Clinical and histopathological significance of PD-1 expression in cutaneous lesions of adult T-cell leukemia-lymphoma

Rapid T-cell lymphoma progression associated with immune checkpoint inhibitors

INTRODUCTION

Immune checkpoint inhibitors (ICIs) are widely used for multiple types of malignancies and are considered the fourth pillar in cancer treatment. Anti-programmed death-1 (PD-1) antibodies pembrolizumab and nivolumab are approved for relapsed/refractory classical Hodgkin lymphoma. Nonetheless, two phase 2 trials for T-cell lymphoma were terminated because of hyperprogression after a single dose in some patients.

AREAS COVERED

In this review, we summarize available information on the rapid progression of peripheral T-cell lymphoma including adult T-cell leukemia/lymphoma (ATLL).

EXPERT OPINION

In the abovementioned two trials, disease subtypes in patients who experienced hyperprogression were mostly ATLL or angioimmunoblastic T-cell lymphoma. Possible hyperprogression mechanisms induced by PD-1 blockade are the compensatory upregulation of the expression of other checkpoints, altered expression of lymphoma-promoting growth factors, functional blockade of stromal PD-ligand 1 acting as a tumor suppressor, and unique immune environment in indolent ATLL. The differentiation between hyperprogression and pseudoprogression is practically essential. There are no established methods to predict hyperprogression before administration of an ICI. In the future, the progress of novel diagnostic modalities such as positron emission tomography with computed tomography and circulating tumor DNA is expected to facilitate early cancer detection.

CCR4 as a Therapeutic Target for Cancer Immunotherapy

Simple Summary

CCR4 is a chemokine receptor selectively expressed on normal T cell subsets such as type 2 helper T cells, skin-homing T cells and regulatory T cells, and on skin-associated T cell malignancies such as adult T cell leukemia/lymphoma (ATLL), which is etiologically associated with human T lymphocyte virus type 1 (HTLV-1), and cutaneous T cell lymphomas (CTCLs). Mogamulizumab is a fully humanized and glyco-engineered monoclonal anti-CCR4 antibody used for the treatment of refractory/relapsed ATLL and CTCLs, often resulting in complete remission. The clinical applications of Mogamulizumab are now being extended to solid tumors, exploring the therapeutic effect of regulatory T cell depletion. This review overviews the expression of CCR4 in various T cell subsets, HTLV-1-infected T cells, ATLL and CTCLs, and the clinical applications of Mogamulizumab.

Abstract

CCR4 is a chemokine receptor mainly expressed by T cells. It is the receptor for two CC chemokine ligands, CCL17 and CCL22. Originally, the expression of CCR4 was described as highly selective for helper T type 2 (Th2) cells. Later, its expression was extended to other T cell subsets such as regulatory T (Treg) cells and Th17 cells. CCR4 has long been regarded as a potential therapeutic target for allergic diseases such as atopic dermatitis and bronchial asthma. Furthermore, the findings showing that CCR4 is strongly expressed by T cell malignancies such as adult T cell leukemia/lymphoma (ATLL) and cutaneous T cell lymphomas (CTCLs) have led to the development and clinical application of the fully humanized and glyco-engineered monoclonal anti-CCR4 Mogamulizumab in refractory/relapsed ATLL and CTCLs with remarkable successes. However, Mogamulizumab often induces severe adverse events in the skin possibly because of its efficient depletion of Treg cells. In particular, treatment with Mogamulizumab prior to allogenic hematopoietic stem cell transplantation (allo-HSCT), the only curative option of these T cell malignancies, often leads to severe glucocorticoid-refractory graft-versus-host diseases. The efficient depletion of Treg cells by Mogamulizumab has also led to its clinical trials in advanced solid tumors singly or in combination with immune checkpoint inhibitors. The main focus of this review is CCR4; its expression on normal and malignant T cells and its significance as a therapeutic target in cancer immunotherapy.

An international, multicenter, retrospective study on the positive impact of cutaneous involvement on the clinical outcome of adult T-cell leukemia/lymphoma

Adult T-cell leukemia/lymphoma (ATLL) is a largely incurable disease. Cutaneous involvement is common and could be first symptom of the disease. We analyzed 169 patients with ATLL of whom 63 had cutaneous involvement. Cutaneous involvement was found in 48, 27, 17, and 60% of acute, lymphomatous, chronic and smoldering ATLL cases, respectively. Eight cases had primary cutaneous tumoral variant. Erythroderma (24%) and plaques (22%) were the most frequent skin lesions. The presence of cutaneous involvement was associated with better overall survival compared to non-cutaneous involvement (aHR 0.55 [95% CI: 0.37-0.82], p < 0.01; 1-year OS 53 vs. 27%, respectively, p = 0.012). Combination zidovudine and interferon-alpha (AZT-IFN) yielded high response rates (overall response, OR = 100%, n = 8; complete response 62.5%) compared to chemotherapy (OR = 33.3%, n = 12/36). In conclusion, cutaneous involvement was associated with better survival in Latin American patients with ATLL. AZT-IFN demonstrated encouraging responses in ATLL patients with cutaneous involvement.

Neoplastic hematological diseases associated with HTLV-1 infection

Adult cell lymphoma/leukemia (ATLL) is a type of lymphoma consisting of T-cells that are related to infection with the human T lymphotropic virus (HTLV-1). Four clinical forms have been described (leukemic, lymphomatous, chronic, smoldering) and the phenotype corresponds to regulatory CD4+ T cells. The histological characteristics are variable, with neoplastic cells showing a size ranging from small to large and atypical nuclei with irregular contours. A series of genetic and molecular alterations have been described, which partially explain the lymphomagenesis of the neoplasm, some of which are also factors related to the clinical course and overall survival. ATLL is a neoplasm with a poor prognosis, but in recent years new targeted therapies have been designed, with encouraging responses. This neoplasm should continue to be studied to improve treatment and evolution.