Combination of Bexarotene and Psoralen-UVA Therapy in a Patient with Mycosis fungoides

Treatment of early-stage mycosis fungoides with oral bexarotene and phototherapy. A systematic review and meta-analysis

BACKGROUND

Mycosis fungoides (MF) is a rare subtype of non-Hodgkin lymphoma, for which no standard treatment exists.

OBJECTIVES

To provide evidence-based recommendations for adult patients with early-stage MF treated with oral bexarotene and phototherapy.

METHODS

A systematic review and meta-analysis was conducted utilizing studies identified via Embase, Pubmed, Web of Science, and the Cochrane Library from inception to April 2020 to evaluate the clinical efficacy and adverse events of oral bexarotene and phototherapy.

RESULTS

Of 645 abstracts retrieved, 17 full-text articles with 143 subjects were included for analysis. There were nine case reports, five retrospective cohort studies, two prospective cohort studies, and one randomized controlled trial. Most subjects were men (24.48%) with stage IB disease (54.4%), and the mean age at presentation was 63. One patient had folliculotropic disease. The retrospective studies' analysis included 67 subjects and indicated that the partial response was 40.36% (95% CI 18.24 to 64.92), complete response was 34.06% (95% CI 10.73 to 62.56), and overall response was 64.48% (95% CI 48.56 to 78.89). Side effects from bexarotene were hypertriglyceridemia (54%), hypothyroidism (50%), and hypercholesterolemia (46%). Similar results were noted in the prospective studies.

CONCLUSIONS

The literature consists mostly of uncontrolled studies which suggest that combination therapy with oral bexarotene and phototherapy is a therapeutic option. Future randomized control studies with longer follow-up and standardized definitions of treatment responses and dosages are needed to support the development of evidence-based approaches for the treatment of early-stage MF. This article is protected by copyright. All rights reserved.

Phototherapy of mycosis fungoides

BACKGROUND/PURPOSE

Among the primary cutaneous T-cell lymphomas, mycosis fungoides (MF) is the most common disease entity. Recently, an improved understanding of the pathology, clinical presentation, and prognosis of MF has lead to the development of new and practically useful classification and staging systems. In most patients, MF presents with patches and plaques and remains confined to the skin for years and decades, making it an ideal target for phototherapy. However, treatment schedules vary widely and this review describes the current knowledge about phototherapy of MF focusing mainly on narrow- and broadband UVB and 8-methoxypsoralen plus UVA, its indications, practical aspects, and clinical outcome.

METHODS

Review and summary of the pertinent literature.

RESULTS AND CONCLUSIONS

Since 1976, when the first report on phototherapy for MF was published, sufficient evidence has accumulated to make narrowband UVB and PUVA safe and effective treatment options for early stages of the disease. In refractory cases or more advanced stages, combination of phototherapy with systemic treatments including mainly interferons and retinoids might be valuable. Additional research is required to further define the optimal treatment schedules and the role of maintenance.

International Union of Pharmacology. LXIII. Retinoid X receptors

The physiological effects of retinoic acids (RAs) are mediated by members of two families of nuclear receptors, the retinoic acid receptors (RARs) and the retinoid X receptors (RXRs), which are encoded by three distinct human genes, RXRalpha, RXRbeta, and RXRgamma. RARs bind both all-trans- and 9-cis-RA, whereas only the 9-cis-RA stereoisomer binds to RXRs. As RXR/RAR heterodimers, these receptors control the transcription of RA target genes through binding to RA-response elements. This review is focused on the structure, mode of action, ligands, expression, and pharmacology of RXRs. Given their role as common partners to many other members of the nuclear receptor superfamily, these receptors have been the subject of intense scrutiny. Moreover, and despite numerous studies since their initial discovery, RXRs remain enigmatic nuclear receptors, and there is still no consensus regarding their role. Indeed, multiple questions about the actual biological role of RXRs and the existence of an endogenous ligand have still to be answered.

Tratamiento de micosis fungoide con PUVA más bexaroteno

INTRODUCTION

The combined use of bexarotene and PUVA is a treatment that is currently being investigated. In this paper, six patients treated with this combination are presented.

OBJECTIVES

To assess the efficacy and safety of treatment with PUVA + bexarotene in patients with mycosis fungoides (MF). Patients, material and methods. Six patients diagnosed with MF in different stages, who received three sessions of PUVA treatment a week (initially 2.35 J/cm 2, with progressive increases to a maximum of 23.5 J/cm 2) + bexarotene (initial dose 300 mg/m 2/day, decreasing to 200, 150 or 75 mg/m 2 if signs of toxicity appeared). All received atorvastatin.

RESULTS

Stage at the start of treatment: two patients IIb, one patient Ib with B2 blood involvement, two patients Ib, one patient Ia. Five of the six patients responded to the treatment (three full remissions [FR], two partial remissions [PR]). One patient did not respond. In those in whom FR was achieved, the time required for the response was 10, 20 and 24 weeks. All presented with hypertriglyceridemia (maximum 1194 mg/ dL). It was necessary to administer thyroid hormone supplements to four of the patients. Two of them had alterations in the hepatic biochemistry values, and two others presented with alterations in the muscle profile analysis.

CONCLUSION

The combination of PUVA and bexarotene is a safe and effective treatment for MF. It will be necessary to await the results of the clinical trials currently underway to see if their combined use is better than treatment with PUVA alone. The response rate (RR) was 86 % (three FR and two PR out of six patients).

Clinical Experience: Practical Management of Five Patients With Cutaneous T-Cell Lymphoma (CTCL)-Related Symptoms

There are now a wide variety of therapeutic options for managing patients with cutaneous T-cell lymphoma-related symptoms. These include skin-directed therapies such as psoralen with UVA irradiation (PUVA), topical chemotherapies such as mechlorethamine (nitrogen mustard) and carmustine (BCNU), electron beam radiation, and systemic therapies such as chemotherapy, photopheresis, and interferons. Although treatment algorithms exist for patients with early stage disease, often treatments are individualized, based on patient specific factors, cost, and accessibility of referral centers for specialized therapies. This article provides details of five real-life case studies to illustrate how cutaneous T-cell lymphoma management can be tailored to the needs of each individual patient.

Therapeutic Advances in Cutaneous T-Cell Lymphoma (CTCL): From Retinoids to Rexinoids

Retinoids comprise a family of polyisoprenoid lipids that include vitamin A (retinol) and its various natural and synthetic analogues. Retinoids are compounds with multiple actions. They are involved in the control of cell proliferation, cell differentiation, and embryonic development. Each retinoid has its own profile of pharmacologic properties that determines its usefulness in clinical dermatology or oncology. Although numerous synthetic retinoids have been synthesized, their biological activities are usually associated with clinical disadvantages such as toxicity and teratogenicity. Retinoids that bind to both the retinoic acid receptor and retinoid X receptor subtypes have shown clinical activity in hematologic malignancies and can mediate genes associated with both growth and differentiation. Retinoid X receptor-specific rexinoids have also shown efficacy in the treatment of cutaneous T-cell lymphomas, but their exact mechanism of action is unclear. This article summarizes the clinical relevance of both groups of compounds in this important patient population.