Pruritus in cutaneous T-cell lymphomas: frequent, often severe and difficult to treat

An update on mechanisms of pruritus and their potential treatment in primary cutaneous T-cell lymphoma

Primary cutaneous T-cell lymphomas (CTCL), which include mycosis fungoides (MF) and Sézary syndrome (SS), are a group of lymphoproliferative disorders characterized by clonal accumulation of neoplastic T-lymphocytes in the skin. Severe pruritus, one of the most common and distressing symptoms in primary CTCL, can significantly impair emotional well-being, physical functioning, and interpersonal relationships, thus greatly reducing quality of life. Unfortunately, effectively managing pruritus remains challenging in CTCL patients as the underlying mechanisms are, as of yet, not fully understood. Previous studies investigating the mechanisms of itch in CTCL have identified several mediators and their corresponding antagonists used for treatment. However, a comprehensive overview of the mediators and receptors contributing to pruritus in primary CTCL is lacking in the current literature. Here, we summarize and review the mediators and receptors that may contribute to pruritus in primary CTCL to explore the mechanisms of CTCL pruritus and identify effective therapeutic targets using the PubMed and Web of Science databases. Studies were included if they described itch mediators and receptors in MF and SS. Overall, the available data suggest that proteases (mainly tryptase), and neuropeptides (particularly Substance P) may be of greatest interest. At the receptor level, cytokine receptors, MRGPRs, and TRP channels are most likely important. Future drug development efforts should concentrate on targeting these mediators and receptors for the treatment of CTCL pruritus.

In the skin lesions of patients with mycosis fungoides, the number of MRGPRX2-expressing cells is increased and correlates with mast cell numbers

Background

Mycosis fungoides (MF) is an indolent T-cell lymphoma that mainly affects the skin and presents with itch in more than half of the patients. Recently, the expression of Mas-related G protein-coupled receptor X2 (MRGPRX2), a receptor of mast cell (MC) responsible for the IgE-independent non-histaminergic itch, has been shown in lesional skin of patients with pruritic skin diseases, including chronic urticaria, prurigo, and mastocytosis. As of yet, limited knowledge exists regarding the MRGPRX2 expression in the skin of patients with MF.

Objectives

To investigate the number of MRGPRX2-expressing (MRGPRX2+) cells in the skin of patients with MF and its correlation with clinical and laboratory characteristics of the disease.

Methods

MRGPRX2 was analyzed in lesional and non-lesional skin of MF patients and healthy skin tissues by immunohistochemistry. Co-localization of MRGPRX2 with the MC marker tryptase was assessed by immunofluorescence. Public single-cell RNAseq data was reanalyzed to identify the MRGPRX2 expression on the distinct cell types.

Results

In lesional skin of MF patients, MRGPRX2+ cell number was higher than in non-lesional skin and healthy control skin (mean:15.12 vs. 6.84 vs. 5.51 cells/mm2, p=0.04), and correlated with MC numbers (r=0.73, p=0.02). MC was the primary cell type expressing MRGPRX2 in MF patients. The ratio of MRGPRX2+ MCs to MRGPRX2+ cells in lesional and non-lesional skin correlated with the severity of disease (r=0.71, p=0.02 and r=0.67, p=0.03, respectively).

Conclusions

Our findings point to the role of MRGPRX2 and MC in the pathogenesis of MF that should be investigated in further studies.

Cutaneous T-cell lymphoma-Focus on some problems, and some solutions

Cutaneous lymphomas are a heterogeneous group of several distinct entities of lymphoproliferative diseases. The diagnosis of a cutaneous lymphoma is a challenge, and it is always the result of a careful analysis of several information's consisting of clinical history, clinical picture, histological and molecular analyses. For this reason, experts taking care of patients with a skin lymphoma need to know all the peculiar diagnostic elements very well, in order not to run into mistakes. In this article, we will focus the discussion on some issues as the skin biopsy (when and where). In addition, we will discuss the approach to the erythrodermic patient, whose differential diagnoses include mycosis fungoides, and Sézary syndrome, beside more frequent inflammatory conditions. Finally, we will address the issue of quality of life and the possible support of the suffering patient with a cutaneous lymphoma, well knowing that the current therapeutic possibilities are unfortunately limited.

Healthcare Provider Experience in Diagnosing and Treating Cutaneous T-Cell Lymphoma

INTRODUCTION

Cutaneous T-cell lymphoma (CTCL) is a rare, heterogeneous group of non-Hodgkin lymphomas characterized by various clinical, molecular, and histopathologic features of the skin. Variants of CTCL share many clinical features with common inflammatory skin diseases such as atopic dermatitis and psoriasis, making accurate and early diagnosis challenging in clinical settings. Inappropriate treatment or a delay in diagnosis can lead to increased morbidity and mortality. Here, we report findings from an online survey that investigated dermatology community practice, knowledge, and education surrounding CTCL.

METHODS

An electronic survey of ten questions was developed and approved by physician experts in CTCL to assess experiences in diagnosing and treating CTCL among healthcare providers (HCPs). The survey was deployed to 10,600 US dermatology HCPs, including medical doctors (MDs), doctors of osteopathic medicine (DOs), nurse practitioners (NPs), and physician assistants (PAs) and excluding HCPs associated with CTCL centers of excellence.

RESULTS

Among 44 HCPs who responded and were eligible for inclusion, 82% had diagnosed between one and ten CTCL cases in the last 5 years. Most respondents (91%) reported that they include CTCL in their differential diagnoses after patients do not respond to treatment of more common conditions. Patients with CTCL were frequently diagnosed with other inflammatory dermatoses-most commonly dermatitis and psoriasis-before a CTCL diagnosis, and many were treated with ineffective therapies for years. The most common length of time before a CTCL diagnosis was made was between 1 and 3 years, though 16% of HCPs reported that patients were treated for other diseases or skin conditions for ≥ 5 years. Two-thirds of HCPs agreed that further education surrounding CTCL is needed.

CONCLUSIONS

Given the infrequency of CTCL and its similar presentation to other common dermatologic conditions, increased education of CTCL is needed in the dermatology community to improve patient outcomes.

Pruritus in cancer patients as a polyetiological symptom

Pruritus is one of the subjective sensations that significantly reduces the quality of life of patients. In patients with malignancies, itch can be caused by different universal or specific pathophysiological factors. This article discusses disorders that cause pruritus in cancer patients: the tumor growth on its own; pathophysiological changes associated with a number of malignancies, paraneoplastic itch, anticancer therapy, concomitant dermatoses, systemic diseases, psychosomatic disorders. Known or proposed mechanisms of the development of pruritus are presented for each of the mentioned provoking factors, and methods of treatment are described, according to the etiological factor. At the end of the article, universal methods for the correction of itching are presented, applicable in cancer patients, regardless of the pruritogenic factor. Special attention is paid to the correction of xerosis as a universal cause of itching in oncological patients.

"Knock Me Out": The Challenges of Managing Pain Due to Cutaneous T Cell Lymphomas: A Case Report

Cutaneous T cell lymphomas are associated with distressing symptoms, including pain and pruritus that negatively impact quality of life. Early involvement of palliative care can provide relief of symptoms and address multifaceted distress. This case highlights the complex management of cutaneous T cell lymphoma pain and associated symptoms, including existential and psychosocial distress. Our patient required frequent titration and rotation of high-dose opioids and adjuvant analgesics, ultimately requiring transfer to the intensive care unit for analgosedation. Total skin loss and disease complications led to his death after a compassionate withdrawal of life support. Cutaneous T cell lymphoma pain can be successfully managed with an interdisciplinary approach, early palliative care, and aggressive pain management. Complications from advanced disease, superinfection, and multidimensional distress complicate the efficacy of a multimodal analgesic approach. Further research is needed to deepen our understanding of how to optimally alleviate suffering within this vulnerable population.

Mast cells and tryptase are linked to itch and disease severity in mycosis fungoides: Results of a pilot study

Introduction

In mycosis fungoides (MF), the most common cutaneous T-cell lymphoma, itch is a frequent clinical symptom. Whether mast cells (MCs), eosinophils (Eos) or their mediators play a role in MF-associated itch or disease severity is controversially discussed. Here, we explored the role of MC and Eo numbers in the skin as well as blood levels of their mediators in disease severity and itch.

Methods

In 10 patients with MF and 10 matched control subjects we assessed disease severity, itch, and quality of life impairment using dedicated tools such as the mSWAT, ItchyQoL and DLQI. We analyzed skin biopsies and measured serum levels of tryptase, a mast cell mediator, as well as of the eosinophil products eosinophil cationic protein (ECP) and major basic protein (MBP).

Results

The presence of chronic itch, in four of 10 patients, was associated with significantly higher disease severity (mSwat), larger body surface area affected, and stronger QoL impairment (Itchy-Qol, DLQI). Serum levels of tryptase, but not ECP and MBP, were linked with patient-reported disease severity, body surface area affected, and the presence of itch. Three of the four patients with chronic itch, but none of the six patients without, had tryptase levels above >6µg/l. Numbers of MCs in the papillary dermis were higher in MF skin lesions then in non-lesional skin of MF patients and skin of healthy controls.

Discussion

The MC-mediator tryptase, in MF, is linked to disease activity and impact, most prominently to itch. Our findings call for larger studies that explore the role of MCs, tryptase and other MC mediators as drivers of itch and their role in MF pathogenesis.

Peripheral Mechanisms of Itch

Itch is a universally experienced sensation, and chronic itch can be as diabolically debilitating as pain. Recent advances have not only identified the neuronal itch sensing circuitry, but also have uncovered the intricate interactions between skin and immune cells that work together with neurons to identify itch-inducing irritants. In this review, we will summarize the fundamental mechanisms of acute itch detection in the skin, as well as highlight the recent discoveries relating to this topic.

IL-31 and IL-8 in Cutaneous T-Cell Lymphoma: Looking for Their Role in Itch

The itch associated with cutaneous T-cell lymphoma (CTCL), including Mycosis Fungoides (MF) and Sézary syndrome (SS), is often severe and poorly responsive to treatment with antihistamines. Recent studies have highlighted the possible role of interleukins in nonhistaminergic itch. We investigated the role of IL-31 and IL-8 in CTCL, concerning disease severity and associated itch. Serum samples of 27 patients with CTCL (17 MF and 10 SS) and 29 controls (blood donors) were analyzed for interleukin- (IL-) 31 and IL-8; correlations with disease and itch severity were evaluated. IL-31 serum levels were higher in CTCL patients than in controls and higher in SS than in MF. Also, serum IL-31 levels were higher in patients with advanced disease compared to those with early disease, and they correlated positively with lactate dehydrogenase and beta 2-microglobulin levels, as well as with the Sézary cell count. Itch affected 67% of CTCL patients (MF: 47%; SS: 100%). Serum IL-31 levels were higher in itching patients than in controls and in patients without itching. There was no association between serum IL-8 and disease severity, nor with itching. Serum IL-8 levels correlated positively with peripheral blood leukocyte and neutrophil counts in CTCL patients. Our study suggests a role for IL-31 in CTCL-associated itch, especially in advanced disease and SS, offering a rational target for new therapeutic approaches. Increased serum IL-8 observed in some patients may be related to concomitant infections, and its role in exacerbating itch by recruiting neutrophils and promoting the release of neutrophil proteases deserves further investigation.

IL-31, itch and hematological malignancies

Pruritus is one of the most common symptoms experienced by neoplastic patients. The pathogenesis of neoplastic itch is complex and multifactorial and could be due to an unbalanced production of humoral mediators by altered immune effector cells. IL-31 is a pro-inflammatory cytokine produced by CD4 + T helper cells. The aim of this review was to evaluate the role of this Th2 cytokine and its receptor IL-31RA, in the onset of neoplastic pruritus. We analysed scientific literature looking for the most relevant original articles linking IL-31to itch in oncologic diseases. Interleukin-31 seems to be a main itch mediator in several hematologic disease such as Cutaneous T cells lymphomas. In these patients IL-31 was positively linked to itch level, and IL-31 matched with disease stage. IL-31 seems to play an important role in the signalling pathway involved in pruritus, but it is also suggested to play a proinflammatory and immunomodulatory role which could play a part in the progression of the neoplastic disease. Further studies will be fundamental in facing pruritus in oncologic patients, since this problem compromise their quality of life worsening an already critic picture.

The changing therapeutic landscape, burden of disease, and unmet needs in patients with cutaneous T-cell lymphoma

Cutaneous T-cell lymphomas (CTCLs) have a chronic, relapsing course, and the most common subtypes are mycosis fungoides and Sézary syndrome. The disease causes visible skin alterations and can also cause alopecia, pruritus and pain, all of which can impact patients' health-related quality of life (HRQoL). The goal of treatment is to reduce symptoms and prevent disease progression. However, treatment recommendations are often based on low levels of evidence due to the lack of well-designed randomised clinical trials and treatment guidelines, and approved drugs vary considerably across different countries and regions. Currently, available treatments rarely lead to durable remissions and eventually become less effective, meaning patients often require multiple therapy changes. Skin-directed therapies (SDTs) are first-line treatments for early-stage CTCL, whereas systemic therapies may be needed for early-stage disease that does not respond to SDT or for advanced-stage disease. However, patients can experience significant side-effects with these treatments or may be unable to tolerate them. Hence, there is an unmet need for effective therapies with good safety profiles for the treatment of early- and late-stage CTCL. Here, we review current treatment guidelines, investigational and approved treatments, the impact of CTCL on patients' HRQoL, and the treatment of pruritus.

How do we treat cutaneous T-cell lymphoma?

Cutaneous T-cell lymphomas are a heterogeneous group of non-Hodgkin lymphomas which are based on the malignant proliferation of skin-related T lymphocytes. The clinical appearance, as well as the course and the associated therapeutic approach, are sometimes very different between the different subtypes. Since allogeneic stem cell transplantation is currently the only curative option, and the morbidity and mortality are not insignificant, a therapy concept should be developed that considers its often rather indolent but chronic course. This concept should enable a good disease control with as few side effects as possible and preserve or improve the quality of life. In the early stages of the disease, skin-oriented therapies are generally used first before systemic and increasingly aggressive therapeutic agents are used as the disease progresses. Considering the current guidelines, literature and subjective experience, we summarize in this review how we treat cutaneous T-cell lymphomas.

Quality of Life Effect of the Anti-CCR4 Monoclonal Antibody Mogamulizumab Versus Vorinostat in Patients With Cutaneous T-cell Lymphoma

BACKGROUND

Sézary syndrome (SS) and mycosis fungoides (MF), 2 types of cutaneous T-cell lymphoma, cause significant morbidity and adversely affect patients' quality of life (QoL). The present study assessed the QoL measurement changes in patients receiving mogamulizumab versus vorinostat.

PATIENTS AND METHODS

A multicenter phase III trial was conducted of patients with stage IB-IV MF/SS with ≥ 1 failed systemic therapy. The QoL measures included Skindex-29 and the Functional Assessment of Cancer Therapy-General. The symptoms, function, and QoL subdomains were longitudinally modeled using mixed models with prespecified covariates. Meaningful change thresholds (MCTs) were defined using distribution-based methods. The categorical changes by group over time and the time to clinically meaningful worsening were analyzed.

RESULTS

Of the 372 randomized patients, mogamulizumab demonstrated improvement in Skindex-29 symptoms (cycles 3, 5, and 7; P < .05) and functional (cycles 3 and 5; P < .05) scales. A significantly greater proportion of mogamulizumab-treated patients improved by MCTs or more from baseline in the Skindex-29 symptoms domain (cycles 3, 5, 7, and 11) and functioning domain (cycle 5). Significant differences in the Functional Assessment of Cancer Therapy-General physical well-being (cycles 1, 3, and 5; P < .05) were observed in favor of mogamulizumab and a greater proportion of patients had declined by MCTs or more at cycles 1, 3, 5, and 7 with vorinostat treatment. The median time to symptom worsening using Skindex-29 was 27.4 months for mogamulizumab versus 6.6 months for vorinostat. In the patients with SS, the time to worsening favored mogamulizumab (P < .005) for all Skindex-29 domains. The time to worsening was similar for the 2 MF treatment arms.

CONCLUSION

The symptoms, function, and overall QoL of patients with MF/SS favored mogamulizumab over vorinostat across all time points. Patients with the greatest symptom burden and functional impairment derived the most QoL benefit from mogamulizumab.

Health-related quality of life and economic implications of cutaneous T-cell lymphoma

BACKGROUND

Cutaneous T-cell lymphoma (CTCL) has been associated with considerable physical, psychological and financial burden. However, its impact on health-related quality of life (QoL) and economic costs are not well studied.

OBJECTIVES

To measure the QoL impact and financial burden of CTCL.

METHODS

A cross-sectional survey of 67 patients with CTCL was conducted using the Ontario Health Utilities Index Mark 3 (HUI3) questionnaire. Normative population data (n = 3310) were obtained from the 2002-2003 Joint Canada/United States Survey of Health. Economic cost was estimated using quality-adjusted life-year (QALY) loss derived from HUI3 scores.

RESULTS

Patients with CTCL had significantly lower aggregate HUI3 scores than the general population (0·68 vs. 0·87, P < 0·001). Multivariable regression analysis adjusting for demographics and comorbidities showed CTCL was associated with significantly poorer performance overall (-0·13, 95% CI -0·21 to -0·06, P < 0·001) and in domains of speech (-0·03, 95% CI -0·05 to -0·01, P = 0·01), ambulation (-0·04, 95% CI -0·08 to 0·00, P = 0·03), emotion (-0·07, 95% CI -0·12 to -0·02, P = 0·01), and pain (-0·07, 95% CI -0·13 to -0·01, P = 0·03). These health utility decrements yielded an average loss of 1·48 QALYs per patient. Using a $50 000 per QALY willingness-to-pay threshold, CTCL was associated with an individual lifetime burden of $73 889 and U.S. societal burden of $2·86 billion.

CONCLUSIONS

These findings suggest CTCL has a pervasive impact on QoL, comparable with debilitating conditions such as end-stage renal disease. The substantial economic burden of CTCL underscores the potential societal benefit of prompt diagnosis and effective management. What's already known about this topic? Cutaneous T-cell lymphoma is associated with physical, psychological and financial burden. What does this study add? The overall quality-of-life impact of cutaneous T-cell lymphoma has not previously been measured using a generic health utility instrument. In this study, we compare the overall quality-of-life burden of patients with cutaneous T-cell lymphoma with that of other populations and calculate the economic burden of the disease.

Is there still a role for UV therapy in itch treatment?

Itching is a frequent and greatly distressing symptom related to many skin and systemic diseases. New insights into the pathophysiology of itchy skin and potentially involved mediators have increased the interest in and development of new treatments that specifically act on targets involved in the transmission and perception of itching. Phototherapy has long been known and used as an effective treatment for various kinds of chronic itching. However, despite its well-known beneficial effects, the mechanisms behind the antipruritic effect of phototherapy are less well-known. In addition, phototherapy requires the use of expensive equipment in dermatology offices, patients must undergo repeated treatments and no large, randomized, controlled trials have yet supported the antipruritic effect of UV. Therefore, phototherapy is rarely recommended as a treatment method for chronic pruritic diseases or only used as a last recourse. However, the wide range of pruritic conditions that can be successfully treated with phototherapy, together with its low acute side effects, extremely low frequency of interactions with other medications, possibilities to combine phototherapy with other treatment modalities and the fact that patients of almost all ages-from childhood to old age, including women during pregnancy or lactation-can be treated make UV therapy advantageous over other treatments of chronic pruritus. Thus, despite the development of new targeted therapies against pruritus, UV therapy is neither outdated nor the 'last recourse', but should be considered early on in the treatment of chronic pruritus.

Pruritus in patients with solid tumors: an overlooked supportive care need

PURPOSE

Pruritus is a common symptom in cutaneous malignancies, but its impact on patients with solid tumors is unclear. We explored the impact and management of pruritus in patients with solid tumors, using patient-reported outcomes (PRO) data from a real-world registry.

METHODS

From 2006 to 2011, patients seen in the Duke Cancer Institute reported their symptoms via the Patient Care Monitor v2.0, a validated PRO tool that includes a 0-10-point question about pruritus severity. From > 25,000 encounters, 203 patients reported severe pruritus (> 6/10) on at least one visit and 506 total visits were abstracted where patients reported either moderate or severe pruritus (> 3/10). From this cohort, we abstracted demographics, diagnosis, stage, cancer therapy, anti-pruritic therapy, and clinicians' responses.

RESULTS

Mean age was 59.8 (SD 13.3), 134 (66%) were female, 125 (62%) were Caucasian, and 65 (32%) were African American. Breast cancer was the most common tumor (36.5%), followed by lung cancer (23.2%). Mean pruritus severity score was 6.8 (SD 1.8) for patients on chemotherapy, 6.9 (SD 1.8) for patients on targeted therapy alone or in combination, and 7.1(SD 1.8) for patients off treatment. Overall, 67% of patients reported at least two episodes of moderate-severe pruritus (mean # of visits 4.2 (SD 2.7)). Despite frequent report of severe and persistent pruritus, this was mentioned in just 28% of clinician notes and an intervention was recommended/prescribed in only 7% of visits.

CONCLUSIONS

Pruritus is an under-addressed symptom in patients with solid tumors. Additional research is needed to understand the burden of pruritus in affected populations.

Pruritus Reduction with Systemic Anti-lymphoma Treatments in Patients with Cutaneous T Cell Lymphoma: A Narrative Review

Cutaneous T-cell lymphomas (CTCL) are a heterogeneous and relatively rare group of non-Hodgkin lymphomas arising from neoplastic skin-homing memory T cells. There is no known cure for CTCL, and current treatments focus on achieving and maintaining remission, controlling symptoms, limiting toxicities and maintaining or improving quality of life. Patients with CTCL often suffer from pruritus (itching), which can be debilitating and can have a significant impact on physical well-being and quality of life. Although progress has been made towards understanding the mechanisms of pruritus, the pathophysiology of CTCL-related pruritus remains unclear. Currently, there is neither a step-wise treatment algorithm for CTCL nor a standardized approach to treating pruritus in patients with CTCL. Treatments which specifically target pruritus have been reported with varying effectiveness. However, systemic treatments that target CTCL have the potential to alleviate pruritus by treating the underlying disease. Several systemic CTCL treatments have reported anti-pruritic properties, some in both objective responders and nonresponders, but the lack of a standardized method to measure and report pruritus makes it difficult to compare the effectiveness of systemic treatments. In this review, we provide an overview of approved and investigational systemic CTCL treatments that report anti-pruritic properties. For each study, the methods used to measure and report pruritus, as well as the study design are examined so that the clinical benefits of each systemic treatment can be more readily evaluated.

Funding: Financial support for medical editorial assistance and article processing charge were provided by Celgene Corporation.

Romidepsin for the treatment of relapsed/refractory cutaneous T-cell lymphoma (mycosis fungoides/Sézary syndrome): Use in a community setting

Cutaneous T-cell lymphoma (CTCL) is a heterogeneous group of rare non-Hodgkin lymphomas that arise in the skin. In advanced stages, CTCL becomes systemic and is associated with poor prognosis. Diagnosis of CTCL and treatment of early-stage disease with topical therapies often occurs under the care of a dermatologist. Community oncologists see few patients with CTCL due to direct referrals from dermatologists to academic or lymphoma specialty centers. However, some patients will continue to be managed in a community setting. Currently there is no evidence-based stepwise algorithm for treatment of patients with CTCL, and guidelines suggest a wide range of systemic therapies, including biologics, targeted agents, and more traditional chemotherapies. To provide optimal care in a community setting, oncologists must become familiar with newer nonchemotherapeutic treatment options. This review highlights romidepsin, a histone deacetylase inhibitor approved for the treatment of patients with CTCL who have received ≥1 prior systemic therapy.

Invisible Mycosis Fungoides: Not to be Missed in Chronic Pruritus

INTRODUCTION

Pruritus without visible dermatoses may be the first manifestation of hematological malignancies such as Hodgkin disease, chronic lymphocytic leukemia and mycosis fungoides (MF) and may precede the definitive diagnosis by weeks to years.

CASE REPORT

We present a case of 'invisible' MF associated with chronic generalized pruritus in an elderly patient.

CONCLUSION

Our case highlights the importance of performing skin biopsies in patients with chronic unexplained pruritus, especially in the absence of cutaneous lesions. This can prompt the clinician to consider possible underlying malignancy, such as 'invisible' MF.

Immunological milieu in mycosis fungoides and Sézary syndrome

Tumor genesis and development are driven by a combination of intrinsic events such as oncogene activation and tumor-suppressor gene inactivation, and extrinsic events that are dependent on the interaction with the stroma. Different types of growth factors, cytokines and chemokines secreted by the surrounding stromal cells are thought to play key roles in solid tumor progression. Accumulating evidence indicates that the immunological milieu plays an essential role in tumor development, not only in solid tumors, but also in hematopoietic malignancies. Understanding the interactions between tumor cells and microenvironment in mycosis fungoides (MF) and Sézary syndrome (SS) could provide a basis for the development of new treatments for these diseases that are sometimes resistant to current therapies. This article focuses on the wide variety of cell types and immunological milieus, affecting the characteristic features of MF and SS, such as skin-homing of tumor cells, T-helper type 2-dominant tumor microenvironment, accumulation of dermal dendritic cells, epidermal hyperplasia, angiogenesis and pruritus.

Antihistamines and itch

Histamine is one of the best-characterized pruritogens in humans. It is known to play a role in pruritus associated with urticaria as well as ocular and nasal allergic reactions. Histamine mediates its effect via four receptors. Antihistamines that block the activation of the histamine H₁receptor, H₁R, have been shown to be effective therapeutics for the treatment of pruritus associated with urticaria, allergic rhinitis, and allergic conjunctivitis. However, their efficacy in other pruritic diseases such as atopic dermatitis and psoriasis is limited. The other histamine receptors may also play a role in pruritus, with the exception of the histamine H₂receptor, H₂R. Preclinical evidence indicates that local antagonism of the histamine H₃receptor, H₃R, can induce scratching perhaps via blocking inhibitory neuronal signals. The histamine H₄receptor, H₄R, has received a significant amount of attention as to its role in mediating pruritic signals. Indeed, it has now been shown that a selective H₄R antagonist can inhibit histamine-induced itch in humans. This clinical result, in conjunction with efficacy in various preclinical pruritus models, points to the therapeutic potential of H₄R antagonists for the treatment of pruritus not controlled by antihistamines that target the H₁R.

Tolerability to romidepsin in patients with relapsed/refractory T-cell lymphoma

Background

Histone deacetylase inhibitor romidepsin has demonstrated durable clinical responses and tolerability in patients with relapsed/refractory peripheral and cutaneous T-cell lymphoma (PTCL, CTCL). Selection of novel drug therapies for patients with relapsed/refractory aggressive lymphoma requires not only considerations regarding efficacy but also careful evaluation of toxicities as well as overall clinical benefit. The purpose of this analysis was to examine common adverse events (AEs) reported in pivotal trials of romidepsin in relapsed/refractory PTCL or CTCL and to more clearly define the overall AE profile in these populations.

Methods

Patients with relapsed/refractory PTCL or CTCL were treated with romidepsin at 14 mg/m² as a 4-hour intravenous infusion on days 1, 8, and 15 of 28-day cycles for up to 6 cycles; patients with at least stable disease could extend therapy until progressive disease or another withdrawal criterion was met. All enrolled patients who received ≥ 1 dose of romidepsin were included in the AE analyses.

Results

Overall, safety profiles of common AEs were similar, although patients with relapsed/refractory PTCL had more frequent hematologic toxicities and grade ≥ 3 infections. In both patient populations, the greatest incidence of grade ≥ 3 AEs and the majority of discontinuations due to AEs occurred during cycles 1–2. Early discontinuations were primarily related to infection, thrombocytopenia, or electrocardiogram abnormalities, confirming the need to closely monitor patients with poor bone marrow reserve or other comorbidities. Despite this, 28% of patients with relapsed/refractory PTCL and 36% of patients with relapsed/refractory CTCL continued on romidepsin treatment for ≥ 6 cycles.

Conclusions

This study demonstrates that patients with relapsed/refractory PTCL or CTCL have similar AE profiles with romidepsin treatment, although patients with PTCL experienced more frequent and more severe hematologic toxicities and more frequent grade ≥ 3 infections. The greatest incidence of grade ≥ 3 AEs and the majority of discontinuations due to AEs occurred during treatment cycles 1–2. Extended dosing of romidepsin can be tolerated in responding patients.

Trial registration

NCT00426764,NCT00106431

Targeted cancer therapy: giving histone deacetylase inhibitors all they need to succeed

Histone deacetylase inhibitors (HDACis) have now emerged as a powerful new class of small-molecule therapeutics acting through the regulation of the acetylation states of histone proteins (a form of epigenetic modulation) and other non-histone protein targets. Over 490 clinical trials have been initiated in the last 10 years, culminating in the approval of two structurally distinct HDACis - SAHA (vorinostat, Zolinza™) and FK228 (romidepsin, Istodax™). However, the current HDACis have serious limitations, including ineffectively low concentrations in solid tumors and cardiac toxicity, which is hindering their progress in the clinic. Herein, we review the primary paradigms being pursued to overcome these hindrances, including HDAC isoform selectivity, localized administration, and targeting cap groups to achieve selective tissue and cell type distribution.

Gabapentin for Pruritus in Palliative care

Itch/pruritus can be very distressing in palliative care population and often is difficult to treat. Conventional antihistamines lack efficacy. Cutaneous and central pathogenesis of itch is extremely complex and unclear, making its treatment challenging. Neuronal mechanisms have been identified in the pathophysiology of itch hence providing a myriad of therapeutic options. It has been established that pruritus and pain neuronal pathway interact with each other, hence neuropathic analgesics like gabapentin has shown to be efficacious antipruritic therapeutic option. Gabapentin impedes transmitting nociceptive sensations to brain, thus also suppressing pruritus. Gabapentin is safe and found to be effective in uremic pruritus, cancer/hematologic causes, opiod-induced itch, brachioradial pruritis, burns pruritus, and pruritus of unknown origin. Further research is required in this area to establish whether gabapentin is consistently effective.

Recent Advances in the Pathobiology of Hodgkin's Lymphoma: Potential Impact on Diagnostic, Predictive, and Therapeutic Strategies

From its first description by Thomas Hodgkin in 1832, Hodgkin's disease, now called Hodgkin's lymphoma, has continued to be a fascinating neoplasm even to this day. In this review, historical aspects, epidemiology, diagnosis, tumor biology, new observations related to host-microenvironment interactions, gene copy number variation, and gene expression profiling in this complex neoplasm are described, with an exploration of chemoresistance mechanisms and potential novel therapies for refractory disease.