Blood Research最新文献

The prognosis of patients with chronic phase (CP) chronic myeloid leukemia (CML) has significantly improved due to the development of potent BCR::ABL1 tyrosine kinase inhibitors (TKIs). However, approximately 15‒20% of patients ultimately experience treatment failure due to resistance or intolerance to TKI therapy. As the prognosis of patients in whom multiple TKIs fail remains poor, an optimal therapeutic approach is required to treat the condition. Asciminib, an allosteric inhibitor that targets ABL1 myristoyl pocket, has been approved by the Food and Drug Administration for use in patients with CP-CML resistant or intolerant to ≥2 prior TKIs or those with T315I mutation. In a phase 1 trial, asciminib monotherapy showed a relatively favorable safety profile and potent efficacy in patients with and without the T315I mutation. In a subsequent phase 3 trial, asciminib treatment was associated with a significantly higher major molecular response rate and lower discontinuation rate than bosutinib in patients with CP-CML for whom two previous TKIs failed. Several clinical trials are being performed in various clinical settings to evaluate the role of asciminib as a frontline treatment for newly diagnosed CP-CML, either as a single agent or in combination with other TKIs as a second-line or additive treatment to improve treatment-free or deep remission. This review summarizes the incidence, available therapies, and outcomes of patients with CP-CML who experienced treatment failure, the mechanism of action, preclinical and clinical data, and ongoing trials for asciminib.

T-cell large granular lymphocyte (T-LGL) leukemia is characterized by clonal expansion of cytotoxic T cells resulting in cytopenia. The proliferation of clonal LGLs is caused by prolonged antigenic stimulation, which leads to apoptotic dysregulation owing mainly to the constitutive activation of survival pathways, notably the JAK/STAT pathway. Understanding how leukemic T-LGL persists can aid in the development of future immunosuppressive therapies. In this review, we summarize the diagnosis and current standard of therapy for T-LGL leukemia, as well as recent advances in clinical trials.

Transfusion support for hematopoietic stem cell transplantation (HSCT) is an essential part of supportive care, and compatible blood should be transfused into recipients. As leukocyte antigen (HLA) matching is considered first and as the blood group does not impede HSCT, major, minor, bidirectional, and RhD incompatibilities occur that might hinder transfusion and cause adverse events. Leukocyte reduction in blood products is frequently used, and irradiation should be performed for blood products, except for plasma. To mitigate incompatibility and adverse events, local transfusion guidelines, hospital transfusion committees, and patient management should be considered.

Chimeric antigen receptor (CAR) T-cell therapy presents a revolutionary advancement in personalized cancer treatment. During the production process, the patient's own T-cells are genetically engineered to express a synthetic receptor that binds to a tumor antigen. CAR T-cells are then expanded for clinical use and infused back into the patient's body to attack cancer cells. Although CAR T-cell therapy is considered a major breakthrough in cancer immunotherapy, it is not without limitations. In this review, we discuss the barriers to effective CAR T-cell therapy in Korea.

Myeloproliferative neoplasms (MPNs) are clonal disorders of hematopoietic stem cells; these include polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF). MPNs are inflammatory cancers, wherein the malignant clone generates cytokines that sustain the inflammatory drive in a self-perpetuating vicious cycle. The course of MPNs follows a biological continuum, that is, from early cancer stages (ET/PV) to advanced myelofibrosis as well as impending leukemic transformation. MPN-related symptoms, e.g., fatigue, general weakness, and itching, are caused by inflammatory cytokines. Thrombosis and bleeding are also exacerbated by inflammatory cytokines in patients with MPN. Until recently, the primary objective of ET and PV therapy was to increase survival rates by preventing thrombosis. However, several medications have recently demonstrated the ability to modify the course of the disease; symptom relief is expected for most patients. In addition, there is increasing interest in the active treatment of patients at low risk with PV and ET. This review focuses on the ET/PV treatment strategies as well as novel treatment options for clinical development.

With impressive clinical advancements in immune effector cell therapies targeting CD19, chimeric antigen receptor (CAR) T-cell therapy has emerged as a new paradigm for treating relapsed/refractory B-cell malignancies. Currently, three second-generation CAR T-cell therapies have been approved, of which only tisagenlecleucel (tisa-cel) is approved for treating children and young adults with B-cell acute lymphoblastic leukemia (ALL) with durable remission rates of approximately 60‒90%. Although CAR T-cell therapies are considered to treat refractory B-ALL, they are associated with unique toxicities such as cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS). The severity of CAR T-cell therapy toxicities can vary according to several clinical factors. In rare cases, severe CRS can progress to a fulminant hyperinflammatory syndrome known as hemophagocytic lymphohistiocytosis, which has a poor prognosis. The first-line treatments for CRS/ICANS include tocilizumab and corticosteroids. When severe CAR T-cell toxicity is resistant to first-line treatment, an additional approach is required to manage the persistent inflammation. In addition to CRS/ICANS, CAR T-cell therapy can cause early and delayed hematological toxicity, which can predispose patients to severe infections. The use of growth factors and anti-infective prophylaxis should follow institutional guidelines according to patient-specific risk factors. This review provides a thorough summary of updated practical recommendations for managing acute and delayed adverse effects following anti-CD19 CAR T-cell therapy in adults and children.

Patients with chronic myeloid leukemia (CML) in the chronic phase receiving tyrosine kinase inhibitor (TKI) therapy are expected to have long-term survival outcomes comparable to those of the general population. Many clinical trials have confirmed that some patients sustain molecular responses without continuing TKI therapy. Treatment-free remission (TFR) is a new goal in treating chronic CML. The safety and outcome of TFR were studied in clinical trials after discontinuing imatinib or the second-generation TKIs dasatinib or nilotinib. TFR was safe in approximately 50% of patients who achieved a deep molecular response to TKI therapy. Patients who relapsed after discontinuing TKI responded immediately to the reintroduction of TKI. The mechanism by which TFR increases the success rate still needs to be understood. The hypothesis that the modulation of immune function and targeting of leukemic stem cells could improve the TFR is under investigation. Despite the remaining questions, the TFR has become a routine consideration for clinicians in the practice of molecular remission in patients with CML.

Mastocytosis is a heterogeneous neoplasm characterized by accumulation of neoplastic mast cells in various organs. There are three main types: cutaneous mastocytosis (CM), systemic mastocytosis (SM), and mast cell sarcoma. CM mainly affects children and is confined to the skin, whereas SM affects adults and is characterized by extracutaneous involvement, with or without cutaneous involvement. Most cases of SM have an indolent clinical course; however, some types of SM have aggressive behavior and a poor prognosis. Recent advances in the understanding of the molecular changes in SM have changed the diagnosis and treatment of aggressive and advanced SM subtypes. The International Consensus Classification and World Health Organization refined the diagnostic criteria and classification of SM as a result of accumulation of clinical experience and advances in molecular diagnostics. Somatic mutations in the KIT gene, most frequently KIT D816V, are detected in 90% of patients with SM. Expression of CD30 and any KIT mutation were introduced as minor diagnostic criteria after the introduction of highly sensitive screening methods. SM has a wide spectrum of clinical features, and only a few drugs are effective at treating advanced SM. Currently, the mainstay of SM treatment is limited to the management of chronic symptoms related to release of mast cell mediators. Small-molecule kinase inhibitors targeting the KIT-downstream and KIT-independent pathways were recently approved for treating advanced SM. I describe recent advances in diagnosis of SM, and review the currently available and emerging therapeutic options for SM management.

Myelofibrosis (MF) includes primary MF, post-essential thrombocythemia MF, and post-polycythemia vera MF. MF is a progressive myeloid neoplasm characterized by ineffective clonal hematopoiesis, extramedullary hematopoiesis, a reactive bone marrow environment resulting in reticulin deposition and fibrosis, and a propensity for leukemia transformation. The identification of driver mutations in JAK2, CALR, and MPL has contributed to a better understanding of disease pathogenesis and has led to the development of MF-specific therapies, such as JAK2 inhibitors. Despite the fact that ruxolitinib and fedratinib have been clinically developed and approved, their use is limited due to adverse effects such as anemia and thrombocytopenia. Recently, pacritinib has been approved for a group of thrombocytopenic patients with significant unmet clinical needs. In symptomatic and anemic patients with prior JAK inhibitor exposure, momelotinib was superior to danazol in preventing exacerbation of anemia and in controlling MF-associated signs and symptoms, such as spleen size. Although the development of JAK inhibitors is remarkable, modifying the natural course of the disease remains a priority. Therefore, many novel treatments are currently under clinical development. Agents targeting bromodomain and extra-terminal protein, anti-apoptotic protein Bcl-xL, and phosphatidylinositol-3-kinase delta have been studied in combination with JAK inhibitors. These combinations have been employed in both the frontline and "add-on" approaches. In addition, several agents are being studied as monotherapies for ruxolitinib-resistant or -ineligible patients. We reviewed several new MF treatments in the advanced stages of clinical development and treatment options for cytopenic patients.