Oral bexarotene in a therapy-resistant Sezary syndrome patient: observations on Sezary cell compartmentalization

Bexarotene in the treatment of cutaneous T-cell lymphoma

Primary cutaneous T-cell lymphomas encompass a spectrum of non-Hodgkin's lymphomas that are characterised by clonal proliferation of skin-homing malignant T lymphocytes. Mycosis fungoides and the leukaemic variant Sézary syndrome, collectively referred to as cutaneous T-cell lymphomas, are the most common entities. No curative therapy exists and patients ultimately develop advanced or relapsed disease that is refractory to standard treatment options. Therefore, there is a great need for the development of novel emerging therapies. Bexarotene is the first synthetic nuclear retinoid X receptor-selective retinoid approved by the FDA for the treatment of refractory cutaneous T-cell lymphoma in all stages, as both an oral capsule and a topical gel formulation. Bexarotene was found to induce apoptosis in a variety of preclinical in vitro and in vivo models including cutaneous T-cell lymphoma cells, and has shown efficacy in two multi-centre, open-label Phase II - III clinical trials for early and advanced stages of cutaneous T-cell lymphoma in patients who have failed or were refractory to standard therapies. New insights into the immunomodulatory function of bexarotene have indicated opportunities for combined treatment with IFN-alpha, denileukin diftitox or phototherapy. This article reviews the biological properties, pharmacokinetics, clinical efficacy, safety and role of bexarotene in the treatment of cutaneous T-cell lymphoma.

The New World Health Organization–European Organization for Research and Treatment of Cancer Classification of Cutaneous Lymphomas

The WHO-EORTC classification of cutaneous lymphomas is a good start to unifying nomenclature, a necessity before coherent consensus diagnoses can be made. There are three provisional diagnoses in this new classification that are not covered in detail in this review because they are rare diseases that still require further study for definitive classification. Much remains to be elucidated about cutaneous lymphomas, but understanding of the major entities within the new classification is an important first step in understanding these diverse diseases.

The spectrum of cutaneous T-cell lymphomas: new insights into biology and therapy

PURPOSE OF REVIEW

Cutaneous T-cell lymphomas represent clinically and biologically a heterogeneous group of non-Hodgkin lymphomas according to the new revised European Organization for Research and Treatment of Cancer and World Health Organization consensus classification for cutaneous lymphomas. Recent progress in immune and molecular biology and novel therapeutic targets have increased our understanding of these diseases and have led to novel treatment approaches. This review outlines the most recent advances.

RECENT FINDINGS

New immunologic and molecular findings may influence tumor phenotype and growth and provide a biologic basis for novel treatment approaches. Several reports have focused on new prognostic markers. Among the novel therapies for cutaneous T-cell lymphoma, interleukin-2 fusion toxins, monoclonal antibodies, histone deacetylase inhibitors, and immunomodulatory cytosine-phosphorothiolated guanine oligomers have shown promising results and are under further investigation.

SUMMARY

This review provides an update of recent findings of immunologic, molecular, and cytogenetic features and treatment approaches for patients with cutaneous T-cell lymphoma with special emphasis on mycosis fungoides and Sezary syndrome.

Bexarotene treatment of late-stage mycosis fungoides and Sézary syndrome: Development of extracutaneous lymphoma in 6 patients∗

Bexarotene is a retinoid drug that is approved for the treatment of cutaneous T-cell lymphoma. We report 6 cases in which the initiation of bexarotene therapy for cutaneous T-cell lymphoma was temporally associated with the progression of internal disease despite improvement in cutaneous signs and symptoms. It is possible that bexarotene contributed to this progression. Although bexarotene therapy may alleviate symptoms and signs of cutaneous T-cell lymphoma, careful surveillance of lymph nodes and solid organs during treatment is advised.