Blood advances最新文献

Tumour 'bulk' has historically been considered an important prognostic marker and clinical tool to guide treatment in patients with lymphoma. However, its use and definitions in trial designs varies significantly and it is unclear how this has influenced the relevance of bulk in contemporary practice. This comprehensive literature review evaluated the definitions, applications and prognostic impact of bulk in phase 3 randomised trials in four major lymphoma subtypes. Overall, 87 studies were identified across follicular lymphoma (FL), diffuse large B-cell lymphoma (DLBCL), peripheral T-cell lymphoma (PTCL) and Hodgkin lymphoma (HL) with a wide range of bulk thresholds employed (5cm, 6cm, 7cm, 7.5cm, 10cm and >1/3 mediastinal mass ratio (MMR)). The most common threshold was: FL; 7cm (58%), DLBCL; 7.5cm and 10cm (44% each), PTCL; 7.5cm (66%) and HL; 1/3 MMR (91%). Bulk threshold was used by trials to determine eligibility (66%), stratification (24%), as a prognostic risk factor (37%) and decision tool for risk-adapted treatment e.g. radiotherapy (29%), however bulk definitions used for these varied both between, and within, lymphoma subtypes, and even within single trials in 25%. Thirty-two studies incorporated bulk in prognostic analyses with only five showing significance for differential survival outcomes. Our analysis demonstrates high inconsistency in thresholds defining tumour bulk and use of bulk in phase 3 lymphoma trials across eligibility, stratification, therapeutic risk-adaptation plus prognostication. This highlights an urgent need for international consensus on definitions of bulk within trials to improve its prognostic and predictive value and refine its application in clinical practice.

CD19-directed chimeric antigen receptor-engineered (CD19 CAR) T-cell therapy elicits high response rates but fails to induce durable responses in most adults with relapsed or refractory (R/R) B-cell acute lymphoblastic leukemia (B-ALL). In a previous clinical trial (NCT01865617), we observed anti-CAR immune responses associated with impaired in vivo CAR T-cell expansion after second infusions. Because these CD8+ T-cell responses were predominantly directed at peptides derived from the murine single chain variable fragment (scFv) in the CAR, we conducted a clinical trial investigating the safety and efficacy of CD19 CAR T-cells engineered with a CAR incorporating a fully human scFv (JCAR021) in adults with R/R B-ALL (NCT03103971). Twenty-three patients received lymphodepletion chemotherapy and JCAR021 infusion. Nineteen patients developed CRS (any grade, 83%; grade 2, 61%) and 12 developed neurotoxicity (52%; grade ≥3, 35%). The overall response and CR/CRi rates were 82% and 64%, respectively. We observed MRD-negative marrow responses in 82% of those with marrow disease and extramedullary responses by PET-CT in 79% (CR, 50%) of those with measurable FDG-avid disease. The median duration of remission (DOR) was 10 months with a 4-year DOR probability of 29%. Four patients underwent allo-HCT while in CR/CRi after JCAR021. Durable remissions were observed in patients with low marrow disease burden. In contrast, the DOR was limited in those with high marrow burden, highlighting a remaining critical need to identify new strategies to prolong remissions. We observed similar outcomes in CAR-naïve adult B-ALL patients receiving CD19 CAR T-cells expressing a fully human or murine scFv-containing CAR.

Despite the success of the CD19xCD3 T cell engager blinatumomab in B-cell acute lymphoblastic leukemia (B-ALL), treatment failure is common and can manifest with antigen loss and extramedullary disease (EMD) relapse. To understand the impact of leukemia genetics on outcomes, we reviewed 267 adult patients with B-ALL treated with blinatumomab and used next generation sequencing to identify molecular alterations. Patients received blinatumomab for relapsed/refractory (R/R) disease (n=150), minimal residual disease (MRD+) (n=88), upfront as induction (n=10), or as consolidation in MRD- state (n=19). In the overall cohort, 50 (19%) patients had Philadelphia chromosome (Ph)-positive ALL, 80 (30%) had Ph-like ALL, 35 (13%) had TP53 mutations (TP53m), 7 (3%) had KMT2A-rearrangement, and 8 (3%) had PAX5-alterations. For patients treated for R/R ALL, the overall complete remission (CR)/CR with incomplete hematological recovery (CRi) rate was 59%. Only pretreatment high disease burden (p<0.01) and active EMD (p<0.01) were associated with inferior CR/CRi rate. Of 169 patients in CR/CRi post-blinatumomab, 79 (47%) patients relapsed, including 22 (28%) with CD19- and 54 (68%) with CD19+ relapse. In multivariable analysis, TP53m was associated with increased risk of CD19- relapse (HR=6.84; 95%CI: 2.68-17.45, p<0.01). Post blinatumomab allogenic stem cell transplantation consolidation was associated with lower risk of CD19- relapse (HR=0.10; 95%CI: 0.03-0.37, p<0.01) and EMD relapse (HR=0.36; 95%CI: 0.18-0.73, p<0.01). In conclusion, leukemia genetics may predict patterns of blinatumomab failure, with TP53m associated with CD19- relapse.

Patients with essential thrombocythemia (ET) have a chronic evolution with a risk of hematological transformation associated with a dismal outcome. Since patients with resistance or intolerance have an adverse prognosis, it is important to identify which patient will respond to first-line treatment. We therefore aim to describe the association between additional mutations and response to first-line treatment in patients with ET. In this retrospective study, we analyzed the molecular landscape of 121 ET patients first-line treated with hydroxyurea (n=86) or pegylated interferon (n=35). Patients undergoing peg-IFN therapy were younger and had higher proportion of low and very low risk of thrombosis recurrence. Sixty-two patients (51%) had ≥1 additional mutations at diagnosis. The most frequent additional mutations involved TET2 (15.7%) DNMT3A (10.7%), non-W515-MPL (6.6%), ASXL1 (4.13%), and splicing factors SRSF2 and SF3B1 (6.6%) genes. At 12-months of treatment, 75 (62%) patients achieved complete response (CR), 37 (31%) partial response, and 7 (6%) no response. The presence of at least one additional mutation at diagnosis was associated with not achieving CR (HR: 0.66;p=0.045), whereas treatment with interferon was associated with higher CR (HR: 2.01;p=0.002). The number of additional mutations at diagnosis was associated with hematologic progressions (p<0.0001). None of the patients receiving peg-IFN therapy progressed to myelofibrosis, while 16/86 patients (19%) treated with HU developed secondary myelofibrosis. In conclusion, our results suggest that the presence of at least one additional mutation at diagnosis is associated with failure to achieve CR and is also associated with an increased risk of hematologic evolution.

Sickle cell anemia (SCA) is recognized globally, but little is known about affected Hispanic populations. In partnership with Dominican Republic, a Hispanic Caribbean Island with a large SCA population, a TCD screening program provided hydroxyurea to children with conditional velocities. Building local capacity, ten Dominican medical graduates were certified in TCD examinations and trained in hydroxyurea management. Stroke Avoidance for Children in REpública Dominicana trial (SACRED, NCT02769845) enrolled 283 children with average age 8.7±3.4 years and 130 (46%) females. At initial screening, treatment-naïve children with conditional velocities (170-199 cm/sec) were younger (6.6±2.7 versus 8.9±3.4 years, p=.0002) and more anemic (hemoglobin 7.4±0.8 versus 8.0±1.2 g/dL, p=.0046) than children with normal screening velocities (<170 cm/sec). Among 57 treatment-naïve children receiving six months of fixed-dose hydroxyurea at 20 mg/kg/day, average TCD velocities decreased 20 cm/sec and 61% became normal. Compared to fixed-dose hydroxyurea, dose escalation to maximum tolerated dose (MTD) led to fewer sickle-related events with incidence rate ratio 0.59, 95% Confidence Intervals 0.36-0.98, p=0.0420. At MTD, TCD benefits were sustained over 5 years, with 81% reverting to normal and average TCD velocity decrease of 27 cm/sec. Brain MRI documented substantial baseline parenchymal disease; during hydroxyurea treatment 10% developed new vasculopathy, plus one stroke and one death. SACRED documents a high burden of cerebrovascular disease among Hispanic children with SCA, but also demonstrates the feasibility of partnership to establish TCD screening programs, the utility of hydroxyurea to reduce TCD velocities and reduce stroke risk, and the sustained benefits of hydroxyurea dose escalation.

Fanconi anemia (FA) is a rare inherited disorder characterized by progressive bone marrow failure (BMF) and a predisposition to malignancy. Systemic reactive-oxygen species (ROS) and increased sensitivity of FA hematopoietic progenitors to ROS play a key role in the pathogenesis of BMF. Treatment with antioxidants improve hematopoietic function in Fancc-/- mice. We report the safety, tolerability, and pharmacokinetics (PK) of quercetin, a naturally occurring antioxidant in the first dose-finding Phase 1 study in patients with FA. Twelve patients (median age 7 years, range: 3-21) received oral quercetin twice daily for 4 months. Quercetin was well tolerated at all dose levels. Allometrically bodyweight-adjusted dose with a maximum adult daily dose of 4000mg/day was established as the recommended dose of quercetin. Patients in an expansion cohort (n=18) were treated using this recommended dose for 6 months. A subset of patients showed reduced ROS levels in the peripheral blood and bone marrow stem cell compartment. Patients in the analysis cohort treated with the recommended dose of quercetin achieved an a priori defined optimal response of 25% reduction in the peripheral blood (PB) ROS level compared to baseline. Platelet counts remained stable to slightly improved over the study period (p=0.06). Absolute neutrophil counts (p=0.01) and hemoglobin levels gradually declined (p=0.001). In those with evidence of BMF at baseline, 8 out of 15 patients (53%) had a hematological response at some point following quercetin treatment. Fluctuations in counts are common in patients with FA limiting accurate assessment of the impact of quercetin use in FA. NCT# 01720147.

In Immune-mediated Thrombotic Thrombocytopenic Purpura (iTTP), patients develop antibodies against ADAMTS13. The majority of patients exhibit inhibitory anti-spacer antibodies. Non-inhibitory antibodies binding to the carboxy-terminal CUB domains have been suggested to enhance the clearance of ADAMTS13 in iTTP. Furthermore, anti-CUB antibodies induce an open conformation, which has been shown to be an important biomarker for disease severity and relapse risk. We explored whether introduction of N-glycans in the CUB domains of ADAMST13 can reduce the binding of pathogenic anti-CUB autoantibodies. The binding of a panel of iTTP patient derived anti-CUB monoclonal antibodies to newly designed N-glycan modified ADAMTS13 CUB domain variants was assessed by ELISA. Additionally, a subset of these variants was screened against plasma samples of iTTP patients which primarily contain antibodies directed towards the carboxy-terminal domains of ADAMTS13. Introduction of N-glycans at amino acid positions of 1251, 1255 and 1368 in the CUB1/2 domains of ADAMTS13 can effectively reduce binding of 6 out of 7 iTTP patient-derived anti-CUB antibodies. Reduced binding to CUB N-glycan variants was observed in 8 out of 9 patient samples. Binding was decreased from 81% to 47% for NGLY3+CUB-NGLY and 60% to 28% for 5ALA+CUB-NGLY variants. Collectively our findings show that the introduction of N-glycans within the CUB-domain of ADAMTS13 is able to prevent the binding of anti-CUB antibodies in patients with iTTP. Based on these findings, we propose that CUB-NGLY modified ADAMTS13 variants can be used for improved treatment of patients with iTTP.

Cytoskeletal remodeling and mitochondrial bioenergetics play important roles in thrombocytopoiesis and platelet function. Recently, α-actinin-1 mutations have been reported in patients with congenital macrothrombocytopenia. However, the role and underlying mechanism of α-actinin-1 in thrombocytopoiesis and platelet function remain elusive. Using MK-specific α-actinin-1 knockout (PF4-Actn1-/-) mice, we demonstrated that PF4-Actn1-/- mice exhibited reduced platelet counts. The decreased platelet number in PF4-Actn1-/- mice was due to defects in thrombocytopoiesis. H&E staining and flow cytometry revealed a decrease in the number of MKs in the bone marrow of PF4-Actn1-/- mice. The absence of α-actinin-1 increased the proportion of 2 N-4 N MKs and decreased the proportion of 8 N-32 N MKs. CFU-MK colony formation, the ratio of proplatelet formation-bearing MKs, and MK migration in response to SDF-1 signaling were inhibited in PF4-Actn1-/- mice. Platelet spreading, clot retraction, aggregation, integrin αIIbβ3 activation, and P-selectin exposure in response to various agonists were decreased in PF4-Actn1-/- platelets. Notably, PF4-Actn1-/- platelets inhibited calcium mobilization, ROS generation, and actin polymerization in response to collagen and thrombin. Furthermore, the PF4-Actn1-/- mice exhibited impaired hemostasis and thrombosis. Mechanistically, proteomic analysis of low-ploidy (2-4 N) and high-ploidy (≥8 N) PF4-Actn1-/- MKs revealed that α-actinin-1 deletion reduced platelet activation and mitochondrial function. PF4-Actn1-/- platelets and Actn1 KO 293T cells exhibited reduced mitochondrial membrane potential, mitoROS generation, mitochondrial calcium mobilization, and mitochondrial bioenergetics. Overall, in this study, we report that mice with α-actinin-1 deficiency in MKs exhibit low platelet count and impaired platelet function, thrombosis, and mitochondrial bioenergetics.

T-cell receptor (TCR) therapies are a promising modality for the treatment of cancers, with significant efforts being directed towards acute myeloid leukaemia (AML), a particularly challenging disease. Chimeric antigen receptor (CAR) T-cells targeting single surface antigens have shown remarkable efficacy for B-cell lymphoblastic leukaemia, lymphomas and multiple myeloma. However, AML presents formidable obstacles to the effectiveness of CAR T-cells due to the widespread expression of heterogenous leukaemia immunophenotypes and surface antigen targets additionally present on normal myeloid cells. TCR therapies are an evolving field of cell therapies that allow targeting intracellular antigenic peptides presented via HLA molecules. The development of TCR therapy for AML is progressing rapidly through preclinical research and successful clinical trials. This review specifically explores the antigens targeted in AML, the diverse methodologies and strategies employed in TCR identification and preclinical TCR T-cell development. The review also discusses innovative molecular designs to improve functional efficacy, mitigate safety concerns and overcome HLA restriction. Specific outcomes of early clinical trials targeting important antigens WT1, PRAME and HA-1 are also highlighted. Ultimately, this review underscores why TCR therapy is poised to become an indispensable component of AML immunotherapy.