Final results of a multicenter phase II study of the purine nucleoside phosphorylase (PNP) inhibitor forodesine in patients with advanced cutaneous T-cell lymphomas (CTCL) (Mycosis fungoides and Sézary syndrome).

BACKGROUND: 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). PATIENTS AND METHODS: 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. RESULTS: 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. CONCLUSION: 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.

From chemotherapy to targeted treatment.

Today, melanoma is considered as a spectrum of melanocytic malignancies that can be characterized by clinical and molecular features, including targetable mutations in several kinases. The successful development of therapies, targeting mutated BRaF (v-raf murine sarcoma viral oncogene homolog B1) or c-KIT (v-kit Hardy-Zuckerman 4 feline sarcoma viral oncogene homolog), has resulted in new treatment options including vemurafenib, imatinib and mitogen-activated protein kinase inhibitors. These molecules are selected if the respective mutation is present. after this first progress in the treatment of advanced melanoma, there is expectation that combinations of kinase inhibitor will additionally improve the overall survival rates and progression-free survival in advanced melanoma.

Cutaneous peripheral T-cell lymphomas, unspecified/NOS and rare subtypes: a heterogeneous group of challenging cutaneous lymphomas.

Cutaneous peripheral T-cell lymphoma, unspecified/not otherwise specified (PTL NOS) represents a phenotypically and prognostically heterogenous group of cutaneous T-cell lymphomas (CTCL) that do not fit into any of well defined defined CTCL subtypes. In the WHO-EORTC classification as well as the WHO classification, three entities have been delineated as provisional rare subtypes of PTL based on their characteristic clinico-pathological, immunophenotypic and prognostic features and have been separated out from PTL, NOS: Primary cutaneous CD4-positive small/medium T-cell lymphoma (CD4+ SMTL), primary cutaneous CD8-positive aggressive epidermotropic T-cell lymphoma (CD8+ AECTCL), and primary cutaneous gamma/delta T-cell lymphoma (CGD-TCL). CD4+ SMTL manifests in most patients with a solitary nodule in the head and neck area and nodular infiltrates of CD4+ small to medium-sized lymphocytes with nuclear pleomorphism. The prognosis of this lymphoproliferation is excellent in patients with a solitary lesion, but may be impaired in patients with multifocal disease. Rapidly evolving erosive or necrotic plaques and nodules with an epidermotropic infiltrate of CD8+ atypical lymphocytes are the hallmark of CD8+ AECTCL, which exhibits a poor prognosis. CGD-TCL displays a broad spectrum of clinical and histological manifestations with expression of the T-cell receptor gamma/delta chain as the common denominator and diagnostic marker. As most of other forms of PTL, CGD-TCL carries a poor prognosis. Despite the rarity of PTL NOS, clinicians as well as dermatopathologists and pathologists should be familiar with these rare CTC, especially since most of these lymphomas exhibit an unfavourable prognosis. Immediate intense treatment with multiagent chemotherapy and hematopoietic stem cell transplantation is indicated in patients with PTL NOS. This review focuses on the clinicopathological aspects, the diagnostic criteria and the classification of the rare subtypes of PTL and PTL NOS.