54 research outputs found
Kreuth V initiative: European consensus proposals for treatment of hemophilia using standard products, extended half-life coagulation factor concentrates and non-replacement therapies
This report contains the updated consensus recommendations for optimal hemophilia care produced in 2019 by three Working Groups (WG) on behalf of the European Directorate for Quality of Medicines and Healthcare in the frame of the Kreuth V Initiative. WG1 recommended access to prophylaxis for all patients, the achievement of plasma factor trough levels of at least 3-5% when extended half-life factor VIII (FVIII) and FIX products are used, a personalized treatment regimen, and a choice of chromogenic assays for treatment monitoring. It was also emphasized that innovative therapies should be supervised by hemophilia comprehensive care centers. WG2 recommended mandatory collection of postmarketing data to assure the long-term safety and efficacy of new hemophilia therapies, the establishment of national patient registries including the core data recommended by the European Medicines Agency and the International Society on Thrombosis and Haemostasis, with adequate support under public control, and greater collaboration to facilitate a comprehensive data evaluation throughout Europe. WG3 discussed methodological aspects of hemophilia care in the context of access decisions, particularly for innovative therapies, and recommended that clinical studies should be designed to provide the quality of evidence needed by regulatory authorities, HTA bodies and healthcare providers. The dialogue between all stakeholders in hemophilia care and patient organizations should be fostered to implement these recommendations
Factor IX Expression within the Normal Range Prevents Spontaneous Bleeds Requiring Treatment Following FLT180a Gene Therapy in Patients with Severe Hemophilia B: Long-Term Follow- up Study of the B-Amaze Program
Introduction: FLT180a (verbrinacogene setparvovec) is an investigational, liver-directed AAV gene therapy for the treatment of patients with hemophilia B (HB). FLT180a consists of a novel, potent, engineered capsid (AAVS3) containing an expression cassette encoding a Factor IX (FIX) gain-of-function protein variant ('Padua'; FIX-R338L). The B-AMAZE study was designed to identify a dose of FLT180a that maintains FIX activity within the normal range (50-150%) and thereby protect patients with severe HB from spontaneous and traumatic bleeds.
Methods: B-AMAZE was a multicentre, open-label Phase 1/2 clinical trial (NCT03369444; sponsored by UCL) that evaluated FLT180a dose levels using an escalating/descending adaptive design in patients with severe (FIX activity <1%) or moderately severe (FIX activity 1-2%) HB who were negative for AAVS3 neutralizing antibodies. A novel regimen of prophylactic corticosteroids with/without tacrolimus was implemented to mitigate the impact of vector-related transaminitis on FIX expression. Patients who completed the 26-week B-AMAZE study were eligible for the ongoing long-term follow-up study (NCT03641703; sponsored by Freeline).
Results: Ten HB patients received a single dose of FLT180a. Four FLT180a doses ranging from 3.84e11 vg/kg to 1.28e12 vg/kg were assessed. As of the data cut-off date, all patients have been followed for ≥16 months.
FLT180a demonstrated a favorable safety profile, without evidence of inhibitors against FIX, infusion-related or allergic reactions. The most common treatment-related adverse event was transient elevation in alanine aminotransferase. An event of AV fistula thrombosis occurred in a 67-year-old patient who received the highest dose of 1.28e12 vg/kg (total dose of 1.15e14 vg) and had supranormal FIX levels; this patient was treated with anticoagulants. While these FIX levels demonstrate the potency of our proprietary AAVS3 capsid, this dose will not be used in future hemophilia studies.
At Week 26 after FLT180a administration, a dose-response relationship was observed with mean FIX activity of 45.0%, 35.5%, 141.5%, and 175.5% for 3.84e11, 6.4e11, 8.32e11, and 1.28e12 vg/kg doses, respectively (Table); FIX activity levels ≥50% were achieved in 7 of 8 patients treated with the three highest doses. One patient (Patient 4) who received 6.4e11 vg/kg lost transgene expression early due to transaminitis and resumed routine factor prophylaxis. The 8.32e11 vg/kg cohort received an extended immune management regimen (9-18 weeks) with prophylactic tacrolimus in addition to prednisolone to prevent breakthrough vector-related transaminitis. However, after cessation of the immune management regimen, transaminitis with concomitant reductions in FIX activity was observed in all patients in the 8.32e11 vg/kg cohort. The combination of prophylactic tacrolimus and prednisolone appeared to have suppressed immune-mediated transaminitis while administered, but recurrence of transaminitis developed soon after cessation. This unique and previously unreported observation suggests that the longer-duration prophylactic immune management regimen may have prevented tolerization to the vector because this was not observed in earlier cohorts where a brief course of tacrolimus was given reactively for breakthrough transaminitis. All patients (including the 8.32e11 vg/kg cohort) have achieved steady state. Patients in the earliest cohort who received the lowest dose (3.84e11 vg/kg) have shown stable FIX activity for >3 years.
There were no spontaneous bleeds that required FIX supplementation in patients who maintained FIX activity above 50%; Patient 4 in the 6.4e11 vg/kg cohort experienced two bleeds (cause unknown) after he lost transgene expression, which were treated with exogenous FIX. One patient received exogenous FIX for treatment of a traumatic bleed, but his FIX activity level was 57% at the time of the event. Additional efficacy and safety results with >3.5 years of follow-up will be presented.
Conclusions: B-AMAZE is the first HB gene therapy study to achieve normal levels of FIX activity using relatively low vector doses. Results suggest that a dose of 7.7e11 vg/kg, coupled with a short course of prophylactic immune management, has the potential to achieve durable FIX activity in the normal range (50-150%) and thereby prevent spontaneous bleeds and normalize hemostasis in the event of traumatic bleeds
Evaluation of participants with suspected heritable platelet function disorders including recommendation and validation of a streamlined agonist panel
Light transmission aggregometry (LTA) is used worldwide for the investigation of heritable platelet function disorders (PFDs), but interpretation of results is complicated by the feedback effects of ADP and thromboxane A(2) (TxA(2)) and by the overlap with the response of healthy volunteers. Over 5 years, we have performed lumi-aggregometry on 9 platelet agonists in 111 unrelated research participants with suspected PFDs and in 70 healthy volunteers. Abnormal LTA or ATP secretion test results were identified in 58% of participants. In 84% of these, the patterns of response were consistent with defects in Gi receptor signaling, the TxA(2) pathway, and dense granule secretion. Participants with defects in signaling to Gq-coupled receptor agonists and to collagen were also identified. Targeted genotyping identified 3 participants with function-disrupting mutations in the P2Y(12) ADP and TxA(2) receptors. The results of the present study illustrate that detailed phenotypic analysis using LTA and ATP secretion is a powerful tool for the diagnosis of PFDs. Our data also enable subdivision at the level of platelet-signaling pathways and in some cases to individual receptors. We further demonstrate that most PFDs can be reliably diagnosed using a streamlined panel of key platelet agonists and specified concentrations suitable for testing in most clinical diagnostic laboratories
FOSS EKV2.6 Verilog-A Compact MOSFET Model
The EKV2.6 MOSFET compact model has had a considerable impact on the academic and industrial community of analog integrated circuit design, since its inception in 1996. The model is available as a free open-source software (FOSS) tool coded in Verilog-A. The present paper provides a short review of foundations of the model and shows its capabilities via characterization and modeling based on a test chip in 180 nm CMOS fabricated via Europractice
Inhibitor development according to concentrate after 50 exposure days in severe hemophilia: data from the European HAemophilia Safety Surveillance (EUHASS)
Background: Patients with hemophilia have a life-long risk of developing neutralizing antibodies (inhibitors) against clotting factor concentrates. After the first 50 exposure days (EDs), ie, in previously treated patients (PTPs), data on inhibitor development are limited. Objectives: To report inhibitor development according to factor (F)VIII or FIX concentrate use in PTPs with severe hemophilia A and B. Methods: Inhibitor development in PTPs was collected since 2008 from 97 centers participating in European HAemophilia Safety Surveillance. Per concentrate, inhibitors were reported quarterly and the number of PTPs treated annually. Incidence rates (IRs)/1000 treatment years with 95% CIs were compared between concentrate types (plasma derived FVIII/FIX, standard half-life recombinant FVIII/FIX, and extended half-life recombinant (EHL-rFVIII/IX) concentrates using IR ratios with CI. Medians and IQRs were calculated for inhibitor characteristics. Results: For severe haemophilia A, inhibitor rate was 66/65,200 treatment years, IR 1.00/1000 years (CI 0.80-1.30), occurring at median 13.5 years (2.7-31.5) and 150 EDs (80-773). IR on plasma-derived pdFVIII (IR, 1.13) and standard half-life recombinant FVIII (IR, 1.12) were similar, whereas IR on EHL-rFVIII was lower at 0.13 (incidence rate ratio, 0.12; 95% CI, 1000). Data were insufficient to compare by type of FIX concentrates. Conclusion: Low inhibitor rates were observed for PTPs with severe hemophilia A and B. Data suggested reduced inhibitor development on EHL-rFVIII, but no significant difference between plasma-derived FVIII and standard half-life recombinant FVIII. FIX inhibitor rates were too low for robust statistical analysis
Correction of a urea cycle defect after ex vivo gene editing of human hepatocytes
Ornithine transcarbamylase deficiency (OTCD) is a monogenic disease of ammonia metabolism in hepatocytes. Severe disease is frequently treated by orthotopic liver transplantation. An attractive approach is the correction of a patient's own cells to regenerate the liver with gene-repaired hepatocytes. This study investigates the efficacy and safety of ex vivo correction of primary human hepatocytes. Hepatocytes isolated from an OTCD patient were genetically corrected ex vivo, through the deletion of a mutant intronic splicing site achieving editing efficiencies >60% and the restoration of the urea cycle in vitro. The corrected hepatocytes were transplanted into the liver of FRGN mice and repopulated to high levels (>80%). Animals transplanted and liver repopulated with genetically edited patient hepatocytes displayed normal ammonia, enhanced clearance of an ammonia challenge and OTC enzyme activity, as well as lower urinary orotic acid when compared to mice repopulated with unedited patient hepatocytes. Gene expression was shown to be similar between mice transplanted with unedited or edited patient hepatocytes. Finally, a genome-wide screening by performing CIRCLE-seq and deep sequencing of >70 potential off-targets revealed no unspecific editing. Overall analysis of disease phenotype, gene expression, and possible off-target editing indicated that the gene editing of a severe genetic liver disease was safe and effective.
Keywords: CRISPR; FRGN; ex vivo; genome editing; hepatocyte transplantation; liver-humanized mouse; primary hepatocytes; urea cycle disorder
Management of COVID‐19‐associated coagulopathy in persons with haemophilia
Introduction
The SARS‐CoV‐2 coronavirus‐induced infection (COVID‐19) can be associated with a coagulopathy mainly responsible for pulmonary microvasculature thrombosis and systemic thromboembolic manifestations. The pathophysiology and management of the COVID‐19 coagulopathy are likely more complex in patients with inherited bleeding diseases such as haemophilia. These individuals might indeed present with both bleeding and thrombotic complications and require simultaneous antithrombotic and haemostatic treatments.
Objective
We propose practical guidance for the diagnosis and management of COVID‐19 coagulopathy in persons with haemophilia.
Results
Continuation of regular haemostatic treatment is recommended for ambulatory patients. For patients requiring hospital admission and on replacement therapy with factors VIII or IX concentrates, prophylaxis with concentrates should be intensified according to the risk of bleeding complications and associated with prophylactic doses of LMWH. For patients on nonreplacement therapy, emicizumab should be continued and possibly combined with factor VIII and prophylactic doses of LMWH depending on the risk of bleeding and thrombosis. Dose escalation of LMWH tailored to the risk of thrombosis can be employed but not supported by evidence.
Conclusions
These practical recommendations are based on the current literature on COVID‐19 with its impact on haemostasis, indications and modalities for thromboprophylaxis mainly in nonhaemophilic patients and how that is likely to affect persons with haemophilia in different circumstances. They will need to be tailored to each patient's clinical status and validated in future studies
A genome-wide association study of resistance to HIV infection in highly exposed uninfected individuals with hemophilia A
Human genetic variation contributes to differences in susceptibility to HIV-1 infection. To search for novel host resistance factors, we performed a genome-wide association study (GWAS) in hemophilia patients highly exposed to potentially contaminated factor VIII infusions. Individuals with hemophilia A and a documented history of factor VIII infusions before the introduction of viral inactivation procedures (1979-1984) were recruited from 36 hemophilia treatment centers (HTCs), and their genome-wide genetic variants were compared with those from matched HIV-infected individuals. Homozygous carriers of known CCR5 resistance mutations were excluded. Single nucleotide polymorphisms (SNPs) and inferred copy number variants (CNVs) were tested using logistic regression. In addition, we performed a pathway enrichment analysis, a heritability analysis, and a search for epistatic interactions with CCR5 Δ32 heterozygosity. A total of 560 HIV-uninfected cases were recruited: 36 (6.4%) were homozygous for CCR5 Δ32 or m303. After quality control and SNP imputation, we tested 1 081 435 SNPs and 3686 CNVs for association with HIV-1 serostatus in 431 cases and 765 HIV-infected controls. No SNP or CNV reached genome-wide significance. The additional analyses did not reveal any strong genetic effect. Highly exposed, yet uninfected hemophiliacs form an ideal study group to investigate host resistance factors. Using a genome-wide approach, we did not detect any significant associations between SNPs and HIV-1 susceptibility, indicating that common genetic variants of major effect are unlikely to explain the observed resistance phenotype in this populatio
Global, regional, and national burden of diabetes from 1990 to 2021, with projections of prevalence to 2050: a systematic analysis for the Global Burden of Disease Study 2021
Background Diabetes is one of the leading causes of death and disability worldwide, and affects people regardless of country, age group, or sex. Using the most recent evidentiary and analytical framework from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD), we produced location-specific, age-specific, and sex-specific estimates of diabetes prevalence and burden from 1990 to 2021, the proportion of type 1 and type 2 diabetes in 2021, the proportion of the type 2 diabetes burden attributable to selected risk factors, and projections of diabetes prevalence through 2050. Methods Estimates of diabetes prevalence and burden were computed in 204 countries and territories, across 25 age
groups, for males and females separately and combined; these estimates comprised lost years of healthy life, measured in disability-adjusted life-years (DALYs; defined as the sum of years of life lost [YLLs] and years lived with disability [YLDs]). We used the Cause of Death Ensemble model (CODEm) approach to estimate deaths due to diabetes, incorporating 25 666 location-years of data from vital registration and verbal autopsy reports in separate total (including both type 1 and type 2 diabetes) and type-specific models. Other forms of diabetes, including gestational and monogenic diabetes, were not explicitly modelled. Total and type 1 diabetes prevalence was estimated by use of a Bayesian meta-regression modelling tool, DisMod-MR 2.1, to analyse 1527 location-years of data from the scientific literature, survey microdata, and insurance claims; type 2 diabetes estimates were computed by subtracting type 1 diabetes from total estimates. Mortality and prevalence estimates, along with standard life expectancy and disability weights, were used to calculate YLLs, YLDs, and DALYs. When appropriate, we extrapolated estimates to a hypothetical population with a standardised age structure to allow comparison in populations with different age structures. We used the comparative risk assessment framework to estimate the risk-attributable type 2 diabetes burden for 16 risk factors falling under risk categories including environmental and occupational factors, tobacco use, high alcohol use, high body-mass index (BMI), dietary factors, and low physical activity. Using a regression framework, we forecast type 1 and type 2 diabetes prevalence through 2050 with Socio-demographic Index (SDI) and high BMI as predictors, respectively.
Findings In 2021, there were 529 million (95% uncertainty interval [UI] 500–564) people living with diabetes worldwide, and the global age-standardised total diabetes prevalence was 6·1% (5·8–6·5). At the super-region level, the highest age-standardised rates were observed in north Africa and the Middle East (9·3% [8·7–9·9]) and, at the regional level, in Oceania (12·3% [11·5–13·0]). Nationally, Qatar had the world’s highest age-specific prevalence of diabetes, at 76·1% (73·1–79·5) in individuals aged 75–79 years. Total diabetes prevalence—especially among older
adults—primarily reflects type 2 diabetes, which in 2021 accounted for 96·0% (95·1–96·8) of diabetes cases and 95·4% (94·9–95·9) of diabetes DALYs worldwide. In 2021, 52·2% (25·5–71·8) of global type 2 diabetes DALYs were attributable to high BMI. The contribution of high BMI to type 2 diabetes DALYs rose by 24·3% (18·5–30·4) worldwide between 1990 and 2021. By 2050, more than 1·31 billion (1·22–1·39) people are projected to have diabetes, with expected age-standardised total diabetes prevalence rates greater than 10% in two super-regions: 16·8% (16·1–17·6) in north Africa and the Middle East and 11·3% (10·8–11·9) in Latin America and Caribbean. By 2050, 89 (43·6%) of 204 countries and territories will have an age-standardised rate greater than 10%.Peer ReviewedPostprint (published version
Telomerecat: A ploidy-agnostic method for estimating telomere length from whole genome sequencing data.
Telomere length is a risk factor in disease and the dynamics of telomere length are crucial to our understanding of cell replication and vitality. The proliferation of whole genome sequencing represents an unprecedented opportunity to glean new insights into telomere biology on a previously unimaginable scale. To this end, a number of approaches for estimating telomere length from whole-genome sequencing data have been proposed. Here we present Telomerecat, a novel approach to the estimation of telomere length. Previous methods have been dependent on the number of telomeres present in a cell being known, which may be problematic when analysing aneuploid cancer data and non-human samples. Telomerecat is designed to be agnostic to the number of telomeres present, making it suited for the purpose of estimating telomere length in cancer studies. Telomerecat also accounts for interstitial telomeric reads and presents a novel approach to dealing with sequencing errors. We show that Telomerecat performs well at telomere length estimation when compared to leading experimental and computational methods. Furthermore, we show that it detects expected patterns in longitudinal data, repeated measurements, and cross-species comparisons. We also apply the method to a cancer cell data, uncovering an interesting relationship with the underlying telomerase genotype
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