forodesine and Sezary-Syndrome

There are few approved therapies for cutaneous T-cell lymphoma (CTCL). The retinoids are the major biologic response modifiers used in CTCL, producing good response rates but few complete responses. For patients with early-stage disease, the oral retinoids can be combined with other therapies, such as psoralen plus ultraviolet A or interferon alpha, to improve response rates. Combined-modality therapy with oral retinoids, combined chemotherapy, electron-beam therapy, and topical mustargen has also proved effective. For the treatment of advanced-stage disease, the targeted therapy denileukin diftitox (Ontak) provides a nonimmunosuppressive alternative to conventional chemotherapy or radiation therapy. Of the conventional chemotherapies that have been tested in CTCL, gemcitabine (Gemzar) has demonstrated good efficacy in producing responses, particularly in patients with tumors. This agent can be used in combination with a maintenance therapy of bexarotene (Targretin) to manage the plaques and patches of mycosis fungoides. Several other targeted therapies are now also in testing, for example, alemtuzumab (CamPath), HuMax-CD4, several histone deacetylase inhibitors, and the transition-state inhibitor forodesine. These drugs, in combination with currently used therapies, may increase the number and combinations of therapies available for the treatment of this chronic condition to optimize long-lasting responses in CTCL.

Topics: Alemtuzumab; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Antibodies, Neoplasm; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Chemotherapy, Adjuvant; Diphtheria Toxin; Dose-Response Relationship, Drug; Humans; Hydroxamic Acids; Immunologic Factors; Interferon-alpha; Interleukin-2; Lymphoma, T-Cell, Cutaneous; Mechlorethamine; Purine Nucleosides; Pyrimidinones; Radiotherapy, Adjuvant; Recombinant Fusion Proteins; Retinoids; Sezary Syndrome; Skin Neoplasms; Vorinostat

Primary cutaneous T-cell lymphomas (CTCLs) are a heterogeneous group of non-Hodgkin's lymphomas characterized by skin infiltration of neoplastic T lymphocytes. Mycosis fungoides and its leukemic variant Sézary syndrome represent the most common CTCL subtypes. Current treatment for patients with mycosis fungoides involves topical and systemic therapies for the cutaneous manifestations. However, no therapy is curative and patients often progress to advanced extracutaneous CTCL with visceral organ complications or relapsed disease that is frequently refractory to most topical and aggressive systemic regimens. The emergence of novel targeted therapies such as biologic agents, histone deacetylase inhibitors, and purine nucleoside phosphorylase inhibitors offers promise for more effective and safer treatment strategies for refractory CTCLs.

Topics: Clinical Trials as Topic; Histone Deacetylases; Humans; Immunologic Factors; Mycosis Fungoides; Purine Nucleosides; Purine-Nucleoside Phosphorylase; Pyrimidinones; Sezary Syndrome; Skin Neoplasms

Forodesine is a potent inhibitor of purine nucleoside phosphorylase (PNP) that leads to intracellular accumulation of deoxyguanosine triphosphate (dGTP) in T and B cells, resulting in apoptosis. Forodesine has demonstrated impressive antitumor activity in early phase clinical trials in cutaneous T-cell lymphoma (CTCL).. In this phase II study, patients with CTCL who had already failed three or more systemic therapies were recruited. We investigated the response rate, safety and tolerability of oral forodesine treatment in subjects with cutaneous manifestations of CTCL, stages IB, IIA, IIB, III and IVA. The safety population encompassing all stages was used for analysis of accountability, demographics and safety. The efficacy population differed from the safety population by exclusion of stage IB and IIA patients.. All 144 patients had performance status 0-2. The median duration of CTCL from diagnosis was 53 months (5-516 months). The median number of pretreatments was 4 (range: 3-15). No complete remissions were observed. In the efficacy group of patients, 11% achieved partial remission and 50% had stable disease. The median time to response was 56 days and the median duration of response was 191 days. A total of 96% of all treated patients reported one or more adverse events (AEs) and 33% reported a serious AE. The majority of AEs were classified as mild or moderate in severity. The most commonly reported AEs (>10%) were peripheral edema, fatigue, insomnia, pruritus, diarrhea, headache and nausea. Overall eight patients died during the study: five due to sepsis and infections, one due to a second malignancy (esophageal cancer), one due to disease progression and one due to liver failure.. Oral forodesine at a dose of 200 mg daily is feasible and shows partial efficacy in this highly selected CTCL population and some durable responses.

Topics: Adult; Aged; Aged, 80 and over; Antineoplastic Agents; Apoptosis; Female; Humans; Male; Middle Aged; Mycosis Fungoides; Purine Nucleosides; Purine-Nucleoside Phosphorylase; Pyrimidinones; Sezary Syndrome; Skin Neoplasms; Treatment Failure