Search

Background Extranodal natural killer/T cell lymphoma, nasal type, is one of the more common subtypes of mature T cell lymphoma, especially in the Far East Asian population. This aggressive histologic subtype of peripheral T cell lymphomas is frequently susceptible to exposure of Epstein–Barr virus infection. The optimal treatment is not well elucidated. For stage IV disseminated extranodal natural killer/T cell lymphoma, induction chemotherapy with consolidative autologus or allogeneic hematopoietic stem cell transplantation is recommended as the major first-line treatment. However, there is controversy over which type of chemotherapy is most appropriate and effective as a bridge to autologus or allogeneic hematopoietic stem cell transplantation in patients with newly diagnosed disseminated advanced-stage or relapsed extranodal natural killer/T cell lymphoma because of cancer chemoresistance or associated complications. Pralatrexate is the first US Food and Drug Administration-approved novel agent for the treatment of refractory/recurrent peripheral T cell lymphomas. In our case, pralatrexate was used as a successful bridge to allogeneic hematopoietic stem cell transplantation in a patient with advanced-stage disseminated extranodal natural killer/T cell lymphoma refractory to first-line chemotherapy. Case presentation We presented a case report of a 29-year-old Asian man diagnosed as having stage IV disseminated extranodal natural killer/T cell lymphoma, nasal type, with skin and bone marrow involvement, whose disease was primary refractory to first-line dexamethasone, methotrexate, ifosfamide, L-asparaginase, and etoposide chemotherapy, but obviously responded to treatment with two cycles of single-agent pralatrexate treatment. Monitoring Epstein–Barr virus viremia revealed dramatic downregulation. In addition to complete remission of the involvement of bone marrow and nasal cavity, skin involvement also obtained partial remission. The extranodal natural killer/T cell lymphoma successfully achieved complete remission after a bridge to allogeneic hematopoietic stem cell transplantation. Conclusions This is the first study to present pralatrexate as a successful bridge to allogeneic hematopoietic stem cell transplantation in a 29-year-old Asian male patient with advanced-stage extranodal natural killer/T cell lymphoma refractory to first-line dexamethasone, methotrexate, ifosfamide, L-asparaginase, and etoposide chemotherapy. This case provides a novel treatment opinion for extranodal natural killer/T cell lymphoma, especially for the Far East Asian population.

PURPOSE: Pralatrexate is a folate analogue indicated for the treatment of relapsed or refractory peripheral T-cell lymphoma. It has not been formally tested in patients with renal impairment. This study evaluated the pharmacokinetic (PK) profile of pralatrexate in patients with renal impairment and with relapsed/refractory advanced solid tumors and lymphoma. METHODS: This was an open-label, nonrandomized, phase 1 study. Eligible patients received pralatrexate administered as an IV push over 3–5 min once weekly for 6 weeks in 7-week cycles until progressive disease or intolerable toxicity. Four cohorts of 6 patients were planned for a total of 24 patients. Patients with normal renal function (Cohort A), mild (Cohort B), and moderate renal impairment (Cohort C) received 30 mg/m(2) pralatrexate once weekly for 6 weeks in 7-week cycles, and patients with severe renal impairment (Cohort D) were to be administered 20 mg/m(2) once weekly for 6 weeks. Plasma and urine samples were collected at pre-specified time points to determine the PK profile of pralatrexate in each treatment cohort. Patients were followed for safety and tolerability. RESULTS: A total of 29 patients were enrolled and 27 patients (14 male) received at least 1 dose of pralatrexate. Because of a qualifying toxicity in Cohort C, the starting dose for Cohort D was reduced to 15 mg/m(2). Chronic renal impairment led to a decrease in renal clearance of the pralatrexate diastereomers, PDX-10a and PDX-10b, but systemic exposure to these diastereomers was not dramatically affected by renal impairment. Pralatrexate exposure in Cohort D (15 mg/m(2)) was similar to the exposure in other cohorts (30 mg/m(2)). No apparent difference in toxicity between the four treatment cohorts was observed, except for an increase in cytopenias in patients with severe renal impairment. CONCLUSION: Pralatrexate exposure, at a dose of 30 mg/m(2), in patients with mild or moderate renal impairment was similar to the exposure in patients with normal renal function. For patients with severe renal impairment only, a pralatrexate dose of 15 mg/m(2) is recommended.

Mycosis fungoides (MF) and its leukemic variant, Sézary syndrome (SS), are malignancies of skin-homing T cells that comprise the majority of cutaneous T cell lymphomas (CTCL). Treatment of CTCL is limited and can be approached by skin-directed therapy or systemic therapy. Recent investigations into the pathogenesis of MF and SS have broadened the therapeutic targets; here, we review emerging concepts in the pathogenesis of MF and SS as well as novel and traditional systemic therapies for MF and SS. These include histone deacetylase inhibitors (vorinostat, romidepsin, panobinostat, and belinostat), monoclonal antibodies (alemtuzumab, brentuximab vedotin, and mogamulizumab) and single-agent cytotoxic chemotherapeutic agents (e.g., pralatrexate, doxorubicin, bendamustine, and forodesine), as well as multi-agent chemotherapy regimens.

Purpose To investigate the effectiveness of a combination of 6-thioguanine (6-TG) and pralatrexate (PDX) in methylthioadenosine phosphorylase (MTAP)-deficient T-cell acute lymphoblastic leukemia (T-cell ALL). Methods CCRF-CEM (MTAP−/−) and Molt4 (MTAP+/+) T-cell ALL cell lines were treated with 6-TG or PDX and evaluated for efficacy 72 h later. NOD/SCID gamma mice bearing CEM or Molt4 xenografts were treated with 6-TG and PDX alone or in combination to evaluate antitumor effects. Results CEM cells were more sensitive to 6-TG and PDX in vitro than Molt4. In vivo, CEM cells were very sensitive to PDX and 6-TG, whereas Molt4 cells were highly resistant to 6-TG. A well-tolerated combination of PDX and 6-TG achieved significant tumor regression in CEM xenografts. Conclusions The loss of MTAP expression may be therapeutically exploited in T-cell ALL. The combination of 6-TG and PDX, with the inclusion of leucovorin rescue, allows for a safe and effective regimen in MTAP-deficient T-cell ALL.

Peripheral T-cell lymphomas (PTCL) are a group of uncommon and heterogeneous malignancies arising from a postthymic or mature T-lymphocyte. The treatment of PTCL remains a challenging endeavor. Compared with the more common aggressive B-cell lymphomas, more patients with PTCL will be refractory to initial therapy and those who achieve responses often will have shorter progression-free survival. Despite retrospective data that suggest that anthracycline-based multiagent chemotherapy regimens may not provide a benefit compared with nonanthracycline regimens, nonanthracycline-based regimens, with the notable exception of L-asparaginase regimens for extranodal NK/T-cell lymphoma, have been disappointing so far. Based on phase II evidence and subset analyses available, we believe that the addition of etoposide to standard regimens and consolidation of first remissions with autologous stem cell transplantation (autoSCT) provides the best outcome in patients with PTCL and currently use CHOEP followed by ASCT for eligible patients with the common PTCL subtype: PTCL-NOS, AITL, and ALK negative ALCL. For those with ALK-positive ALCL standard CHOP or CHOEP is appropriate with consideration of ASCT only for those with high-risk disease. Other strategies to incorporate additional agents, such as with dose-adjusted EPOCH or sequential CHOP-ICE regimens are logical options; however, they lack the supporting literature of CHOEP. Whereas the above recommendation is our current off-protocol approach, with the possible exception of low risk ALK positive ALCL, none of these choices is supported by strong enough data to supplant a well-conceived clinical trial as the truly preferred strategy in PTCL. The novel agents, romidepsin, pralatrexate, and brentuximab vedotin, are currently approved in the relapsed/refractory setting. These agents are being studied as additions or substitutions for other agents in up-front multiagent chemotherapy regimens. In the relapsed/refractory setting, both pralatrexate and romidepsin remain well-studied choices with some patients achieving a response with durability. Clinical trials of new agents in PTCL continue to be a valuable option and an important part of routine patient management as progressive disease often is seen. Lastly, we believe patients with relapsed/refractory PTCL should be considered for allogeneic stem cell transplantation if a suitable response is demonstrated and a willing donor is available.

Treating peripheral T-cell lymphomas (PTCL) remains a clinical challenge harbouring an often aggressive course and furthermore, no standard therapy is established. In more detail, PTCL comprises a heterogeneous group of haematological tumours constituting less than 15 % of all non-Hodgkin’s lymphomas (NHLs) in adults in the western hemisphere. The following short review will provide an up-date based on data presented at ASH meeting 2011 in PTCL providing improved understanding of patho-mechanism and further development of more specific therapy options.

Peripheral T-cell lymphomas (PTCL) comprise a heterogeneous group of lymphatic neoplasms, which originate from mature (post-thymic) T-cells. Although comprising less than 15% of all non-Hodgkin lymphomas (NHL) in adults in Western countries, T-cell lymphomas still pose a considerable clinical challenge. To date, no standard therapy is available for the treatment of these T-cell malignancies. Treatment options that brought about substantial clinical progress in B-cell lymphomas perform only very poorly when used for T-cell lymphomas. With standard chemotherapy such as CHOP approximately 30% of T-cell lymphomas show a primary refractory course and only 35% of patients survive after 3–5 years. Therefore, novel treatment approaches need to be designed and validated in clinical trials. Here we discuss recent data including those presented at the last annual meeting of the American Society of Haematology (ASH 2009). Currently under investigation are new treatment modalities such as immune modulatory drugs, antifolates or histone deacetylase inhibitors. In addition, we present the ongoing trials that incorporate these new modalities.

Aggressive T-cell lymphomas represent a particularly poor-prognosis subgroup of lymphomas. This is especially true for patients with recurrent or refractory disease who typically have a limited response to salvage therapy and an extremely poor overall survival. There is thus a strong need to develop potentially active drugs for these malignancies. Pralatrexate is a novel antifolate designed to have high affinity for the reduced folate carrier type 1. Preclinical and clinical studies have demonstrated that pralatrexate has significant activity against T-cell lymphomas.The dose-limiting toxicity for pralatrexate is mucositis,which could be abrogated with folic acid and vitamin B12 supplementation. Pralatrexate is now being evaluated in phase II clinical trials for the treatment of peripheral T-cell lymphoma, and in a phase I/II trial in combination with gemcitabine for the treatment of non-Hodgkin's lymphoma. Because of the limited therapies available for aggressive T-cell lymphoma, pralatrexate could secure a niche for the treatment of this condition, provided on going clinical trials and future phase III trials confirm the efficacy of the drug.

Peripheral T-cell lymphomas (PTCLs), several entities with great clinical, histologic, and biologic heterogeneity, represent 8% to 15% of all malignant lymphomas. With current treatment regimens, 5-year survival is only about 30% to 35%. Outcome is poorer with PTCL than with aggressive B-cell lymphoma because of more frequent adverse clinical features at diagnosis, a lower response rate to chemotherapy, and a higher incidence of relapses, but it is also known that the T-cell phenotype itself is associated with a poor prognosis independent of other prognostic factors. Initial treatment of patients with advanced-stage PTCL mostly consists of six to eight courses of anthracycline-based chemotherapy such as CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone). In fit elderly patients, standard therapy is still six cycles of CHOP-14, but up-front consolidation with intensive chemotherapy and autologous stem cell transplantation are often used in younger patients. The humanized CD52 monoclonal antibody alemtuzumab has shown activity in some T-cell malignancies; with appropriate antibiotic and virostatic prophylaxis, its use seems feasible for PTCL, both as a single agent and in conjunction with chemotherapy. New drugs such as denileukin diftitox, histone deacetylase inhibitors, and pralatrexate have shown promising activity in PTCL.

The advances in low-grade lymphoma & T-cell lymphoma from the 2008 ASH meeting were presented. These included therapeutic regimens for low grade lymphoma, frontline bendamustine plus rituximab data, radioimmunotherapy consolidation in advanced disease, idiotype vaccine, and other novel therapeutic agents such as next generation anti-CD20 GA101, syk inhibitor Fostamatinib in treatment of low-grade lymphoma. In T-cell lymphoma, updates were discussed on phase II HOVON 69 trial data of combination of alemtuzumab/CHOP, pralatrexate and romidepsin for relapsed/refractory PTCL, L-asparaginase-containing regimen for extranodal NK/T-cell lymphoma.