of Cancer convened an expert panel, which met to consider the current role of approved and emerging immunotherapy agents in MM and provide guidance to the oncology community by developing consensus recommendations. As immunotherapy evolves as a therapeutic option for the treatment of MM, these guidelines will be updated.

The BiTE (bispecific T-cell engager) platform: Development and future potential of a targeted immuno-oncology therapy across tumor types

Immuno-oncology therapies engage the immune system to treat cancer. BiTE (bispecific T-cell engager) technology is a targeted immuno-oncology platform that connects patients' own T cells to malignant cells. The modular nature of BiTE technology facilitates the generation of molecules against tumor-specific antigens, allowing off-the-shelf immuno-oncotherapy. Blinatumomab was the first approved canonical BiTE molecule and targets CD19 surface antigens on B cells, making blinatumomab largely independent of genetic alterations or intracellular escape mechanisms. Additional BiTE molecules in development target other hematologic malignancies (eg, multiple myeloma, acute myeloid leukemia, and B-cell non-Hodgkin lymphoma) and solid tumors (eg, prostate cancer, glioblastoma, gastric cancer, and small-cell lung cancer). BiTE molecules with an extended half-life relative to the canonical BiTE molecules are also being developed. Advances in immuno-oncology made with BiTE technology could substantially improve the treatment of hematologic and solid tumors and offer enhanced activity in combination with other treatments.

Anti-CS1 × Anti-CD3 Bispecific Antibody (BiAb)-Armed Anti-CD3 Activated T Cells (CS1-BATs) Kill CS1+ Myeloma Cells and Release Type-1 Cytokines

Background: Multiple myeloma (MM) remains incurable despite significant advances in chemotherapy, targeted therapies, and immunotherapy. Bispecific antibody (BiAb)-armed activated T cells (BATs) have been developed for targeting and treatment of solid and hematologic malignancies. BATs are serial killers of tumor cells, secrete Th₁ cytokines, and induce adaptive cellular and humoral immune responses in patients (pts). This study provides preclinical data using bispecific anti-CS1 (elotuzumab) × anti-CD3 (OKT3) antibody (CS1Bi)-armed activated T cells (CS1- BATs) that provide a strong rationale for applying CS1-BATs to pts with MM.

Methods: CS1-BATs and unarmed activated T cells (ATC) were incubated with MM cell targets at various effector to target ratios (E:T) in a quantitative flow cytometry-based assay to determine the degree of cell loss relative to target cells incubated without ATC. ATC from up to 8 normal donors were armed with various concentrations of CS1 BiAb and tested against 5 myeloma cells lines for CS1-BATs-mediated killing and release of Th₁ cytokines, chemokines and granzyme B.

Results: CS1-BATs from normal donors killed each of 5 MM cell lines proportional to E:T ratios ranging between 1:1 and 10:1 and arming concentrations of 12.5 to 50 ng/million ATC, which was accompanied by release of Th₁ cytokines, chemokines and granzyme B. CS1-BATs prepared from MM pts' peripheral blood mononuclear cells (PBMC) showed increasing cytotoxicity and T cell expansion over time against ARH77 MM cells. The optimal arming dose of CS1Bi is 50 ng/10⁶ ATC.

Conclusions: These data demonstrate the therapeutic potential of CS1-BATs-mediated cytotoxicity and Th₁ cytokines release at low E:T and support advancing their clinical development in pts with MM.

Endothelial cell function and endothelial-related disorders following haematopoietic cell transplantation

Use of haematopoietic cell transplantation (HCT) in the treatment of haematologic and neoplastic diseases may lead to life-threatening complications that cause substantial morbidity and mortality if untreated. In addition to patient- and disease-related factors, toxicity associated with HCT puts patients at risk for complications that share a similar pathophysiology involving endothelial cells (ECs). Normally, the endothelium plays a role in maintaining homeostasis, including regulation of coagulation, vascular tone, permeability and inflammatory processes. When activated, ECs acquire cellular features that may lead to phenotypic changes that induce procoagulant, pro-inflammatory and pro-apoptotic mediators leading to EC dysfunction and damage. Elevated levels of coagulation factors, cytokines and adhesion molecules are indicative of endothelial dysfunction, and endothelial damage may lead to clinical signs and symptoms of pathological post-HCT conditions, including veno-occlusive disease/sinusoidal obstruction syndrome, graft-versus-host disease, transplant-associated thrombotic microangiopathy and idiopathic pneumonia syndrome/diffuse alveolar haemorrhage. The endothelium represents a rational target for preventing and treating HCT complications arising from EC dysfunction and damage. Additionally, markers of endothelial damage may be useful in improving diagnosis of HCT-related complications and monitoring treatment effect. Continued research to effectively manage EC activation, injury and dysfunction may be important in improving patient outcomes after HCT.

Toxicity Induced by a Bispecific T Cell-Redirecting Protein Is Mediated by Both T Cells and Myeloid Cells in Immunocompetent Mice

Bispecific T cell engagers have demonstrated clinical efficacy; however, their use can be accompanied by severe toxicity. Mechanistic understanding of these toxicities is limited by a lack of suitable immunocompetent preclinical models. In this study, we describe an immunocompetent mouse tumor model that exhibits bispecific T cell engager-induced toxicity and recapitulates key features similar to those in human cytokine release syndrome. In this study, toxicity occurred between the second and fourth injections of an NK Group 2D bispecific T cell engager protein. Symptoms were transient, peaking 3-4 h after treatment and resolving by 8 h. Mice developed weight loss, elevated plasma cytokines, a significant reduction in spleen white pulp, and lymphocyte infiltration in the liver. Systemic cellular immune changes also occurred; notably, an increase in CD8⁺ T cell activation, an increase in myeloid cells in the blood, and a population of Ly-6C^int monocytes (CD11b⁺Ly-6G^-F4/80^-) emerged in the liver and spleens of bispecific protein-treated mice. IFN-γ was primarily produced by CD8⁺ T cells in the spleen and was required for the observed changes in both T cell and myeloid populations. Rag deficiency, IFN-γ deficiency, or depletion of either CD4⁺ or CD8⁺ T cells prevented toxicity, whereas perforin deficiency, GM-CSF deficiency, or modulation of the myeloid population through clodronate-mediated depletion showed a partial abrogation of toxicity. Together, these findings reveal that T cell activation by a bispecific T cell engager leads to changes in the host myeloid cell population, both of which contribute to treatment induced toxicity in immunocompetent mice.

Acute Kidney Injury after CAR-T Cell Therapy: Low Incidence and Rapid Recovery

Chimeric antigen receptor (CAR) T cell therapy using engineered cytotoxic T cells has shown promising responses in various hematologic malignancies. Cytokine release syndrome (CRS) and immune effector cell-associated neurologic syndrome (ICANS) are recognized toxicities of CAR-T, whereas kidney injury remains less well recognized. The objective of the present study was to identify the incidence of acute kidney injury (AKI) after CAR-T cell therapy, potential risk factors, and recovery of kidney function. We performed a retrospective review of 46 adult patients with non-Hodgkin lymphoma treated with CAR-T therapy between February 2018 and February 2019 at our institution. Serum creatinine values before CAR-T therapy through day 100 were used to assess AKI, as defined by the Kidney Disease Improving Global Outcomes (KDIGO) criteria: grade 1, 1.5- to <2-fold of baseline; grade 2, 2- to <3-fold of baseline; grade 3, ≥3-fold of baseline. CRS and ICANS were graded using the consensus criteria of the American Society of Transplantation and Cellular Therapy. The overall incidence of CRS was 78.3% (95% confidence interval [CI], 66% to 90.5%), of whom 13% (95% CI, 3.3% to 22.8%) developed grade 3-4 CRS, whereas the overall incidence of ICANS was lower at 45.7% (95% CI, 3.1% to 60.3%). The cumulative incidence of any grade AKI by day 100 was 30% (95% CI, 16.9% to 43.9%), with a grade 1 AKI incidence of 21.7% (95% CI, 9.7% to 33.8%) and a grade 2-3 AKI incidence of 8.7% (95% CI, .4% to 17%). No patients developed severe AKI necessitating renal replacement therapy. Patients with previous autologous or allogeneic stem cell transplantation, those requiring intensive care unit level care and with grade 3-4 CRS had a higher incidence of AKI. Most patients recovered, with kidney function returning to baseline within 30 days. We conclude that with early recognition and management of CAR-T complications, the incidence of AKI is low, the severity of injury is mild, and most patients recover kidney function within 30 days.

Management of toxicities associated with novel immunotherapy agents in acute lymphoblastic leukemia

The advent of novel immunotherapies, such as blinatumomab, inotuzumab, and chimeric antigen receptor (CAR) T cell therapy, has revolutionized the therapeutic landscape in the treatment of relapsed/refractory B cell acute lymphoblastic leukemia, but can be associated with specific toxicities. We review unique toxicities of each of these in this article. Blinatumomab, a bispecific T cell engager, has been associated with cytokine release syndrome (CRS) and neurological toxicities, both of which can be prevented and managed with corticosteroids. Inotuzumab is a calicheamicin-conjugated CD22 targeting antibody. The calicheamicin component of the drug is likely associated with the hepatotoxicity seen with inotuzumab, especially sinusoidal obstruction syndrome, which can happen both in the context of the drug alone, and also with allogeneic stem cell transplantation. QT prolongation has also been noted with inotuzumab. CAR T therapy uses genetically modified autologous T cells directed against CD19, a known target on B cells. CRS and neurological symptoms, formally termed as immune-effector-cell-associated neurological syndrome, have been described along with hypogammaglobulinemia, cytopenias, and infections.

Central nervous system emergencies in haematological malignancies

Neurological emergencies are frequently catastrophic events in the course of haematological malignancies (HM) that, if not promptly recognized and treated, may lead to lethal outcomes or chronic sequelae. They may occur at any time during the disease course, but are more frequently observed following relapse. Practice guidelines are lacking in the management of most central nervous system (CNS) complications in HM. Herein we review the pathophysiology, presentation and treatment of elevated intracranial pressure, spinal cord compression, status epilepticus, neurovascular complications, CNS infection, leucostasis and hyperviscosity. Further, we discuss the expanding spectrum of neurological complications of old and novel treatments in HM.

Immune-Based Therapies in Acute Leukemia

Treatment resistance remains a leading cause of acute leukemia-related deaths. Thus, there is an unmet need to develop novel approaches to improve outcome. New immune-based therapies with chimeric antigen receptor (CAR) T cells, bi-specific T cell engagers (BiTEs), and immune checkpoint blockers (ICBs) have emerged as effective treatment options for chemoresistant B cell acute lymphoblastic leukemia (B-ALL) and acute myeloid leukemia (AML). However, many patients show resistance to these immune-based approaches. This review describes crucial lessons learned from immune-based approaches targeting high-risk B-ALL and AML, such as the leukemia-intrinsic (e.g., target antigen loss, tumor heterogeneity) and -extrinsic (e.g., immunosuppressive microenvironment) mechanisms that drive treatment resistance, and discusses alternative approaches to enhance the effectiveness of these immune-based treatment regimens.

Monoclonal Antibodies: Past, Present and Future

Monoclonal antibodies (mAbs) are immunoglobulins designed to target a specific epitope on an antigen. Immunoglobulins of identical amino-acid sequence were originally produced by hybridomas grown in culture and, subsequently, by recombinant DNA technology using mammalian cell expression systems. The antigen-binding region of the mAb is formed by the variable domains of the heavy and light chains and contains the complementarity-determining region that imparts the high specificity for the target antigen. The pharmacokinetics of mAbs involves target-mediated and non-target-related factors that influence their disposition.Preclinical safety evaluation of mAbs differs substantially from that of small molecular (chemical) entities. Immunogenicity of mAbs has implications for their pharmacokinetics and safety. Early studies of mAbs in humans require careful consideration of the most suitable study population, route/s of administration, starting dose, study design and the potential difference in pharmacokinetics in healthy subjects compared to patients expressing the target antigen.Of the ever-increasing diversity of therapeutic indications for mAbs, we have concentrated on two that have proved dramatically successful. The contribution that mAbs have made to the treatment of inflammatory conditions, in particular arthritides and inflammatory bowel disease, has been nothing short of revolutionary. Their benefit has also been striking in the treatment of solid tumours and, most recently, as immunotherapy for a wide variety of cancers. Finally, we speculate on the future with various new approaches to the development of therapeutic antibodies.