Narin Apisarnthanarax

Treatment of cutaneous T cell lymphoma: Current status and future directions

The treatment of cutaneous T cell lymphoma (CTCL), which includes mycosis fungoides and Sezary syndrome, has been in a state of continual change over recent decades, as new therapies are constantly emerging in the search for more effective treatments for the disease. However, prognosis and survival of patients with CTCL remains dependent upon overall clinical stage (stage IA-IVB) at presentation, as well as response to therapy. Past therapies have been limited by toxicity or the lack of consistently durable responses, and few treatments have been shown to actually alter survival, especially in the late stages of disease. Even aggressive chemotherapy has not been shown to improve overall survival compared to conservative sequential therapy in advanced disease, and adds the risk of immunosuppressive complications. Over the last decade, extracorporeal photopheresis has been the only single treatment that has been shown to improve survival in patients with Sezary syndrome, although its true efficacy and place in combination therapy remain unclear. Much of the focus of current research has been on combinations of skin-directed therapies and biological response modifiers, which improve response rates. The results of various trials over the years have also brought into favor the use of post-remission maintenance therapy with topical corticosteroids, topical mechlorethamine (nitrogen mustard), interferon-α, or phototherapy to prevent disease relapse. Recent novel developments in CTCL therapy include oral bexarotene, a retinoid X receptor-selective retinoid that has activity in all stages of CTCL, and the topical gel formulation of bexarotene, which plays a role in treating localized lesions. US Food and Drug Administration (FDA)-approved, oral systemic bexarotene has the advantage of a 48% overall response rate at a dosage of 300 mg/m2/day, and avoids immunosuppression and risk of central line and catheter-related infectious complications that are associated with other systemic therapies. Monitoring of triglycerides and use of concomitant lipid-lowering agents and thyroid replacement is required in most patients. Also recently FDA-approved, denileukin diftitox is the first of a novel class of fusion toxin proteins and is selective for interleukin-2R (CD25+) T cells, targeting the malignant T cell clones in CTCL. Denileukin diftitox is associated with capillary leak syndrome in 20 to 30% of patients, which may be ameliorated by hydration and corticosteroids. Higher response rates are possible by combining bexarotene with ‘statin’ drugs and active CTCL therapies. Studies are being conducted on combining bexarotene and denileukin diftitox with other modalities. Biological response modifier therapies that are in current or future investigational trials include topical tazarotene, pegylated interferon, interleukin-2, and interleukin-12. At the forefront of systemic chemotherapy development, pegylated liposomal doxorubicin, gemcitabine, and pentostatin appear to have the greatest potential for success in CTCL therapy. Bone marrow transplantation, which is currently limited by the risk of graft-versus-host disease, offers the greatest potential for disease cure. Further developments for CTCL may include more selective immunomodulatory agents, vaccines, and monoclonal antibodies.

Treatment of refractory peripheral T-cell lymphoma with denileukin diftitox (ONTAK).

Peripheral T-cell lymphomas (PTCLs) are an uncommon and heterogeneous group of well-differentiated, post-thymic T-cell malignancies that can present in the skin as cutaneous T-cell lymphomas. In general, their prognosis is poor, and specific therapy is not well defined. We report the successful treatment of a patient with relapsed, refractory PTCL who after failing 13 standard single and multiple chemotherapy regimens and experimental agents had a dramatic prolonged response to diftitoxin denileukin (ONTAK ® ). This fusion protein, composed of diphtheria toxin coupled to interleukin-2, is approved for cutaneous T-cell lymphomas, including mycosis fungoides, and should be considered for treatment of the rare subset of peripheral T-cell lymphomas.

Phase I Clinical Trial of O6-Benzylguanine and Topical Carmustine in the Treatment of Cutaneous T-Cell Lymphoma, Mycosis Fungoides Type

OBJECTIVES To evaluate the toxic effects and maximum tolerated dose of topical carmustine [1,3-bis(2-chloroethyl)-1-nitrosourea] following intravenous O6-benzylguanine in the treatment of cutaneous T-cell lymphoma (CTCL), and to determine pharmacodynamics of O6-alkylguanine DNA alkyltransferase activity in treated CTCL lesions. DESIGN Open-label, dose-escalation, phase I trial. SETTING Dermatology outpatient clinic and clinical research unit at a university teaching hospital. PATIENTS A total of 21 adult patients (11 male, 10 female)with early-stage (IA-IIA) refractory CTCL, mycosis fungoides type, treated with topical carmustine following intravenous O6-benzylguanine. INTERVENTION Treatment once every 2 weeks with 120 mg/m(2) intravenous O6-benzylguanine followed 1 hour later by whole-body, low-dose topical carmustine starting at 10 mg, with 10-mg incremental dose-escalation in 3 patient cohorts. Cutaneous T-cell lymphoma lesional skin biopsy specimens were taken at baseline and 6 hours, 24 hours, and 1 week after the first O6-benzylguanine infusion for analysis of O6-alkylguanine-DNA alkyltransferase activity. MAIN OUTCOME MEASURES Clinical response measured by physical examination and severity-weighted assessment tool measurements, safety data acquired by review of adverse events at study visits, and O6-alkylguanine-DNA alkyltransferase activity in treated lesion skin biopsy specimens. RESULTS A minimal toxic effect was observed through the 40-mg carmustine dose level with 76% of adverse events being grade 1 based on the National Cancer Institute Common Terminology Criteria for Adverse Events. Mean baseline O6-alkylguanine-DNA alkyltransferase activity in CTCL lesions was 3 times greater than in normal controls and was diminished by a median of 100% at 6 and 24 hours following O6-benzylguanine with recovery at 1 week. Clinical disease reduction correlated positively with O6-alkylguanine-DNA alkyltransferase activity at 168 hours (P=.02) and inversely with area under the curve of O6-alkylguanine-DNA alkyltransferase over 1 week (P=.01). Twelve partial responses and 4 complete responses were observed (overall response, 76% [95% CI, 0.55-0.89]). Five patients discontinued therapy owing to adverse events with a possible, probable, or definite relationship to the study drug. CONCLUSION O6-benzylguanine significantly depletes O6-alkylguanine-DNA alkyltransferase in CTCL lesions and in combination with topical carmustine is well tolerated and shows meaningful clinical responses in CTCL at markedly reduced total carmustine treatment doses.

Mycosis fungoides with follicular mucinosis displaying aggressive tumor-stage transformation: Successful treatment using radiation therapy plus oral bexarotene combination therapy

Follicular mucinosis is a tissue reaction pattern characterized by mucin deposition with follicular sebaceous units and is found as an idiopathic, primary, benign process (alopecia mucinosa), or as a secondary process due to inflammatory and neoplastic disorders (mycosis fungoides). When associated with follicular mucinosis, mycosis fungoides commonly pursues an aggressive course, often undergoing large-cell transformation, which is associated with resistance to therapy and poor prognosis. We present a case of mycosis fungoides with follicular mucinosis that was treated with incomplete courses of interferon, isotretinoin, and polychemotherapy with subsequent rapid progression to tumor-stage mycosis fungoides with large cell transformation and nodal and bone marrow involvement. In this setting, the patient was treated with local radiation therapy, total-skin electron beam therapy, and therapy and maintenance with the oral retinoid-X-receptor retinoid bexarotene, and achieved a durable complete remission.

Therapy options in cutaneous T-cell lymphoma

The treatment of cutaneous T-cell lymphoma (CTCL) is continually evolving, as new and emerging drugs are added to the growing arsenal of CTCL therapy. The availability of newly approved investigational therapies, such as bexarotene, denileukin diftitox (DAB389-IL2), monoclonal antibodies and novel chemotherapeutic agents, adds complexity to decisions on the management and treatment of CTCL patients. In formulating a treatment plan, therapeutic options are best approached through consideration of overall clinical staging (stage IA–IVB) and skin staging (T1–T4), which affect prognosis and the characteristics of each individual patient’s disease. This article will present and discuss the optimal therapeutic agents for all clinical stages of CTCL patients, based on currently available and investigational agents.

Cutaneous T-cell lymphoma. New immunomodulators.

During the most recent decades, much knowledge has been gained concerning the immunologic and pathologic mechanisms of CTCL. The development of immunomodulators aimed at correcting aberrations in immunology and cellular growth and differentiation reflects this increased understanding. This review of the currently available immune-response modifying drugs shows that recombinant forms of natural cytokines and retinoids can be developed with tolerable toxicity profiles and substantial efficacy. Although milestone drugs such as bexarotene have been approved by the FDA- for treatment of CTCL, other agents such as IL-12 may also have a place in treatment of the disease. Even though unapproved, IFN-alpha may be the most active single immunomodulating agent against CTCL. It seems that further delineation of CTCL cytokine profile changes and immunologic aberrations are key in developing effective immunomodulators that are able to reverse these alterations.