The eTHINK Study: Cognitive and Behavioral Outcomes in Children with Hemophilia.

OBJECTIVE: To assess cognitive, behavioral, and adaptive functions in children and young adults with hemophilia treated according to contemporary standards of care. STUDY DESIGN: Evolving Treatment of Hemophilia's Impact on Neurodevelopment, Intelligence, and Other Cognitive Functions (eTHINK) is a US-based, prospective, cross-sectional, observational study (September 2018 through October 2019). Males (aged 1-21 years) with hemophilia A or B of any severity, with or without inhibitors, were eligible. Participants underwent neurologic examinations and age-appropriate neuropsychological assessments, including standardized tests/ratings scales of early development, cognition, emotional/behavioral adjustment, and adaptive skills. RESULTS: Five hundred and fifty-one males with hemophilia A (n = 433) or B (n = 101) were enrolled. Performance on cognitive tests was largely comparable with that of age-matched US population norms, although participants in certain age groups (4-5 and 10-21 years) performed worse on measures of attention and processing speed. Furthermore, adolescents and young adults and those with comorbid attention-deficit/hyperactivity disorder (ADHD; n = 64) reported more adaptive and executive function problems in daily life. Incidence of ADHD in adolescents (21%) was higher than expected in the general population. CONCLUSIONS: In general, males with hemophilia demonstrated age-appropriate intellectual, behavioral, and adaptive development. However, specific patient/age groups showed poorer attention performance and concerns for executive and adaptive development. This study established a normative data set for monitoring neurodevelopment in individuals with hemophilia and highlight the importance of screening and intervention for challenges with cognitive and adaptive skills in this population. CLINICAL TRIAL REGISTRATION: Evolving Treatment of Hemophilia's Impact on Neurodevelopment, Intelligence, and Other Cognitive Functions (eTHINK); NCT03660774; https://clinicaltrials.gov/ct2/show/NCT03660774.

Benefits and risks of non-factor therapies: Redefining haemophilia treatment goals in the era of new technologies.

INTRODUCTION: Over the last decades progress in haemophilia treatment has been remarkable and prophylaxis with clotting factor concentrates in haemophilia A and B has been established as the standard of care in individuals with haemophilia and a severe bleeding phenotype. Besides clotting factor products with prolonged half-life non-factor therapies were developed which enable prophylaxis via subcutaneous administration. Factor VIIIa mimetics like emicizumab facilitate the coagulation pathway and are used in routine clinical practice for indivdiduals with haemophilia A. Rebalancing therapeutic agents like fitusiran, concizumab, marstacimab and serpin PC block the anticoagulant pathway and clinical trials using these products in individuals with haemophilia A and B are ongoing. AIM AND METHODS: A narrative review to asess the benefits and risks of non-factor therapies taking in to account re-defined haemophilia treatment goals. RESULTS: Prophylaxis for prevention of bleeds using non-factor products by subcutaneous administration is effective and results in reductions of bleeding episodes in individuals with haemophilia A or B with and without inhibitors. The treatment with emicizumab showed tolerable safety both in clinical trials and long-term real-world observations with few thrombotic events. In some clinical trials with rebalancing therapies (fitusiran and concizumab) thrombotic events occurred. Monitoring of the haemostatic function of novel therapies especially with concomitant haemostatic treatment is not yet established. CONCLUSION: With the advent of novel therapeutic agents including factor concentrates with ultra-long half-life and improved FVIIIa mimetics aimed at raising the bar of protection into the non-hemophilic range redefinition of haemophilia treatment goals is eagerly needed.

Antithrombin lowering in hemophilia: a closer look at fitusiran.

Thrombin is a key enzyme in the maintenance of normal hemostatic function and is the central product of an interconnected set of simultaneously occurring cellular and proteolytic events. Antithrombin (AT) is a natural anticoagulant that downregulates different components of the clotting process, particularly thrombin generation. In good health, well-regulated hemostasis is the result of a balance between procoagulant and anticoagulant elements. Cumulative understanding of the regulation of thrombin generation and its central role in hemostasis and bleeding disorders has led to the clinical development of therapeutic strategies that aim to rebalance hemostasis in individuals with hemophilia and other coagulation factor deficiencies to improve bleeding phenotype. The aim of this review is to discuss the rationale for AT lowering in individuals with hemophilia, with a focus on fitusiran, its mechanism of action, and its potential as a prophylactic therapy for individuals with hemophilia A or B, with or without inhibitors. Fitusiran is an investigational small, interfering RNA therapeutic that targets and lowers AT. It is currently in phase III clinical trials and results have shown its potential to increase thrombin generation, leading to enhanced hemostasis and improved quality of life while reducing the overall treatment burden.

Evaluation of venous thromboembolism risk factors reveals subtype heterogenicity in children with central venous catheters: a multicenter study from the Children's Hospital Acquired Thrombosis consortium.

BACKGROUND: Acutely ill and medically complex children frequently rely on central venous catheters (CVCs) to provide life-sustaining treatment. Unfortunately, catheter-related thrombosis (CRT) is a serious and common complication. Little is known why some with a CVC develop CRT and others develop venous thromboembolism unrelated to the CVC (non-CRT). OBJECTIVES: The aim of this study was to identify factors associated with CRT in children with hospital-acquired venous thromboembolism (HA-VTE). METHODS: This case-case study included participants in the Children's Hospital Acquired Thrombosis Registry with HA-VTE and CVC aged 0 to 21 years from 8 US children's hospitals. Participants were excluded if they developed HA-VTE prior to CVC insertion or if the CVC insertion date was unknown. Logistic regression models were used to assess associations between clinical factors and CRT status. RESULTS: There were 1144 participants with HA-VTE who had a CVC. CRT developed in 833 participants, and 311 developed non-CRT. Multivariable analysis showed increased odds of CRT (compared with non-CRT) in participants with peripherally inserted central catheters (odds ratio [OR], 3.80; 95% CI, 2.04-7.10; p < .001), CVCs inserted in the femoral vein (OR, 4.45; 95% CI, 1.70-11.65; p = .002), multiple CVCs (OR, 1.42; 95% CI, 1.18-1.71; p < .001), and CVC malfunction (OR, 3.30; 95% CI, 1.80-6.03; p < .001). CONCLUSION: The findings of this study provide new insights on risk factor differences between CRT and non-CRT. Prevention efforts should be directed at modifying the type of CVC, insertion location, and/or number of CVCs placed, if possible, to decrease the incidence of CRT.

Building the foundation for a community-generated national research blueprint for inherited bleeding disorders: facilitating research through infrastructure, workforce, resources and funding.

BACKGROUND: The National Hemophilia Foundation (NHF) conducted extensive, inclusive community consultations to guide prioritization of research in coming decades in alignment with its mission to find cures and address and prevent complications enabling people and families with blood disorders to thrive. RESEARCH DESIGN AND METHODS: With the American Thrombosis and Hemostasis Network, NHF recruited multidisciplinary expert working groups (WG) to distill the community-identified priorities into concrete research questions and score their feasibility, impact, and risk. WG6 was charged with identifying the infrastructure, workforce development, and funding and resources to facilitate the prioritized research. Community input on conclusions was gathered at the NHF State of the Science Research Summit. RESULTS: WG6 detailed a minimal research capacity infrastructure threshold, and opportunities to enable its attainment, for bleeding disorders centers to participate in prospective, multicenter national registries. They identified challenges and opportunities to recruit, retain, and train the diverse multidisciplinary care and research workforce required into the future. Innovative collaborative approaches to trial design, resource networking, and funding to surmount obstacles facing research in rare disorders were elucidated. CONCLUSIONS: The innovations in infrastructure, workforce development, and resources and funding proposed herein may contribute to facilitating a National Research Blueprint for Inherited Bleeding Disorders.

Research is critical to advancing the diagnosis and care of people with inherited bleeding disorders (PWIBD). This research requires significant infrastructure, including people and resources. Hemophilia treatment centers (HTC) need many different skilled care professionals including doctors, nurses, and other providers; also statisticians, data managers, and other experts to process patients' clinical information into research. Attracting diverse qualified professionals to the clinical and research work requires long-term planning, recruiting individuals in training programs and retaining them as they become experts. Research infrastructure includes physical servers running database software, networks that link them, and the environment in which these components function. US Centers for Disease Control and Prevention (CDC) and American Thrombosis and Hemostasis Network (ATHN) coordinate and fund data collection at HTCs on the health and well-being of thousands of PWIBD into a registry used in research studies.National Hemophilia Foundation (NHF) and ATHN asked our group of health care professionals, technology experts, and lived experience experts (LEE) to identify the infrastructure, workforce, and resources needed to do the research most important to PWIBD. We identified the types of CDC/ATHN studies all HTCs should be able to perform, and the physical and human infrastructure this requires. We prioritized finding the best clinical trial designs to study inherited bleeding disorders, identifying ways to share personnel and tools between HTCs, and innovating how research is governed and funded. Involving LEEs in designing, managing, and carrying out research will be key in conducting research to improve the lives of PWIBD.

Surgical outcomes in people with hemophilia A taking emicizumab prophylaxis: experience from the HAVEN 1-4 studies.

Many people with hemophilia A (PwHA) undergo surgery in their lifetime, often because of complications of their disease. Emicizumab is the first bispecific monoclonal antibody prophylactic therapy for PwHA, and its efficacy and safety have been previously demonstrated; however, there is a need to build an evidence base on the management of PwHA on emicizumab undergoing surgery. Data from the HAVEN 1-4 phase 3 clinical trials were pooled to provide a summary of all minor and major surgeries in PwHA with or without factor VIII (FVIII) inhibitors who were receiving emicizumab prophylaxis. Overall, 233 surgeries were carried out during the HAVEN 1-4 trials: 215 minor surgeries (including minor dental and joint procedures, central venous access device placement or removal, and endoscopies) in 115 PwHA (64 with FVIII inhibitors) and 18 major surgeries (including arthroplasty and synovectomy) in 18 PwHA (10 with FVIII inhibitors). Perioperative hemostatic support was at the discretion of the treating physician. Overall, the median (interquartile range [IQR]) age was 33.5 (13.0-49.0) years and the median (IQR) emicizumab exposure time before surgery was 278.0 (177.0-431.0) days. Among the 215 minor surgeries, 141 (65.6%) were managed without additional prophylactic factor concentrate, and of those, 121 (85.8%) were not associated with a postoperative bleed. The majority (15 of 18 [83.3%]) of major surgeries were managed with additional prophylactic factor concentrate. Twelve (80.0%) of these 15 surgeries were associated with no intraoperative or postoperative bleeds. The data demonstrate that minor and major surgeries can be performed safely in PwHA receiving emicizumab prophylaxis. These trials are registered at www.clinicaltrials.gov as #NCT02622321, #NCT02795767, #NCT02847637, and #NCT03020160.

Hemophilia A/B.

Adeno-associated virus (AAV)-mediated gene transfer has successfully raised, and in some cases transiently normalized, FVIII or FIX activity levels in adults with severe hemophilia. Raising FVIII/IX levels, particularly greater than ∼15 IU/dL (mild deficiency), corresponds to a marked decrease in spontaneous and provoked bleeding, dramatic reduction in factor concentrate use, and improved quality of life (QoL). Limited understanding of innate and adaptive immune system responses and hepatocyte transgene expression and stress responses to AAV-mediated gene transfer contribute to the variability in initial and long-term factor protein expression. Lentiviral (LV) and CRISPR/Cas-9 gene therapy approaches may further bolster the range of eligible participants and improve transgene expression and durability.

Kaposiform Lymphangiomatosis: Pathologic Aspects in 43 Patients.

Kaposiform lymphangiomatosis is an uncommon generalized lymphatic anomaly with distinctive clinical, radiologic, histopathologic, and molecular findings. Herein, we document the pathology in 43 patients evaluated by the Boston Children's Hospital Vascular Anomalies Center from 1999 to 2020. The most frequent presentations were respiratory difficulty, hemostatic abnormalities, and a soft tissue mass. Imaging commonly revealed involvement of some combination of mediastinal, pulmonary, pleural, and pericardial compartments and most often included spleen and skeleton. Histopathology was characterized by dilated, redundant, and abnormally configured lymphatic channels typically accompanied by dispersed clusters of variably canalized, and often hemosiderotic, spindled lymphatic endothelial cells that were immunopositive for D2-40, PROX1, and CD31. An activating lesional NRAS variant was documented in 9 of 10 patients. The clinical course was typically aggressive, marked by hemorrhage, thrombocytopenia, diminished fibrinogen levels, and a mortality rate of 21%.

Quality of life in a large multinational haemophilia B cohort (The B-Natural study) - Unmet needs remain.

INTRODUCTION: The B-Natural study is a multicentre, multinational, observational study of haemophilia B (HB) designed to increase understanding of clinical manifestations, treatment and quality of life (QoL). AIM: To characterise and compare QoL in HB across disease severity groups and individuals with inhibitors to identify gaps in treatment. METHODS: A total of 224 individuals from 107 families were enrolled from a total of 24 centres in North America (n = 16), Europe (n = 7) and Asia (n = 1). Of these, 68 (30.4%) subjects had severe (<1 IU/dL), median age 15.6 years, 114 (50.9%) moderate (1-5 IU/dL), age 13.3 years, and 42 (18.8%) mild (>5-< 40 IU/dL), age 12.1 years, disease. Twenty-nine participants had inhibitors or a history of inhibitors. Three versions of the EQ-5D instrument were used as a measure of QoL: proxy (ages 4-7), youth (ages 8-15) and self (age 16+). Each instrument included a visual analogue scale ranging from 100 (best health) to 0 (worst health) to assess current day's health (EQ VAS). Range-of-motion (ROM) for elbows, knees and ankles was assessed using a four-point scale, from which a composite score was calculated. RESULTS: In all severity groups, a proportion of subjects showed less than optimal QoL. The majority of the mild and moderate severe participants reported a normal EQ-5D health profile (79% and 72%, respectively), whereas about half (47%) of the severe participants and only 13% of the inhibitor participants reported this profile. CONCLUSION: The B-Natural study reveals impacted QoL in all disease severities of HB including those with inhibitors. Unmet needs remain and include nonsevere HB.

Health care costs and resource utilization among commercially insured adult patients with hemophilia A managed with FVIII prophylaxis in the United States.

BACKGROUND: Standard of care for patients with severe hemophilia A (HA) is life-long prophylaxis with factor VIII (FVIII) concentrate or other hemostatic agents. Published literature highlights a wide range of treatment costs for patients with HA. OBJECTIVE: To estimate average annual health care costs and resource utilization for a cross-section of adult patients managed with FVIII concentrate prophylaxis using recent data from a large US commercial claims database. METHODS: Adult males with 1 or more claim with HA diagnosis, continuous commercial plan enrollment, and 4 or more FVIII prescription dispenses during 12 months were identified from IBM MarketScan Research Database from January 2013 to September 2019, excluding those with FVIII inhibitors, an HIV/AIDS diagnosis, or diagnosis and treatment for hepatitis B or C. Patients were classified as using FVIII prophylaxis if they met any of the following definitions: (1) 6 or more FVIII dispenses, (2) a gap of 60 days or less between dispenses, and (3) at least 273 days supply in the 12-month period. Additionally, subgroups of patients meeting each individual definition were examined, with some patients included in all 3 subgroups. RESULTS: The overall cohort included 411 patients who met 1 or more of the 3 definitions, with a mean age of 28.9 years. Subgroups of 401, 325, and 237 patients met the first, second, and third FVIII prophylaxis definitions, respectively. Per-patient mean (SD) annual all-cause health care costs were $654,571 ($380,762) in the overall cohort and ranged from $650,065 ($382,196) to $759,661 ($387,040) among subgroups. Cost of FVIII concentrate accounted for more than 96% of total costs in the overall cohort and in each subgroup. Cost of FVIII in the overall cohort varied according to type of concentrate, with the highest among patients who were treated with both standard and extended half-life (SHL and EHL) FVIII ($784,945), followed by EHL FVIII only ($708,928), SHL FVIII only ($647,800), and plasma-derived FVIII ($535,614). The most common treatment type was SHL FVIII only (45.7% of all patients). In the overall cohort, the majority had 1 or more outpatient visits (94.9%), while emergency department visits, hospital admissions, and home health visits occurred less frequently (27.0%, 7.1%, and 7.1%, respectively). CONCLUSIONS: Commercially insured patients with HA incur substantial all-cause annual health care costs, with FVIII concentrate accounting for a majority of costs. DISCLOSURES: This study was funded by BioMarin Pharmaceutical Inc, which was involved in the protocol development, analysis plan development, data interpretation, manuscript preparation, and publication decisions. All authors contributed to protocol development, analysis plan development, data interpretation, and manuscript development and maintained control over the final content. Thornburg has received professional fees from BioMarin Pharmaceutical, CSL Behring, Genentech, Novo Nordisk, Sanofi Genzyme, HEMA Biologics, and Spark Therapeutics and institutional research funding from BioMarin Pharmaceutical, Novo Nordisk, and Sanofi Genzyme. Adamski, Cook, and Sendhil are employees of Analysis Group, a consulting company that was contracted by BioMarin Pharmaceutical to conduct this study and develop the manuscript. Vembusubramanian is a former employee of Analysis Group. Hinds, Chen, and Sammon are employees and shareholders of BioMarin Pharmaceutical. Solari is a former employee of BioMarin Pharmaceutical. Garrison has received consulting fees from BioMarin Pharmaceutical and Analysis Group. Croteau has received professional fees from BioMarin Pharmaceutical, Bayer, CSL Behring, HEMA Biologics, and Pfizer and institutional research funding from Novo Nordisk and Spark Therapeutics.

Symptomatic pulmonary embolus after catheter removal in children with catheter related thrombosis: A report from the CHAT Consortium.

BACKGROUND: Appropriate timing of central venous catheter (CVC) removal, in relation to start of anticoagulation, in children after the diagnosis of a CVC-related thrombosis (CRT) is not well established. OBJECTIVES: This retrospective cohort study evaluated the incidence of symptomatic pulmonary embolism (PE) after CVC removal using data from the multi-institutional Children's Hospital-Acquired Thrombosis (CHAT) Consortium Registry. PATIENTS/METHODS: The CHAT Registry consists of data from children aged 0-21 years with a hospital-acquired venous thromboembolism. Eligible subjects were those with CRT diagnosed <3 days after CVC removal. Subjects were excluded if the CRT was due to a failed CVC insertion. Subjects were divided into three groups: those with CVC removal without anticoagulation, those with CVC removal <48 h after starting anticoagulation, and those with CVC removal ≥48 h after starting anticoagulation. RESULTS: A total of 687 CRT events from 663 subjects were included. A majority of CRT events were in subjects with peripherally inserted central catheters (62.3%, n = 428). For the 611 CRT events in which the CVC was removed, there was only one case of symptomatic PE (0.16%), which occurred <48 h after initiation of anticoagulation. CONCLUSIONS: While current guidelines suggest anticoagulation before CVC removal in the setting of a CRT to prevent embolization, CVC removal is not associated with symptomatic PE regardless of duration of anticoagulation before CVC removal.

A New Risk Assessment Model for Hospital-Acquired Venous Thromboembolism in Critically Ill Children: A Report From the Children's Hospital-Acquired Thrombosis Consortium.

OBJECTIVES: To create a risk model for hospital-acquired venous thromboembolism in critically ill children upon admission to an ICU. DESIGN: Case-control study. SETTING: ICUs from eight children's hospitals throughout the United States. SUBJECTS: Critically ill children with hospital-acquired venous thromboembolism (cases) 0-21 years old and similar children without hospital-acquired venous thromboembolism (controls) from January 2012 to December 2016. Children with a recent cardiac surgery, asymptomatic venous thromboembolism, or a venous thromboembolism diagnosed before ICU admission were excluded. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The multi-institutional Children's Hospital-Acquired Thrombosis registry was used to identify cases and controls. Multivariable logistic regression was used to determine the association between hospital-acquired venous thromboembolism and putative risk factors present at or within 24 hours of ICU admission to develop the final model. A total of 548 hospital-acquired venous thromboembolism cases (median age, 0.8 yr; interquartile range, 0.1-10.2) and 187 controls (median age, 2.4 yr; interquartile range, 0.2-8.3) were analyzed. In the multivariable model, recent central venous catheter placement (odds ratio, 4.4; 95% CI, 2.7-7.1), immobility (odds ratio 3.6, 95% CI, 2.1-6.2), congenital heart disease (odds ratio 2.9, 95% CI, 1.7-4.7), length of hospital stay prior to ICU admission greater than or equal to 3 days (odds ratio, 2.5; 95% CI, 1.1-5.6), and history of autoimmune/inflammatory condition or current infection (odds ratio, 2.1; 95% CI, 1.2-3.4) were each independently associated with hospital-acquired venous thromboembolism. The risk model had an area under the receiver operating characteristic curve of 0.79 (95% CI, 0.73-0.84). CONCLUSIONS: Using the multicenter Children's Hospital-Acquired Thrombosis registry, we identified five independent risk factors for hospital-acquired venous thromboembolism in critically ill children, deriving a new hospital-acquired venous thromboembolism risk assessment model. A prospective validation study is underway to define a high-risk group for risk-stratified interventional trials investigating the efficacy and safety of prophylactic anticoagulation in critically ill children.

Multiyear Factor VIII Expression after AAV Gene Transfer for Hemophilia A.

BACKGROUND: The goal of gene therapy for patients with hemophilia A is to safely impart long-term stable factor VIII expression that predictably ameliorates bleeding with the use of the lowest possible vector dose. METHODS: In this phase 1-2 trial, we infused an investigational adeno-associated viral (AAV) vector (SPK-8011) for hepatocyte expression of factor VIII in 18 men with hemophilia A. Four dose cohorts were enrolled; the lowest-dose cohort received a dose of 5 × 1011 vector genomes (vg) per kilogram of body weight, and the highest-dose cohort received 2 × 1012 vg per kilogram. Some participants received glucocorticoids within 52 weeks after vector administration either to prevent or to treat a presumed AAV capsid immune response. Trial objectives included evaluation of the safety and preliminary efficacy of SPK-8011 and of the expression and durability of factor VIII. RESULTS: The median safety observation period was 36.6 months (range, 5.5 to 50.3). A total of 33 treatment-related adverse events occurred in 8 participants; 17 events were vector-related, including 1 serious adverse event, and 16 were glucocorticoid-related. Two participants lost all factor VIII expression because of an anti-AAV capsid cellular immune response that was not sensitive to immune suppression. In the remaining 16 participants, factor VIII expression was maintained; 12 of these participants were followed for more than 2 years, and a one-stage factor VIII assay showed no apparent decrease in factor VIII activity over time (mean [±SD] factor VIII activity, 12.9±6.9% of the normal value at 26 to 52 weeks when the participants were not receiving glucocorticoids vs. 12.0±7.1% of the normal value at >52 weeks after vector administration; 95% confidence interval [CI], -2.4 to 0.6 for the difference between matched pairs). The participants had a 91.5% reduction (95% CI, 88.8 to 94.1) in the annualized bleeding rate (median rate, 8.5 events per year [range, 0 to 43.0] before vector administration vs. 0.3 events per year [range, 0 to 6.5] after vector administration). CONCLUSIONS: Sustained factor VIII expression in 16 of 18 participants who received SPK-8011 permitted discontinuation of prophylaxis and a reduction in bleeding episodes. No major safety concerns were reported. (Funded by Spark Therapeutics and the National Heart, Lung, and Blood Institute; ClinicalTrials.gov numbers, NCT03003533 and NCT03432520.).

Phage display broadly identifies inhibitor-reactive regions in von Willebrand factor.

BACKGROUND: Correction of von Willebrand factor (VWF) deficiency with replacement products containing VWF can lead to the development of anti-VWF alloantibodies (i.e., VWF inhibitors) in patients with severe von Willebrand disease (VWD). OBJECTIVE: Locate inhibitor-reactive regions within VWF using phage display. METHODS: We screened a phage library displaying random, overlapping fragments covering the full-length VWF protein sequence for binding to a commercial anti-VWF antibody or to immunoglobulins from three type 3 VWD patients who developed VWF inhibitors in response to treatment with plasma-derived VWF. Immunoreactive phage clones were identified and quantified by next-generation DNA sequencing (NGS). RESULTS: Next-generation DNA sequencing markedly increased the number of phages analyzed for locating immunoreactive regions within VWF following a single round of selection and identified regions not recognized in previous reports using standard phage display methods. Extending this approach to characterize VWF inhibitors from three type 3 VWD patients (including two siblings homozygous for the same VWF gene deletion) revealed patterns of immunoreactivity distinct from the commercial antibody and between unrelated patients, though with notable areas of overlap. Alloantibody reactivity against the VWF propeptide is consistent with incomplete removal of the propeptide from plasma-derived VWF replacement products. CONCLUSION: These results demonstrate the utility of phage display and NGS to characterize diverse anti-VWF antibody reactivities.

The B-Natural study-The outcome of immune tolerance induction therapy in patients with severe haemophilia B.

INTRODUCTION: Inhibitors develop less frequently in haemophilia B (HB) than haemophilia A (HA). However, when present, the success of tolerization by immune tolerance induction (ITI) therapy is lower and the risk of complications higher. AIM: To evaluate the use and outcome of ITI in patients with HB and inhibitors. METHODS: Subjects include singletons or siblings with a current/history of inhibitors enrolled in B-Natural-an observational study designed to increase understanding of clinical management of patients with HB. Patients were followed for 6 months and information on demographics, medical and social history, and treatment were recorded. RESULTS: Twenty-nine patients with severe HB and inhibitors were enrolled in 24 centres. Twenty-two underwent one or more courses of ITI with or without immune suppression. Eight patients (36.4%) were successfully tolerized after the first course of ITI. One of these successes (12.5%) experienced allergic manifestations, whereas the corresponding number for the 10 treatment failures was five (50%). One of seven (14.2%) patients with large deletions and three of eight (37.5%) with nonsense mutations were tolerized at the first attempt, and all patients experiencing nephrosis either failed or were on-going. At study end, 11 (50%) were considered successfully tolerized after one or more ITI courses, three were unsuccessful, and eight were still undergoing treatment. CONCLUSION: Our data underscore the possibilities and difficulties of achieving tolerization in patients with HB with inhibitors. The type of mutation and complications appear to correlate with ITI outcome, but more accurate definitions of successful ITI are warranted.

Health care resource utilization and costs among adult patients with hemophilia A on factor VIII prophylaxis: an administrative claims analysis.

BACKGROUND: Standard of care for bleed prevention in patients with severe congenital hemophilia A is continuous prophylaxis with factor VIII (FVIII), typically administered intravenously 2-3 times per week in the home setting. Nonfactor prophylaxis and gene therapy are emerging novel prophylaxis strategies for hemophilia A, and it is important to compare their health economics with that of FVIII prophylaxis. Current data on resource utilization and costs in the adult hemophilia A prophylaxis population are limited, and a structured approach to analyze annual costs in these patients using administrative claims data has not been previously reported. OBJECTIVE: To assess health care resource utilization and costs of continuous FVIII prophylaxis in commercially insured adults with hemophilia A without inhibitors. METHODS: Administrative claims records from beneficiaries covered by major selfinsured companies in the United States from January 1999 through March 2017 (OptumHealth Care Solutions) were queried, and records for adult patients (aged 18-64 years) diagnosed with hemophilia A who received FVIII were extracted. Three criteria were defined to distinguish patients most likely to be managed with continuous FVIII prophylaxis from those on episodic treatment based on the frequency and timing of FVIII claims over a 12-month period of continuous enrollment: (1) having ≥ 4 FVIII claims, (2) having ≥ 6 FVIII claims, or (3) having no gaps > 60 days between FVIII claims. Patients with evidence of bypassing agent use were excluded. Health care resource utilization and costs were assessed for all patients with any FVIII use and for patients defined as being managed with continuous FVIII prophylaxis based on each criterion. RESULTS: The analysis included 189 patients with a diagnosis code for hemophilia A (ICD 9-CM code 286.0; ICD-10-CM code D66) from January 1999 through March 2017 who had at least 12 months of continuous enrollment and at least 1 noninpatient/nonemergency department claim for FVIII concentrate (any type) during their last 12 months of continuous enrollment (overall cohort). Within the overall cohort, 118, 94, and 61 patients met the criteria for FVIII prophylaxis based on the first, second, and third definitions, respectively. Per patient mean (SD) total health care costs for the overall cohort was $287,055 (306,933). For patients meeting criteria 1 through 3, per patient costs ranged from $407,752 (321,036) to $551,645 (302,841). FVIII concentrate accounted for over 90% of costs, with mean (SD) annual FVIII costs of $264,777 (292,423) in the overall cohort and $384,197 (303,826), $433,029 (313,711), and $531,098 (297,142) among patients meeting the respective definitions for prophylaxis. CONCLUSIONS: This analysis highlights the substantial economic burden associated with managing adults with hemophilia A on FVIII prophylaxis, where per patient mean total annual health care costs ranged from $407,752 to $551,645. Over 90% of such costs were attributable to FVIII concentrate dispensed. DISCLOSURES: This study was funded by BioMarin Pharmaceutical, which was involved in protocol development, analysis plan development, data interpretation, manuscript preparation, and publication decisions. All authors contributed to protocol development, analysis plan development, data interpretation, and manuscript development. All authors maintained control over the final content. Sammon, Solari, Kim, and Hinds are employees and shareholders of BioMarin Pharmaceutical. Cook, Sheikh, and Chawla are employees of Analysis Group, a consulting company that was contracted by BioMarin Pharmaceutical to conduct this study and develop the manuscript. Croteau has received professional fees from BioMarin Pharmaceutical, Bayer, CSL Behring, Genentech, and Pfizer. Thornberg has received professional fees from BioMarin Pharmaceutical, Genentech, Novo Nordisk, Sanofi, and Spark Therapeutics, as well as research funding from Novo Nordisk and Sanofi.

Outcomes for studies assessing the efficacy of hemostatic therapies in persons with congenital bleeding disorders.

INTRODUCTION: Management strategies and hemostatic treatments to achieve control of bleeding are relevant across many disease areas. Identification of primary outcomes for studies assessing hemostatic intervention was the objective of a National Heart, Lung and Blood Institute (NHLBI) sponsored multidisciplinary initiative. The aim of this report is to summarize the evidence reviewed, and the outcomes identified by the subgroup tasked to assess outcomes for inherited bleeding disorders. METHODS: The subgroup decided to focus on haemophilia, the prototypal congenital bleeding disorder and the one with the largest available body of evidence. MEDLINE, EMBASE and PsycINFO, The Cochrane Review, CINAHL, and Web of Science were searched for systematic and narrative reviews on outcomes used in haemophilia clinical trials. Three different clinical goals were identified as typical objectives of future research. RESULTS: Out of 1322 unique citations, 24 reviews published in the period 2002-2019 were included. We identified 113 outcome measures, categorized in 6 domains: health-related quality of life (HRQoL), comorbidities and mortality, overall physical functioning and participation, bleeding and hemostasis, joint health, and costs and resource use. Three different clinical goals were identified as typical objectives of future research: Episodic 'on demand' replacement therapy, prevention of bleeding (Prophylaxis), and long-term and overall impact of bleeding. For each of these scenarios, specific outcomes were recommended. CONCLUSIONS: Primary outcomes for clinical trials assessing the efficacy of hemostatic treatment in achieving control, prevention and limiting long-term consequences of bleeding in inherited bleeding disorders are suggested, and their strength and limitations discussed.

Decreased platelet surface phosphatidylserine predicts increased bleeding in patients with severe factor VIII deficiency.

BACKGROUND: Bleeding phenotypes among individuals with severe factor VIII (FVIII) deficiency are variable, even with routine prophylactic FVIII administration. Activated platelets, in addition to their role in primary hemostasis, play a major role in coagulation by providing a phospholipid surface to which coagulation factors bind. OBJECTIVES: The aim of this study was to determine whether platelet function is associated with past and/or future bleeding in patients with severe FVIII deficiency on prophylaxis. PATIENTS/METHODS: Platelet function quantified by platelet surface expression of phosphatidylserine, platelet surface glycoprotein (GP) VI, platelet surface activated GPIIb-IIIa, platelet surface P-selectin, the percentage of coated platelets, and the percentage of platelet-derived microparticles in the presence or absence of in vitro activation by various agonists was assessed in 34 patients. RESULTS: Decreased platelet surface phosphatidylserine expression (identified by annexin V binding), both in the presence and absence of ADP/thrombin receptor activating peptide, demonstrated a significant association with both prior and subsequent bleeding in any location and specifically with hemarthrosis. No significant difference between patients with and without bleeding was observed in any of the other platelet activity markers. CONCLUSIONS: Decreased platelet surface phosphatidylserine expression measured by annexin V binding predicts increased bleeding in severe FVIII deficient patients on prophylaxis.

2021 clinical trials update: Innovations in hemophilia therapy.

Therapies engineered to prolong clotting factor protein circulation time, manipulate the balance of pro-coagulant and anti-coagulant proteins, or introduce new genetic material to enable endogenous factor protein production dominate the clinical trial landscape of hemophilia. The availability of clotting factor concentrates and the establishment of primary prophylaxis have dramatically improved health outcomes for hemophilia patients. But, the burden of hemostatic therapy remains significant, and many barriers to consistent longitudinal use of prophylaxis exist. Several types of emerging therapeutics including engineered factor concentrates, substitutive therapies, rebalancing therapies, and gene transfer/editing all aim to reduce the challenges of current hemophilia treatment. Emerging treatment options may reduce treatment frequency or need for intravenous administration. They may also introduce new challenges in laboratory assessment of hemostasis. These novel therapies must not introduce significant new health risks and continue to support similar or improved outcomes. The potential ramifications of rebalancing the coagulation cascade, particularly in a stress or inflammatory state, or introduction of new genetic material are not trivial. The focus of this review is to provide an overview of active and recently completed clinical trials as well as emerging preclinical data investigating new therapeutic possibilities for hemophilia patients and potentially other rare bleeding disorders.