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Hemophilia A (HA) and hemophilia B (HB) are rare inherited bleeding disorders. Although causative genetic variants are clinically relevant, in 2012 only 20% of US patients had been genotyped.My Life, Our Future (MLOF) was a multisector cross-sectional US initiative to improve our understanding of hemophilia through widespread genotyping.Subjects and potential genetic carriers were enrolled at US hemophilia treatment centers (HTCs). Bloodworks performed genotyping and returned results to providers. Clinical data were abstracted from the American Thrombosis and Hemostasis Network dataset. Community education was provided by the National Hemophilia Foundation.From 2013 to 2017, 107 HTCs enrolled 11 341 subjects (68.8% male, 31.2% female) for testing for HA (n = 8976), HB (n = 2358), HA/HB (n = 3), and hemophilia not otherwise specified (n = 4). Variants were detected in most male patients (98.2%% HA, 98.1% HB). 1914 unique variants were found (1482 F8, 431 F9); 744 were novel (610 F8, 134 F9). Inhibitor data were available for 6986 subjects (5583 HA; 1403 HB). In severe HA, genotypes with the highest inhibitor rates were large deletions (77/80), complex intron 22 inversions (9/17), and no variant found (7/14). In severe HB, the highest rates were large deletions (24/42). Inhibitors were reported in 27.3% of Black versus 16.2% of White patients.The findings of MLOF are reported, the largest hemophilia genotyping project performed to date. The results support the need for comprehensive genetic approaches in hemophilia. This effort has contributed significantly towards better understanding variation in the F8 and F9 genes in hemophilia and risks of inhibitor formation.

Gene therapy for hemophilia is designed to produce health gains for patients over many years. Rewarding that value creation on the basis of a one-time treatment implies a large upfront cost. This cost can only be justified by long-term health benefits and being cost-effective compared with conventional treatments. Yet, uncertainties about the long-term benefits make it challenging to assess clinical and economic value of gene therapies at launch. We identify and discuss key methodological challenges in assessing the value of gene therapy for hemophilia, including the immaturity of evidence on the durability of benefits, lack of definition and valuation of cure for chronic diseases, absence of randomized controlled trials, limitations of traditional quality of life measures in hemophilia, approach for qualifying cost-savings compared with current treatments, and choice of perspective. The Institute for Clinical and Economic Review has developed a framework for assessing single or short-term therapies (ICER-SST) and has applied it in hemophilia. After reviewing this framework and its application, we recommend the following when assessing the value of hemophilia gene therapies: (1) leveraging expert clinical opinion to justify assumptions on the durability of benefits; (2) using external synthetic controls and lead-in, self-controlled trials to assess comparative effectiveness; (3) addressing limitations of traditional quality of life measures through the use of modified utility collection approaches; (4) adjusting cost offsets from gene therapies with caution; (5) considering outcome-based contracting to address uncertainties about prices and long-term outcomes; and (6) presenting societal and healthcare system perspectives in parallel.

Factor VIII protein (FVIII) as a coagulation replacement factor has for decades been used as the standard of care for management of people with haemophilia A. It is effective for treatment of bleeding events, as prophylaxis to prevent bleeding events and preserve joint function, and to support surgery in people with haemophilia A. Despite long experience in treating haemophilia A, we are only beginning to understand the functions of FVIII beyond its established role as a coenzyme to factor IXa to expedite thrombin generation through the intrinsic pathway of coagulation. Here, we review the current role of FVIII coagulant (FVIII:C) in haemophilia A management and emerging evidence for the role of FVIII across multiple systems, including the cardiovascular system, angiogenesis and maintenance of bone health. For instance, supraphysiological FVIII levels are a risk factor for venous thromboembolism. von Willebrand factor (VWF), which forms a non-covalent complex with circulating FVIII, is an established marker and regulator of angiogenesis. In a mouse model of haemophilia, treatment with FVIII decreased expression of receptor activator of nuclear factor kappa-Β ligand (RANKL), a marker for bone turnover. Longitudinal follow-up data in people with haemophilia A are needed to confirm and extend these observations.

Essentials Assays are needed to aid in the diagnosis of platelet dysfunction in the neonatal population. We developed small-volume assays to assess neonatal platelet activation and aggregation. Compared to adult platelets, neonatal platelet activation and secretion was reduced. The extent of neonatal and adult platelet adhesion and aggregate formation were similar. SummaryBackground Acquired and inherited bleeding disorders may present in the neonatal period with devastating lifelong effects. Diagnosing bleeding disorders in the neonatal population could aid in preventing and treating the associated complications. However, currently available platelet function testing is limited in neonates, owing to difficulties in obtaining an adequate blood volume, a lack of normal reference ranges, and an incomplete understanding of the neonatal platelet functional phenotype. Objective To develop small-volume, whole blood platelet function assays in order to quantify and compare neonatal and adult platelet function. Methods and Results Peripheral blood was obtained from healthy, full-term neonates at 24 h of life. Platelet activation, secretion and aggregation were measured via flow cytometry. Platelet adhesion and aggregation were assessed under static and flow conditions. As compared with adult platelets, peripheral neonatal platelet P-selectin expression and integrin glycoprotein IIbIIIa activation were significantly reduced in response to the G-protein-coupled receptor (GPCR) agonists thrombin receptor activator peptide-6 (TRAP-6), ADP, and U46619, and the immunoreceptor tyrosine-based activation motif (ITAM) signaling pathway agonists collagen-related peptide (CRP) and rhodocytin. Neonatal platelet aggregation was markedly reduced in response to TRAP-6, ADP, U46619, CRP and rhodocytin as compared with adult platelets. The extents of neonatal and adult platelet adhesion and aggregate formation under static and shear conditions on collagen and von Willebrand factor were similar. Conclusions As compared with adult platelets, we found that neonatal platelet activation and secretion were blunted in response to GPCR or ITAM agonists, whereas the extent of neonatal platelet adhesion and aggregate formation was similar to that of adult platelets.

SummaryBackground Vatreptacog alfa, a recombinant human factor VIIa (rFVIIa) analog developed to improve the treatment of bleeds in hemophilia patients with inhibitors, differs from native FVIIa by three amino acid substitutions. In a randomized, double-blind, crossover, confirmatory phase III trial (adept™2), 8/72 (11%) hemophilia A or B patients with inhibitors treated for acute bleeds developed anti-drug antibodies (ADAs) to vatreptacog alfa. Objectives To characterize the formation of anti-vatreptacog alfa ADAs in hemophilia patients with inhibitors. Methods/patients This was a post hoc analysis of adept™2. Immunoglobulin isotype determination, specificity analysis of rFVIIa cross-reactive antibodies, epitope mapping of rFVIIa single mutant analogs and pharmacokinetic (PK) profiling were performed to characterize the ADAs. Results Immunoglobulin isotyping indicated that the ADAs were of the immunoglobulin G subtype. In epitope mapping, none of the rFVIIa single mutant analogs (V158D, E296V or M298Q) contained the complete antibody epitope, confirming that the antibodies were specific for vatreptacog alfa. In two patients, for whom PK profiling was performed both before and after the development of ADAs, vatreptacog alfa showed a prolonged elimination phase following ADA development. During the follow-up evaluation, the rFVIIa cross-reactivity disappeared after the last vatreptacog alfa exposure, despite continued exposure to rFVIIa as part of standard care. Conclusions Results from the vatreptacog alfa phase III trial demonstrate that the specific changes made, albeit relatively small, to the FVIIa molecule alter its clinical immunogenicity.

Objectives There is limited understanding of the effects of bleeding episodes on the daily lives of patients with congenital hemophilia with inhibitors and their caregivers. This analysis of the Dosing Observational Study in Hemophilia examined the impact of acute bleeding episodes on work, school, and family activities. Methods Patients and caregivers participated in a diary study for 90 or more days or until patients experienced four bleeding episodes. All bleed treatments, interference with daily activities, and quality-of-life assessments were captured in daily records. Patients and caregivers reported planned workdays or school days eligible to be "lost" so as to differentiate from days lost because of disability or nonworking status, weekends, and vacations. Results Diaries were completed for 39 patients (18 adults and 21 children). Bleeding episodes that continued for 3 or more days (16.4%) accounted for most of the major changes to family plans. For the 38 patients with bleeding episodes, 47% of 491 bleed days fell on planned workdays or school days; the remainder fell on weekends, holidays, or nonworkdays or non–school days and therefore did not count as "lost days." Patients reported a loss of productivity on a greater percentage of eligible bleed days than did caregivers (3.9% vs. 0.8%, respectively). Patients and caregivers reported 13.5%/9.3% fully missed and 3.5%/7.6% partially missed days. Conclusions This study demonstrated that in hemophilia with inhibitors, bleeding episodes interfere with the daily activities of patients and their caregivers. Furthermore, documenting only lost days underestimated the impact of bleeding episodes because of the high percentage of days without planned work or school.

IntroductionQuality-of-life (QOL) assessments in frequently bleeding patients with congenital hemophilia with inhibitors and their families are confounded by preexisting arthropathy and family circumstances. Periodic QOL assessments typically made on nonbleed days may not provide complete reflections of the burden on patients/families.AimTo evaluate the impact of bleeding episodes on patients/caregivers/families and the association between monthly QOL scores and patients' average diary experiences.MethodsFrequently bleeding inhibitor patients (≥four bleeds in 3 months), or their caregivers, provided daily assessment of EuroQol five-dimensional questionnaire and EuroQol five-dimensional questionnaire visual analogue scale, pain (11-point Likert scale), and family anxiety/stress/activity change over 3 to 6 months. QOL scores were stratified by bleed/nonbleed days.ResultsPatient QOL assessments were recorded by 37 of the 39 enrolled patients/caregivers (3771 of 3777 eligible dairy days, 472 bleed/3299 nonbleed days). Median (range) diary duration was 91 (66–180) days, with 8.2% (0%–72.2%) bleed days. Mean health scores were significantly worse on bleed days than on nonbleed days (P < 0.0001 for all): EuroQol five-dimensional questionnaire index, 0.66 versus 0.82; visual analogue scale health, 69.7 versus 77.4; and pain score, 4.1 versus 1.8. Bleed days also had higher (P < 0.001) proportions of days with abnormalities in family anxiety/stress (42% vs. 30%) and family activity changes (34% vs. 21%).ConclusionsAssessing the impact of hemophilia with inhibitors on patient/family QOL typically includes periodic (likely nonbleed day) evaluations reflecting baseline abnormalities. Daily assessment, however, indicated that frequent acute bleeds impair QOL beyond patient's nonbleed day baseline. New approaches are required to assess the cumulative impact of frequent acute bleeds on patients and their families.

Context As life expectancy in individuals with congenital hemophilia approaches that of the general population, we hypothesize that public health risks, including overweight and obesity, also follow a similar trend. Evidence acquisition A search of the literature included terms relating to overweight, sequelae of being overweight, and hemophilia. Studies were included if they reported the frequency or clinical significance of known complications of overweight and obesity, including musculoskeletal disease, aerobic capacity, cardiovascular disease, diabetes, hyperlipidemia, decreased quality of life, and change in pharmacokinetics of infused clotting factor in hemophilia. Recommendations from medical organizations were searched for preventive and management strategies applicable to this population. Evidence synthesis Overweight and obesity are now more prevalent in the hemophilia population than previous generations, with rates similar to and, in certain subsets even higher, than that of the general population. Increased BMI leads to limitations in joint range of motion in the general population and even more so in persons with hemophilia. Conclusions Overweight and obesity in hemophilia are an increasing problem. Simple steps can be taken to encourage patients to decrease caloric intake and increase physical activity. Prevention and management of overweight, obesity, and their sequelae must be addressed in clinical practice in order to maximize the overall health of the hemophilia population.