Phase I/II Study of an Anti-CD30 Monoclonal Antibody (MDX-060) in Hodgkin's Lymphoma and Anaplastic Large-Cell Lymphoma

Interplay between proteasome inhibitors and NF-κB pathway in leukemia and lymphoma: a comprehensive review on challenges ahead of proteasome inhibitors

The current scientific literature has extensively explored the potential role of proteasome inhibitors (PIs) in the NF-κB pathway of leukemia and lymphoma. The ubiquitin-proteasome system (UPS) is a critical component in regulating protein degradation in eukaryotic cells. PIs, such as BTZ, are used to target the 26S proteasome in hematologic malignancies, resulting in the prevention of the degradation of tumor suppressor proteins, the activation of intrinsic mitochondrial-dependent cell death, and the inhibition of the NF-κB signaling pathway. NF-κB is a transcription factor that plays a critical role in the regulation of apoptosis, cell proliferation, differentiation, inflammation, angiogenesis, and tumor migration. Despite the successful use of PIs in various hematologic malignancies, there are limitations such as resistant to these inhibitors. Some reports suggest that PIs can induce NF-κB activation, which increases the survival of malignant cells. This article discusses the various aspects of PIs' effects on the NF-κB pathway and their limitations. Video Abstract.

Advances in immunotherapeutic targets for childhood cancers: A focus on glypican-2 and B7-H3

Cancer immunotherapies have revolutionized how we can treat adult malignancies and are being translated to pediatric oncology. Chimeric antigen receptor T-cell therapy and bispecific antibodies targeting CD19 have shown success for the treatment of pediatric patients with B-cell acute lymphoblastic leukemia. Anti-GD2 monoclonal antibody has demonstrated efficacy in neuroblastoma. In this review, we summarize the immunotherapeutic agents that have been approved for treating childhood cancers and provide an updated review of molecules expressed by pediatric cancers that are under study or are emerging candidates for future immunotherapies. Advances in our knowledge of tumor immunology and in genome profiling of cancers has led to the identification of new tumor-specific/associated antigens. While cell surface antigens are normally targeted in a major histocompatibility complex (MHC)-independent manner using antibody-based therapies, intracellular antigens are normally targeted with MHC-dependent T cell therapies. Glypican 2 (GPC2) and B7-H3 (CD276) are two cell surface antigens that are expressed by a variety of pediatric tumors such as neuroblastoma and potentially can have a positive impact on the treatment of pediatric cancers in the clinic.

Biology and Molecular Pathogenesis of Mature T-Cell Lymphomas

Peripheral T-cell lymphomas (PTCLs) constitute a highly heterogeneous group of hematological diseases with complex clinical and molecular features consistent with the diversity of the T-cell type from which they originate. In the past several years, the systematic implementation of high-throughput genomic technologies for the analysis of T-cell malignancies has supported an exponential progress in our understanding of the genetic drivers of oncogenesis and unraveled the molecular complexity of these diseases. Recent findings have helped redefine the classification of T-cell malignancies and provided novel biomarkers to improve diagnosis accuracy and analyze the response to therapy. In addition, multiple novel targeted therapies including small-molecule inhibitors, antibody-based approaches, and immunotherapy have shown promising results in early clinical analysis and have the potential to completely change the way T-cell malignancies have been treated traditionally.

Management of ALCL and other CD30+ peripheral T-cell lymphomas with a focus on Brentuximab vedotin

Peripheral T-cell lymphomas (PTCL) are rare lymphoproliferative disorders with poor outcomes and high rates of relapse. Incidence varies although the most common subtypes include PTCL-not-otherwise specified, anaplastic large cell lymphoma, and angioimmunoblastic T-cell lymphoma. Anaplastic large cell lymphoma is characterized by near-universal CD30 expression and serves as a prototypic model for other CD30-expressing lymphomas. Historically, these neoplasms have been treated with regimens used in the treatment of aggressive B-cell lymphomas. Over the last decade, brentuximab vedotin, an antibody-drug conjugate, has been investigated to treat peripheral T-cell lymphomas expressing CD30. While first studied in the relapsed and refractory setting, it was later studied in the frontline setting in the ECHELON-2 trial with positive results and is now an approved treatment for CD30-expressing peripheral T-cell lymphomas. Other treatment options in the relapsed and refractory setting include histone deacetylase inhibitors, pralatrexate, and salvage multiagent chemotherapy regimens. Current research is underway regarding combination therapies and the use of other novel agents.

Invasive Fungal Diseases in Children with Hematological Malignancies Treated with Therapies That Target Cell Surface Antigens: Monoclonal Antibodies, Immune Checkpoint Inhibitors and CAR T-Cell Therapies

Since 1985 when the first agent targeting antigens on the surface of lymphocytes was approved (muromonab-CD3), a multitude of such therapies have been used in children with hematologic malignancies. A detailed literature review until January 2021 was conducted regarding pediatric patient populations treated with agents that target CD2 (alefacept), CD3 (bispecific T-cell engager [BiTE] blinatumomab), CD19 (denintuzumab mafodotin, B43, BiTEs blinatumomab and DT2219ARL, the immunotoxin combotox, and chimeric antigen receptor [CAR] T-cell therapies tisagenlecleucel and axicabtagene ciloleucel), CD20 (rituximab and biosimilars, 90Y-ibritumomab tiuxetan, ofatumumab, and obinutuzumab), CD22 (epratuzumab, inotuzumab ozogamicin, moxetumomab pasudotox, BiTE DT2219ARL, and the immunotoxin combotox), CD25 (basiliximab and inolimomab), CD30 (brentuximab vedotin and iratumumab), CD33 (gemtuzumab ozogamicin), CD38 (daratumumab and isatuximab), CD52 (alemtuzumab), CD66b (90Y-labelled BW 250/183), CD248 (ontuxizumab) and immune checkpoint inhibitors against CTLA-4 (CD152; abatacept, ipilimumab and tremelimumab) or with PD-1/PD-L1 blockade (CD279/CD274; atezolizumab, avelumab, camrelizumab, durvalumab, nivolumab and pembrolizumab). The aim of this narrative review is to describe treatment-related invasive fungal diseases (IFDs) of each category of agents. IFDs are very common in patients under blinatumomab, inotuzumab ozogamicin, basiliximab, gemtuzumab ozogamicin, alemtuzumab, and tisagenlecleucel and uncommon in patients treated with moxetumomab pasudotox, brentuximab vedotin, abatacept, ipilimumab, pembrolizumab and avelumab. Although this new era of precision medicine shows promising outcomes of targeted therapies in children with leukemia or lymphoma, the results of this review stress the necessity for ongoing surveillance and suggest the need for antifungal prophylaxis in cases where IFDs are very common complications.

A new immunotherapy strategy targeted CD30 in peripheral T-cell lymphomas: CAR-modified T-cell therapy based on CD30 mAb

Chimeric antigen receptor T-cell immunotherapy (CAR-T) has shown remarkable efficacy in treating tumors of lymphopoietic origin. Herein, we demonstrate an effective CAR-T cell treatment for recurrent and malignant CD30-positive peripheral T-cell lymphomas (PTCL) has been demonstrated. The extracellular fragment gene sequences of CD30 were obtained from tumor tissues of PTCL patients and cloned into a plasmid vector to express the CD30 antigen. The CD30 targeting single-chain antibody fragment (scFv) was obtained from CD30-positive monoclonal hybridoma cells, which were obtained from CD30 antigen immunized mice. After a second-generation of CAR lentiviral construction, CD30 CAR T cells were produced and used to determine the cytotoxicity of this construct toward Karpas 299 cells. The results of CD30 CAR T-mediated cell lysis show that 9C11-2 CAR T cells could significantly promote the lysis of CD30-positive Karpas 299 cells in both LDH and real-time cell electronic sensing (RTCA) assays. In vivo data show that 9C11-2 CAR T cells effectively suppress the tumor growth in a Karpas 299 cell xenograft NCG mouse model. The CD30 CAR T cells exhibited an efficient cytotoxic effect after being co-cultured with the target cells and they also exhibited a significant tumor-inhibiting ability after being intravenously injected into PTCL xenograft tumors; these observations suggest that the new CD30 CAR-T cell may be a promising therapeutic candidate for cancer therapy.

Brentuximab Vedotin in the Treatment of Peripheral T Cell Lymphoma and Cutaneous T Cell Lymphoma

PURPOSE OF REVIEW

The recent development of brentuximab vedotin (BV), an antibody-drug conjugate targeting CD30-positive cells, has led to therapeutic advances in the treatment of T cell lymphomas. In this review, we discuss key studies of BV in peripheral T cell lymphoma (PTCL) and cutaneous T cell lymphoma (CTCL) and highlight important questions for further investigation.

RECENT FINDINGS

Monotherapy with BV has proven to be effective and well tolerated in patients with relapsed/refractory (R/R) CD30-positive CTCL. BV has shown significant activity in R/R PTCL as well, with particularly durable responses in patients with anaplastic large cell lymphoma (ALCL). In a landmark phase III study (ECHELON-2), BV + CHP demonstrated superior progression-free and overall survival relative to CHOP as frontline therapy for patients with CD30-expressing PTCL, representing the first randomized trial demonstrating an overall survival benefit in PTCL. Though BV is overall well tolerated, peripheral neuropathy remains a clinically significant adverse effect. BV is a major therapeutic advance in the treatment of patients with R/R CTCL and of those with PTCL in both the R/R and frontline settings. Key ongoing areas of investigation include optimization of CD30 expression as a predictive biomarker as well as the role of BV in consolidation therapy.

An overview of antibody-drug conjugates in oncological practice

Antibody–drug conjugates (ADCs) are designed to manipulate the toxic efficacy of specific chemotherapeutic compounds, employing the high affinity of antibody-mediated delivery so as to drive them selectively to target cancer cells. These immunoconjugates encompass the general tendency towards precision medicine and avert the systemic toxicities of conventional chemotherapy, accomplishing an improved therapeutic index. Cumulative experience acquired from first-generation ADCs offers new perspectives to these promising therapeutic modalities for various hematological and solid cancers and propels their clinical development in a faster-than-ever pace, as indicated by the approval of four novel ADCs during the last year. This paper aims to provide an up-to-date overview of the eight ADCs approved by the US Food and Drug Administration and their current indications in oncological practice. Starting from their bio-pharmaceutical background, we track their clinical evolution, with an emphasis on the pivotal trials that led to their commercial release. Late-stage studies examining these eight ADCs in other-than-approved settings as well as the investigation of potential new candidates are also reviewed. In the close future, more data are expected to expand ADCs’ oncological utility and to further reshape their role in cancer therapeutics.

Safety and Efficacy of Brentuximab Vedotin in the Treatment of Classic Hodgkin Lymphoma

Classical Hodgkin lymphoma (cHL) is a B-cell-derived lymphoid malignancy with the most favorable prognosis among various adult malignancies. However, once it becomes refractory disease to chemotherapy or relapses after high-dose chemotherapy (HDC) with autologous stem cell transplantation (ASCT), it is difficult to manage with conventional cytotoxic chemotherapy. The introduction of brentuximab vedotin (BV) has changed the treatment landscape of cHL in the past decade. Several studies demonstrated high efficacy of BV monotherapy in heavily treated patients with cHL relapsed or refractory after HDC/ASCT. Recent studies also reported high efficacy of concurrent or sequential combination of BV and chemotherapy in patients with transplant-eligible relapsed/refractory cHL at the second-line setting. In addition, a randomized phase III trial ECHELON-1 reported a positive result of BV in combination with AVD (doxorubicin, vinblastine, and dacarbazine) in patients with newly diagnosed advanced-stage cHL. In this review, we summarize available data of BV for cHL and discuss the current and future role of BV in the management of cHL.

Passive Monoclonal and Polyclonal Antibody Therapies

Passive antibody therapies have a long history of use. In the 19th century, antibodies from xenographic sources of polyclonal antibodies were used to treat infections (diphtheria). They were used often as protection from infectious agents and toxins. Complications related to their use involved development of immune complexes and severe allergic reactions. As a result, human source plasma for polyclonal antibodies became the preferential source for antibodies. They are used to treat infection, remove toxins, prevent hemolytic disease of the newborn, modify inflammatory reactions, and control autoimmune diseases. Continued improvements in processing decreased the transfusion/infusion transmission of infections. In the late 20th century (∼1986), monoclonal antibodies were developed. The first monoclonal antibodies were of xenographic source and were wrought with problems of immunogenicity. These forms of antibodies did not gain favor until chimerization took pace in the mid-1990s and in 1998 two monoclonal antibodies were approved one to treat respiratory syncytial virus and the other for breast cancers. Further development of humanized and then fully human monoclonal antibodies has led to an evolution of therapies with these agents. Monoclonal antibodies are being researched or approved to treat a multitude of diseases to include oncologic, inflammatory, autoimmune, cardiovascular, respiratory, neurologic, allergic, benign hematologic, infections, orthopedic, coagulopathy, metabolic and to decrease morbidity of disease (diminution of pain), modify disease progression, and potentially anatomic development. In this chapter, we will review the history of use of these passive antibody therapies, their mechanism of action, pharmacologic-therapeutic classification, particular medical indication, adverse reactions, and potential future use of these medications.

The rapidly changing landscape in mature T-cell lymphoma (MTCL) biology and management

Historical advances in the care of patients with non-Hodgkin lymphoma (NHL) have been restricted largely to patients with B-cell lymphoma. The peripheral T-cell lymphomas (PTCLs), which are rare and heterogeneous in nature, have yet to experience the same degree of improvement in outcome over the past 20 to 30 years. It is estimated that there are approximately 80,000 and 14,000 cases, respectively, of NHL and Hodgkin lymphoma per year in the United States. As a subgroup of NHL, the PTCLs account for 6% to 10% of all cases of NHL, making them exceedingly rare. In addition, the World Health Organization 2017 classification describes 29 distinct subtypes of PTCL. This intrinsic diversity, coupled with its rarity, has stymied progress in the disease. In addition, most subtypes carry an inferior prognosis compared with their B-cell counterparts, an outcome largely attributed to the fact that most treatment paradigms for patients with PTCL have been derived from B-cell neoplasms, a radically different disease. In fact, the first drug ever approved for patients with PTCL was approved only a decade ago. The plethora of recent drug approvals in PTCL, coupled with a deeper understanding of the molecular pathogenesis of the disease, has stimulated the field to pursue new avenues of research that are now largely predicated on the development of novel, targeted small molecules, which include a host of epigenetic modifiers and biologics. There is an expectation these advances may begin to favorably challenge the chemotherapy paradigms that have been used in the T-cell malignancies.

Brentuximab vedotin in the treatment of CD30+ PTCL

In this timely Blood Spotlight, Barta et al summarize for the practicing hematologist the strengths and limitations of current data on brentuximab vedotin–based treatment in peripheral T-cell lymphoma (PTCL).

The Evolving Role of Brentuximab Vedotin in Classical Hodgkin Lymphoma

The arrival of the CD30 directed antibody-drug conjugate, brentuximab vedotin (BV), has altered the approach to patients with classical Hodgkin lymphoma. Since initial approval in 2011, BV has been extensively studied in previously untreated and relapsed/refractory patients. Treatment indications for the antibody-drug conjugate have been expanded from the previously treated population to include maintenance therapy after autologous stem cell transplantation and recently, combination with chemotherapy in newly diagnosed advanced stage patients. This article will review the evolution of BV in classical Hodgkin lymphoma, detailing the studies that led to the approved indications and discussion of recent trials in combination with chemotherapy and immunotherapy.

Immunotherapy in Hodgkin Lymphoma: Present Status and Future Strategies

Although classical Hodgkin lymphoma (cHL) is usually curable, 20-30% of the patients experience treatment failure and most of them are typically treated with salvage chemotherapy and autologous stem cell transplantation (autoSCT). However, 45-55% of that subset further relapse or progress despite intensive treatment. At the advanced stage of the disease course, recently developed immunotherapeutic approaches have provided very promising results with prolonged remissions or disease stabilization in many patients. Brentuximab vedotin (BV) has been approved for patients with relapsed/refractory cHL (rr-cHL) who have failed autoSCT, as a consolidation after autoSCT in high-risk patients, as well as for patients who are ineligible for autoSCT or multiagent chemotherapy who have failed ≥ two treatment lines. However, except of the consolidation setting, 90-95% of the patients will progress and require further treatment. In this clinical setting, immune checkpoint inhibitors (CPIs) have produced impressive results. Both nivolumab and pembrolizumab have been approved for rr-cHL after autoSCT and BV failure, while pembrolizumab has also been licensed for transplant ineligible patients after BV failure. Other CPIs, sintilimab and tislelizumab, have been successfully tested in China, albeit in less heavily pretreated populations. Recent data suggest that the efficacy of CPIs may be augmented by hypomethylating agents, such as decitabine. As a result of their success in heavily pretreated disease, BV and CPIs are moving to earlier lines of treatment. BV was recently licensed by the FDA for the first-line treatment of stage III/IV Hodgkin lymphoma (HL) in combination with AVD (only stage IV according to the European Medicines Agency (EMA)). CPIs are currently being evaluated in combination with AVD in phase II trials of first-line treatment. The impact of BV and CPIs was also investigated in the setting of second-line salvage therapy. Finally, combinations of targeted therapies are under evaluation. Based on these exciting results, it appears reasonable to predict that an improvement in survival and a potential increase in the cure rates of cHL will soon become evident.

Immunotherapy in Hodgkin Lymphoma: Present Status and Future Strategies

Although classical Hodgkin lymphoma (cHL) is usually curable, 20-30% of the patients experience treatment failure and most of them are typically treated with salvage chemotherapy and autologous stem cell transplantation (autoSCT). However, 45-55% of that subset further relapse or progress despite intensive treatment. At the advanced stage of the disease course, recently developed immunotherapeutic approaches have provided very promising results with prolonged remissions or disease stabilization in many patients. Brentuximab vedotin (BV) has been approved for patients with relapsed/refractory cHL (rr-cHL) who have failed autoSCT, as a consolidation after autoSCT in high-risk patients, as well as for patients who are ineligible for autoSCT or multiagent chemotherapy who have failed ≥ two treatment lines. However, except of the consolidation setting, 90-95% of the patients will progress and require further treatment. In this clinical setting, immune checkpoint inhibitors (CPIs) have produced impressive results. Both nivolumab and pembrolizumab have been approved for rr-cHL after autoSCT and BV failure, while pembrolizumab has also been licensed for transplant ineligible patients after BV failure. Other CPIs, sintilimab and tislelizumab, have been successfully tested in China, albeit in less heavily pretreated populations. Recent data suggest that the efficacy of CPIs may be augmented by hypomethylating agents, such as decitabine. As a result of their success in heavily pretreated disease, BV and CPIs are moving to earlier lines of treatment. BV was recently licensed by the FDA for the first-line treatment of stage III/IV Hodgkin lymphoma (HL) in combination with AVD (only stage IV according to the European Medicines Agency (EMA)). CPIs are currently being evaluated in combination with AVD in phase II trials of first-line treatment. The impact of BV and CPIs was also investigated in the setting of second-line salvage therapy. Finally, combinations of targeted therapies are under evaluation. Based on these exciting results, it appears reasonable to predict that an improvement in survival and a potential increase in the cure rates of cHL will soon become evident.

Overview of Current Targeted Anti-Cancer Drugs for Therapy in Onco-Hematology

The upgraded knowledge of tumor biology and microenviroment provides information on differences in neoplastic and normal cells. Thus, the need to target these differences led to the development of novel molecules (targeted therapy) active against the neoplastic cells' inner workings. There are several types of targeted agents, including Small Molecules Inhibitors (SMIs), monoclonal antibodies (mAbs), interfering RNA (iRNA) molecules and microRNA. In the clinical practice, these new medicines generate a multilayered step in pharmacokinetics (PK), which encompasses a broad individual PK variability, and unpredictable outcomes according to the pharmacogenetics (PG) profile of the patient (e.g., cytochrome P450 enzyme), and to patient characteristics such as adherence to treatment and environmental factors. This review focuses on the use of targeted agents in-human phase I/II/III clinical trials in cancer-hematology. Thus, it outlines the up-to-date anticancer drugs suitable for targeted therapies and the most recent finding in pharmacogenomics related to drug response. Besides, a summary assessment of the genotyping costs has been discussed. Targeted therapy seems to be an effective and less toxic therapeutic approach in onco-hematology. The identification of individual PG profile should be a new resource for oncologists to make treatment decisions for the patients to minimize the toxicity and or inefficacy of therapy. This could allow the clinicians to evaluate benefits and restrictions, regarding costs and applicability, of the most suitable pharmacological approach for performing a tailor-made therapy.

Novel Therapies and Approaches to Relapsed/Refractory HL Beyond Chemotherapy

Although Hodgkin lymphoma (HL) is highly curable with first-line therapy, relapses occur in approximately 10–20% of patients with early stage disease and 30–40% of patients with advanced stage disease. The standard approach for relapsed or refractory disease is salvage therapy, followed by consolidation with high dose therapy and autologous stem cell transplant (ASCT). Patients who achieve a complete response to salvage therapy prior to ASCT have better outcomes, thus recent studies have focused on incorporating newer agents in this setting. Major challenges in the management of relapsed patients remain how to choose and sequence the many salvage therapies that are currently available and how to best incorporate novel agents in the current treatment paradigms. In this article, we will summarize the most recent advances in the management of patients with recurrent HL and will mainly focus on the role of new agents approved and under investigation. Aside from brentuximab vedotin and checkpoint inhibitors, other novel agents and therapies are showing promising early results. However, at least with some of the newest targeted strategies, it is important to recognize that we are facing new challenges in terms of toxicities, which require very close monitoring and education of both the patient and treating physician.

Humanized anti-CD123 antibody facilitates NK cell antibody-dependent cell-mediated cytotoxicity (ADCC) of Hodgkin lymphoma targets via ARF6/PLD-1

CD123 (IL-3Rα) is frequently expressed by malignant Hodgkin lymphoma (HL) cells. Naked monoclonal antibodies (mAb) against HL lack clinical benefit, partially due to absence of natural killer (NK) cells in the tumor microenvironment. Here we show that the combination of a fully humanized anti-CD123 mAb (CSL362) and high-affinity Fcγ-receptor NK-92 cells (haNK) effectively target and kill HL cells in vitro. First, we confirmed high expression of CD123 in 2 of the 3 HL cell lines (KM-H2 and L-428), and its absence in NK cells. Cytotoxicity of haNK cells against CD123-positive HL cells was significantly higher in the presence of CSL362. This was also shown with IL-15-activated primary NK cells, although haNK cells showed a 10.87-fold lower estimated half-maximal stimulatory effective concentration (EC₅₀). CSL362 facilitated a significant increase in the expression of CD107a, intracellular IFN-γ and TNF-α and enhanced expression of c-JUN, PLD-1, and ARF6 by NK cells. Inhibition of the ARF6–PLD-1 axis (NAV2729), but not of the MAPK pathway (U0126), completely abrogated CSL362-facilitated antibody-dependent cell-mediated cytotoxicity (ADCC) in haNK and activated primary NK cells. Our results support CD123 as an immunotherapeutic target for HL and the combination of NK cells and CSL362 as a treatment strategy for HL.

Optimizing the role of brentuximab vedotin in classical Hodgkin lymphoma therapy

The US Food and Drug Administration approval of brentuximab vedotin (BV) in 2011 marked an important milestone in the management of classical Hodgkin lymphoma (HL). Although initially approved for use in the relapsed or refractory setting, its high efficacy and favorable toxicity profile led to numerous studies evaluating BV in the front-line, second-line, and posttransplant settings. BV is now approved for use (in combination with chemotherapy) as frontline treatment of advanced-stage patients and as maintenance therapy following autologous stem cell transplant. Additional studies demonstrate its promise as second-line therapy and for elderly patients, as well. Although studies have demonstrated its promise in multiple settings, the ideal timing for use of BV is evolving. Studies evaluating individualized treatment strategies will ultimately define the optimal place for BV in HL treatment.

Determining the sequence of novel therapies in the treatment of relapsed Hodgkin's lymphoma

INTRODUCTION

Hodgkin's lymphoma (HL) accounts for about 10% of all lymphomas in the U.S.A. Exceptional progress has been made in the treatment of HL with complete response (CR) rates up to 94% in limited stage and 88% in advanced stage disease with regimens such as adriamycin, bleomycin, vinblastine, and dacarbazine in the frontline setting. Nevertheless, up to 10% of patients with limited stage disease and 20-30% of those with advanced stage HL relapse. In the last decade, newer agents such as brentuximab vedotin (BV) and checkpoint inhibitors have been approved by the FDA for treatment of patients with relapsed or refractory HL. As these newer agents are increasingly incorporated in both the frontline and relapsed settings, their optimal sequence becomes challenging for clinicians. Areas covered: This review will discuss the evidence behind the approval of BV and checkpoint inhibitors in HL and the appropriate sequence for using them in relapsed HL. Expert commentary: The appropriate sequence of BV and/or checkpoint inhibitors in the relapsed setting depends on the regimen used in the frontline setting.

Cancer Immunotherapy and the Immune Response in Hodgkin Lymphoma

Patients with classical Hodgkin lymphoma (cHL) have an impaired cellular immune response as indicated by an anergic reaction against standard recall antigens and a diminished rejection reaction of allogeneic skin transplant. This clinical observation can be linked to the histopathological feature of cHL since the typical pattern of a cHL manifestation is characterized by sparse large CD30⁺ tumor-infiltrating Hodgkin–Reed–Sternberg (HRS) cells that are surrounded by a dense inflammatory immune microenvironment with mixed cellularity. Despite this extensive polymorphous inflammatory infiltrate, there is only a poor antitumor immune response seen to the neoplastic HRS cells. This is primarily mediated by a high expression of PD-L1 and PD-L2 ligands on the HRS cell surface which in turn antagonizes the activity of programmed death-1 (PD-1) antigen-positive T cells. PD-L1/L2 overexpression is caused by gene amplification at the 9p24.1 locus and/or latent Epstein–Barr virus infection present in around 40% of cHL cases. The blockade of the PD-L1/L2–PD-1 pathway by monoclonal antibodies can restore local T cell activity and leads to impressive tumor responses, some of which are long lasting and eventually curative. Another feature of HRS cells is the high CD30 antigen expression. Monoclonal antibody technology allowed for the successful development of CD30-specific immunotoxins, bispecific antibodies, and reprogrammed autologous T cells with the first one already approved for the treatment of high risk or relapsed cHL. Altogether, the discovery of the described pathomechanism of immune suppression and the identification of preferential target antigens has rendered cHL to be a prime subject for the successful development of new immunotherapeutic approaches.

Advances in CD30- and PD-1-targeted therapies for classical Hodgkin lymphoma

CD30 and programmed cell death protein 1 (PD-1) are two ideal therapeutic targets in classical Hodgkin lymphoma (cHL). The CD30 antibody-drug conjugate (ADC) brentuximab vedotin and the PD-1 antibodies nivolumab and pembrolizumab are highly efficacious in treating relapsed and/or refractory cHL. Ongoing studies are evaluating their efficacy in earlier lines of therapy and have demonstrated encouraging results. These agents are expected to further change the landscape of cHL management. Increased cure rates and reduced long-term toxicity from traditional chemotherapy and radiotherapy are likely with the emergence of these novel targeted therapies.

Immunotherapy for the Treatment of Hodgkin Lymphoma: An Evolving Paradigm

Classical Hodgkin lymphoma (cHL) is one of the most common lymphomas in the Western world. Although most patients are cured with standard first-line therapy, up to 20% of patients will have relapsed or refractory disease. Although the conventional approach to treatment has consisted of chemotherapy, radiation, and for those who relapse, autologous or allogeneic transplantation, newer approaches have become available in recent years, including immunoconjugates and checkpoint inhibitors. These approaches have shown significant efficacy in clinical trials and might be associated with fewer long-term toxicities compared with conventional therapies. In this review we discuss the biology of cHL as it pertains to the immunosuppressive tumor microenvironment and then review the existing clinical trial results of several emerging immunotherapies in this context, including immune checkpoint inhibitors and adoptive cellular therapy. Finally, several clinical practice issues pertaining to the use of immunotherapies are discussed.

Brentuximab vedotin: clinical updates and practical guidance

Brentuximab vedotin (BV), a potent antibody-drug conjugate, targets the CD30 antigen. Owing to the remarkable efficacy shown in CD30-positive lymphomas, such as Hodgkin's lymphoma and systemic anaplastic large-cell lymphoma, BV was granted accelerated approval in 2011 by the US Food and Drug Administration. Thereafter, many large-scale trials in various situations have been performed, which led to extensions of the original indication. The aim of this review was to describe the latest updates on clinical trials of BV and the in-practice guidance for the use of BV.

Understanding CD30 biology and therapeutic targeting: a historical perspective providing insight into future directions

CD30 is a member of the tumor necrosis factor receptor superfamily. It is characteristically expressed in certain hematopoietic malignancies, including anaplastic large cell lymphoma and Hodgkin lymphoma, among others. The variable expression of CD30 on both normal and malignant lymphoid cells has focused research efforts on understanding the pathogenesis of CD30 upregulation, its contribution to lymphomagenesis through anti-apoptotic mechanisms, and its effect on cell survival. Given the restriction of CD30 to certain tumor types, the logical extension of this has been to attempt to exploit it as a therapeutic target. The efficacy of naked anti-CD30 antibodies in practice was, however, modest. Moreover, combinations with bacterial toxins and radioimmunoconjugates have also had limited success. The development of the antibody-drug compound brentuximab vedotin (BV), however, has rejuvenated interest in CD30 as a tumor target. Phase I and II clinical trials in Hodgkin lymphoma, peripheral T-cell lymphoma, cutaneous T cell lymphoma, and even CD30-expressing B-cell lymphomas, have shown the compound is well tolerated, but more importantly, able to deliver meaningful disease control even in patients with multiply relapsed or refractory disease. FDA approval has been granted for its use in relapsed Hodgkin lymphoma and systemic anaplastic large cell lymphoma. A recent phase III trial of BV in cutaneous T-cell lymphoma has confirmed its superiority to standard of care therapies. In this manuscript, we explore the history of CD30 as a tumor marker and as a therapeutic target, both in the laboratory and in the clinic, with a view to understanding future avenues for further study.

The evolving role of targeted drugs in the treatment of Hodgkin lymphoma

INTRODUCTION

Hodgkin lymphoma (HL) is a B-cell-derived malignancy mostly affecting young adults. More than 80% of patients are cured after stage-adapted first-line treatment with chemotherapy and/or radiotherapy. About 50% of patients with disease recurrence achieve long-term remission with second-line treatment consisting of high-dose chemotherapy and autologous stem cell transplantation. However, HL treatment is often associated with acute toxicity and in part life-threatening late effects. Implementing targeted drugs may reduce toxicity and potentially further optimize efficacy. In recent years, the CD30-directed antibody-drug conjugate brentuximab vedotin (BV) and anti-PD-1 antibodies, nivolumab and pembrolizumab, underwent extensive evaluation in HL. They have exhibited encouraging single agent activity and a favorable toxicity profile in patients with multiple relapses. Therefore, they are currently under investigation in different additional indications. Areas covered: This article gives an overview over clinical trials evaluating targeted drugs either as single agent or as part of combination therapies in HL patients. Expert commentary: A multitude of targeted drugs are investigated in HL. Promising data have particularly emerged from studies with BV and anti-PD-1 antibodies. However, mature data needed for final conclusions are still pending.

Diagnostic, prognostic and therapeutic role of CD30 in lymphoma

INTRODUCTION

CD30 is a cell surface receptor expressed in classical Hodgkin lymphoma (HL), anaplastic large cell lymphoma (ALCL), and many other lymphomas to a variable degree. It has been identified as an important therapeutic target in lymphoma. Areas covered: CD30 testing is essential in diagnosis of classical HL and ALCL, and expression can also be seen in other lymphoma subtypes. Development of Brentuximab vedotin (BV), an antibody-drug conjugate directed to CD30, has been an important advance in lymphoma treatment. It is approved in treatment of relapsed HL and ALCL, as well as post-transplant maintenance for HL, and has been shown to be effective in other CD30-expressing lymphomas. This review describes the role of CD30 and the use of CD30-targeted agents in HL, ALCL, and other lymphomas, including review of relevant trials of BV. Expert commentary: Recognition of CD30 expression in lymphoma has led to the development of important therapeutic options. Multiple trials are ongoing combining BV with other agents, such as chemotherapy or immunotherapy, to develop more effective regimens. In addition, treatments targeting CD30 in different ways are being developed, such as bispecific antibodies and chimeric antigen receptor (CAR) T-cells.

Prognostic Biomarkers for Hodgkin Lymphoma

The prognosis of patients with classical Hodgkin lymphoma following chemo- and radiotherapy has been excellent during the last 4 decades. However, the development of secondary malignancies is of major concern. Therefore, the reduction of radiotherapy application is a major objective of ongoing clinical trials. De-escalation of treatment may increase the risk of relapses and thus may lead to reappearance of prognostic factors. Prognostic biomarkers might help to identify patients who are at increased risk of relapse. This review summarizes the current knowledge about potential prognostic biomarkers for patients with classical Hodgkin lymphoma.

Targeting CD30 in hodgkin lymphoma: antibody-drug conjugates make a difference

CD30 expression is characteristic of the malignant Reed-Sternberg cell in Hodgkin lymphoma (HL) and several other lymphoid malignancies, such as anaplastic large-cell lymphoma (ALCL). Although unconjugated anti-CD30 antibodies have had minimal therapeutic activity in patients with HL as single agents, the CD30-directed antibody-drug conjugate (ADC) brentuximab vedotin has demonstrated activity that has resulted in its recent regulatory approval for the treatment of patients with relapsed HL and ALCL. Approximately 75% of patients with recurrent HL achieve objective responses, with the principal toxicity being peripheral neuropathy. Ongoing studies are evaluating treatment with this agent as part of first-line therapy, for patients with relapsed disease, and for patients with resistant disease and limited other options. Brentuximab vedotin demonstrates the therapeutic value of antibody-drug conjugation and serves as a model of how a novel, targeted approach can be employed to potentially further improve outcomes in settings where curative chemotherapeutic regimens are already available.

The future of antiviral immunotoxins

There is a constant need for new therapeutic interventions in a wide range of infectious diseases. Over the past few years, the immunotoxins have entered the stage as promising antiviral treatments. Immunotoxins have been extensively explored in cancer treatment and have achieved FDA approval in several cases. Indeed, the design of new anticancer immunotoxins is a rapidly developing field. However, at present, several immunotoxins have been developed targeting a variety of different viruses with high specificity and efficacy. Rather than blocking a viral or cellular pathway needed for virus replication and dissemination, immunotoxins exert their effect by killing and eradicating the pool of infected cells. By targeting a virus-encoded target molecule, it is possible to obtain superior selectivity and drastically limit the side effects, which is an immunotoxin-related challenge that has hindered the success of immunotoxins in cancer treatment. Therefore, it seems beneficial to use immunotoxins for the treatment of virus infections. One recent example showed that targeting of virus-encoded 7 transmembrane (7TM) receptors by immunotoxins could be a future strategy for designing ultraspecific antiviral treatment, ensuring efficient internalization and hence efficient eradication of the pool of infected cells, both in vitro and in vivo. In this review, we provide an overview of the mechanisms of action of immunotoxins and highlight the advantages of immunotoxins as future anti-viral therapies.

Clinical Options in Relapsed or Refractory Hodgkin Lymphoma: An Updated Review

Hodgkin lymphoma (HL) is a potentially curable lymphoma, and modern therapy is expected to successfully cure more than 80% of the patients. Second-line salvage high-dose chemotherapy and autologous stem cell transplantation (auto-SCT) have an established role in the management of refractory and relapsed HL, leading to long-lasting responses in approximately 50% of relapsed patients and a minority of refractory patients. Patients progressing after intensive treatments, such as auto-SCT, have a very poor outcome. Allogeneic SCT represents the only strategy with a curative potential for these patients; however, its role is controversial. Based on recent knowledge of HL pathology, biology, and immunology, antibody-drug conjugates targeting CD30, small molecule inhibitors of cell signaling, and antibodies that inhibit immune checkpoints are currently explored. This review will discuss the clinical results regarding auto-SCT and allo-SCT as well as the current role of emerging new treatment strategies.

Strategies and Advancement in Antibody-Drug Conjugate Optimization for Targeted Cancer Therapeutics

Antibody-drug conjugates utilize the antibody as a delivery vehicle for highly potent cytotoxic molecules with specificity for tumor-associated antigens for cancer therapy. Critical parameters that govern successful antibody-drug conjugate development for clinical use include the selection of the tumor target antigen, the antibody against the target, the cytotoxic molecule, the linker bridging the cytotoxic molecule and the antibody, and the conjugation chemistry used for the attachment of the cytotoxic molecule to the antibody. Advancements in these core antibody-drug conjugate technology are reflected by recent approval of Adectris(®) (anti-CD30-drug conjugate) and Kadcyla(®) (anti-HER2 drug conjugate). The potential approval of an anti-CD22 conjugate and promising new clinical data for anti-CD19 and anti-CD33 conjugates are additional advancements. Enrichment of antibody-drug conjugates with newly developed potent cytotoxic molecules and linkers are also in the pipeline for various tumor targets. However, the complexity of antibody-drug conjugate components, conjugation methods, and off-target toxicities still pose challenges for the strategic design of antibody-drug conjugates to achieve their fullest therapeutic potential. This review will discuss the emergence of clinical antibody-drug conjugates, current trends in optimization strategies, and recent study results for antibody-drug conjugates that have incorporated the latest optimization strategies. Future challenges and perspectives toward making antibody-drug conjugates more amendable for broader disease indications are also discussed.

Peripheral T-cell and NK cell lymphoproliferative disorders: cell of origin, clinical and pathological implications

T-cell lymphoproliferative disorders are a heterogeneous group of neoplasms with distinct clinical-biological properties. The normal cellular counterpart of these processes has been postulated based on functional and immunophenotypic analyses. However, T lymphocytes have been proven to be remarkably capable of modulating their properties, adapting their function in relationship with multiple stimuli and to the microenvironment. This impressive plasticity is determined by the equilibrium among a pool of transcription factors and by DNA chromatin regulators. It is now proven that the acquisition of specific genomic defects leads to the enforcement/activation of distinct pathways, which ultimately alter the preferential activation of defined regulators, forcing the neoplastic cells to acquire features and phenotypes distant from their original fate. Thus, dissecting the landscape of the genetic defects and their functional consequences in T-cell neoplasms is critical not only to pinpoint the origin of these tumors but also to define innovative mechanisms to re-adjust an unbalanced state to which the tumor cells have become addicted and make them vulnerable to therapies and targetable by the immune system. In our review, we briefly describe the pathological and clinical aspects of the T-cell lymphoma subtypes as well as NK-cell lymphomas and then focus on the current understanding of their pathogenesis and the implications on diagnosis and treatment.

Recent advances in antibody-based therapies for Hodgkin Lymphoma

Although a poster child for the development and refinement of multi-modal multi-agent therapeutic strategies, Hodgkin Lymphoma has, until recently, lagged behind other lymphomas in terms of the use of therapeutic monoclonal antibodies. This situation has now changed dramatically, with the rapid emergence both of a toxin-conjugated tumour-selective anti-CD30 antibody, and of antibodies targeting immunological checkpoints, most notably PD-1 (also termed PDCD1). The former provides an efficient targeting vehicle for delivery of a potent synthetic anti-mitotic drug, with ultimate efficacy independent of immunological activity. The latter are members of a class of drugs representing a new paradigm in immune-oncological therapies that are designed to enhance pre-existent anti-tumour T cell activities. The role of both in the overall treatment pathway will continue to evolve over coming years. Hodgkin Lymphoma has once again become emblematic of the major trend shifts in cancer therapy.

Management of relapsed or refractory hodgkin lymphoma with second-generation antibody-drug conjugates: focus on brentuximab vedotin

Brentuximab vedotin (Adcetris, Seattle Genetics) is an antibody-drug conjugate (ADC) that joins an anti-CD 30 monoclonal antibody with the anti-tubulin agent monomethyl auristatin E via a dipeptide linker. It has demonstrated significant activity in CD 30-positive lymphomas and is currently approved by the US FDA for treatment of Hodgkin lymphoma that has relapsed following autologous stem-cell transplantation, or after two lines of chemotherapy in non-transplant candidates. Brentuximab vedotin has also been approved for the treatment of relapsed anaplastic large-cell lymphoma after front-line chemotherapy. We briefly review the biology of Hodgkin lymphoma, with a focus on the pathogenic role of CD 30 as well as the development of CD 30-targeted therapy. We also discuss both the current role of brentuximab vedotin in the management of relapsed and refractory Hodgkin lymphoma and the likely future developments for this agent.

Primary nodal peripheral T-cell lymphomas: diagnosis and therapeutic considerations

Nodal peripheral T-cell lymphomas are a rare group of neoplasms derived from post-thymic and activated T lymphocytes. A review of scientific articles listed in PubMed, Lilacs, and the Cochrane Library databases was performed using the term “peripheral T-cell lymphomas”. According to the World Health Organization classification of hematopoietic tissue tumors, this group of neoplasms consists of peripheral T-cell lymphoma not otherwise specified (PTCL-NOS), angioimmunoblastic T-cell lymphoma (AITL), anaplastic large cell lymphoma-anaplastic lymphoma kinase positive (ALCL-ALK⁺), and a provisional entity called anaplastic large cell lymphoma-anaplastic lymphoma kinase negative (ALCL-ALK⁻). Because the treatment and prognoses of these neoplasms involve different principles, it is essential to distinguish each one by its clinical, immunophenotypic, genetic, and molecular features. Except for anaplastic large cell lymphoma-anaplastic lymphoma kinase positive, which has no adverse international prognostic index, the prognosis of nodal peripheral T-cell lymphomas is worse than that of aggressive B-cell lymphomas. Chemotherapy based on anthracyclines provides poor outcomes because these neoplasms frequently have multidrug-resistant phenotypes. Based on this, the current tendency is to use intensified cyclophosphamide, doxorubicin, vincristine, prednisolone (CHOP) regimens with the addition of new drugs, and autologous hematopoietic stem cell transplantation. This paper describes the clinical features and diagnostic methods, and proposes a therapeutic algorithm for nodal peripheral T-cell lymphoma patients.

A novel antibody-drug conjugate targeting SAIL for the treatment of hematologic malignancies

Although several new therapeutic approaches have improved outcomes in the treatment of hematologic malignancies, unmet need persists in acute myeloid leukemia (AML), multiple myeloma (MM) and non-Hodgkin's lymphoma. Here we describe the proteomic identification of a novel cancer target, SAIL (Surface Antigen In Leukemia), whose expression is observed in AML, MM, chronic lymphocytic leukemia (CLL), diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL). While SAIL is widely expressed in CLL, AML, MM, DLBCL and FL patient samples, expression in cancer cell lines is mostly limited to cells of AML origin. We evaluated the antitumor activity of anti-SAIL monoclonal antibodies, 7-1C and 67-7A, conjugated to monomethyl auristatin F. Following internalization, anti-SAIL antibody–drug conjugates (ADCs) exhibited subnanomolar IC₅₀ values against AML cell lines in vitro. In pharmacology studies employing AML cell line xenografts, anti-SAIL ADCs resulted in significant tumor growth inhibition. The restricted expression profile of this target in normal tissues, the high prevalence in different types of hematologic cancers and the observed preclinical activity support the clinical development of SAIL-targeted ADCs.

CD30 as a therapeutic target for lymphoma

Hodgkin's lymphoma (HL) and ALK(+) anaplastic large-cell lymphoma (ALCL) have become highly curable due to the success of modern regimens of chemotherapy and radiotherapy. However, up to one-third of the patients experience relapse or do not respond to first-line therapy, and half of them relapse again after secondary therapy with limited options for further treatment. In the last 15 years, monoclonal antibodies (mAbs) directed to surface receptors became a new and valuable therapeutic option in many hematologic malignancies. Due to its restricted expression on normal activated lymphocytes and its high expression on malignant cells, CD30 represents an attractive target molecule for HL and ALCL therapy. However, unconjugated CD30 mAbs have demonstrated a lack of objective clinical responses in patients with recurrent HL. CD30 exhibits complex signaling pathways, and binding of its natural ligand or anti-CD30 mAbs can induce apoptosis but may also promote proliferation and activation depending on the cellular context. Moreover, CD30 rapidly internalizes after crosslinking, which counteracts efficient recruitment of immunologic effectors but also provides the opportunity to transfer cytotoxic payloads coupled to CD30-specific mAbs into the tumor cells. Several tumor targeting approaches have been studied, including radio-immunoconjugates, immunotoxins, immunoRNases, immunokinases, and antibody drug conjugates (ADCs). In 2011, the ADC brentuximab-vedotin, consisting of the CD30-specific chimeric mAb cAC10 and the potent tubulin toxin monomethyl auristatin E, gained regulatory approval as a well tolerated and highly active drug in patients with refractory and relapsed HL and ALCL. SGN-35 is on the way to being incorporated in the standard management of CD30(+) lymphoma with significant therapeutic impact. This review gives a critical overview about anti-CD30 therapies with unconjugated, engineered, and conjugated mAbs and the therapeutic challenges of treatment of CD30(+) lymphoma.

Brentuximab vedotin in relapsed/refractory Hodgkin lymphoma post-autologous transplant: meta-analysis versus historical data

OBJECTIVE

This meta-analysis evaluated the antitumor activity of brentuximab vedotin versus historical values in patients with relapsed/refractory Hodgkin lymphoma post-autologous stem cell transplantation (ASCT).

METHODS

A systematic literature review identified studies (1993-February 2013) reporting complete remission (CR) rates in patients with relapsed/refractory Hodgkin lymphoma post-ASCT. Publications reporting CR rates, identified through interrogation of multiple electronic databases and manual searches (with search terms used to capture 'relapsed', 'refractory', 'HL', and 'ASCT'), were included if they reported: ≥20 relapsed/refractory Hodgkin lymphoma patients, where ≥80% were aged ≥12 years and ≥50% had failed prior ASCT. Overall CR rate was determined using a random-effect model, and compared with that reported for brentuximab vedotin in a pivotal phase 2 trial (SG035-0003).

MAIN OUTCOME MEASURES

Across 17 evaluable studies of historical or experimental agents (n = 812), the estimated overall CR rate was 11.1% (95% confidence interval [CI] 7.0, 17.6; range, 0-38.5%) versus 33.3% (95% CI 25.3, 43.9) for brentuximab vedotin (p < 0.0001). In sensitivity analyses, the estimated overall CR rates for historical/experimental agents were 13.6% (95% CI 8.7, 21.4) when only HL trials that reported a CR rate of >0% were included (13 studies; n = 696; p = 0.0009 vs. brentuximab vedotin), and 9.0% (95% CI 4.9, 16.6) when only HL trials were included where CR definition was reported and was measured using the same criteria as in the SG035-0003 study (12 studies; n = 562; p = 0.0001 vs. brentuximab vedotin).

CONCLUSIONS

Indirect comparisons against a heterogeneous historical sample population naturally limit our ability to draw comparisons, yet the results from this quantitative meta-analysis suggest that the antitumor activity of brentuximab vedotin may exceed that of other therapies used to treat patients with relapsed/refractory Hodgkin lymphoma post-ASCT.

Achieving incompatible transplantation through desensitization: current perspectives and future directions

The application of life-saving transplantation is severely limited by the shortage of organs, and histoincompatibility. To increase transplant rates in sensitized patients, new protocols for HLA and blood type incompatible (ABOi) desensitization have emerged. These approaches require significant desensitization using intravenous immunoglobulin, rituximab and plasma exchange. In addition, the development of donor-specific antibody responses post transplant is the major cause of allograft failure with return to dialysis. This increases patient morbidity/mortality and cost. Immunotherapeutic agents used for desensitization evolved from drug development in oncology and autoimmune diseases. Currently, there is a renaissance in development of novel drugs likely to improve antibody reduction in transplantation. These include agents that inactivate IgG molecules, anticytokine antibodies, costimulatory molecule blockade, anticomplement agents and therapies aimed at the plasma cell.

The epidemiology and targeted therapies for relapsed and refractory CD30+ lymphomas

BACKGROUND

Hodgkin lymphoma (HL) and systemic anaplastic large cell lymphoma (sALCL) both have consistent expression of CD30, a cytokine receptor that is expressed by activated T and B cells but is largely absent from normal tissue.

METHODS

A literature search was conducted via PubMed, Google Scholar, and UpToDate to identify relevant peer-reviewed original research or review articles on HL, sALCL, and CD30 targeted therapies.

RESULTS

These lymphomas are both more common among males, young adults and the elderly. Although many patients with HL and sALCL can achieve long-term remission after standard first-line therapy, up to a third of these patients are refractory to or relapse after initial therapy. Among these relapsed/refractory patients, many experience disease progression and/or death despite subsequent treatment, and treatment-related adverse events and mortality are not uncommon. To address the need for safer and more effective therapies for these relapsed/refractory patients, researchers have developed therapies that specifically target CD30-expressing cells. Brentuximab vedotin, an antibody-drug conjugate that selectively delivers a toxic microtubule-disrupting agent to malignant cells with CD30 expression, is the first such therapy to be approved in the US and Europe. In clinical trials, brentuximab vedotin has demonstrated efficacy and safety in patients with HL after failure of autologous stem cell transplantation (ASCT), or after failure of at least two prior multi-agent chemotherapy regimens in patients who are not ASCT candidates, and in patients with sALCL after failure of at least one prior multi-agent chemotherapy regimen.

CONCLUSION

HL and sALCL are both CD30+ lymphomas, and therapies like brentuximab vedotin that target cells expressing CD30 hold promise for the treatment of these diseases.

Role of CD30 targeting in malignant lymphoma

CD30 is an important therapeutic target for the treatment of malignant lymphomas. CD30 is a member of the TNF cell receptor superfamily and is highly expressed in a variety of lymphoma subsets, including Hodgkin lymphoma and anaplastic large cell lymphoma. Initial studies evaluated the safety and efficacy of several monoclonal antibodies targeting CD30, with limited success. More recently, the anti-CD30 drug-conjugate brentuximab vedotin produced high response rates with an excellent safety profile. These results lead to the approval of brentuximab vedotin for the treatment of patients with relapsed Hodgkin lymphoma and anaplastic large cell lymphoma. Current studies are focusing on incorporating brentuximab vedotin in front-line regimens and expanding its potential clinical utility in other CD30-expressing malignancies.

Advances in understanding the pathogenesis of systemic anaplastic large cell lymphomas

The currently used 2008 World Health Organization classification recognizes two types of systemic anaplastic large T cell lymphoma according to ALK protein expression in tumour cells. First, the 'anaplastic large cell lymphoma, ALK positive' (ALK(+) ALCL) that is characterized by the presence of ALK gene rearrangements and consequent ALK protein expression, and, second, the 'anaplastic large cell lymphoma, ALK negative' (ALK(-) ALCL) that is a provisional entity lacking ALK protein expression but cannot be distinguished morphologically from ALK(+) ALCL. In this review we summarize the current knowledge on the genetic lesions and biological features that underlie the pathogenesis of ALK(+) and the ALK(-) ALCL and that can lead to the use of targeted anti-cancer agents.

Targeted cancer immunotherapy via combination of designer bispecific antibody and novel gene-engineered T cells

Background

Redirection of T lymphocytes against tumor antigens can induce dramatic regression of advanced stage malignancy. The use of bispecific antibodies (BsAbs) that bind both the T-cell receptor (TCR) and a target antigen is one promising approach to T-cell redirection. However, BsAbs indiscriminately bind all CD3+ T-cells and trigger TCR activation in the absence of parallel costimulatory signals required to overcome T-cell unresponsiveness or anergy.

Methods

To address these limitations, a combination platform was designed wherein a unique BsAb referred to as frBsAb exclusively engages T-cells engineered to express a novel chimeric receptor comprised of extracellular folate receptor fused to intracellular TCR and CD28 costimulatory signaling domains in tandem; a BsAb-binding immune receptor (BsAb-IR). As a surrogate TCR, the BsAb-IR allows for concomitant TCR and costimulatory signaling exclusively in transduced T-cells upon engagement with specific frBsAbs, and can therefore redirect T-cells on command to desired antigen. Human primary T-cells were transduced with lentiviral vector and expanded for 14–18 days. BsAb-IRs were harvested and armed with frBsAbs to test for redirected cytotoxicity against CD20 positive cancer cell lines.

Results

Using frBsAbs specific for CD20 or HER2, the lytic activity of primary human T-cells expressing the BsAb-IR was specifically redirected against CD20+ leukemic cells or HER2+ epithelial cancer cells, respectively, while non-engineered T-cells were not activated. Notably, elimination of the CD28 costimulatory domain from the BsAb-IR construct significantly reduced frBsAb-redirected antitumor responses, confirming that frBsAbs are capable of delivering simultaneous TCR activation and costimulatory signals to BsAb-IR T-cells.

Conclusion

In summary, our results establish the proof of concept that the combination of BsAbs with optimized gene-engineered T-cells provides the opportunity to specify and augment tumor antigen-specific T-cell activation and may improve upon the early success of conventional BsAbs in cancer immunotherapy.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-014-0347-2) contains supplementary material, which is available to authorized users.