Occurrence of hemophilia in the United States. The Hemophilia Surveillance System Project Investigators

Application of machine learning approaches for predicting hemophilia A severity

BACKGROUND

Hemophilia A (HA) is an X-linked congenital bleeding disorder, which leads to deficiency of clotting factor (F) VIII. It mostly affects males, and females are considered carriers. However, it is now recognized that variants of F8 in females can result in HA. Nonetheless, most females go undiagnosed and untreated for HA, and their bleeding complications are attributed to other causes. Predicting the severity of HA for female patients can provide valuable insights for treating the conditions associated with the disease, such as heavy bleeding.

OBJECTIVES

To predict the severity of HA based on F8 genotype using a machine learning (ML) approach.

METHODS

Using multiple datasets of variants in the F8 and disease severity from various repositories, we derived the sequence for the FVIII protein. Using the derived sequences, we used ML models to predict the severity of HA in female patients.

RESULTS

Utilizing different classification models, we highlight the validity of the datasets and our approach with predictive F1 scores of 0.88, 0.99, 0.93, 0.99, and 0.90 for all the validation sets.

CONCLUSION

Although with some limitations, ML-based approaches demonstrated the successful prediction of disease severity in female HA patients based on variants in the F8. This study confirms previous research findings that ML can help predict the severity of hemophilia. These results can be valuable for future studies in achieving better treatment and clinical outcomes for female patients with HA, which is an urgent unmet need.

Race and ethnicity reporting and representation in hemophilia clinical trials

ABSTRACT

Racial and ethnic representativeness in clinical trials is crucial to mitigate disparities in outcomes; however, diversity among hemophilia trials is unknown. The aim of this study is to examine the reporting and representation of race and ethnicity in trials of people with hemophilia (PwH). In this cross-sectional study, the ClinicalTrials.gov database was queried in April 2023 for interventional clinical trials involving PwH between 2007 and 2022. The distribution of participants (observed) was compared with expected proportions based on US Hemophilia Treatment Center (HTC) and country-specific census data with observed-to-expected ratios (OERs). Of 129 trials included, 94.6% were industry sponsored, with a mean of 62 participants and mean age of 26.8 years. Overall, 52.0% (n = 66) of trials reported data on race and ethnicity, increasing from 13.9% in 2007-2012 to 22.5% in 2013-2016 to 100% in 2017-2022 (P = .001). Among these 66 trials, 65.8%, 22.8%, 5.1%, 3.9% of participants were White, Asian, Hispanic, and Black, respectively. OERs were 10% to 20% lower for White participants vs US HTC, and US, UK, and Canadian census populations and ∼75% lower for Black or Hispanic participants when compared with US HTC and US census population. OERs for Asian participants were 1.6 to 3 times higher than Canada, US, and UK census populations. The reporting of race and ethnicity in hemophilia trials has drastically improved; however, Black and Hispanic PwH remain especially underrepresented. To address these disparities, stakeholders across the clinical trial enterprise need to implement strategies to ensure equitable participation.

Exploiting urine-derived induced pluripotent stem cells for advancing precision medicine in cell therapy, disease modeling, and drug testing

The field of regenerative medicine has witnessed remarkable advancements with the emergence of induced pluripotent stem cells (iPSCs) derived from a variety of sources. Among these, urine-derived induced pluripotent stem cells (u-iPSCs) have garnered substantial attention due to their non-invasive and patient-friendly acquisition method. This review manuscript delves into the potential and application of u-iPSCs in advancing precision medicine, particularly in the realms of drug testing, disease modeling, and cell therapy. U-iPSCs are generated through the reprogramming of somatic cells found in urine samples, offering a unique and renewable source of patient-specific pluripotent cells. Their utility in drug testing has revolutionized the pharmaceutical industry by providing personalized platforms for drug screening, toxicity assessment, and efficacy evaluation. The availability of u-iPSCs with diverse genetic backgrounds facilitates the development of tailored therapeutic approaches, minimizing adverse effects and optimizing treatment outcomes. Furthermore, u-iPSCs have demonstrated remarkable efficacy in disease modeling, allowing researchers to recapitulate patient-specific pathologies in vitro. This not only enhances our understanding of disease mechanisms but also serves as a valuable tool for drug discovery and development. In addition, u-iPSC-based disease models offer a platform for studying rare and genetically complex diseases, often underserved by traditional research methods. The versatility of u-iPSCs extends to cell therapy applications, where they hold immense promise for regenerative medicine. Their potential to differentiate into various cell types, including neurons, cardiomyocytes, and hepatocytes, enables the development of patient-specific cell replacement therapies. This personalized approach can revolutionize the treatment of degenerative diseases, organ failure, and tissue damage by minimizing immune rejection and optimizing therapeutic outcomes. However, several challenges and considerations, such as standardization of reprogramming protocols, genomic stability, and scalability, must be addressed to fully exploit u-iPSCs' potential in precision medicine. In conclusion, this review underscores the transformative impact of u-iPSCs on advancing precision medicine and highlights the future prospects and challenges in harnessing this innovative technology for improved healthcare outcomes.

Risk of Intracranial Hemorrhage in Persons with Hemophilia A in the United States: Real-World Retrospective Cohort Study Using the ATHNdataset

Introduction

Intracranial hemorrhage (ICH), a serious complication in persons with hemophilia A (PWHA), causes high rates of mortality and morbidity. Identified ICH risk factors from patient data spanning 1998-2008 require reassessment in light of changes in the current treatment landscape.

Aim and methods

PWHA identified in the ATHNdataset were evaluated retrospectively to assess incidence of ICH and determine the association between ICH risk and key characteristics using time-to-event analyses (Cox proportional-hazards models, survival curves, and sensitivity analyses).

Results

Over a median follow-up time of 10.7 patient-years, 135 of 7837 PWHA over 2 years of age in the ATHNdataset (1.7%) experienced an ICH. Stratification by prophylaxis status and inhibitor status resulted in an incidence rate (IR) ratio (IRR) (IR+/IR-) of 0.63 (95% confidence interval [CI], 0.43-0.94; P=0.020) and 1.76 (95% CI, 0.97-3.20; P=0.059), respectively. Characteristics associated with greater risk of developing ICH include being aged 2-12 years; being covered by Medicaid; having had HIV, hepatitis C, or hypertension; and never having received factor VIII or prophylactic treatment. In multivariable analysis with interaction, the estimated hazard ratio for PWHA never receiving prophylaxis was 7.67 (95% CI, 2.24-26.30), which shrunk to 2.03 (95% CI, 1.30-9.12) in bootstrapping analysis and 3.09 in the highest-penalty ridge-regression analysis but was still significant. Inhibitor status was found not to be statistically associated with ICH in all analyses.

Conclusion

These results align with previous studies demonstrating that prophylaxis confers a protective effect against ICH. Previously, inhibitor positivity had been shown to increase risk for ICH; however, this study did not corroborate those findings.

Personalized Prophylaxis with myPKFiTCE: A Real-World Cost-Effectiveness Analysis in Haemophilia A Patients

Background and Objectives: This study aimed to assess the effectiveness and costs associated with pharmacokinetics-driven (PK) prophylaxis based on the myPKFiT® device in patients affected by hemophilia A (HA) in Italy. Materials and Methods: An observational retrospective study was conducted in three Italian hemophilia centers. All patients with moderate or severe HA, aged ≥ 18 years, capable of having PK estimated using the myPKFiT device, and who had had a clinical visit between 1 November 2019 and 31 March 2022 were included. Differences in clinical, treatment, health resources, and cost data were assessed comparing post-PK prophylaxis with pre-PK. The incremental cost-effectiveness ratio (ICER) was estimated as cost (EUR) per bleed avoided. Results: The study enrolled 13 patients with HA. The mean annual bleeding rate decreased by -1.45 (-63.80%, p = 0.0055) after the use of myPKFiT®. Overall, the consumption of FVIII IU increased by 1.73% during follow-up compared to the period prior the use of the myPKFiT. Prophylaxis based on the myPKFiT resulted in an ICER of EUR 5099.89 per bleed avoided. Conclusions: The results of our study support the idea that the use of PK data in clinical practice can be associated with an improvement in the management of patients, as well as clinical outcomes, with a reasonable increase in costs.

Application of peripherally inserted central catheter in immune tolerance induction treatment of children with hemophilia A and accompanying inhibitors in China

OBJECTIVE

To explore the feasibility, safety and cost effectiveness of the use of peripherally inserted central catheter (PICC) in children with hemophilia A and inhibitors who underwent ITI treatment.

METHOD

This retrospective cohort study evaluated the effect of PICC placement and ITI on bleeding rates, costs, and parents' satisfaction before and within 6 months after PICC placement in children with hemophilia A and inhibitors.

RESULTS

A total of 20 children with hemophilia A and high-titer inhibitors were included, with a success rate for PICC placement of 100%, at a cost of ¥6730.50. Parents' satisfaction with PICC was 100%, and the total length of catheter indwelling was 6055 days. In terms of curative effect, the success rate of ITI treatment was 75%, and the annualized bleeding rate was decreased from 10.90 ± 12.16 times before placement to 2.10 ± 3.32 times (p < 0.05). The transportation expense for children and their parents to the clinic decreased from ¥20,920 ± 32,274.57 before catheter placement to ¥2915 ± 2195.99 (p < 0.05). Time of children missed school and their parents missed work decreased from 10.85 ± 22.36 days to 1.90 ± 3.58 (p < 0.05) days and 40.33 ± 46.11 days to 3.83 ± 7.11 days (p < 0.05), respectively.

CONCLUSION

The use of PICC for ITI treatment in children with hemophilia A and accompanying inhibitors in developing countries (e.g. China) can ensure the effect of ITI, reducing expense and improving the quality of life without obvious side effects.

Race, ethnicity, and immune tolerance induction in hemophilia A in the United States

Background

In racially diverse communities, treatment of chronic diseases can vary across racial and ethnic groups.

Objectives

To examine healthcare disparities in hemophilia care in the United States by evaluating receipt of immune tolerance induction (ITI) among different racial and ethnic groups.

Methods

In this cross-sectional study, people with severe hemophilia A with an inhibitor who entered the Center for Disease Control and Prevention Community Counts registry between 2013 and 2017, were aged ≥5 years at study entry, and had a history of an inhibitor (n = 614) were included. The proportion of participants receiving ITI was examined according to race and ethnicity in bivariable analysis and multivariable analysis adjusting for demographic and clinical covariates. Unadjusted and adjusted prevalence ratios and corresponding 95% CIs were computed.

Results

Among 614 participants included in the study, 56.4% were non-Hispanic (NH) White, 19.7% were NH Black, 18.4% were Hispanic, and 4.9% were Asian. ITI was received by 85.2% of participants. On bivariable analysis, ITI treatment did not vary by race or ethnicity. On multivariable analysis, NH Black and Hispanic participants were significantly less likely to receive ITI compared to NH White participants (adjusted prevalence ratio, 0.91 [95% CI, 0.84-0.99] and 0.84 [95% CI, 0.75-0.93], respectively).

Conclusion

Although the role of ITI may evolve with growing use of emicizumab and the introduction of new hemophilia treatment products, understanding characteristics that influence care, particularly race and ethnicity, where physician bias and patient mistrust can occur, will remain relevant and applicable to other complex therapies, including gene therapy.

Racial and ethnic differences in reported haemophilia death rates in the United States

INTRODUCTION

People with haemophilia's life expectancies have improved over time. Whether progress has been experienced equitably is unknown.

AIM

To examine recorded haemophilia death (rHD) rates according to race and ethnicity in the United States (US).

METHODS

In this cohort study, rHDs were examined with US National Vital Statistics' 1999-2020 Multiple Cause-of-Death data. rHD was defined as having a haemophilia A (D66) or B (D67) ICD-10 code in the death certificate (underlying or multiple causes of death). Age-adjusted rHD rates were compared with age-adjusted rate ratios (aRR) and 95% Confidence Intervals (CI).

RESULTS

There were 3115 rHDs in males with an rHD rate of 0.98 per 1 million males. Between 1999 and 2020, rHD rates declined by 46% in NH (Non-Hispanic) White, 44% in NH Black (aRR = 0.56, 95%CI 0.43, 0.74), and 42% in Hispanic (aRR = 0.58, 95%CI 0.39, 0.88) males. However, rHD rates remained higher and were on average 30% greater in NH Black versus NH White males (aRR = 1.30 95% CI 1.16, 1.46). Among males with rHD, the median age at death rose from 54.5 to 65.5 years between 1999 and 2020 and was 12 years lower in NH Black (56 years) versus NH White (68 years) males in 2010-2020. There were 930 females with rHD, with an age-adjusted rate of 0.22 per 1 million females, which was consistent between 1999 and 2020.

CONCLUSION

Reported haemophilia-death rates improved in males across all race/ethnicities, but rates were higher Black versus White males. Given the inherent limitations of the current study's data source, further investigation of survival rates and disparities in haemophilia are needed.

The Use of Bypassing Treatment Strategies in Hemophilia and Their Effect on Laboratory Testing

Factor VIII and IX inhibitors in congenital hemophilia A and B, respectively, neutralize the infused coagulation factor concentrate rendering them ineffective. Bypassing agents (BPAs) that circumvent the block imposed by the inhibitors are used for the prevention and management of bleeding. Activated prothrombin complex concentrate was the original BPA, recombinant activated factor VII was then introduced, and more recently nonfactor agents that target the procoagulant and anticoagulant systems have been developed and are in clinical use (e.g., emicizumab, a bispecific antibody for hemophilia A). Other BPAs are in clinical trials (e.g., fitusiran targets antithrombin, concizumab and marstacimab target tissue factor pathway inhibitor, and SerpinPC targets activated protein C). The BPAs have a varied effect on coagulation assays, and as more patients are exposed to these agents, it is important to be aware of the effects. Herein, we present an overview of the effect of BPAs on routine and specialized coagulation assays including thrombin generation and viscoelastic assays.

Perioperative Management of Spontaneous Intracranial Hemorrhage in a Patient With Hemophilia A in a Resource Limited Country

Intracranial hemorrhage (ICH) is a serious complication of hemophilia A with high morbidity and mortality. The management of such cases is complicated by nonspecific and often delayed presentation, increased frequency of rebleeding, low awareness regarding clotting factor replacement, and debate regarding the efficacy of surgical interventions. We report a case of an 18-year-old male patient with hemophilia A, who first presented to the emergency department in India in a comatose state. Neuroimaging revealed subdural hematoma with midline shift and uncal herniation. The patient was successfully managed with perioperative cryoprecipitate and factor VIII replacement, tiered intracranial pressure lowering strategies, and early decompressive craniectomy with clot evacuation. In India, there are no standardized guidelines for screening and routine care for hereditary diseases like hemophilia. In a resource-deficient country, management was complicated by the limited availability of factor VIII in the emergent setting, as well as the inability to obtain serial factor levels in the postoperative period. We hope that this article helps to guide the management of ICH and hemophilia in resource-limited countries.

Testing strategies used in the diagnosis of rare inherited bleeding disorders

INTRODUCTION

Rare Bleeding Disorders have a low population prevalence and may not be recognized by most clinicians. In addition, knowledge gaps of the indicated laboratory tests and their availability add to the potential for delayed diagnosis or misdiagnosis. The lack of widely available commercial, regulatory body approved esoteric tests limit them to reference laboratories, thus limiting easy access for patients.

AREAS COVERED

A literature search of Pubmed, Medline, Embase and review of international society guidelines was performed. Additional references from published articles were reviewed. A patient-centered approach to recognition and evaluation of RBD is discussed.

EXPERT OPINION

Recognition of RBD relies on obtaining a detailed patient personal and family hemostatic history. Inquiry into a history of involvement of other organ systems is important and if present should lead to suspicion of an inherited platelet disorder or a variant of Ehlers Danlos Syndrome. Multiple factors contribute to the complexity of development of efficient algorithms for diagnostic testing. Limitations in diagnostic sensitivity and specificity of screening tests, diagnostic tests, and esoteric tests further compound the complexity of establishing a diagnosis. Educational efforts focusing on clinician awareness of RBDs and available testing options are vital for optimal management of such patients.

Hemorrhagic and thrombotic adverse events associated with emicizumab and extended half-life factor VIII replacement drugs: EudraVigilance data of 2021

BACKGROUND

Safety concerns for an increased risk of thrombotic complications in patients with hemophilia A have been pointed out, particularly during nonreplacement treatment with emicizumab and concomitant bypassing agents. Surveillance with the Roche Global Database reporting adverse events for emicizumab has been discontinued on May 2021.

OBJECTIVES

The objective of this study was to evaluate the reporting rate of hemorrhagic and thrombotic adverse drug reactions (ADRs) associated with nonreplacement (emicizumab) and replacement extended half-life (EHL) factor VIII (FVIII) products as retrieved from the EudraVigilance database.

METHODS

Total ADR reported during treatment with emicizumab or EHL FVIII products from January 1 to December 31, 2021, were collected. The proportional reporting ratio and the reporting odds ratio (ROR) with their 95% CIs were calculated to express the hemorrhagic and thrombotic ADR reporting frequency ratio between emicizumab and EHL FVIII products.

RESULTS

Overall, 406 and 376 ADRs were reported for emicizumab and for EHL FVIII products, respectively. Hemorrhagic and thrombotic ADRs were 232 and 24 for emicizumab and 275 and 9 for the EHL FVIII products. Approximately 25% of thrombotic ADRs were reported concomitantly with eptacog alfa. ROR of 0.49 (95% CI, 0.36-0.66) for hemorrhagic and of 2.56 (95% CI, 1.18-5.59) for thrombotic ADRs were obtained for emicizumab compared with EHL FVIII products.

CONCLUSION

The analysis of 2021 EudraVigilance reports shows a lower reporting rate of hemorrhagic ADR vs a higher reporting rate of thrombotic ADR for emicizumab than for EHL FVIII products. These signals stress the importance of monitoring novel drugs in hemophilia, particularly when administered in association with bypassing agents.

Healthcare costs among hemophilia A patients in the United States treated with rurioctocog alfa pegol (FVIII-PEG) or antihemophilic factor (recombinant), FC fusion protein (rFVIIIFc) using real-world data

AIMS

To compare healthcare costs in patients with non-inhibitor hemophilia A treated with Rurioctocog Alfa Pegol (FVIII-PEG) versus Antihemophilic Factor (Recombinant), FC Fusion Protein (rFVIIIFc).

MATERIALS AND METHODS

Administrative claims data from the Merative MarketScan Commercial (Commerical) and Medicaid (Medicaid) databases were used for these analyses. Males with non-inhibitor hemophilia A treated with FVIII-PEG or rFVIIIFc from 1 January 2016 to 31 March 2021 were identified (earliest treatment = index). Patients were required to have continuous database enrollment for six months before and after the index date. Follow-up was variable in length until disenrollment or study end. All-cause and hemophilia-related healthcare costs were reported per-patient per month [PPPM] and the average weekly dose during follow-up was compared between treatment groups. Generalized linear regressions were used to estimate multivariable-adjusted differences in total costs and weekly dosage in the two treatment groups.

RESULTS

A total of 131 FVIII-PEG (66 Commercial; 65 Medicaid) and 204 rFVIIIFc (111 Commercial; 93 Medicaid) patients were eligible. Mean age was 20.5 and 24.4 for FVIII-PEG and rFVIIIFc in Commercial and 14.9 and 17.5 for FVIII-PEG and rFVIIIFc in Medicaid. PPPM mean (standard deviations [SD]) total healthcare costs in Commercially insured patients were $35,868 [$21,717] for FVIII-PEG vs $40,424 [$25,882] for rFVIIIFc. Costs in Medicaid were $27,495 [$23,243] for FVIII-PEG vs $30,237 [$28,430] for rFVIIIFc. After adjusting for baseline characteristics, the costs for rFVIIIFc (vs FVIII-PEG) were higher by $5,215 in Commercial and $3,895 in Medicaid, but the differences were not statistically significant (p > 0.05). Similar findings were observed for hemophilia-specific healthcare costs. The adjusted mean weekly dose was 6,047 vs 4,892 IU, p = 0.21 for FVIII-PEG vs rFVIIIFc in Commercial and 5,549 vs 7,228 IU, p = 0.07 for FVIII-PEG vs rFVIIIFc in Medicaid.

CONCLUSIONS

Healthcare costs and treatment dosing were similar (p > 0.05) for non-inhibitor hemophilia A patients treated with FVIII-PEG and rFVIIIFc.

Proof-of-Concept Study of a 3-D Ultrasound Scanner Used for Ankle Joint Assessment

Joint arthropathies often require continuous monitoring of the joint condition, typically performed using magnetic resonance (MR) or ultrasound (US) imaging. US imaging is often the preferred screening or diagnostic tool as it is fast and inexpensive. However, conventional 2-D US has limited capability to compare imaging results between examinations because of its operator dependence and challenges related to repeat imaging in the same location and orientation. Comparison between several imaging sessions is crucial to assess the interval progression of joint conditions. We propose a novel 3-D US scanner for ankle joint assessment that can partially overcome these issues by enabling 3-D imaging. Here, we (i) present the design of the 3-D US ankle scanner system, (ii) validate the geometric reconstruction accuracy of the system, (iii) provide preliminary images of healthy volunteer ankles and (iv) compare 3-D US imaging results with MR imaging. The 3-D ankle scanner consists of a tub filled with water, a linear US probe attached to the wall of the tub and a motorized unit that rotates the US probe 360° around the center of the tub. As the probe rotates, a 3-D US image is formed of the ankle of the patient positioned in the middle of the tub. US probe height, angle and distance from the tub center can be adjusted. The reconstruction accuracy of the system was validated in each of the coordinate directions at different probe angles using two test phantoms. A phantom consisting of numerous Ø200-µm nylon threads with known spacing and a metal rod with machined grooves was used for validation in the horizontal and vertical directions, respectively. The volumetric reconstruction accuracy validation was performed by imaging an agar phantom with two embedded spheres of known volumes and comparing the segmented sphere volume and surface area with the expected. Three-dimensional US and MR images of both ankles of five healthy volunteers were acquired. Distal tibia and proximal talus were segmented in both imaging modalities and the surfaces of these segmentations were compared using the 95% Hausdorff and mean surface distances. The observed mean linear measurement error in all the coordinate directions and over several probe angles was 2.98%. The mean measured volumetric measurement error was 3.45%. The volunteer study revealed useful features for joint assessment present in the 3-D ankle scanner images, such as joint spacing, distal tibia and proximal talus. The mean 95% Hausdorff and mean surface distances between segmentations in 3-D US and MR images were 5.68 ± 0.83 and 2.01 ± 0.30 mm, respectively. In this proof-of-concept study, the 3-D US ankle scanner enabled visualization of the ankle joint features that are useful for joint assessment.

Co-administration of FVIII with IVIG reduces immune response to FVIII in hemophilia A mice

Hemophilia A is an X-linked recessive congenital bleeding disorder. Exogenous infusion of FVIII is the treatment of choice, and the development of immunoglobulins against FVIII (inhibitors) remains the major challenge in clinical management of the disease. Here, we investigated the effect of co-administration of FVIII with intravenous immunoglobulin (IVIG) on the development of inhibitors in previously untreated hemophilia A mice. A group of hemophilia A mice (C57BL/6^FVIII-/-) received weekly injections of recombinant human FVIII (rFVIII) for twelve consecutive weeks while a second group received co-injections of rFVIII + IVIG. An in-house enzyme-linked immunosorbent assay (ELISA) was designed to detect antibodies to rFVIII. Every mouse in the first group developed antibodies to rFVIII. In contrast, mice treated with rFVIII + IVIG showed significantly lower antibody titers. Interestingly, when co-administration of IVIG was discontinued after 12 weeks in some mice (rFVIII continued), these mice experienced an increase in antibody titer. In contrast, mice that continued to receive rFVIII + IVIG retained significantly lower titers. In conclusion, prophylactic rFVIII co-administration with IVIG modulated the immune response to FVIII and resulted in decreased anti-FVIII antibody titer. These findings suggest that co-injection therapy with IVIG could potentially be effective in the management of hemophilia A patients at risk of inhibitor development.

A real-world study comparing pre-post billed annualized bleed rates and total cost of care among non-inhibitor patients with hemophilia A switching from FVIII prophylaxis to emicizumab

OBJECTIVE

Factor VIII (FVIII) replacement and emicizumab have demonstrated efficacy for prevention of bleeds among patients with hemophilia A (PwHA) compared to on-demand (OD) use. Evidence investigating clinical outcomes and healthcare costs of non-inhibitor PwHA switching from prophylaxis with FVIII concentrates to emicizumab has not been well-established within large real-world datasets. This study aimed to investigate billed annualized bleed rates (ABR_b) and total cost of care (TCC) among non-inhibitor PwHA switching from FVIII-prophylaxis to emicizumab-prophylaxis.

METHODS

This retrospective, observational study was conducted using IQVIA PharMetrics Plus, a US administrative claims database. The date of first claim for emicizumab was defined as the index date. OD patients and inhibitor patients were excluded. Bleeds were identified using a list of 535 diagnosis codes. Bayesian models were developed to estimate the probability ABR_b worsens and TCC increases after switching to emicizumab. Wilcoxon rank-sum tests were used to test statistical significance of changes in ABR_b and TCC after switch.

RESULTS

Among the 121 identified patients, the difference in mean ABR_b between FVIII-prophylaxis (0.68 [SD = 1.28]) and emicizumab (0.55 [SD = 1.48]) was insignificant (p = .142). The mean annual TCC significantly increased for patients switching from FVIII-prophylaxis ($518,151 [SD = $289,934]) to emicizumab ($652,679 [SD = $340,126]; p < .0001). The Bayesian models estimated a 21.0% probability of the ABR_b worsening and a 99.9% probability of increasing TCC after switch.

CONCLUSIONS

This study found that in male non-inhibitor PwHA, switching from FVIII prophylaxis to emicizumab incurs substantial cost increase with no significant benefit in ABR_b. This evidence may help guide providers, payers, and patients in shared decision-making conversations around best treatment options.

Advances in Hemophilia A Management

Hemophilia A is an inherited insufficiency of Factor VIII (FVIII), one of the critical clotting factors. The gold standard for the management of moderate-to-severe hemophilia A is prophylaxis using regular replacement therapy with clotting factor concentrates. Compared with conventional treatment, extended half-life products reduce the burden of frequent factor replacement injections. Of note, up to 30% of patients with hemophilia A receiving prophylactic factor infusions develop "inhibitors," neutralizing anti-FVIII autoantibodies. Therapeutic options for patients with hemophilia A and inhibitors include the immune tolerance induction (ie, eradication of inhibitors) and the management of acute bleeds with bypassing agents and/or emicizumab. Emicizumab is a biphasic monoclonal antibody mimicking activated FVIII, approved for patients with hemophilia A with/without inhibitors. Gene therapy is an emerging therapy for hemophilia A, essentially curing patients with hemophilia A or transforming them to a milder phenotype by establishing continuous endogenous expression of FVIII after one-time treatment.

Health care utilization and expenditures of parents of children with and without hemophilia A

BACKGROUND: Caring for children with hemophilia A (HA) impacts many aspects of parents' lives. How this translates to caregivers' utilization of health services is unknown, and its elicitation can inform future evaluations of interventions that address caregiver burden for HA. OBJECTIVE: To understand the impact of caring for children with HA on parents' utilization of nonmental and mental health services by comparing 1-year costs and number of claims with parents of children without HA. METHODS: Retrospective matched cohort study using MarketScan commercial medical and pharmacy claims from 2011 to 2019. Children with HA were male sex, aged younger than 18 years, dependent policyholders, and had at least 1 HA-related medical claim from 2011 to 2018 and either an HA-related procedure or drug claim. Parents of children with HA (PCH) were primary or secondary policyholders, shared the same family ID as children with HA, and were continuously enrolled for 1-year post-index. PCH were matched (1:2) with parents of children without HA on age, sex, beneficiary type, child's age, number of children, index month and year, health plan type, employment status, and region. Primary outcomes were nonmental and mental health care costs (2020 US dollars). Secondary outcomes were number of nonmental health outpatient claims and utilization of mental health outpatient or drug claim. Subgroup analyses excluding parents with HA were also conducted. Productivity loss was also explored. Outcomes were compared using 2-sided, paired t-tests, and McNemar test. RESULTS: 1,068 PCH met inclusion criteria and were matched to 2,122 control parents. Mean 1-year cost for PCH was higher for nonmental health (mean difference $1,826 [95% CI = -1,000 to 4,652; P = 0.20]) and similar for mental health services (mean difference $14 [95% CI = -77 to 105; P = 0.76]). When parents with HA were excluded in the subgroup analyses, mental health cost was significantly higher for PCH (mean difference $676 [95% CI = 399 to 953; P < 0.001]). PCH had more nonmental health outpatient claims compared with parents of children without HA (mean difference 1.9 [95% CI = -1.1 to 4.9; P = 0.21]) and were 1.2 times (95% CI = 0.99 to 1.45; P = 0.07) more likely to have a mental health outpatient or drug claim. CONCLUSIONS: PCH had moderately higher health care costs and utilization compared with parents of children without HA; however, these results were not statistically significant. Future studies to better characterize HA disease severity and assess its impact on caregiver burden or to expand caregivers to spouses of adult patients with HA may be warranted. Limitations include inability to ascertain severity of HA in children and the use of claims data to capture complex effects on health care utilization. DISCLOSURES: Dr. Kim's postdoctoral fellowship is supported by Genentech, Inc. Dr. Raimundo is an employee of Genentech, Inc.

Resource utilization and treatment costs of patients with severe hemophilia A: Real‐world data from the ATHNdataset

Hemophilia A is characterized by unpredictable spontaneous bleeds and chronic comorbidities. However, limited data exists at the national level into detailed management patterns related to patient clinical characteristics, representative real‐world dosing and treatment frequency, and costs. To assess and characterize the US severe hemophilia A (SHA) population, including subgroups of patients, in terms of clinical and demographic characteristics, healthcare resource utilization received at hemophilia treatment centers (HTCs), and projected annual costs of treatment utilizing data from the ATHNdataset of the American Thrombosis and Hemostasis Network (ATHN). Adult male people with SHA (PwSHA) (FVIII < 1%) were identified in the ATHNdataset between January 2013 and September 2019. This retrospective cohort study described patients’ demographic and clinical characteristics, clinical history, as well as the HTC‐related health resource utilization (HRU), treatment utilization, and projected annual treatment costs of US PwSHA received over the most recent year. Results are reported for the overall population and for three mutually exclusive subpopulations of patients: PwSHA with a history of and/or current inhibitors, PwSHA without a history of inhibitors but with (or a history of) one or more transfusion‐transmitted infections (hepatitis B virus [HBV], hepatitis C virus [HCV], or human immunodeficiency virus [HIV]), and PwSHA without a history of inhibitors or of transfusion‐transmitted infections (HBV, HCV, or HIV). Of the overall PwSHA cohort (N = 3677), there was a high prevalence of HCV (24.1%) and HIV (13.7%), while the prevalence of HBV (4.9%) was lower. Note that 20.5% of PwSHA overall currently or ever had FVIII inhibitors. On average, PwSHA had 2.8 total HTC visits per year, including 0.9 comprehensive care visits, 1.1 telephone contact visits, 0.5 office visits, and 0.1 surgeries or other procedures. However, 23.3% of PwSHA were not seen at an HTC, and 33.8% of PwSHA did not have a comprehensive care visit during their most recent year of data. HTC‐related HRU was similar between the overall cohort and across the patient subpopulations, although PwSHA and inhibitors had more frequent HTC visits (a mean of 3.6 visits annually vs. 2.5–2.8 in the other groups). Using reported treatment frequency and dosing, estimated mean annual hemophilia treatment costs varied by treatment and across the three subpopulations: extended half‐life factor product ($893,609–934,301 by subpopulation), standard half‐life factor product ($798,700–930,812), plasma‐derived factor product ($613,220–801,061), and non‐factor product treatment ($765,289—833,240). This study summarized recent sociodemographic and clinical characteristics, HTC‐related HRU, and HA treatments and projected costs among adult PwSHA, including among key subpopulations of PwSHA. PwSHA experience substantial clinical and resource burden on a chronic basis, despite the care coordination efforts of ATHN‐affiliated HTCs. These findings motivate further exploration of the drivers of resource utilization, observed differences across subpopulations and other disparities, and ongoing monitoring of clinical and treatment burden in the face of an evolving care landscape.

Comorbidities, Health-Related Quality of Life, Health-care Utilization in Older Persons with Hemophilia—Hematology Utilization Group Study Part VII (HUGS VII)

Purpose

We compare the impact of hemophilia on comorbidities, joint problems, health-related quality of life (HRQoL) and health-care utilization between two age groups: 40–49 years and ≥50 years.

Patients and Methods

The HUGS VII study recruited persons with hemophilia A or B age ≥40 years. Participants completed surveys to collect data on sociodemographic and clinical characteristics, hemophilia treatment regimen, pain, joint problems, comorbidities, HRQoL, depression and anxiety, at baseline and 6-months later. Clinical chart reviews documented hemophilic severity and treatment.

Results

The sample includes 69 males, 65.2% aged ≥50 years, 75.4% with hemophilia A. Individuals ≥50 years were more likely to have mild or moderate hemophilia (68.9% vs 41.7%, P = 0.03) than those 40–49 years old. Among persons with mild/moderate hemophilia, those ≥50 years old reported a higher rate of joint pain (83.9% vs 70.0%, P = 0.34 at baseline, 91.3% vs 57.1%, P = 0.06 at follow up) or range of motion limitation (73.3% vs 60.0%, P = 0.43 at baseline, 73.9% vs 28.6%, P = 0.04 at follow up) than the younger group. Compared to the younger group, the older group reported fewer emergency room visits (4.5% vs 21.7%, P = 0.03), and physical therapy visits (15.9% vs 43.5%, P = 0.01) at baseline. The sample depression rate was 85.7%, but the differences among the age groups were not significant. The mean covariate-adjusted EQ-5D index score was lower in older persons (0.77 vs 0.89, P = 0.02).

Conclusion

Older persons with hemophilia in this sample are over-represented by individuals with mild/moderate disease, potentially due to premature death among those with severe disease. Although this group included a larger proportion of individuals with mild disease than the younger group, they experienced lower quality of life, more comorbidities both of aging and of hemophilic arthropathy, and lower rates of health-care utilization.

Prevention of bleeding after percutaneous biopsy with a small intestinal submucosa hemostatic plug

Percutaneous biopsies (PBs) are the gold standard diagnostic procedures indicated for renal and hepatic disorders. Nevertheless, they can cause hemorrhages and are contraindicated for coagulopathic patients. In this study we designed, fabricated, and evaluated a small intestinal submucosa (SIS) plug to reduce, and potentially cease, bleeding to decrease death risk after percutaneous hepatic and renal biopsies in healthy and coagulopathic in vivo models. First, the plug's blocking capacity was determined with an increase in its diameter of 24 ± 11% after immersion in human blood, and the capacity to induce clotting on its surface. The plug's in vivo performance was evaluated in a healthy porcine model, which showed minimal inflammatory reaction without side effects confirmed by histological results after 30 days. The plug's response in the coagulopathic model was assessed using heparinized swine for 2 days, which revealed localized microhemorrhages and mild inflammatory response without any lesions to the surrounding tissue. No major adverse events nor macroscopic hemorrhages were detected in the animal models. Furthermore, we assessed the plug's efficacy to reduce and stop bleeding using a transplant-discarded human liver model (n = 14). In this case, the mass of blood lost was 43.8 ± 21.8% lower in plugged transplant-discarded human liver biopsies compared to control biopsies without a plug. The bleeding was stopped within three minutes in 92% of plugged cases, but only in 8% of non-plugged cases. We demonstrated the feasibility of making a hemostatic SIS plug, which does not induce major inflammatory reaction and can effectively reduce and stop bleeding after PBs in non-coagulopathic and coagulopathic in vivo models, and in a transplant-discarded human liver model. STATEMENT OF SIGNIFICANCE: Percutaneous biopsy (PB) is a gold standard diagnostic procedure, but it can provoke life-threatening complications and is contraindicated for patients with coagulopathic disorders. This study demonstrates that small intestinal submucosa (SIS) can be manufactured into a biocompatible thrombogenic plug, insertable through a commercial Tru-Cut needle sheath. This device takes advantage of the collagen-rich composition of SIS to stop and reduce bleeding more effectively than the traditional PB, indicating that it could be routinely employed in a traditional biopsy to increase safety, or as a cost and time-reducing alternative to transjugular biopsy for coagulopathic patients.

Port removal in patients receiving emicizumab prophylaxis: A single centre experience and review of the literature

INTRODUCTION

Treatment of patients with Haemophilia A has improved significantly in recent years since the advent of novel therapeutic agents such as emicizumab. The low annualised bleeding rates associated with emicizumab have liberated many patients from the need for central venous access devices (CVAD). Optimal peri-operative management of CVAD removal is not currently known and there are no specific formal recommendations available.

AIM

We reviewed outcomes in a paediatric cohort in our centre undergoing CVAD removal without pre-operative factor or bypassing agent and reviewed the literature regarding port removal in patients on Emicizumab.

METHODS

Ten male patients with severe Haemophilia A underwent CVAD removal without planned administration of factor concentrate or bypassing agent. Patients were monitored in hospital for 24 h with routine laboratory testing pre- and post-operatively.

RESULTS

No significant bleeding episodes occurred in any patient, no patient required factor concentrate or bypassing agent and no patients were readmitted due to bleeding within 7 days of surgery.

CONCLUSION

We propose that, in the era of emicizumab, prophylactic factor administration pre-operatively for elective CVAD removal is not required in the majority of cases.

Hemophilia A Gene Therapy: Current and Next-Generation Approaches

INTRODUCTION

: Hemophilia comprises a group of X-linked hemorrhagic disorders that result from a deficiency of coagulation factors. The disorder affects mainly males and leads to chronic pain, joint deformity, reduced mobility, and increased mortality. Current therapies require frequent administration of replacement clotting factors, but the emergence of alloantibodies (inhibitors) diminishes their efficacy. New therapies are being developed to produce the deficient clotting factors and prevent the emergence of inhibitors.

AREAS COVERED

: This article provides an update on the characteristics and disease pathophysiology of hemophilia A, as well as current treatments, with a special focus on ongoing clinical trials related to gene replacement therapies.

EXPERT OPINION

: Gene replacement therapies provide safe, durable, and stable transgene expression while avoiding the challenges of clotting factor replacement therapies in patients with hemophilia. Improving the specificity of the viral construct and decreasing the therapeutic dose are critical toward minimizing cellular stress, induction of the unfolded protein response, and the resulting loss of protein production in liver cells. Next-generation gene therapies incorporating chimeric DNA sequences in the transgene can increase clotting factor synthesis and secretion, and advance the efficacy, safety, and durability of gene replacement therapy for hemophilia A as well as other blood clotting disorders.

Health insurance coverage and switching among people with hemophilia A in the United States

BACKGROUND: Hemophilia A (HA) is marked by substantial economic burden, including costs of ongoing treatment, increased monitoring, bleed events, and other health care utilization associated with managing the disease and comorbidities related to the disease. Gene therapies and other anticipated breakthrough treatments hold potential to substantially offset long-term traditional factor VIII (FVIII) prophylaxis in specific populations. Fragmentation of the US insurance system, however, may impact payers' approaches to coverage of new treatments, given concerns about patients "switching" insurance and the payer's ability to offset costs over time. OBJECTIVE: To assess insurance coverage and switching across payers among people with severe HA (SHA) using real-world data. METHODS: Adult men with SHA (FVIII measuring < 1%) in the American Thrombosis and Hemostasis Network dataset between January 2013 and September 2019 were identified. Patients' primary insurance category (ie, commercial, Medicaid, Medicare) and insurance switching over time were described. Outcomes included distribution of current primary insurance coverage by category and mean years of coverage per payer for commercially insured patients, including those with 2 or more commercial payers, and for those who switched insurance categories (eg, coverage by a commercial payer and government payer). RESULTS: Among the cohort of patients with SHA (N = 3,677), 51.9% had commercial primary insurance and 29.0% had coverage by Medicaid (including state-funded programs). The mean duration of follow-up in the database was 6.3 years for patients with at least 1 year of follow-up. Among patients who had ever been commercially insured, 74.9% had the same commercial payer for the entire follow-up period. The mean time covered by the same commercial insurance was 4.8 years. Only 7.5% of patients switched insurance categories (eg, from commercial to Medicaid). Among those who switched categories, patients averaged 3.9 years of commercial coverage, 4.0 years of Medicaid coverage, and 4.8 years of Medicare coverage during the follow-up period. CONCLUSIONS: Both commercially and government-insured patients with SHA typically maintain continuous coverage for extended periods, with limited switching between payers and insurance categories over time. These findings suggest that should breakthrough treatments be approved, payers would likely be able to realize substantial cost savings associated with avoiding long-term prophylactic therapies during the several years after treatment. DISCLOSURES: This study was funded by BioMarin Pharmaceutical Inc. Hinds, Chen, and Sammon are employees of BioMarin Pharmaceutical Inc. and own stock/stock options. Solari was an employee of BioMarin Pharmaceutical Inc. at the time of the study. Pezalla is CEO of Enlightenment Bioconsult, LLC. He, Cheng, and Recht are, or were at the time of this study, employees of American Thrombosis and Hemostasis Network (ATHN), which has received ATHNdataset licensing and other fees from BioMarin Pharmaceutical Inc. Research funding to Recht's employers has come from Bayer, BioMarin Pharmaceutical Inc., CSL Behring, Genentech, Grifols, Hema Biologics, LFB, Novo Nordisk, Octapharma, Pfizer, Sanofi, Spark, Takeda, and uniQure. Recht has also worked as a consultant for Catalyst Biosciences, CSL Behring, Genentech, Hema Biologics, Kedrion, Novo Nordisk, Pfizer, Sanofi, Takeda, and uniQure; sits on the board of directors of the Foundation for Women and Girls with Blood Disorders and of Partners in Bleeding Disorders; and is an employee of the Oregon Health & Science University. Data from this study were presented as a poster at AMCP Nexus 2021; October 18-21, 2021; Denver, CO.

Transduction of modified factor VIII gene improves lentiviral gene therapy efficacy for hemophilia A

Hemophilia A (HA) is a bleeding disorder caused by deficiency of the coagulation factor VIII (F8). F8 replacement is standard of care, whereas gene therapy (F8 gene) for HA is an attractive investigational approach. However, the large size of the F8 gene and the immunogenicity of the product present challenges in development of the F8 gene therapy. To resolve these problems, we synthesized a shortened F8 gene (F8-BDD) and cloned it into a lentiviral vector (LV). The F8-BDD produced mainly short cleaved inactive products in LV-transduced cells. To improve F8 functionality, we designed two novel F8-BDD genes, one with an insertion of eight specific N-glycosylation sites (F8-N8) and another which restored all N-glycosylation sites (F8-299) in the B domain. Although the overall protein expression was reduced, high coagulation activity (>100-fold) was detected in the supernatants of LV-F8-N8- and LV-F8-299-transduced cells. Protein analysis of F8 and the procoagulation cofactor, von Willebrand Factor, showed enhanced interaction after restoration of B domain glycosylation using F8-299. HA mouse hematopoietic stem cell transplantation studies illustrated that the bleeding phenotype was corrected after LV-F8-N8 or -299 gene transfer into the hematopoietic stem cells. Importantly, the F8-299 modification markedly reduced immunogenicity of the F8 protein in these HA mice. In conclusion, the modified F8-299 gene could be efficiently packaged into LV and, although with reduced expression, produced highly stable and functional F8 protein that corrected the bleeding phenotype without inhibitory immunogenicity. We anticipate that these results will be beneficial in the development of gene therapies against HA.

Incidence and mortality rates of intracranial hemorrhage in hemophilia: a systematic review and meta-analysis

Intracranial hemorrhage (ICH) is a severe complication that is relatively common among hemophilia patients. This systematic review aimed to obtain more precise estimates of ICH incidence and mortality in hemophilia, which may be important for patients, caregivers, researchers and health policy-makers. PubMed and EMBASE were systematically searched using terms related to "hemophilia" and "intracranial hemorrhage" or "mortality". Studies that allowed calculation of ICH incidence or mortality rates in a hemophilia population of at least 50 patients were included. We summarized evidence on ICH incidence and calculated pooled ICH incidence and mortality in three age groups: (1) persons of all ages with hemophilia, (2) children and young adults below 25 years of age with hemophilia and (3) neonates with hemophilia. Incidence and mortality were pooled with a Poisson-Normal model or a Binomial-Normal model. We included 45 studies that represented 54 470 patients, 809 151 person-years and 5326 live births of hemophilia patients. In persons of all ages, the pooled ICH incidence and mortality rates were 2.3 (95% CI 1.2-4.8) and 0.8 (95% CI 0.5-1.2) per 1000 person-years, respectively. In children and young adults, the pooled ICH incidence and mortality rates were 7.4 (95% CI 4.9-11.1) and 0.5 (95% CI 0.3-0.9) per 1000 person-years, respectively. In neonates, the pooled cumulative ICH incidence was 2.1% (95% CI 1.5-2.8) per 100 live births. ICH was classified as spontaneous in 35-58% of cases. Our findings suggest that ICH is an important problem in hemophilia that occurs among all ages, requiring adequate preventive strategies.

Hemophilia A (Factor VIII Deficiency)

Remarkable changes are occurring in the diagnosis and management of individuals with hemophilia A. Genetic testing, including next-generation sequencing, enables family planning, carrier testing, and prenatal diagnosis. Musculoskeletal ultrasound examination facilitates the early detection of acute bleeds and joint disease in clinic, enabling more rapid bleed resolution and treatment planning. Novel therapies offer simpler weekly or monthly administration, some by subcutaneous injection, with better compliance and quality of life, as well as fewer bleeds. Gene therapy provides a 1-time phenotypic "cure" that is cost effective, but may be complicated by waning levels, vector immune responses, and hepatotoxicity.

Gut dysbiosis modulates the immune response to factor VIII in murine hemophilia A

The development of neutralizing FVIII antibodies is the most serious complication of hemophilia A treatment. The currently known patient- and treatment-related risk factors for inhibitor development do not accurately predict this adverse event in all patients. The composition of the gut microbiota has been shown to influence immune-mediated diseases at distant anatomical sites (eg, lungs, brain, and joints). We demonstrate that a disrupted gut microbiota can be created in a mouse model of hemophilia A using a broad-spectrum antibiotic. Under controlled conditions, this sustained dysbiosis was associated with an increase in splenic B cells and the development of higher titer, FVIII-specific immunoglobulin G antibodies after FVIII challenge. Splenic and mesenteric lymph node cytokines, T cells, and dendritic cells were unaffected before administration of FVIII. However, the immune transcriptome of both aforementioned secondary lymphoid organs was significantly modified. Short-chain fatty acids (SCFAs), which are immunomodulatory microbial metabolites, were depleted in cecal contents of the dysbiotic mice. Furthermore, supplementation of the drinking water with butyrate, the most immunologically active SCFA, successfully achieved attenuation of the FVIII immune response. Collectively, data from this exploratory study suggest that the composition of the gut microbiota alters the FVIII immune response via the action of specific microbial metabolites on the immune cell transcriptome and that oral supplementation with butyrate effectively reduces the FVIII immune response.

Novel treatments for hemophilia through rebalancing of the coagulation cascade

Hemophilia A and B are inherited hemorrhagic disorders that result from alterations in the coagulation cascade. Aside from spontaneous bleeding, the main complication of hemophilia is hemarthrosis. Progress over the last three decades, specifically prophylaxis using recombinant factor, has prevented hemarthrosis and lengthened patient life expectancies. However, many treatments require frequent dosing up to three times a week, and alloantibodies (inhibitors) against replacement factor continues to be an issue. These problems call for novel treatments for patients with hemophilia. Although there has been progress in extended half-life factors and mimetics of factor VIII, an alternative treatment methodology is to rebalance the activities of pro- and anticoagulant factors through inhibition of the natural anticoagulants: antithrombin, tissue factor pathway inhibitor, protein C, and protein S. This review will explore the efficacy of targeting these inhibitory pathways from preclinical development through clinical trials, and delve into concerns of thrombotic risk.

Phase 4 Safety and Efficacy Study of Antihemophilic Factor (Recombinant) in Previously Treated Chinese Patients With Severe/Moderately Severe Hemophilia A

Antihemophilic factor (recombinant) (rAHF; ADVATE^®; Baxalta US Inc., a Takeda company, Lexington, MA, USA) is indicated for the treatment and prevention of bleeding in patients with hemophilia A. We aimed to assess the safety and efficacy of standard prophylaxis versus on-demand treatment with rAHF in previously treated Chinese patients with severe/moderately severe hemophilia A. This open-label, sequential, interventional, postapproval study (NCT02170402) conducted in China included patients of any age with hemophilia A with factor VIII (FVIII) level ≤2%. Patients received 6 months’ on-demand rAHF then 6 months’ rAHF prophylaxis (20-40 IU/kg every 48 ± 6 hours). The primary objective was percentage reduction in annualized bleeding rate (ABR) in the per-protocol analysis set (PPAS); secondary objectives included ABR by bleeding subtype, hemostatic efficacy, immunogenicity, and safety. Of 72 patients who received ≥1 rAHF dose, 61 were included in the PPAS. Total ABR was lower during prophylaxis (mean 2.5, 95% CI 1.5-3.7; median 0) versus on-demand treatment (mean 58.3, 95% CI 52.5-64.7; median 53.9), representing a 95.9% risk reduction. Similar findings in favor of prophylaxis were observed for all types of bleeding event by cause and location. rAHF hemostatic efficacy was rated as “excellent”/“good” in 96.1% of treated bleeding events. Transient FVIII inhibitors (0.6-1.7 BU) in 4 patients resolved before study end; no unexpected safety issues were observed. rAHF prophylaxis in this study of previously treated Chinese patients with severe/moderately severe hemophilia A resulted in a clear reduction in bleeding events versus rAHF on-demand treatment, with no change in safety profile.

Trends in coagulation factor replacement therapy and medical costs in patients with haemophilia in Taiwan: A population-based, 15-year analysis

INTRODUCTION

Taiwan's National Health Insurance Program approved reimbursement of prophylactic coagulation factor replacement therapy (CFRT) for patients with haemophilia (PWH) in 2014.

AIM

To examine 15-year trends and the impact of reimbursement for prophylactic CFRT on its utilization and related medical costs for PWH.

METHODS

We analysed Taiwan's National Health Insurance Database from 2003 to 2017. We included patients with haemophilia A (PWHA) or B (PWHB) receiving coagulating factor. Female patients were excluded because of small sample size. We analysed annual consumption of CFRT units and medical costs. High proportion of days covered (PDC) with CFRT served as an indicator for prophylactic treatment since it reflects routine use of CFRT. We applied interrupted time series analysis (ITSA) to evaluate the impact of reimbursement for prophylactic CFRT on usage patterns and medical costs.

RESULTS

We included 896 male PWHA and 181 male PWHB, with 38.1% and 37.0% aged under 18 years, respectively. By ITSA, we found the trends in coagulation factor consumption and PDC significantly increased after reimbursement for prophylactic CFRT in both PWHA and PWHB (p values for trend change <0.05). The overall medical costs per patient increased with increasing consumption of coagulation factor; however, ITSA revealed non-CFRT cost decreased after reimbursement of prophylactic CFRT for both PWHA and PWHB (p values <.05).

CONCLUSION

Reimbursement for prophylactic CFRT facilitated growth in rates of prophylactic CFRT and increased related costs, but curbed rising non-CFRT costs. These findings provide strong grounds for future cost-effectiveness studies to leverage prophylactic CFRT for its therapeutic benefits.

Maternal Hematologic Conditions and Fetal/Neonatal Outcomes of Pregnancy

Hematologic conditions in reproductive-age women can complicate pregnancy and the neonatal period. Affected pregnancies have a higher risk of severe morbidity and mortality. Coagulation factor changes that occur in the normal state of pregnancy can delay detection and recognition of a bleeding disorder in cases without an apparent bleeding history, thus hindering the appropriate management during gestation and the neonatal period. In addition, unique maternal immunologic changes occur during pregnancy, which are meant to protect the fetus who shares paternal antigens. Rarely, derangement of the maternal immune system may result in alloimmunization against fetal platelet antigens, leading to the development of fetal and/or neonatal thrombocytopenia. Bleeding and platelet disorders pose significant risk of intracranial hemorrhage for the fetus and newborn that is associated with significant morbidity and mortality. We discuss contemporary diagnosis and management of rare bleeding and platelet disorders in pregnancy and their effect on the neonatal period.

Real-world evidence on Kovaltry (81-8973) in children with moderate or severe hemophilia A in Europe: a nested cohort analysis

Background

Untreated hemophilia A patients may experience recurrent bleeding events leading to debilitating joint damages. While RCT and pharmacokinetic data support the value of Kovaltry [an unmodified full-length recombinant factor VIII (FVIII) product], real world evidence in children is lacking. This report describes a descriptive and multivariate analysis of the effectiveness of Kovaltry in children with hemophilia A in the real-world setting, using data from medical chart abstraction and cross-sectional surveys of physicians, patients, and caregivers.

Results

Male patients aged < 18 years with moderate or severe hemophilia A, residing in five European countries and treated with FVIII were studied. The co-primary endpoints were the annualized bleeding rate (ABR) and the annual FVIII utilization rate. Twenty nine patients treated with Kovaltry were included, of whom 93% had severe disease and 75% were on continuous prophylactic treatment. The mean ABR was 2.66 ± 2.06, with rates decreasing with age. The children received on average 2.45 infusions per week, consistent across age groups (median 3; range 1–3). There were no reports of inhibitor development or adverse events in the study (AEs), and all patients were satisfied or very satisfied with the treatment. An exploratory multivariate analysis suggests no significant difference in ABR or units utilized between Kovaltry and some extended half life products in children with severe hemophilia A, though characteristics of these patient cohorts were markedly different.

Conclusion

This analysis demonstrates the effectiveness and safety of Kovaltry in a pan-European pediatric population with severe hemophilia A.

Synthetically Engineered Adeno-Associated Virus for Efficient, Safe, and Versatile Gene Therapy Applications

Gene therapy directly targets mutations causing disease, allowing for a specific treatment at a molecular level. Adeno-associated virus (AAV) has been of increasing interest as a gene delivery vehicle, as AAV vectors are safe, effective, and capable of eliciting a relatively contained immune response. With the recent FDA approval of two AAV drugs for treating rare genetic diseases, AAV vectors are now on the market and are being further explored for other therapies. While showing promise in immune privileged tissue, the use of AAV for systemic delivery is still limited due to the high prevalence of neutralizing antibodies (nAbs). To avoid nAb-mediated inactivation, engineered AAV vectors with modified protein capsids, materials tethered to the capsid surface, or fully encapsulated in a second, larger carrier have been explored. Many of these engineered AAVs have added benefits, including avoided immune response, overcoming the genome size limit, targeted and stimuli-responsive delivery, and multimodal therapy of two or more therapeutic modalities in one platform. Native and engineered AAV vectors have been tested to treat a broad range of diseases, including spinal muscular atrophy, retinal diseases, cancers, and tissue damage. This review will cover the benefits of AAV as a promising gene vector by itself, the progress and advantages of engineered AAV vectors, particularly synthetically engineered ones, and the current state of their clinical translation in therapy.

Inhibitors and mortality in persons with nonsevere hemophilia A in the United States

Although persons with nonsevere hemophilia A (NSHA) account for about one-half of the hemophilia A population, epidemiological data in this subset of individuals are scarce. We set out to describe the clinical characteristics of persons with NSHA with inhibitors, and to determine mortality rates, predictors of mortality, and primary causes of death in persons with NSHA in the United States over a 9-year period (2010-2018). We queried the American Thrombosis and Hemostasis Network dataset (ATHNdataset) for information on demographics, inhibitor status, and date and cause of death. A total of 6624 persons with NSHA (86.0% men; 14.0% women) were observed for an average of 8.5 years; total 56 119 person-years . The prevalence of inhibitors was 2.6% (n = 171), occurring at a median age of 13 years. At the end of follow-up, 136 persons died at a median age of 63 years; an age-adjusted mortality rate of 3.3 deaths per 1000 person-years. Three deaths occurred in inhibitor participants. Presence of inhibitors was not associated with increased mortality risk (hazard ratio [HR], 0.7, 95% confidence interval [CI], 0.2-2.3). Factors independently associated with increased risk of death (HR, 95% CI) were the following: age (10-year increase) (2.1, 2.0-2.4); male (2.6, 1.0-6.4); hepatitis C (2.2, 1.5-3.1); and HIV (3.6, 2.2-6.0). The most common primary cause of death was malignancy (n = 27, 20.0%). In persons with NSHA, the development of inhibitors occurred at an early age and was not associated with increased mortality.

Evaluation of CDC's Hemophilia Surveillance Program - Universal Data Collection (1998-2011) and Community Counts (2011-2019), United States

Problem/Condition

Hemophilia is an X-linked genetic disorder that primarily affects males and results in deficiencies in blood-clotting proteins. Hemophilia A is a deficiency in factor VIII, and hemophilia B is a deficiency in factor IX. Approximately one in 5,000 males are born with hemophilia, and hemophilia A is about four times as common as hemophilia B. Both disorders are characterized by spontaneous internal bleeding and excessive bleeding after injuries or surgery. Hemophilia can lead to repeated bleeding into the joints and associated chronic joint disease, neurologic damage, damage to other organ systems, and death. Although no precise national U.S. prevalence estimates for hemophilia exist because of the difficulty identifying cases among persons who receive care from various types of health care providers, two previous state-based studies estimated hemophilia prevalence at 13.4 and 19.4 per 100,000 males. In addition, these studies showed that 67% and 82% of persons with hemophilia received care in a federally funded hemophilia treatment center (HTC), and 86% and 94% of those with the most severe cases of hemophilia (i.e., those with the lowest levels of clotting factor activity in the circulating blood) received care in a federally funded HTC. As of January 2020, the United States had 144 HTCs.

Period Covered

1998–2019.

Description of the System

Surveillance for hemophilia, which is a complex, chronic condition, is challenging because of its low prevalence, the difficulty in ascertaining cases uniformly, and the challenges in routinely characterizing and tracking associated health complications. Over time, two systems involving many stakeholders have been used to conduct ongoing hemophilia surveillance. During 1998–2011, CDC and the HTCs collaborated to establish the Universal Data Collection (UDC) surveillance system. The purposes of the UDC surveillance system were to monitor human immunodeficiency virus (HIV) and bloodborne viral hepatitis in persons with hemophilia, thereby tracking blood safety, and to track the prevalence of and trends in complications associated with hemophilia. HTC staff collected clinical data and blood specimens from UDC participants and submitted them to CDC. CDC tested specimens for viral hepatitis and HIV. In 2011, the UDC surveillance system was replaced by a new hemophilia surveillance system called Community Counts. CDC and the HTCs established Community Counts to expand laboratory testing and the collection of clinical data to better identify and track emerging health issues in persons with hemophilia.

Results

This report is the first comprehensive summary of CDC’s hemophilia surveillance program, which comprises both UDC and Community Counts. Data generated from these surveillance systems have been used in the development of public health and clinical guidelines and practices to improve the safety of U.S. blood products and either prevent hemophilia-related complications or identify complications early. Several factors have played a role in the effectiveness of the UDC and Community Counts systems, including 1) a stable data collection design that was developed and is continually reviewed in close partnership with HTC regional leaders and providers to ensure surveillance activities are focused on maximizing the scientific and clinical impact; 2) flexibility to respond to emerging health priorities through periodic updates to data collection elements and special studies; 3) high data quality for many clinical indicators and state-of-the-art laboratory testing methods for hemophilia treatment product inhibitors (developed and refined in part based on CDC research); 4) timely data and specimen collection and submission, laboratory specimen testing, analysis, and reporting; and 5) the largest and most representative sample of persons with hemophilia in the United States and one of the largest and most comprehensive data collection systems on hemophilia worldwide.

Interpretation

CDC has successfully developed, implemented, and maintained a surveillance system for hemophilia. The program can serve as an example of how to conduct surveillance for a complex chronic disease by involving stakeholders, improving and building new infrastructure, expanding data collection (e.g., new diagnostic assays), providing testing guidance, establishing a registry with specimen collection, and integrating laboratory findings in clinical practice for the individual patient.

Public Health Action

Hemophilia is associated with substantial lifelong morbidity, excess premature deaths, and extensive health care needs throughout life. Through monitoring data from Community Counts, CDC will continue to characterize the benefits and adverse events associated with existing or new hemophilia treatment products, thereby contributing to maximizing the health and longevity of persons with hemophilia.

Bridging the Missing Link with Emicizumab: A Bispecific Antibody for Treatment of Hemophilia A

Hemophilia A, characterized by absent or ineffective coagulation factor VIII (FVIII), is a serious bleeding disorder that entails severe and potentially life-threatening bleeding events. Current standard therapy still involves replacement of FVIII, but is often complicated by the occurrence of neutralizing alloantibodies (inhibitors). Management of patients with inhibitors is challenging and necessitates immune tolerance induction for inhibitor eradication and the use of bypassing agents (activated prothrombin complex concentrates or recombinant activated factor VII), which are expensive and not always effective. Emicizumab is the first humanized bispecific monoclonal therapeutic antibody designed to replace the hemostatic function of activated FVIII by bridging activated factor IX and factor X (FX) to activate FX and allow the coagulation cascade to continue. In the majority of hemophilic patients with and without inhibitors, emicizumab reduced the annualized bleeding rate to almost zero in several clinical trials and demonstrated a good safety profile. However, the concurrent use of emicizumab and activated prothrombin complex concentrate imposes a high risk of thrombotic microangiopathy and thromboembolic events on patients and should be avoided. Yet, the management of breakthrough bleeds and surgery remains challenging with only limited evidence-based recommendations being available. This review summarizes published clinical trials and preliminary reports of emicizumab and discusses the clinical implications of emicizumab in treatment of hemophilia A.

Occurrence rates of haemophilia among males in the United States based on surveillance conducted in specialized haemophilia treatment centres

INTRODUCTION

Estimates of the size and characteristics of the US haemophilia population are needed for healthcare planning and resource needs assessment. A network of comprehensive haemophilia treatment centres (HTCs) located throughout the United States receives federal support for diagnosis and management of haemophilia and other rare bleeding disorders.

AIM

Estimate the incidence and prevalence of haemophilia among US males using the HTC network.

METHODS

During the period 2012-2018, de-identified surveillance data were collected on all males who visited an HTC that included year of birth, gender, race, Hispanic ethnicity, residence zip code, haemophilia type and severity. Data from all patients were used to calculate period prevalence by haemophilia type, severity and state of residence. Data from a subset of patients born 1995-2014 were used to estimate incidence rates over the 20-year period.

RESULTS

During the period, 21 748 males with haemophilia visited the HTCs resulting in an age-adjusted prevalence of 15.7 cases per 100 000 males (12 for haemophilia A and 3.7 for haemophilia B). Prevalence was higher among whites (15.1) than blacks (12.4) or Hispanics of either race (12.4). State-specific prevalence varied from 1.6 to 23.3 cases per 100 000. Based on 9587 males born during the index period, the average haemophilia incidence was 1 case per 4334 live male births.

CONCLUSION

Based on these data, we estimate that there are between 29 761 and 32 985 males with haemophilia living in the United States today, the majority of whom receive comprehensive care in specialized clinical centres.

Molecular Mechanisms of Inhibitor Development in Hemophilia

The development of neutralizing antibodies in hemophilia is a serious complication of factor replacement therapy. These antibodies, also known as “inhibitors”, significantly increase morbidity within the hemophilia population and lower the quality of life for these patients. People with severe hemophilia A have an overall 25–40% lifetime risk of inhibitor development, compared to that of 5–15% lifetime risk in those with moderate/mild hemophilia A. The risk is lower in hemophilia B population (about 1–5%) and occurrence of inhibitors is almost only seen in patients with severe hemophilia B. The understanding of the pathophysiological mechanism leading to the development of inhibitors in patients with hemophilia has improved considerably over the last 2 decades. Identification of early biomarkers which predict inhibitor development in previously untreated patients with hemophilia will assist in risk identification and possible early intervention strategies. In this review, we aim to summarize the molecular mechanisms of inhibitor development in hemophilia and to identify potential areas in need of further investigation.

Origins and organization of the NHLBI State of the Science Workshop: Generating a national blueprint for future research on factor VIII inhibitors

INTRODUCTION

The major complication of protein replacement therapy for haemophilia A is the development of anti-FVIII antibodies or inhibitors that occur in 25%-30% of persons with severe haemophilia A. Alternative therapeutics such as bypassing agents or immune tolerance induction protocols have additional challenges and are not always effective.

AIM

Assemble a National Heart, Lung and Blood Institute (NHLBI) State of the Science (SOS) Workshop to generate a national blueprint for research on inhibitors to solve the problem of FVIII immunogenicity.

METHODS

An Executive Steering Committee was formed in October 2017 to establish the scientific focus and Scientific Working Groups for the SOS Workshop in May 2018. Four working groups were assembled to address scientific priorities in basic, translational and clinical research on inhibitors.

RESULTS

Working Group 1 was charged with determining the scientific priorities for clinical trials to include the integration of non-intravenous, non-factor therapeutics including gene therapy into the standard of care for people with haemophilia A with inhibitors. Working Group 2 established the scientific priorities for 21st-century data science and biospecimen collection for observational inhibitor cohort studies. The scientific priorities for acquiring an actionable understanding of FVIII immunogenicity and the immunology of the host response and FVIII tolerance were developed by Working Group 3. Working Group 4 designed prospective pregnancy/birth cohorts to study FVIII immunogenicity, inhibitor development and eradication.

CONCLUSION

The NHLBI SOS Workshop generated a focused summary of scientific priorities and implementation strategies to overcome the challenges of eradicating and preventing inhibitors in haemophilia A.

Hemophilia A ameliorated in mice by CRISPR-based in vivo genome editing of human Factor VIII

Hemophilia A is a monogenic disease with a blood clotting factor VIII (FVIII) deficiency caused by mutation in the factor VIII (F8) gene. Current and emerging treatments such as FVIII protein injection and gene therapies via AAV-delivered F8 transgene in an episome are costly and nonpermanent. Here, we describe a CRISPR/Cas9-based in vivo genome editing method, combined with non-homologous end joining, enabling permanent chromosomal integration of a modified human B domain deleted-F8 (BDD-F8) at the albumin (Alb) locus in liver cells. To test the approach in mice, C57BL/6 mice received tail vein injections of two vectors, AAV8-SaCas9-gRNA, targeting Alb intron 13, and AAV8-BDD-F8. This resulted in BDD-F8 insertion at the Alb locus and FVIII protein expression in the liver of vector-, but not vehicle-, treated mice. Using this approach in hemophilic mice, BDD-F8 was expressed in liver cells as functional human FVIII, leading to increased plasma levels of FVIII and restoration of blood clotting properties in a dose-dependent manor for at least 7 months, with no detectable liver toxicity or meaningful off-target effects. Based on these findings, our BDD-F8 genome editing approach may offer an efficacious, long-term and safe treatment for patients with hemophilia A.

Endovascular Management of Hemarthrosis in Patients with Bleeding Diatheses: Systematic Review

PURPOSE

In this systematic review, we report the safety and efficacy of embolization for treating hemarthrosis in patients with bleeding diatheses with or without a history of prior arthroplasty.

MATERIALS AND METHODS

A systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines. A structured search was performed in PubMed, Web of Science, MEDLINE, and SCOPUS databases of patients undergoing embolization for hemarthrosis. Demographic data, clinical history, angiographic findings, interventions, and outcomes were extracted and tabulated.

RESULTS

The search identified 97 unique titles of which 15 were deemed relevant comprising 78 patients with coagulopathies undergoing 93 embolization procedures. Mean follow-up time was 29 months (range 3-116.5). In the 29 patients who underwent arthroplasty prior to embolization for hemarthrosis, there were 11 bleeding recurrences (37.9%). Of these patients who experienced recurrences, 10 underwent repeat embolization as coagulation factor replacement was not sufficient to address the re-bleeding. In the 49 patients with bleeding diatheses who underwent embolization for hemarthrosis with no history of prior arthroplasty, there were 11 recurrences (22.4%) and 4 of these patients underwent repeat embolization with favorable results. There were four major procedure-related complications.

CONCLUSION

Transarterial embolization is safe and effective in addressing recurrent hemarthrosis in patients with bleeding diatheses with or without a history of arthroplasty of the affected joint.

Quantification of coagulation factor VIII in human plasma with liquid chromatography tandem mass spectrometry using a selective sample purification with camelid nanobodies

Patients with hemophilia A are currently diagnosed and monitored by measuring the activity of coagulation factor VIII (FVIII) in plasma mostly with the one-stage clotting assay (OSA). Although the OSA is routinely available in many clinical laboratories, it has in some circumstances relatively low sensitivity and specificity. Therefore, the FVIII activity as a biomarker does not always correlate with the bleeding phenotype. Therefore, we have developed a liquid chromatography tandem mass spectrometry method to quantify the concentration of coagulation FVIII in plasma which would allow us to investigate the relation between FVIII plasma concentration, FVIII activity and bleeding tendency in future studies. LC-MS/MS method was set up by firstly dissociation Von Willebrand factor (VWF) from coagulation factor VIII by triggering the coagulation cascade to occur thus generating active factor VIII (FVIIIa). FVIIIa was then selectively extracted by means of immunoaffinity interaction using anti-FVIII camelid nanobody, after which FVIIIa was eluted, heat denatured and trypsin digested. Finally, a FVIII specific peptide was used as a surrogate for quantification by mass spectrometry. Critical method parameters such as antibody amount, incubation time, sample volume and type of streptavidin 96 well plate were optimized. The method was validated according to European Medicines Agency (EMA) guidelines where an LLOQ of 1 ng/mL was obtained using 50 μL of citrate plasma sample. Within-run and between-run accuracy and precision for quality control (QC) samples, LLOQ (1 ng/mL), QC Low (5 ng/mL), QC Med (150 ng/mL), QC High (300 ng/mL) were within the threshold of 15% relative standard deviation (RSD) and Bias. The selective immunoaffinity method which was used in combination with a highly sensitive mass spectrometer allowed for an unpresented LLOQ of 1 ng/mL utilizing 50 μL plasma sample. This method will be used to investigate the beneficial value of FVIII plasma concentration which may be used in conjunction with FVIII activity for patient diagnosis and dosage optimization.

Measurement of plasma and platelet tissue factor pathway inhibitor, factor V and Protein S in people with haemophilia

INTRODUCTION

Tissue factor pathway inhibitor (TFPI) is a naturally occurring anticoagulant found in plasma, where it circulates bound to lipoproteins, factor V (FV) or Protein S (PS), and in platelets. Therapeutic agents targeting TFPI are under development for the treatment of haemophilia A and haemophilia B.

AIM

To begin to understand how TFPI, FV and PS interact to modulate haemophilia bleeding.

METHODS

Plasma and platelet antigen concentrations of these factors were determined in 73 people with haemophilia A and 18 with haemophilia B. Using multiple regression models, these were compared to the same analytes measured in 224 male blood donors.

RESULTS

There were no differences in plasma or platelet TFPI, FV or PS concentrations between haemophilia types or severities. However, compared to blood donors, people with haemophilia had approximately one-third lower plasma PS, 9% lower plasma TFPIα, 50% higher platelet FV and 26% lower platelet Protein S.

CONCLUSION

Together, the presented data suggest that individuals with haemophilia may have a compensatory procoagulant response of both plasma and platelet proteins to the decreased concentrations of FVIII or FIX.

Correlation of Body Mass Index with Pelvis and Lumbar Spine Alignment in Sagittal Plane in Hemophilia Patients

Introduction: Concern about weight gain among people has been high due to negative health consequences in addition to the increasing prevalence of the problem. Overweight and obesity also occur in patients with hemophilia. Analysis of literature shows that increased body weight might have a biomechanical effect on the spatial orientation of the pelvis and the lumbar spine. The aim of this study was to determine the correlation between body mass index (BMI) and the parameters characterizing the alignment of the sacrum (SS, sacral slope), the pelvis (PT, pelvic tilt; PI, pelvic incidence) and the angle value of lumbar lordosis (LL, lumbar lordosis) assessed in the sagittal plane among patients with hemophilia. Materials and methods: A total of 49 patients were subjected to the study, 23 of whom met the inclusion criteria. Body weight and height were measured. Measurement of the angle values of indicators characterizing the position of the lumbar–pelvic complex was established based on X-ray imaging analysis. Results: Analysis of the correlation between the BMI and sacral, pelvic, and lumbar indicators evaluated in the sagittal plane in the study group of patients with hemophilia showed a correlation between BMI and SS (r = 0.48). SS values were significantly and positively related to PI (r = 0.6; p = 0.002) and LL (r = 0.46; p = 0.02). The results obtained indicate the BMI relationship with the setting of the sacrum in the sagittal plane (SS). After adjusting for the knee flexion contracture, the correlation on the border of significance (b = 0.73, p = 0.07) between the body mass index and the spatial orientation of the pelvis and the spine was revealed. Conclusion: We hypothesize that increased body weight among people with hemophilia might have an effect on the positioning of the lumbosacral region. Therefore, it is believed that preventing obesity among people with hemophilia can contribute to a smaller number of intra-articular hemorrhages and better orthopedic condition of the limb joints, and thus could avoid changes in the lumbosacral region as well as their consequences.