Angioimmunoblastic T-cell lymphoma and correlated neoplasms with T-cell follicular helper phenotype: from molecular mechanisms to therapeutic advances.

Angioimmunoblastic T-cell lymphoma (AITL) is the second most frequent subtype of mature T-cell lymphoma (MTCL) in the Western world. It derives from the monoclonal proliferation of T-follicular helper (TFH) cells and is characterized by an exacerbated inflammatory response and immune dysregulation, with predisposition to autoimmunity phenomena and recurrent infections. Its genesis is based on a multistep integrative model, where age-related and initiator mutations involve epigenetic regulatory genes, such as TET-2 and DNMT3A. Subsequently, driver-mutations, such as RhoA G17V and IDH-2 R172K/S promote the expansion of clonal TFH-cells ("second-hit"), that finally begin to secrete cytokines and chemokines, such as IL-6, IL-21, CXCL-13 and VEGF, modulating a network of complex relationships between TFH-cells and a defective tumor microenvironment (TME), characterized by expansion of follicular dendritic cells (FDC), vessels and EBV-positive immunoblasts. This unique pathogenesis leads to peculiar clinical manifestations, generating the so-called "immunodysplastic syndrome", typical of AITL. Its differential diagnosis is broad, involving viral infections, collagenosis and adverse drug reactions, which led many authors to use the term "many-faced lymphoma" when referring to AITL. Although great advances in its biological knowledge have been obtained in the last two decades, its treatment is still an unmet medical need, with highly reserved clinical outcomes. Outside the setting of clinical trials, AITL patients are still treated with multidrug therapy based on anthracyclines (CHOP-like), followed by up-front consolidation with autologous stem cell transplantation (ASCT). In this setting, the estimated 5-year overall survival (OS) is around 30-40%. New drugs, such as hypomethylating agents (HMAs) and histone deacetylase inhibitors (HDAi), have been used for relapsed/refractory (R/R) disease with promising results. Such agents have their use based on a biological rationale, have significant potential to improve the outcomes of patients with AITL and may represent a paradigm shift in the therapeutic approach to this lymphoma in the near future.

Síndromes mielodisplásicos, más allá de los hipometilantes / Myelodysplastic syndromes: beyond hypomethylating agents

Introducción: El comportamiento heterogéneo de los síndromes mielodisplásicos, así como los progresos en los últimos años en el campo de la genética y la biología molecular, han provocado la aparición de múltiples investigaciones con diferentes enfoques terapéuticos. Los agentes hipometilantes son hasta el momento el tratamiento estándar para esta entidad, pero desafortunadamente no son efectivos en el 100 % de los casos y la duración de su respuesta es variable. Objetivo: Analizar las opciones terapéuticas actuales para el tratamiento de los síndromes mielodisplásicos. Métodos: Se realizó una revisión de la literatura, en inglés y español, a través del sitio web PubMed y el motor de búsqueda Google académico de artículos publicados en los últimos 5 años. Se hizo un análisis y resumen de la bibliografía revisada. Análisis y síntesis de la información: Actualmente existen múltiples opciones de tratamiento, la mayor parte dirigidos contra los eventos epigenéticos fundamentales: la hipermetilación, la modificación de las histonas diacetilasa y la activación de la respuesta inmune citotóxica contra clones anormales. Sin embargo, como no se ha establecido una única alteración, los tratamientos en la mayoría de los protocolos se adaptan al riesgo, incluyen un número reducido de casos y los resultados son limitados. Conclusiones: Se considera que una posible solución es dirigir el tratamiento a la alteración específica con base en las alteraciones moleculares y la medicina de precisión, fundamentalmente en los pacientes refractarios o en recaída postratamiento con los actuales agentes hipometilantes(AU)

Introduction: The heterogeneous characteristics of myelodysplastic syndromes, as well as the progress in recent years in the field of genetics and molecular biology, have led to the appearance of multiple investigations with different therapeutic approaches. Hypomethylating agents are so far the standard treatment for this entity, but unfortunately they are not effective in 100% of cases and the duration of their response is variable. Objective: To analyze current therapeutic options for the treatment of myelodysplastic syndromes. Methods: A literature review was carried out, in English and Spanish, through the PubMed website and the Google Scholar search engine, for articles published in the last five years. An analysis and summary of the revised bibliography was carried out. Information analysis and synthesis: Currently, there are multiple treatment options, most of which are directed against fundamental epigenetic events: hypermethylation, modification of histone diacetylase, and activation of the cytotoxic immune response against abnormal clones. However, as long as a single alteration has not been established, treatments, in most protocols, are adapted to risk and include a small number of cases, while their outcomes are limited. Conclusions: It is considered that a possible solution is to direct treatment to specific alteration based on molecular alterations and precision medicine, fundamentally in refractory or relapsed patients after treatment with current hypomethylating agents(AU)

Updates on DNA methylation modifiers in acute myeloid leukemia.

Acute myeloid leukemia (AML) is the most common acute leukemia in adults. Chemotherapy with cytotoxic agents is the standard of care, but is associated with a high rate of adverse events. Elderly patients are frequently intolerant to such treatment, presenting a very poor prognosis. The hypomethylating agents (HMA) azacitidine or decitabine represent one of the main therapeutic alternatives for these patients. Isocitrate dehydrogenase inhibitors (IDH) constitute another therapeutic class with DNA methylation effects in AML. In this article, we review the use of first- and second-generation HMA and IDH inhibitors in AML. The data collected demonstrated that HMA are generally considered effective and safe for AML patients who are not eligible for standard chemotherapy. The combination of azacitidine or decitabine with venetoclax was recently approved by the US Food and Drug Administration (FDA) for older AML patients and those unfit for intense chemotherapy. IDH inhibitors also showed encouraging results for relapsed/refractory AML patients harboring an IDH mutation and received FDA approval. Therefore, recent studies have led to the emergence of new therapeutic options using HMA and IDH inhibitors for specific groups of AML patients, representing an important step in the treatment of this aggressive malignancy. New options should emerge from the ongoing studies in the coming years.

Encouraging results with the compassionate use of hydralazine/valproate (TRANSKRIP™) as epigenetic treatment for myelodysplastic syndrome (MDS).

The hypomethylating agents azacytidine and decitabine are unaffordable for many patients with MDS. The combination of the DNA methyltransferase inhibitor hydralazine and the histone deacetylase inhibitor valproate has shown preliminary efficacy in MDS. The aim of this study is to evaluate the clinical efficacy and safety of hydralazine/valproate in a case series of MDS patients treated in a compassionate manner. Hydralazine was dosed according to the acetylation genotype of patients (slow acetylators 83 mg daily; fast acetylators 182 mg daily), and valproate was dosed at 30 mg/kg/day. Both drugs were given daily until disease progression. Response and toxicity were evaluated with the International Working Group criteria and CTCAE, version 4, respectively. Survival parameters were estimated with the Kaplan-Meier method. From 2009 to 2012, 14 patients were treated. The median age ± SD was 55.2 ± 19.52 (range 23-87) years. According to the IPSS, cases were graded as intermediate-1 (n = 8/14; 57.2%) or intermediate-2 (n = 6/14; 42.8%). Responses were as follows: five (35.7%) complete response, one (7.1%) partial response, and two (14.28%) became transfusion independent. The mean duration of response ± SD was 60 ± 35.28 months (range 5-94). Three patients progressed to AML. At a median follow-up of 57 months (range 1-106), the median OS was 27 months. At that point, five patients remained on the treatment, one with partial response and four with complete response. The median OS was not reached in the eight patients who saw a clinical benefit from the treatment, in comparison to an OS of 7 months in the six patients who had no treatment. The combination of hydralazine and valproate is safe and effective in MDS, and its further testing is highly desirable.