[Rinsho ketsueki] The Japanese journal of clinical hematology最新文献

Hematopoietic stem cell (HSC)-targeted gene therapy is curative for various genetic blood diseases, and its efficacy has been demonstrated in recent clinical trials. HSCs have self-renewal and hematopoietic multipotency; therefore, repairing pathological mutations or defects in HSCs allows for a lifelong cure with a single treatment. Autologous HSC gene therapy has been developed by lentiviral gene addition or gene editing, and is an option for most patients because it does not require a compatible donor. Current HSC gene therapy is based on ex vivo methods, in which patient HSCs are harvested, genetically modified ex vivo, and autologously transplanted into patients. However, the complexity of this process and the high cost of treatment are hindering the spread of gene therapy. Therefore, in vivo HSC gene therapy is being developed to deliver gene therapy tools directly into bone marrow HSCs by administration without ex vivo culture.

Mitochondrial metabolic dependencies characteristic of acute myeloid leukemia (AML) have recently been identified, demonstrating that metabolic enzymes regulate AML gene expression and control cell differentiation and stemness. These mitochondrial metabolic adaptations occur independently of underlying genomic abnormalities and contribute to chemotherapy resistance and relapse. Mitochondrial alterations also lead to metabolic vulnerability of AML cells, whose metabolism is characterized by dependence on oxidative phosphorylation, fatty acid oxidation, reactive oxygen species (ROS) production, and mitochondrial dynamics. Currently, mitochondrial properties of AML cells and leukemia stem cells are being investigated, focusing on metabolism, signal transduction, mitochondrial respiration, ROS generation, and mitophagy. In addition, mitochondria-targeted agents have shown promising results in clinical trials. This paper outlines recent findings from preclinical and clinical trials on the utility of agents targeting mitochondria-related molecules and metabolic pathways and their efficacy in combination with existing chemotherapies.

Although alectinib is effective for relapsed or refractory ALK-positive anaplastic large cell lymphoma (ALCL) and has a favorable safety profile, its role as a bridging therapy for allogeneic hematopoietic stem cell transplantation (allo-HSCT) and the role of allo-HSCT itself in this setting are unknown. A 35-year-old man with ALK-positive ALCL experienced relapse after first-line therapy with CHOP. Brentuximab vedotin led to partial response and high-dose chemotherapy combined with autologous HSCT was performed. However, disease progressed 15 months after transplantation, and alectinib was initiated. Complete response (CR) was achieved after three months of treatment, and alectinib was continued for 5 months. After cessation of alectinib, allogeneic bone marrow transplantation from an HLA 1-locus mismatched unrelated donor was performed after conditioning with fludarabine, busulfan, and total body irradiation. GVHD prophylaxis consisted of tacrolimus and short-term methotrexate. The post-transplant course was unremarkable except for grade I acute GVHD. The lymphoma has not recurred for 2 years after allo-HSCT without resuming alectinib. The clinical course of our case suggests that alectinib bridging therapy and allo-HSCT are effective in relapsed/refractory ALK-positive ALCL.

Hematopoietic cell transplantation (HCT) is considered a curative treatment for hematological malignancies. However, HCT recipients often face complications such as graft-versus-host disease (GVHD) and disease relapse. Clinical factors like age and HLA disparity are recognized as risks for GVHD. Notably, sex-mismatched HCT, particularly with female donors and male recipients (F→M), is reported to increase the risk of chronic GVHD. This adverse effect of F→M HCT is thought to result from allogeneic immune response against minor histocompatibility antigens encoded on the Y-chromosome of a male recipient (HY-antigens). Indeed, antibodies against HY-antigens (HY-Abs) were detected three months after F→M HCT, and the cumulative number of HY-Abs was significantly associated with increased risks of chronic GVHD and non-relapse mortality. This review focuses on F→M HCT, shedding light on its impact in several clinical settings and presenting clinical evidence of its allogeneic response, encompassing GVHD and graft-versus-leukemia (GVL) effects. Additionally, potential clinical options to mitigate adverse effects in F→M HCT will be discussed. Further investigation is required to improve clinical outcomes and understand allogenic immunological reconstitution after F→M HCT.

VEXAS syndrome is a new disease entity characterized by the presence of cytoplasmic vacuoles in blood cells, X-linked autoinflammatory symptoms, and somatic variants in UBA1, which encodes an E1 ubiquitin-activating enzyme. Around 30-50% of VEXAS syndrome patients have concurrent MDS. We and others have recently analyzed clinical and genetic features of MDS associated with VEXAS syndrome and found that most of these cases are categorized in the low-risk subgroup with low bone marrow blast percentages. MDS associated with VEXAS syndrome tended to involve a smaller number of genes and lower-risk genetic alterations than classical MDS. In addition, anemia in MDS associated with VEXAS syndrome with active inflammation before treatment tended to respond well to steroids. In this review, we will present our recent findings together with others, focusing on the new disease entity and pathophysiology of VEXAS syndrome and clinical/genetic features of associated MDS.

B-cell maturation antigen (BCMA)-targeting therapy is the most common approach to immunotherapy and cellular therapy for multiple myeloma (MM). Three major agents, CAR-T cells, bispecific antibodies, and ADC have been developed as novel therapeutic agents. CAR-T therapy showed favorable efficacy in the treatment of relapsed and refractory MM (RR MM) and was tried in early lines of therapy. Similarly, bispecific antibodies targeting BCMA or other targets have also shown promising effects in treatment of RR MM, and have been now tested in combination with other agents. Although issues such as poor fitness or exhaustion of T cells and increased susceptibility to viral infection remain to be fully resolved, novel immunotherapies and cellular therapies should further improve the prognosis of patients with RR MM.

The blood cancer field has played a pioneering role in advancing precision medicine, with milestones such as development of ABL1 inhibitors for chronic myeloid leukemia. The significance of gene mutation information in AML treatment has increased, evident in classifications and guidelines from organizations such as WHO and ELN. This article examines the anticipated roles of cancer genome panels (CGPs) in AML treatment from three perspectives: diagnosis, risk stratification, and treatment selection. Use of CGPs enables more accurate diagnosis and risk stratification. In treatment selection, CGPs not only complements but also substitutes existing companion diagnostics, and is expected to be a crucial information source for future drug adoption and investigation of tumor-agnostic therapies. However, various challenges remain to be addressed, including the purpose and timing of CGPs, the time required for the tests, and how to utilize expert panels.

Imatinib, the first ABL-tyrosine kinase inhibitor (TKI), was approved in 2000 for the treatment of chronic myeloid leukemia (CML). Second- and third-generation TKIs, as well as asciminib, which targets a different site of BCR-ABL1 (the myristoyl pocket), were later approved in 2022. Currently, six drugs are approved for the treatment of CML. Revisions to the clinical guidelines for hematopoietic tumors in 2023 provided new guidance on the utility of new agents as well as TKI dose reduction and treatment discontinuation. This article outlines recently reported predictions regarding TKI treatment response, the role of asciminib in the treatment of CML, and development of new agents, as well as the latest findings regarding the current state of TKI treatment discontinuation.

Health surveys to assess adverse events after peripheral blood stem cell harvest (PBSCH) have conventionally been conducted by phone, but phone calls are suboptimal for conducting frequent surveys. We developed a web-based application (donor app) that enables donors to inform healthcare professionals (HCPs) of their health status as an electronic patient-reported outcome (ePRO). In this prospective observational study, we compared the usefulness of this donor app to phone calls for conducting health surveys. App users reported ePRO daily, and patients called by HCPs reported their health status at least once a week when called. The observation period was from the first administration of granulocyte colony-stimulating factor to the first follow-up visit after PBSCH, excluding the hospitalization period. Each group consisted of eight donors with a median age of 32 years (range: 19-58). Nine (56.3%) were female. There were eight related donors in the phone call group and four in the donor app group. During the observation period, HCPs obtained health status reports more frequently from app users than from phone call recipients (mean proportion of days with reports made during the observation period, 27.0% vs 53.5%; p<0.05). Average time spent by the HCPs for one follow-up and total follow-ups were both significantly shorter when the donor app was used. There were no differences in donor burden or satisfaction with donation. Our study suggests that use of a donor app could provide more detailed health survey data without increasing the burden on donors and HCPs.

CAR-T cell therapy targeting CD19 and BCMA for relapsed or refractory hematopoietic tumors has been adopted in routine practice and has shown dramatic results. However, half of patients who achieve remission with CAR-T therapy eventually relapse, and thus efforts to improve the efficacy of CAR-T therapy are gaining momentum. Notably, studies have described innovative technologies that enable control of cell kinetics after infusion, which is not possible with conventional CAR-T therapies. In this article, we review the challenges of CAR-T cell therapy and the development of new technologies.