Mogamulizumab for the treatment of cutaneous T-cell lymphoma: recent advances and clinical potential

Evaluation of the CCL17/CCL22-CCR4 axis in pediatrics with B-cell acute lymphoblastic leukemia before and after a chemotherapy course

AIMS

Acute lymphoblastic leukemia (ALL) is the most common type of pediatrics cancer. Chemokines exert different roles in leukemia process through leukocyte recruitment and regulation of disease severity. Due to the prominent roles of chemokine/receptor axes, this study aimed to measure the blood expression levels of CCR4 and their ligands in pediatrics with B-cell ALL (B-ALL). We also evaluated the impact of cytotoxic chemotherapy on this axis.

MATERIAL AND METHOD

Thirty children suffering from B-ALL were included in the study and followed up for 30 days after completion of a chemotherapy course. The blood sampling was performed before and after chemotherapy. 30 healthy donors have also entered the study as control subjects. The mRNA expression of CCL17, CCL22 and CCR4 genes was determined by quantitative real-time PCR. The frequency of the peripheral blood mononuclear cells expressing CCR4 (CCR4 + PBMCs) was also evaluated by the flow cytometry method. Moreover, we evaluated the association of the CCL17/CCL22-CCR4 axis with some diagnostic, prognostic and predictive biomarkers in ALL patients.

RESULTS

There was overexpression of the CCL17/CCL22-CCR4 axis along with lactate dehydrogenase (LDH) in pediatrics with B-ALL compared to healthy controls. After induction of chemotherapy, the blood expression levels of the CCL17/CCL22-CCR4 axis have reached the levels of healthy controls. The findings for the blood expression levels of CCR4 were also confirmed using flow cytometry.

CONCLUSION

The CCL17/CCL22-CCR4 axis can be used as a novel predictive and prognostic biomarker in B-ALL.

Comprehensive approaches to preclinical evaluation of monoclonal antibodies and their next-generation derivatives

Biotherapeutics hold great promise for the treatment of several diseases and offer innovative possibilities for new treatments that target previously unaddressed medical needs. Despite successful transitions from preclinical to clinical stages and regulatory approval, there are instances where adverse reactions arise, resulting in product withdrawals. As a result, it is essential to conduct thorough evaluations of safety and effectiveness on an individual basis. This article explores current practices, challenges, and future approaches in conducting comprehensive preclinical assessments to ensure the safety and efficacy of biotherapeutics including monoclonal antibodies, toxin-conjugates, bispecific antibodies, single-chain antibodies, Fc-engineered antibodies, antibody mimetics, and siRNA-antibody/peptide conjugates.

Delving into the Metabolism of Sézary Cells: A Brief Review

Primary cutaneous lymphomas (PCLs) are a heterogeneous group of lymphoproliferative disorders caused by the accumulation of neoplastic T or B lymphocytes in the skin. Sézary syndrome (SS) is an aggressive and rare form of cutaneous T cell lymphoma (CTCL) characterized by an erythroderma and the presence of atypical cerebriform T cells named Sézary cells in skin and blood. Most of the available treatments for SS are not curative, which means there is an urgent need for the development of novel efficient therapies. Recently, targeting cancer metabolism has emerged as a promising strategy for cancer therapy. This is due to the accumulating evidence that metabolic reprogramming highly contributes to tumor progression. Genes play a pivotal role in regulating metabolic processes, and alterations in these genes can disrupt the delicate balance of metabolic pathways, potentially contributing to cancer development. In this review, we discuss the importance of targeting energy metabolism in tumors and the currently available data on the metabolism of Sézary cells, paving the way for potential new therapeutic approaches aiming to improve clinical outcomes for patients suffering from SS.

Quantitative Analysis of Therapeutic Antibody Interactions with Fcγ Receptors Using High-Speed Atomic Force Microscopy

This study employed high-speed atomic force microscopy to quantitatively analyze the interactions between therapeutic antibodies and Fcγ receptors (FcγRs). Antibodies are essential components of the immune system and are integral to biopharmaceuticals. The focus of this study was on immunoglobulin G molecules, which are crucial for antigen binding via the Fab segments and cytotoxic functions through their Fc portions. We conducted real-time, label-free observations of the interactions of rituximab and mogamulizumab with the recombinant FcγRIIIa and FcγRIIa. The dwell times of FcγR binding were measured at the single-molecule level, which revealed an extended interaction duration of mogamulizumab with FcγRIIIa compared with that of rituximab. This is linked to enhanced antibody-dependent cellular cytotoxicity that is attributed to the absence of the core fucosylation of Fc-linked N-glycan. This study also emphasizes the crucial role of the Fab segments in the interaction with FcγRIIa as well as that with FcγRIIIa. This approach provided quantitative insight into therapeutic antibody interactions and exemplified kinetic proofreading, where cellular discrimination relies on ligand residence times. Observing the dwell times of antibodies on the effector molecules has emerged as a robust indicator of therapeutic antibody efficacy. Ultimately, these findings pave the way for the development of refined therapeutic antibodies with tailored interactions with specific FcγRs. This research contributes to the advancement of biopharmaceutical antibody design and optimizing antibody-based treatments for enhanced efficacy and precision.

Chlormethine gel in combination with other therapies for treatment of mycosis fungoides: a review with patient cases

Topical chlormethine gel has been approved as monotherapy for treatment of adult patients with mycosis fungoides (MF), the most common form of cutaneous T-cell lymphoma. In clinical practice, chlormethine gel is often combined with other skin-directed or systemic therapies to optimize response and target recalcitrant lesions. Positive outcomes with combination regimens using chlormethine gel and topical corticosteroids, phototherapy, retinoids, methotrexate, or interferon-α have been reported in literature. However, there are no treatment guidelines on the use of combination regimens with chlormethine gel. To provide real-world evidence and guidance on the use of chlormethine gel combination regimens, several cases of patients treated with chlormethine gel combined with phototherapy (n = 5), retinoids (n = 16), or mogamulizumab (n = 3) are presented. These different combination regimens showed promising results. Most patients had a complete or partial response following treatment and the combinations were well-tolerated over extended treatment periods. Patients receiving chlormethine gel with retinoids had long-term periods of remission, even after treatment discontinuation. Durations of response of up to 3 years were observed in these patients. This long-term disease control may be the result of disease-modifying effects of chlormethine. Previous studies have shown targeted reductions in malignant T-cell clones in patients treated with chlormethine gel as well as improved post-treatment responses. Further research is needed to determine the effectiveness and safety of combination treatment regimens with chlormethine gel and to assess the impact chlormethine gel has on disease control.

Structure, function and drug discovery of GPCR signaling

G protein-coupled receptors (GPCRs) are versatile and vital proteins involved in a wide array of physiological processes and responses, such as sensory perception (e.g., vision, taste, and smell), immune response, hormone regulation, and neurotransmission. Their diverse and essential roles in the body make them a significant focus for pharmaceutical research and drug development. Currently, approximately 35% of marketed drugs directly target GPCRs, underscoring their prominence as therapeutic targets. Recent advances in structural biology have substantially deepened our understanding of GPCR activation mechanisms and interactions with G-protein and arrestin signaling pathways. This review offers an in-depth exploration of both traditional and recent methods in GPCR structure analysis. It presents structure-based insights into ligand recognition and receptor activation mechanisms and delves deeper into the mechanisms of canonical and noncanonical signaling pathways downstream of GPCRs. Furthermore, it highlights recent advancements in GPCR-related drug discovery and development. Particular emphasis is placed on GPCR selective drugs, allosteric and biased signaling, polyphamarcology, and antibody drugs. Our goal is to provide researchers with a thorough and updated understanding of GPCR structure determination, signaling pathway investigation, and drug development. This foundation aims to propel forward-thinking therapeutic approaches that target GPCRs, drawing upon the latest insights into GPCR ligand selectivity, activation, and biased signaling mechanisms.

EORTC consensus recommendations for the treatment of mycosis fungoides/Sézary syndrome - Update 2023

On behalf of the EORTC Cutaneous Lymphoma Tumours Group (EORTC-CLTG) and following up on earlier versions published in 2006 and 2017 this document provides an updated standard for the treatment of mycosis fungoides and Sézary syndrome (MF/SS). It considers recent relevant publications and treatment options introduced into clinical practice after 2017. Consensus was established among the authors through a series of consecutive consultations in writing and a round of discussion. Treatment options are assigned to each disease stage and, whenever possible and clinically useful, separated into first- and second line options annotated with levels of evidence. Major changes to the previous version include the incorporation of chlormethine, brentuximab vedotin, and mogamulizumab, recommendations on the use of pegylated interferon α (after withdrawal of recombinant unpegylated interferons), and the addition of paragraphs on supportive therapy and on the care of older patients. Still, skin-directed therapies are the most appropriate option for early-stage MF and most patients have a normal life expectancy but may suffer morbidity and impaired quality of life. In advanced disease treatment options have expanded recently. Most patients receive multiple consecutive therapies with treatments often having a relatively short duration of response. For those patients prognosis is still poor and only for a highly selected subset long term remission can be achieved with allogeneic stem cell transplantation. Understanding of the disease, its epidemiology and clinical course, and its most appropriate management are gradually advancing, and there is well-founded hope that this will lead to further improvements in the care of patients with MF/SS.

CCR8 as a Therapeutic Novel Target: Omics-Integrated Comprehensive Analysis for Systematically Prioritizing Indications

Target identification is a crucial process in drug development, aiming to identify key proteins, genes, and signal pathways involved in disease progression and their relevance in potential therapeutic interventions. While C-C chemokine receptor 8 (CCR8) has been investigated as a candidate anti-cancer target, comprehensive multi-omics analyzes across various indications are limited. In this study, we conducted an extensive bioinformatics analysis integrating genomics, proteomics, and transcriptomics data to establish CCR8 as a promising anti-cancer drug target. Our approach encompassed data collection from diverse knowledge resources, gene function analysis, differential gene expression profiling, immune cell infiltration assessment, and strategic prioritization of target indications. Our findings revealed strong correlations between CCR8 and specific cancers, notably Breast Invasive Carcinoma (BRCA), Colon Adenocarcinoma (COAD), Head and Neck Squamous Cell Carcinoma (HNSC), Rectum adenocarcinoma (READ), Stomach adenocarcinoma (STAD), and Thyroid carcinoma (THCA). This research advances our understanding of CCR8 as a potential target for anti-cancer drug development, bridging the gap between molecular insights and creating opportunities for personalized treatment of solid tumors.

Development of tolerance to chemokine receptor antagonists: current paradigms and the need for further investigation

Chemokine G-protein coupled receptors are validated drug targets for many diseases, including cancer, neurological, and inflammatory disorders. Despite much time and effort spent on therapeutic development, very few chemokine receptor antagonists are approved for clinical use. Among potential reasons for the slow progress in developing chemokine receptor inhibitors, antagonist tolerance, a progressive reduction in drug efficacy after repeated administration, is likely to play a key role. The mechanisms leading to antagonist tolerance remain poorly understood. In many cases, antagonist tolerance is accompanied by increased receptor concentration on the cell surface after prolonged exposure to chemokine receptor antagonists. This points to a possible role of altered receptor internalization and presentation on the cell surface, as has been shown for agonist (primarily opioid) tolerance. In addition, examples of antagonist tolerance in the context of other G-protein coupled receptors suggest the involvement of noncanonical signal transduction in opposing the effects of the antagonists. In this review, we summarize the available progress and challenges in therapeutic development of chemokine receptor antagonists, describe the available knowledge about antagonist tolerance, and propose new avenues for future investigation of this important phenomenon. Furthermore, we highlight the modern methodologies that have the potential to reveal novel mechanisms leading to antagonist tolerance and to propel the field forward by advancing the development of potent "tolerance-free" antagonists of chemokine receptors.

Therapeutic Targets of Monoclonal Antibodies Used in the Treatment of Cancer: Current and Emerging

Cancer is one of the leading global causes of death and disease, and treatment options are constantly evolving. In this sense, the use of monoclonal antibodies (mAbs) in immunotherapy has been considered a fundamental aspect of modern cancer therapy. In order to avoid collateral damage, it is indispensable to identify specific molecular targets or biomarkers of therapy and/or diagnosis (theragnostic) when designing an appropriate immunotherapeutic regimen for any type of cancer. Furthermore, it is important to understand the currently employed mAbs in immunotherapy and their mechanisms of action in combating cancer. To achieve this, a comprehensive understanding of the biology of cancer cell antigens, domains, and functions is necessary, including both those presently utilized and those emerging as potential targets for the design of new mAbs in cancer treatment. This review aims to provide a description of the therapeutic targets utilized in cancer immunotherapy over the past 5 years, as well as emerging targets that hold promise as potential therapeutic options in the application of mAbs for immunotherapy. Additionally, the review explores the mechanisms of actin of the currently employed mAbs in immunotherapy.

Cutaneous T cell lymphoma treated with mogamulizumab monotherapy and mogamulizumab plus etoposide combined therapy: A real-world case series

Since the efficacy of mogamulizumab has been confirmed by a phase III, randomized study, mogamulizumab is one of the promising first-line therapies for advanced cutaneous T cell lymphoma (CTCL), though its efficacy is not completely satisfactory. Therefore, several anti-lymphoma drugs such as etoposide were recently used to enhance the anti-tumor effects of mogamulizumab for the treatment of mycosis fungoides (MF). In this report, the anti-tumor effects of mogamulizumab and post mogamulizumab therapy were retrospectively evaluated in 11 cases of CTCL in real-world clinical practice. The best response rate (RR) was 45.5% (95% confidence interval [CI], 21.3%-72.0%) for the total cohort, 50.0% (95%CI, 21.5%-78.5%) for the MF cohort, and 33.3% (95%CI, 5.6%-79.8%) for the primary cutaneous peripheral T cell lymphoma not otherwise specified (PCPTCL-NOS) cohort. The objective response rate (ORR) at 1 month (ORR1) for the total cohort was 45.5% (95%CI, 21.3%-72.0%), and ORR at 4 months (ORR4) was 27.3% (95%CI, 9.2%-57.1%). The mean time to next treatment (TTNT) was 16.0 weeks (3-100 weeks) for all patients, 16.5 months (3-100 weeks) for the MF cohort, and 9.0 (7-16) weeks for the PCPTCL-NOS cohort. The efficacy rate of etoposide-based therapy was 71.4% (95%CI, 35.9%-98.0%) for all patients, 80% (95%CI, 35.9%-98.0%) in the MF cohort, and 50% (95%CI, 9.5%-90.5%) in the PCPTCL-NOS cohort. The median duration of response was 182 (45-323) weeks. The safety profile of mogamulizumab monotherapy in the present cohort was comparable to the previous phase III, randomized trial. The present study suggests that the efficacy and safety profiles of mogamulizumab monotherapy as second-line therapy and beyond in a real-world Japanese cohort were comparable to those in the previous phase III, randomized trial.

Targeted and cellular therapies in lymphoma: Mechanisms of escape and innovative strategies

The therapeutic landscape for lymphomas is quite diverse and includes active surveillance, chemotherapy, immunotherapy, radiation therapy, and even stem cell transplant. Advances in the field have led to the development of targeted therapies, agents that specifically act against a specific component within the critical molecular pathway involved in tumorigenesis. There are currently numerous targeted therapies that are currently Food and Drug Administration (FDA) approved to treat certain lymphoproliferative disorders. Of many, some of the targeted agents include rituximab, brentuximab vedotin, polatuzumab vedotin, nivolumab, pembrolizumab, mogamulizumab, vemurafenib, crizotinib, ibrutinib, cerdulatinib, idelalisib, copanlisib, venetoclax, tazemetostat, and chimeric antigen receptor (CAR) T-cells. Although these agents have shown strong efficacy in treating lymphoproliferative disorders, the complex biology of the tumors have allowed for the malignant cells to develop various mechanisms of resistance to the targeted therapies. Some of the mechanisms of resistance include downregulation of the target, antigen escape, increased PD-L1 expression and T-cell exhaustion, mutations altering the signaling pathway, and agent binding site mutations. In this manuscript, we discuss and highlight the mechanism of action of the above listed agents as well as the different mechanisms of resistance to these agents as seen in lymphoproliferative disorders.

Lack of impact of type and extent of prior therapy on outcomes of mogamulizumab therapy in patients with cutaneous T cell lymphoma in the MAVORIC trial

Patients with mycosis fungoides (MF) and Sézary syndrome (SS) often require multiple lines of systemic therapy. In the phase 3 MAVORIC study (NCT01728805), mogamulizumab demonstrated superiority to vorinostat in median progression-free survival (PFS) and confirmed overall response rate (ORR) in patients with MF/SS. This post hoc analysis examined the effects of number and type of prior systemic therapies on mogamulizumab response. MAVORIC patients randomized to mogamulizumab (1.0 mg/kg intravenously weekly) or vorinostat (400 mg orally daily) were grouped by number of prior therapies and immunomodulatory activity of immediate prior systemic therapy while also considering time elapsed since treatment. ORR, PFS, and duration of response (DOR) did not vary with number of prior therapies. ORR and DOR remained consistent regardless of immediate prior therapy type. Additionally, immunomodulatory activity of the last prior therapy and time from prior treatment generally did not affect the ORR or PFS observed in response to mogamulizumab.

Safety and efficacy profile of mogamulizumab (Poteligeo) in the treatment of cancers: an update evidence from 14 studies

BACKGROUND

CC chemokine receptor 4 (CCR4), the receptor for CCL22 and CCL17, is expressed on the surface of effector Tregs that have the highest suppressive effects on antitumor immune response. CCR4 is also widely expressed on the surface of tumor cells from patients with adult T-cell leukemia/lymphoma (ATL), peripheral T-cell lymphoma (PTCL) and cutaneous T-cell lymphoma (CTCL). Mogamulizumab is a humanized, IgG1 kappa monoclonal antibody that is directed against CCR4. By reducing the number of CCR4-positive Tregs and tumor cells, the mogamulizumab can reduce tumor burden and boost antitumor immunity to achieve antitumor effects.

METHODS

We examined the PubMed and ClinicalTrials.gov until 1 February 2020. Considering variability in different studies, we selected the adverse events (AEs), overall survival (OS), progression-free survival (PFS), objective responses rate (ORR) and Hazard Ratio (HR) for PFS to evaluate the safety and efficacy profile of mogamulizumab.

RESULTS

When patients were treated with mogamulizumab monotherapy, the most common all-grade AEs were lymphopenia, infusion reaction, fever, rash and chills while the most common grade ≥ 3 AEs were lymphopenia, neutropenia and rash. When patients were treated with combined therapy of mogamulizumab and other drugs, the most common all-grade AEs were neutropenia, anaemia, lymphopenia and gastrointestinal disorder, while the most common grade ≥ 3 AEs was lymphopenia. For patients treated with mogamulizumab monotherapy, the pooled ORR and mean PFS were 0.430 (95% CI: 0.393-0.469) and 1.060 months (95% CI: 1.043-1.077), respectively. For patients treated with combined therapy of mogamulizumab and other drugs, the pooled ORR was 0.203 (95% CI: 0.022-0.746) while the pooled PFS and OS were 2.093 months (95% CI: 1.602-2.584) and 6.591 months (95% CI: 6.014-7.167), respectively.

CONCLUSIONS

Based on present evidence, we believed that mogamulizumab had clinically meaningful antitumor activity with acceptable toxicity which is a novel therapy in treating patients with cancers.

Critical concepts and management recommendations for cutaneous T-cell lymphoma: A consensus-based position paper from the Italian Group of Cutaneous Lymphoma

In this paper, we present a review of critical concepts, and produce recommendations on management issues in cutaneous T-cell lymphomas (CTCLs) of adults. A panel of nine experts was selected for their expertise in research and clinical practice of CTCLs. During an initial meeting, the areas of major concern in the management of CTCLs were selected by generating and rank-ordering clinical key questions using the criterion of clinical relevance, through group discussion. Recommendations were achieved by multiple-step formalized procedures to reach a consensus after a comprehensive analysis of the scientific literature. The panel produced recommendations on how to facilitate the clinical suspicion of CTCL; indication of cutaneous biopsy; optimal histological diagnosis, immunohistochemistry and genetic markers; and staging pathway and up-to-date therapeutics (with particular focus on new treatments). The critical concept of integration of the different medical expertise in the management of the patients with CTCL was thoroughly examined. These recommendations are intended for use not only by expert centers but above all by "not experienced" dermatologists and hematologists as well as general practitioners.

Serum CCL22 levels decreased in parallel with disease activity in CCR4-positive mycosis fungoides treated with mogamulizumab

Mogamulizumab is a humanized anti-C-C chemokine receptor type (CCR)4 antibody that shows cytotoxicity against CCR4+ lymphoma cells via antibody-dependent cell-mediated cytotoxicity in advanced cutaneous T cell lymphoma (CTCL) patients. The production levels of ligands for CCR4, that is, Chemokine (C-C motif) ligand (CCL)17 and CCL22, are important for the assessment of the disease activity in CTCL patients. We evaluated the serum levels of CCL17, CCL19, CCL22, C-X-C motif chemokine ligand (CXCL)10, and CXCL13, which are ligands for CCR4, CCR7, CCR4, C-X-C Motif Chemokine Receptor (CXCR)3, and CXCR5, respectively, at baseline and 4 weeks after the administration of mogamulizumab in five patients with mycosis fungoides. The serum levels of CCL22 were significantly decreased in patients who responded to mogamulizumab, but no differences were identified in the serum levels of CCL17, CCL19, CXCL10, or CXCL13. Immunofluorescence staining revealed that the majority of CCL22-producing cells were cluster of differentiation (CD)163+ tumor-associated macrophages, and they were surrounded by CCR4+ CTCL cells. Our present data suggested that the serum CCL22 level may be a predictive marker of the efficacy of mogamulizumab for the treatment of CCR4+ CTCL.

Cutaneous T Cell Lymphoma: A Difficult Diagnosis Demystified

Cutaneous T cell lymphoma (CTCL) represents a heterogeneous group of extranodal non-Hodgkin lymphomas in which monoclonal T lymphocytes infiltrate the skin. The mechanism of CTCL development is not fully understood, but likely involves dysregulation of various genes and signaling pathways. A variety of treatment modalities are available, and although they can induce remission in most patients, the disease may recur after treatment cessation. Owing to relatively low incidence and significant chronicity of disease, and the high morbidity of some therapeutic regimens, further clinical trials are warranted to better define the ideal treatment option for each subtype of CTCL.

Leukaemic variants of cutaneous T-cell lymphoma: Erythrodermic mycosis fungoides and Sézary syndrome

Mycosis fungoides (MF) and Sézary syndrome (SS) are the most common types of cutaneous lymphoma, accounting for approximately 60% of cutaneous T-cell lymphomas. Diagnosis requires correlation of clinical, histologic, and molecular features. A multitude of factors have been linked to the aetiopathogenesis, however, none have been definitively proven. Erythrodermic MF (E-MF) and SS share overlapping clinical features, such as erythroderma, but are differentiated on the degree of malignant blood involvement. While related, they are considered to be two distinct entities originating from different memory T cell subsets. Differential expression of PD-1 and KIR3DL2 may represent a tool for distinguishing MF and SS, as well as a means of monitoring treatment response. Treatment of E-MF/SS is guided by disease burden, patients' ages and comorbidities, and effect on quality of life. Current treatment options include biologic, targeted, immunologic, and investigational therapies that can provide long term response with minimal side effects. Currently, allogeneic stem cell transplantation is the only potential curative treatment.

T-cell positioning by chemokines in autoimmune skin diseases

Autoimmune skin diseases are complex processes in which autoreactive cells must navigate through the skin tissue to find their targets. Regulatory T cells in the skin help to mitigate autoimmune inflammation and may in fact be responsible for the patchy nature of these conditions. In this review, we will discuss chemokines that are important for global recruitment of T cell populations to the skin during disease, as well as signals that fine-tune their localization and function. We will describe prototypical disease responses and chemokine families that mediate these responses. Lastly, we will include an overview of chemokine-targeting drugs that have been tested as new treatment strategies for autoimmune skin diseases.

Nanobodies: New avenues for imaging, stabilizing and modulating GPCRs

The family of G protein-coupled receptors (GPCRs) is the largest class of membrane proteins and an important drug target due to their role in many (patho)physiological processes. Besides small molecules, GPCRs can be targeted by biologicals including antibodies and antibody fragments. This review describes the use of antibodies and in particular antibody fragments from camelid-derived heavy chain-only antibodies (nanobodies/VHHs/sdAbs) for detecting, stabilizing, modulating and therapeutically targeting GPCRs. Altogether, it becomes increasingly clear that the small size, structure and protruding antigen-binding loops of nanobodies are favorable features for the development of selective and potent GPCRs-binding molecules. This makes them attractive tools to modulate GPCR activity but also as targeting modalities for GPCR-directed therapeutics. In addition, these antibody-fragments are important tools in the stabilization of particular conformations of these receptors. Lastly, nanobodies, in contrast to conventional antibodies, can also easily be expressed intracellularly which render nanobodies important tools for studying GPCR function. Hence, GPCR-targeting nanobodies are ideal modalities to image, stabilize and modulate GPCR function.

Primary Cutaneous T-Cell Lymphomas: Mycosis Fungoides and Sezary Syndrome

Mycosis fungoides and Sézary syndrome are the most common subtypes of all primary cutaneous lymphomas and represent complex diseases that require a multidisciplinary assessment by dermatologists, oncologists, and pathologists. Staging and work-up are critical to guarantee an optimal treatment plan that includes skin-directed and/or systemic regimens depending on the clinical stage, tumor burden, drug-related side effect profile, and patient comorbidities. However, there is no cure and patients frequently relapse, requiring repeated treatment courses for disease control. The study of the tumor microenvironment and molecular mechanisms of these rare neoplasms may assist in the development of new immune therapies providing promising treatment approaches tailored for patients with relapse/refractory disease.

Phenotypic analysis of mice xenografted with canine epitheliotropic cutaneous T-cell lymphoma cells

BACKGROUND

In canine epitheliotropic cutaneous T-cell lymphoma (ECTCL), neoplastic cells cause skin lesions and potentially metastasize to lymph nodes, blood and other organs. Murine models are potentially valuable for elucidating the molecular mechanisms responsible for regulation of ECTCL cell migration.

HYPOTHESIS/OBJECTIVES

To describe a phenotype of mice xenografted with canine ECTCL cells (EO-1 cells).

ANIMALS

Four NOD.CB17-Prkdc^scid /J (NOD SCID) mice were used.

METHODS AND MATERIALS

EO-1 cells were subcutaneously xenografted into NOD SCID mice. After four weeks, the development of tumour lesions in skin and other organs was investigated.

RESULTS

Mice developed skin lesions with metastasis to the lymph nodes, spleen, lung, blood and liver.

CONCLUSIONS AND CLINICAL IMPORTANCE

Mice xenografted with EO-1 cells may be useful for studying the pathogenesis of canine ECTCL.

Integrating novel systemic therapies for the treatment of mycosis fungoides and Sézary syndrome

Novel systemic therapies are generally prescribed to patients with advanced-stage disease or those with early-stage disease refractory to skin-directed therapies. In general, systemic chemotherapy should be reserved for patients who fail to respond to biological agents. Such biological agents include interferon alfa, bexarotene, histone deacetylase inhibitors (vorinostat, romidepsin), brentuximab vedotin and mogamulizumab. Extracorporeal photopheresis is particularly effective for patients with Sézary Syndrome. Allogeneic transplantation is becoming increasing used for younger patients. Novel agents in advanced development include the monoclonal antibody IPH4102,duvelisib,and the new modified formulation of denileukin diftitox. The choice of agents for patients is typically a balance of patient factors (age, co-morbidities, geographic location), relative efficacy and toxicity.

Glycosylation of IgG-Fc: a molecular perspective

Antibodies of the IgG class carry a pair of oligosaccharides (N-glycans) in the Fc region. The importance of the N-glycan is clearly demonstrated by its profound effect in the physicochemical and biological properties of antibodies. The term 'glycoengineering' has been coined to describe contemporary strategies to improve the performance of therapeutic monoclonal antibodies on the basis of modifications in the structure and composition of the N-glycan. These methodologies have resulted in the approval and commercialization of a new generation of antibodies with improved therapeutic efficacy. So far, these advances have been driven by herculean efforts in a process of trial-and-error. The collective work of researchers in this field is progressively revealing the molecular basis of N-glycans for the function of antibodies. This knowledge will ultimately be conducive to the application of rational approaches for the successful manipulation of antibodies using glycoengineering strategies. Herein, we review advances in our understanding of the role of the N-glycan in the structural and dynamic integrity, and biological activity, of antibodies. Since the N-glycan has a multifaceted effect in antibodies, in this review we have emphasized the importance of integrating various techniques that address this problem from multiple points of view. In particular, the combination of X-ray crystallography with nuclear magnetic resonance, molecular dynamics simulations and biophysical approaches based on thermodynamic principles, has emerged as a powerful combination that is deepened our understanding of this unique system with critical implications for human well-being.

Successful Treatment of Erythrodermic Mycosis Fungoides with Mogamulizumab Followed by Etoposide Monotherapy

Mogamulizumab induces cytotoxicity against CCR4+ lymphoma cells by antibody-dependent cell-mediated cytotoxicity in advanced cutaneous T-cell lymphoma patients. Since the efficacy of mogamulizumab in mycosis fungoides (28.6%) is lower than that in Sézary syndrome (47.1%), reagents that enhance the antitumor immune response induced by mogamulizumab are needed to further optimize its use for the treatment of erythrodermic mycosis fungoides. In this report, we present a case of erythrodermic mycosis fungoides successfully treated with mogamulizumab followed by etoposide monotherapy.

The C-C Chemokines CCL17 and CCL22 and Their Receptor CCR4 in CNS Autoimmunity

Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system (CNS). It affects more than two million people worldwide, mainly young adults, and may lead to progressive neurological disability. Chemokines and their receptors have been shown to play critical roles in the pathogenesis of experimental autoimmune encephalomyelitis (EAE), a murine disease model induced by active immunization with myelin proteins or transfer of encephalitogenic CD4⁺ T cells that recapitulates clinical and neuropathological features of MS. Chemokine ligand-receptor interactions orchestrate leukocyte trafficking and influence multiple pathophysiological cellular processes, including antigen presentation and cytokine production by dendritic cells (DCs). The C-C class chemokines 17 (CCL17) and 22 (CCL22) and their C-C chemokine receptor 4 (CCR4) have been shown to play an important role in homeostasis and inflammatory responses. Here, we provide an overview of the involvement of CCR4 and its ligands in CNS autoimmunity. We review key clinical studies of MS together with experimental studies in animals that have demonstrated functional roles of CCR4, CCL17, and CCL22 in EAE pathogenesis. Finally, we discuss the therapeutic potential of newly developed CCR4 antagonists and a humanized anti-CCR4 antibody for treatment of MS.

Opportunities for therapeutic antibodies directed at G-protein-coupled receptors

G-protein-coupled receptors (GPCRs) are activated by a diverse range of ligands, from large proteins and proteases to small peptides, metabolites, neurotransmitters and ions. They are expressed on all cells in the body and have key roles in physiology and homeostasis. As such, GPCRs are one of the most important target classes for therapeutic drug discovery. The development of drugs targeting GPCRs has therapeutic value across a wide range of diseases, including cancer, immune and inflammatory disorders as well as neurological and metabolic diseases. The progress made by targeting GPCRs with antibody-based therapeutics, as well as technical hurdles to overcome, are presented and discussed in this Review. Antibody therapeutics targeting C-C chemokine receptor type 4 (CCR4), CCR5 and calcitonin gene-related peptide (CGRP) are used as illustrative clinical case studies.

Second- and third-generation drugs for immuno-oncology treatment-The more the better?

Recent success in cancer immunotherapy (anti-CTLA-4, anti-PD1/PD-L1) has confirmed the hypothesis that the immune system can control many cancers across various histologies, in some cases producing durable responses in a way not seen with many small-molecule drugs. However, only less than 25% of all patients do respond to immuno-oncology drugs and several resistance mechanisms have been identified (e.g. T-cell exhaustion, overexpression of caspase-8 and β-catenin, PD-1/PD-L1 gene amplification, MHC-I/II mutations). To improve response rates and to overcome resistance, novel second- and third-generation immuno-oncology drugs are currently evaluated in ongoing phase I/II trials (either alone or in combination) including novel inhibitory compounds (e.g. TIM-3, VISTA, LAG-3, IDO, KIR) and newly developed co-stimulatory antibodies (e.g. CD40, GITR, OX40, CD137, ICOS). It is important to note that co-stimulatory agents strikingly differ in their proposed mechanism of action compared with monoclonal antibodies that accomplish immune activation by blocking negative checkpoint molecules such as CTLA-4 or PD-1/PD-1 or others. Indeed, the prospect of combining agonistic with antagonistic agents is enticing and represents a real immunologic opportunity to 'step on the gas' while 'cutting the brakes', although this strategy as a novel cancer therapy has not been universally endorsed so far. Concerns include the prospect of triggering cytokine-release syndromes, autoimmune reactions and hyper immune stimulation leading to activation-induced cell death or tolerance, however, toxicity has not been a major issue in the clinical trials reported so far. Although initial phase I/II clinical trials of agonistic and novel antagonistic drugs have shown highly promising results in the absence of disabling toxicity, both in single-agent studies and in combination with chemotherapy or other immune system targeting drugs; however, numerous questions remain about dose, schedule, route of administration and formulation as well as identifying the appropriate patient populations. In our view, with such a wealth of potential mechanisms of action and with the ability to fine-tune monoclonal antibody structure and function to suit particular requirements, the second and third wave of immuno-oncology drugs are likely to provide rapid advances with new combinations of novel immunotherapy (especially co-stimulatory antibodies). Here, we will review the mechanisms of action and the clinical data of these new antibodies and discuss the major issues facing this rapidly evolving field.

Mechanisms of Regulation of the Chemokine-Receptor Network

The interactions of chemokines with their G protein-coupled receptors promote the migration of leukocytes during normal immune function and as a key aspect of the inflammatory response to tissue injury or infection. This review summarizes the major cellular and biochemical mechanisms by which the interactions of chemokines with chemokine receptors are regulated, including: selective and competitive binding interactions; genetic polymorphisms; mRNA splice variation; variation of expression, degradation and localization; down-regulation by atypical (decoy) receptors; interactions with cell-surface glycosaminoglycans; post-translational modifications; oligomerization; alternative signaling responses; and binding to natural or pharmacological inhibitors.

Management Strategies for Mycosis Fungoides in India

Mycosis fungoides is the most common primary cutaneous T-cell lymphoma. The approach to diagnosis and further follow-up is outlined. Evidence for interventions is based classically on a Tumor Node Metastasis Blood TNMB “stage-based” approach. The treatment options in India are limited. The options as per risk stratification and prognostic index are discussed. Early stages and low-risk patients can be managed with expectant policy or skin-directed therapies including topical steroids and phototherapy; intermediate-risk patients can be opted for interferons or retinoids or low dose methotrexate along with radiotherapy including total skin electron beam therapy while high-risk patients are managed most often with single agent or multiagent palliative chemotherapy. Patients who are intermediate- or high-risk need management by a multispecialty team at tertiary care centers.