Clearance of folliculotropic and tumor mycosis fungoides with topical 5% imiquimod

Imiquimod as Local Immunotherapy in the Management of Premalignant Cutaneous Conditions and Skin Cancer

Cutaneous cancers are, by far, the most common malignant neoplasms of the human being. Due to the great array of clinical conditions, their worldwide increasing incidence and the steady ageing of the population, non-invasive treatments modalities that show a good clinical response, a proper benefit-risk ratio and cosmetic results are becoming increasingly important in the clinical setting. Imiquimod is a topically applied immunomodulator which is often used in the management of several premalignant and malignant cutaneous disorders. This article is a review of the current literature on its mechanism of action, pharmacokinetics, and therapeutical effects.

New developments in skin-directed treatments of cutaneous T-cell lymphoma

The therapeutic approach for mycosis fungoides, the most common type of primary cutaneous T-cell lymphoma, is based mainly on the stage of the disease, and skin-directed treatment is recommended by all international guidelines as the first-line treatment in early-stage disease. Skin-directed treatments may be also given in combination with systemic therapies in early-stage mycosis fungoides patients recalcitrant to different types of skin-directed treatments, or in certain patients with high-risk features. Advanced-stage mycosis fungoides is treated mainly with systemic treatments, which may be combined with skin-directed treatments. Due to the rarity of mycosis fungoides, controlled clinical trials of the different skin-directed treatment modalities are almost non-existent, with a few exceptions, and therefore recommendations are largely based on cohort studies and expert opinion. This paper reviews the new developments in skin-directed treatments and provides an update on new studies of already well-known therapies, and an update on novel treatments.

How to Sequence Therapies in Mycosis Fungoides

OPINION STATEMENT

Choice of therapy in mycosis fungoides is based on both patient- and lymphoma-specific factors, such as disease characteristics, comorbidities, symptoms and effect on quality of life, potential associated toxicities of therapy, response and tolerance to prior lines of therapy, and convenience and practicality. Generally, we sequence therapies from least toxic, targeted, nonimmunosuppressive to more toxic, immunosuppressive and from single agent to multiple agents, as necessary. If more toxic, immunosuppressive agents are required to alleviate disease burden or symptoms, we generally use them just long enough to control the disease, then transition to a maintenance regimen with less toxic, less immunosuppressive agents.

Cell signaling in cutaneous T-cell lymphoma microenvironment: promising targets for molecular-specific treatment

Cutaneous T-cell lymphomas (CTCL) result from the infiltration and proliferation of a population of T cells in the skin, inducing changes in the activity of both T cells and surrounding skin cells. In the CTCL microenvironment, cell interactions mediated by cell signaling pathways are altered. Defining changes in cell signaling enables to understand T-cell deregulations in the CTCL microenvironment and thus the progression of the disease. Moreover, characterizing signaling networks activated in CTCL stages can lead to consider new molecular biomarkers and therapeutic targets. Focusing on mycosis fungoides (MF), the most frequent variant of CTCL, and Sézary syndrome (SS), its leukemic variant, this review highlights recent molecular and genetic findings revealing modifications of key signaling pathways involved in (1) cell proliferation, cell growth, and cell survival such as MAP kinases and PI3K/Akt; (2) immune responses derived from TCR, TLR, JAK/STAT, and NF-kB; and (3) changes in tissue conditions such as extracellular matrix remodeling, hypoxia, and angiogenesis. Alterations in these signaling networks promote malignant T-cell proliferation and survival, T-cell migration, inflammation, and suppression of immune regulation of malignant T cells, making a skin microenvironment that allows disease progression. Targeting key proteins of these signaling pathways, using molecules already available and used in research, in clinical trials, and with other disease indications, can open the way to different therapeutic options in CTCL treatment.

The immunopathogenesis and immunotherapy of cutaneous T cell lymphoma: Current and future approaches

In the past few decades, immunotherapy has emerged as an effective therapeutic option for patients with cutaneous T cell lymphoma (CTCL). CTCL is characterized by progressive impairment of multiple arms of the immune system. Immunotherapy targets these deficits to stimulate a more robust antitumor response, thereby both clearing the malignant T cells and repairing the immune dysfunction. By potentiating rather than suppressing the immune system, immunotherapy can result in longer treatment responses than alternatives such as chemotherapy. In recent years, advances in our understanding of the pathogenesis of CTCL have led to the development of several new agents with promising efficacy profiles. The second article in this continuing medical education series describes the current immunotherapeutic options for treatment of CTCL, with a focus on how they interact with the immune system and their treatment outcomes in case studies and clinical trials. We will discuss established CTCL immunotherapies, such as interferons, photopheresis, and retinoids; emerging therapies, such as interleukin-12 and Toll-like receptor agonists; and new approaches to targeting tumor antigens and checkpoint molecules, such as mogamulizumab, anti-programmed cell death protein 1, anti-CD47, and chimeric antigen receptor T cell therapy. We also describe the principles of multimodality immunotherapy and the use of total skin electron beam therapy in such regimens.

Revisiting Imiquimod for Treatment of Folliculotropic Mycosis Fungoides: A Case Report and Review of the Literature

Folliculotropic mycosis fungoides (FMF) is an aggressive variant of mycosis fungoides (MF) characterized by infiltration of the hair follicle epithelium by neoplastic T cells. FMF demonstrates poor response rates to standard skin-directed therapies such as phototherapy and topical corticosteroids. Imiquimod, an immunomodulatory agent that stimulates the antitumor immune response, has been used successfully in treatment of early-stage MF. We report a 21-year-old patient with unilesional FMF who achieved clinical remission with imiquimod application. This case highlights a potential for use of imiquimod as a treatment option for patients with FMF and limited skin involvement.

New Therapies and Immunological Findings in Cutaneous T-Cell Lymphoma

Primary cutaneous lymphomas comprise a group of lymphatic malignancies that occur primarily in the skin. They represent the second most common form of extranodal non-Hodgkin’s lymphoma and are characterized by heterogeneous clinical, histological, immunological, and molecular features. The most common type is mycosis fungoides and its leukemic variant, Sézary syndrome. Both diseases are considered T-helper cell type 2 (Th2) diseases. Not only the tumor cells but also the tumor microenvironment can promote Th2 differentiation, which is beneficial for the tumor cells because a Th1 environment enhances antitumor immune responses. This Th2-dominant milieu also underlies the infectious susceptibility of the patients. Many components, such as tumor-associated macrophages, cancer-associated fibroblasts, and dendritic cells, as well as humoral factors, such as chemokines and cytokines, establish the tumor microenvironment and can modify tumor cell migration and proliferation. Multiagent chemotherapy often induces immunosuppression, resulting in an increased risk of serious infection and poor tolerance. Therefore, overtreatment should be avoided for these types of lymphomas. Interferons have been shown to increase the time to next treatment to a greater degree than has chemotherapy. The pathogenesis and prognosis of cutaneous T-cell lymphoma (CTCL) differ markedly among the subtypes. In some aggressive subtypes of CTCLs, such as primary cutaneous gamma/delta T-cell lymphoma and primary cutaneous CD8⁺ aggressive epidermotropic cytotoxic T-cell lymphoma, hematopoietic stem cell transplantation should be considered, whereas overtreatment should be avoided with other, favorable subtypes. Therefore, a solid understanding of the pathogenesis and immunological background of cutaneous lymphoma is required to better treat patients who are inflicted with this disease. This review summarizes the current knowledge in the field to attempt to achieve this objective.

Complete resolution of mycosis fungoides tumors with imiquimod 5% cream: a case series

OBJECTIVE

To demonstrate the clinical efficacy of topical 5% imiquimod for mycosis fungoides (MF) tumors.

BACKGROUND

Treatment of tumor-stage MF represents a therapeutic challenge because of a limited number of effective topical therapies. Single tumors can be treated with localized radiation but may recur. Systemic therapies are also an option but are associated with serious adverse effects. Imiquimod is a topical agent whose efficacy has been documented in treating MF patches and plaques as well as one case of tumor-stage disease.

METHODS

We present two stage IIB MF patients, including one with large cell transformation, whose tumors were treated with imiquimod 5% cream after failing prior therapies.

RESULTS

The MF tumors in both patients demonstrated a complete response to imiquimod 5% cream without recurrence over 8 years and 2 years of follow-up, respectively. One patient experienced application site irritation and flu-like symptoms as adverse effects.

CONCLUSIONS

Our case series is only the second report in the literature demonstrating complete resolution of MF tumors with topical imiquimod. An additional therapeutic option for tumor-stage MF, imiquimod may represent an effective alternative to localized radiation for isolated MF tumors and warrants further investigation in the treatment of various stages of MF.