Successful Bridging to Allogeneic Transplantation With Valemetostat in Two Refractory/relapsed Peripheral T-cell lymphoma patients

We report the case of 2 patients with relapsed/refractory peripheral T-cell lymphoma treated with valemetostat tosylate, a selective dual inhibitor of histone-lysine N-methyltransferases enhancer of zest homolog 1 and 2, and subsequently bridged to allogeneic stem cell transplantation. Valemetostat led to a quick response and was well tolerated, offering a promising bridge therapy to transplantation for patients with relapsed/refractory peripheral T-cell lymphoma, which is still an unmet medical need.

Current and emerging therapeutic strategies in adult T-cell leukemia-lymphoma

Adult T-cell leukemia-lymphoma (ATL) is classified into four clinical subtypes: acute, lymphoma, chronic, and smoldering. Chronic ATL is further divided into unfavorable and favorable chronic types according to serum lactate dehydrogenase, blood urea nitrogen, and serum albumin values. Acute, lymphoma, and unfavorable chronic types are categorized as aggressive ATL, whereas favorable chronic and smoldering types are categorized as indolent ATL. Intensive chemotherapy alone is not sufficient to prevent relapse of aggressive ATL. Allogeneic hematopoietic stem cell transplantation is a potential therapeutic option to cure aggressive ATL in younger patients. Reduced-intensity conditioning regimens have decreased transplantation-related mortality, and increased donor availability has dramatically improved transplant access. New agents, including mogamulizumab, brentuximab vedotin, tucidinostat, and valemetostat, have recently become available for patients with aggressive ATL in Japan. Here, I provide an overview of recent advances in therapeutic strategies for ATL.

[Adult T-cell leukemia/lymphoma: progress in understanding of pathogenesis and treatment]

Adult T-cell leukemia/lymphoma (ATL) is an exceedingly refractory peripheral T-cell lymphoma. Despite the approval of a few new drugs for managing patients with newly diagnosed or relapsed/refractory ATL in recent years, the prognosis has yet to be substantially ameliorated. This study focuses on recent topics on the development of innovative therapies and the identification of prognostic indicators, considering the recent elucidation of the pathogenesisof ATL. Specifically, this study also delineates the advancements in developing novel EZH1/2 inhibitors and comprehensive genetic analysis; the molecular pathogenesis determined through comprehensive gene knockdown and knockout techniques, with its potential as a therapeutic target; the latest discoveries from the analysis of super-enhancer regions; and the prognostic factors extracted from comprehensive genetic analysis.

[Adult T-cell leukemia/lymphoma]

Adult T-cell leukemia/lymphoma (ATL) is an extremely refractory peripheral T-cell lymphoma that develops after persistent human T-lymphotropic virus type 1 (HTLV-1) infection. In recent years, the number of HTLV-1 carriers has decreased due to lifestyle changes and different measures. Rapid progression in comprehensive genetic analysis techniques has revealed the molecular basis of ATL. Therefore, in addition to conventional prognostic indices based on clinical parameters, prognostic indices incorporating genetic mutations have been proposed. The standard treatment for untreated aggressive ATL is combination chemotherapy such as VCAP-AMP-VECP or CHOP, followed by allogeneic hematopoietic stem cell transplantation, as appropriate. Combined mogamulizumab and chemotherapy is a promising first-line treatment option for patients not eligible for transplantation. Salvage treatment with lenalidomide, brentuximab vedotin, tucidinostat, and valemetostat, in addition to mogamulizumab, has been introduced over the last decade. Advancements in allogeneic transplantation therapy, including early induction and transplantation with post-transplant cyclophosphamide for GVHD prophylaxis, have also improved patient outcomes. This article highlights recent developments in the field of ATL.