CD52 expression in peripheral T-cell lymphomas determined by combined immunophenotyping using tumor cell specific T-cell receptor antibodies

Novel clinical risk stratification and treatment strategies in relapsed/refractory peripheral T-cell lymphoma

Peripheral T cell lymphoma (PTCL) represents a group of heterogeneous hematological malignancies, which are notoriously challenging to treat and outcomes are typically poor. Over the past two decades, clinical prognostic indices for patient risk stratification have evolved, while several targeted agents are now available to complement combination chemotherapy in the frontline setting or as a salvage strategy. With further understanding of the molecular pathobiology of PTCL, several innovative approaches incorporating immunomodulatory agents, epigenetic therapies, oncogenic kinase inhibitors and immunotherapeutics have come to the forefront. In this review, we provide a comprehensive overview of the progress in developing clinical prognostic indices for PTCL and describe the broad therapeutic landscape, emphasizing novel targetable pathways that have entered early phase clinical studies.

Melatonin: a modulator in metabolic rewiring in T-cell malignancies

Melatonin, (N-acetyl-5-methoxytryptamine) an indoleamine exerts multifaced effects and regulates numerous cellular pathways and molecular targets associated with circadian rhythm, immune modulation, and seasonal reproduction including metabolic rewiring during T cell malignancy. T-cell malignancies encompass a group of hematological cancers characterized by the uncontrolled growth and proliferation of malignant T-cells. These cancer cells exhibit a distinct metabolic adaptation, a hallmark of cancer in general, as they rewire their metabolic pathways to meet the heightened energy requirements and biosynthesis necessary for malignancies is the Warburg effect, characterized by a shift towards glycolysis, even when oxygen is available. In addition, T-cell malignancies cause metabolic shift by inhibiting the enzyme pyruvate Dehydrogenase Kinase (PDK) which in turn results in increased acetyl CoA enzyme production and cellular glycolytic activity. Further, melatonin plays a modulatory role in the expression of essential transporters (Glut1, Glut2) responsible for nutrient uptake and metabolic rewiring, such as glucose and amino acid transporters in T-cells. This modulation significantly impacts the metabolic profile of T-cells, consequently affecting their differentiation. Furthermore, melatonin has been found to regulate the expression of critical signaling molecules involved in T-cell activations, such as CD38, and CD69. These molecules are integral to T-cell adhesion, signaling, and activation. This review aims to provide insights into the mechanism of melatonin's anticancer properties concerning metabolic rewiring during T-cell malignancy. The present review encompasses the involvement of oncogenic factors, the tumor microenvironment and metabolic alteration, hallmarks, metabolic reprogramming, and the anti-oncogenic/oncostatic impact of melatonin on various cancer cells.

Emerging predictive biomarkers for novel therapeutics in peripheral T-cell and natural killer/T-cell lymphoma

Peripheral T-cell lymphoma (PTCL) and natural killer/T-cell lymphoma (NKTCL) are rare subtypes of non-Hodgkin's lymphoma that are typically associated with poor treatment outcomes. Contemporary first-line treatment strategies generally involve the use of combination chemoimmunotherapy, radiation and/or stem cell transplant. Salvage options incorporate a number of novel agents including epigenetic therapies (e.g. HDAC inhibitors, DNMT inhibitors) as well as immune checkpoint inhibitors. However, validated biomarkers to select patients for individualized precision therapy are presently lacking, resulting in high treatment failure rates, unnecessary exposure to drug toxicities, and missed treatment opportunities. Recent advances in research on the tumor and microenvironmental factors of PTCL and NKTCL, including alterations in specific molecular features and immune signatures, have improved our understanding of these diseases, though several issues continue to impede progress in clinical translation. In this Review, we summarize the progress and development of the current predictive biomarker landscape, highlight potential knowledge gaps, and discuss the implications on novel therapeutics development in PTCL and NKTCL.

Interleukin-15 augments NK cell-mediated ADCC of alemtuzumab in patients with CD52+ T-cell malignancies

Interleukin-15 (IL-15) monotherapy substantially increases the number and activity of natural killer (NK) cells and CD8+ T cells but has not produced clinical responses. In a xenograft mouse model, IL-15 enhanced the NK cell-mediated antibody-dependent cell cytotoxicity (ADCC) of the anti-CD52 antibody alemtuzumab and led to significantly more durable responses than alemtuzumab alone. To evaluate whether IL-15 potentiates ADCC in humans, we conducted a phase 1 single-center study of recombinant human IL-15 and alemtuzumab in patients with CD52-positive mature T-cell malignances. We gave IL-15 subcutaneously 5 days per week for 2 weeks in a 3 + 3 dose escalation scheme (at 0.5, 1, and 2 μg/kg), followed by standard 3 times weekly alemtuzumab IV for 4 weeks. There were no dose-limiting toxicities or severe adverse events attributable to IL-15 in the 11 patients treated. The most common adverse events were lymphopenia (100%), alemtuzumab-related infusion reactions (90%), anemia (90%), and neutropenia (72%). There were 3 partial and 2 complete responses, with an overall response rate of 45% and median duration of response 6 months. Immediately after 10 days of IL-15, there was a median 7.2-fold increase in NK cells and 2.5-fold increase in circulating CD8+ T cells, whereas the number of circulating leukemic cells decreased by a median 38% across all dose levels. Treatment with IL-15 was associated with increased expression of NKp46 and NKG2D, markers of NK-cell activation, and increased ex vivo ADCC activity of NK cells, whereas inhibitory receptors PD1 and Tim3 were decreased. This trial was registered at www.clinicaltrials.gov as #NCT02689453.

Biomarker-driven management strategies for peripheral T cell lymphoma

Peripheral T cell lymphomas are heterogeneous diseases which remain treatment challenges. Recent advances in molecular and genomic profiling have provided unprecedented insight into disease pathogenesis driven by distinct cells of origins and molecular pathways. The discovery and clinical application of molecular biomarkers in PTCL subtypes has the potential to transform personalized care for patients with PTCL in diagnosis, prognosis, and therapy. Targeting CD30+ PTCL with the antibody-drug conjugate brentuximab vedotin in the relapsed setting and in combination with chemotherapy in the frontline setting has improved patient survivals. Epigenetic modifying agents, including HDAC inhibitors and hypomethylating agents, have demonstrated broad clinical efficacy and durability and are in clinical development for combination strategies for both relapsed and frontline settings. Wide-ranging novel agents targeting critical intracellular pathways and tumor microenvironment are in active exploration to define clinical activities. This review summarizes PTCL-specific biomarkers which are increasingly incorporated in clinical practice to guide precision diagnosis and personalized treatment.

Peripheral T-Cell Lymphoma, not Otherwise Specified (PTCL-NOS)

Peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS) is a World Health Organization (WHO)-defined diagnostic category within the highly heterogeneous group of mature post-thymic T-cell neoplasms. It is the most common subtype of mature post-thymic T-cell neoplasms globally, accounting for up to 35% of PTCL cases in Europe and North America. PTCL-NOS is a diagnosis of exclusion, comprising several disease entities that differ in biology, clinical presentation, and outcome. The diagnosis of PTCL-NOS is made based on the presence of typical histopathological features of lymphoma, an aberrant T-cell immunophenotype, often with a loss of CD5 and CD7, and a clonal T-cell receptor (TCR) gene rearrangement, in the appropriate clinical context. Unlike other types of T-cell lymphoma, recurrent mutations to assist with the diagnosis have not been identified. Patients often present with advanced stage. Prognosis is poor, with a 5-year overall survival (OS) of 20-30%. Anthracycline-based combination chemotherapy remains the most frequently used frontline strategy, with overall response rates (ORR) of 50-60%, and complete response rates (CRR) of 20-30%. Prospective studies with intent-to-treat analyses have shown that consolidation with high-dose chemotherapy and autologous stem cell transplant (ASCT) results in progression-free survivals (PFS) that compare favorably with historical cohorts and may improve OS in selected patient populations. However, randomized data are still lacking. Over the past decade, therapeutic agents approved in the relapsed and refractory setting have produced response rates of up to 33% and median PFS up to 18 months. Overall, outcomes remain poor and there is a dire need for more effective treatments. This review discusses the latest information on the diagnosis and treatment of PTCL-NOS.

Impact of alemtuzumab on HIV persistence in an HIV-infected individual on antiretroviral therapy with Sezary syndrome

OBJECTIVE

To study the effects of alemtuzumab on HIV persistence in an HIV-infected individual on antiretroviral therapy (ART) with Sezary syndrome, a rare malignancy of CD4 T cells.

DESIGN

Case report.

METHODS

Blood was collected 30 and 18 months prior to presentation with Sezary syndrome, at the time of presentation and during alemtuzumab. T-cell subsets in malignant (CD7-CD26-TCR-VBeta2+) and nonmalignant cells were quantified by flow cytometry. HIV-DNA in total CD4 T cells, in sorted malignant and nonmalignant CD4 T cells, was quantified by PCR and clonal expansion of HIV-DNA assessed by full-length next-generation sequencing.

RESULTS

HIV-hepatitis B virus coinfection was diagnosed and antiretroviral therapy initiated 4 years prior to presentation with Sezary syndrome and primary cutaneous anaplastic large cell lymphoma. The patient received alemtuzumab 10 mg three times per week for 4 weeks but died 6 weeks post alemtuzumab. HIV-DNA was detected in nonmalignant but not in malignant CD4 T cells, consistent with expansion of a noninfected CD4 T-cell clone. Full-length HIV-DNA sequencing demonstrated multiple defective viruses but no identical or expanded sequences. Alemtuzumab extensively depleted T cells, including more than 1 log reduction in total T cells and more than 3 log reduction in CD4 T cells. Finally, alemtuzumab decreased HIV-DNA in CD4 T cells by 57% but HIV-DNA remained detectable at low levels even after depletion of nearly all CD4 T cells.

CONCLUSION

Alemtuzumab extensively depleted multiple T-cell subsets and decreased the frequency of but did not eliminate HIV-infected CD4 T cells. Studying the effects on HIV persistence following immune recovery in HIV-infected individuals who require alemtuzumab for malignancy or in animal studies may provide further insights into novel cure strategies.

The Comparative Diagnostic Features of Canine and Human Lymphoma

The non-Hodgkin lymphomas (NHLs) are a heterogeneous family of lymphoid malignancies that are among the most common neoplasms of both dogs and humans. Owing to shared molecular, signaling, incidence, and pathologic features, there is a strong framework supporting the utilization of canine lymphoma as a comparative, large animal model of human NHL. In alignment with the biologic similarities, the current approach towards the diagnosis and classification of canine lymphoma is based upon the human World Health Organization guidelines. While this approach has contributed to an increasing appreciation of the potential biological scope of canine lymphoma, it has also become apparent that the most appropriate diagnostic philosophy must be multimodal, namely by requiring knowledge of microscopic, immunophenotypic, and clinical features before establishing a final disease diagnosis. This review seeks to illustrate the comparative similarities and differences in the diagnosis of canine lymphoma through the presentation of the microscopic and immunophenotypic features of its most common forms.

Hepatosplenic γδ T-cell lymphoma: an overview

Peripheral T-cell lymphomas are a heterogeneous group of lymphoid malignancies. Among these, hepatosplenic γδ T-cell lymphoma (HTCL) represents an aggressive and treatment-resistant subgroup for which new avenues of treatment are critically needed. HTCL is characterized by primary extranodal distribution of the malignant cells with typical intrasinusoidal infiltration of the liver, spleen, and bone marrow, which results in hepatosplenomegaly and peripheral blood cytopenias. Another characteristic feature is the expression of γδ T-cell receptors. HTCL exhibits a rapid progressive course and an extremely poor response to currently known therapeutic strategies, with a 5-year overall survival rate of only 7%. In this review, we discuss the clinical, pathologic, and molecular characteristics of this disease, along with the challenges that are associated with its diagnosis and treatment.

Intensified chemo-immunotherapy with or without stem cell transplantation in newly diagnosed patients with peripheral T-cell lymphoma

Peripheral T-cell lymphomas (PTCLs) receiving conventional treatment have a poor clinical outcome. We conducted a phase II study to evaluate the feasibility and efficacy of chemo-immunotherapy in young (⩽60 years old, Clin A study) and elderly (>60 and < or =75 years old, Clin B study) patients with newly diagnosed PTCL. Clin A patients (n=61) received two courses of CHOP (cyclophosphamide, adriamycin, vincristine, prednisone)-21 with alemtuzumab (AL, 30 mg) followed by two courses of high-dose chemotherapy. On the basis of donor availability, patients in response received allogeneic (allo) or autologous (auto) stem cell transplantation (SCT). Clin B patients (n=25) received six courses of CHOP-21 and AL (10 mg). Clin A responding patients were 38 of 61 (62%) and received alloSCT (n=23) or autoSCT (n=14); one complete remission (CR) patient was not transplanted. At a median follow-up of 40 months, the 4-year overall survival (OS), progression-free survival (PFS) and disease-free survival (DFS) rates were 49, 44 and 65%, respectively. In Clin B study, the response rate was 72%. At a median follow-up of 48 months, the 4-year OS, PFS and DFS rates were 31, 26 and 44%, respectively. In conclusion, front-line alloSCT or autoSCT is effective in prolonging DFS in young patients; AL in elderly improved response with no survival benefit.

New molecular insights into peripheral T cell lymphomas

Peripheral T cell lymphomas (PTCLs) are heterogeneous neoplasms and represent about 12% of all lymphoid malignancies. They are often regarded as "orphan diseases," a designation that does not reflect their real incidence but rather signifies the difficulties encountered in their classification, diagnosis, and treatment. Here we revise the current understanding of the pathobiological characteristics of the most common nodal PTCLs by focusing on the contribution given by high-throughput technologies and the identification of potential therapeutic targets proposed by translational studies.

Novel treatment avenues for peripheral T-cell lymphomas

INTRODUCTION

Peripheral T-cell lymphomas (PTCLs) and natural killer (NK) or T-cell non-Hodgkin's lymphomas (NHLs) are a rare and heterogeneous class of diseases with generally poor prognosis. This work intends to provide a focused primer on clinical diagnosis, current treatment regimens, and novel therapeutic approaches. The recent WHO classification has defined 18 different subtypes of PTCL and NK T-cell lymphomas. Diagnosis is mainly based on histology, flow-cytometric analysis of surface molecules in the blood and bone marrow, cytogenetics/fluorescence in situ hybridization (FISH), and T-cell receptor (TCR) rearrangement. Staging as well as follow-up diagnostic procedures rely on imaging techniques such as computerized tomography (CT) and positron emission tomography (PET). Current chemotherapeutic regimens such as CHOP result in a 60 - 70% response rate; however, 5-year survival is only around 30%. Therefore, new treatment strategies are urgently needed. Currently, different drug classes are under scrutiny.

AREAS COVERED

The authors discuss substances that directly target the tumor cells. The article includes such substances as antimetabolites, antibodies, histone deacetylase inhibitors, tyrosine kinase inhibitors, and immunomodulatory substances such as lenalidomide.

EXPERT OPINION

In the future a close collaboration of geneticists, biochemists, and clinicians together with new technologies such as deep sequencing will allow the refinement of treatment strategies in many diseases including PTCLs and NHLs. This refinement will allow treatments to be prepared according to the need of the individual patient.

Targeted molecular therapy in peripheral T-cell lymphomas

Peripheral T-cell lymphomas (PTCLs) are rare neoplasms constituting a heterogeneous group of diseases. At present, available chemotherapy regimens that have improved outcomes in B-cell lymphomas appear to be less efficacious in the context of PTCLs and, thus, alternative strategies are warranted. In the last few years, based on the recent, deeper understanding of PTCL biology, several molecules and/or pathways have been proposed for targeted therapy in this setting, including surface antigens, tyrosine kinases, the NF-κB pathway, folate metabolism, histone modification and others. Of particular interest, histone deacetylase and proteasome inhibitors, as well as novel chemotherapeutic agents such as pralatrexate, have already demonstrated efficacy in PTCL therapy. In addition, a strong biological rationale and early clinical evidence supports the future study of tyrosine kinase inhibitors in this setting. In this article, the authors review the available literature on targeted therapy in PTCLs and also, based on their own experience, discuss potential opportunities in this intriguing area.

New drug therapies in peripheral T-cell lymphoma

Peripheral T-cell lymphomas (PTCLs) are a heterogeneous collection of lymphomas that are associated with very poor prognosis. Conventional therapies, historically based on protocols for aggressive B-cell lymphomas, deliver less than adequate outcomes; the majority of patients experience early relapse after front-line treatment and current 5-year overall survival is only 10-30%. Clearly, new approaches are needed. In recent years there has been a plethora of novel agents showing activity in PTCL, often in patients with advanced relapsed or refractory disease. These agents include antifolate drugs (pralatrexate), histone deacetylase inhibitors (vorinostat, romidepsin, panobinostat and belinostat), nucleoside analogues (gemcitabine, forodesine and clofarabine), monoclonal antibodies (anti-CD52, anti-CD4 and anti-CD2), fusion toxins (denileukin diftitox), immunomodulatory agents (lenalidomide) and proteasome inhibitors (bortezomib). This is an exciting time in the treatment of PTCL, as our ever improving understanding of the distinguishing features, pathogenesis, molecular biology and progression of PTCL, and the knowledge of the mechanism and efficacy of novel therapies, may see a real improvement in outcomes for patients. The purpose of this article is to focus on these novel therapies and the results of recent clinical trials in PTCL.

Molecular predictors of response in aggressive T-cell lymphomas

Aggressive T-cell lymphomas are a heterogeneous group of malignancies of mature T and natural killer cells, many of which have recently been identified as distinct entities in the classification of non-Hodgkin lymphomas according to the World Health Organization. Owing in part to a limited understanding of the molecular features and pathogenesis of many of these disorders, treatment strategies using conventional lymphoma regimens have been used, with generally inferior outcomes. Recent data are now emerging from gene expression profiling and molecular analysis of tumors, which has led to development of novel, targeted therapeutic strategies and has provided a basis for more accurate diagnosis and prognostic characterization.

CD52 as a molecular target for immunotherapy to treat acute myeloid leukemia with high EVI1 expression

Ecotropic viral integration site 1 (EVI1) is an oncogenic transcription factor in human acute myeloid leukemia (AML) with chromosomal alterations at 3q26. Because a high expression of EVI1 protein in AML cells predicts resistance to chemotherapy with a poor outcome, we have searched for molecular targets that will treat these patients with AML. In this study, we determined that CD52, which is mainly expressed on lymphocytes, is highly expressed in most cases of AML with a high EVI1 expression (EVI1(High)). CAMPATH-1H, a humanized monoclonal antibody against CD52, has been used to prevent graft-versus-host disease and treat CD52-positive lymphoproliferative disorders. Here, we investigated the antitumor effect of CAMPATH-1H on EVI1(High) AML cells. CAMPATH-1H significantly inhibited cell growth and induced apoptosis in CD52-positive EVI1(High) leukemia cells. Furthermore, CAMPATH-1H induced complement-dependent cytotoxicity and antibody-dependent cellular cytotoxicity against CD52-positive EVI1(High) leukemia cells. After an intravenous injection of CAMPATH-1H into NOD/Shi-scid/IL-2Rγ;null mice with subcutaneous engraftment of EVI1(High) leukemia cells, tumor growth rates were significantly reduced, and the mice survived longer than those in the phosphate-buffered saline-injected control group. Thus, CAMPATH-1H is a potential therapeutic antibody for the treatment of patients with EVI1(High) leukemia.

Intensified alemtuzumab-CHOP therapy for peripheral T-cell lymphoma

BACKGROUND

The prognosis of T-cell lymphoma is poor. To explore the addition of the monoclonal antibody alemtuzumab, we studied the efficacy and tolerability of an intensified alemtuzumab-chemotherapy combination for aggressive T-cell lymphoma in a phase II study by Dutch-Belgian Hemato-Oncology Group (HOVON).

PATIENTS AND METHODS

Patients (≤65 years) with newly diagnosed T-cell lymphoma received eight CHOP cycles (cyclophosphamide, doxorubicin, vincristine, prednisone) 2-weekly, each cycle with three doses of 30 mg alemtuzumab. Prophylaxis consisted of cotrimoxazole, fluconazole and valaciclovir. Cytomegalovirus (CMV) monitoring took place at least every fortnight.

RESULTS

Twenty patients from 10 centers, median age 50 years, were included. Eighty-five percent received six or more cycles. The overall response was 90% [12 complete remissions (CRs), 1 CR unconfirmed, 5 partial remissions]. Median duration of follow-up of patients still alive was 29 months (range 19-41 months). Median overall survival (OS) and event-free survival (EFS) were 27 and 10 months, with 55%/27% OS/EFS at 2 years. Adverse events consisted of neutropenic fever (n = 8) and CMV reactivation (n = 7), with one CMV disease. Three patients developed secondary Epstein-Barr virus (EBV)-related lymphoma, all after end of treatment.

CONCLUSIONS

Although intensified alemtuzumab-CHOP induces high responses, many patients relapse, and the scheme is associated with serious infection-related adverse events. EBV monitoring after end of treatment is required.