Neuroinflammatory markers in patients with haemophilia and healthy controls: Where are the differences?

INTRODUCTION

People with haemophilia (PwH) suffer from haemophilic arthropathy which is accompanied by acute and chronic inflammation. The aim of this study was to examine the neuroinflammatory network operative in PwH and to compare it to healthy controls.

MATERIAL AND METHODS

Blood samples were collected from 41 PwH (age 54.7 ± 11.7 years) and 33 healthy controls (age 50.9 ± 10.5 years) and the levels of 13 neuroinflammatory markers were analyzed by applying an antibody-based detection kit in a flow cytometer.

RESULTS

From 13 analyzed markers, three-ß-nerve growth factor (ß-NGF), soluble receptor for advanced glycation endproducts (sRAGE) and Interleukin-18 (IL-18) differed significantly between the groups (ß-NGF p = .045; sRAGE p = .003; IL-18 p = .007). While ß-NGF was downregulated in PwH, sRAGE and IL-18 were upregulated. None of the analyzed markers corelated to the joint status of PwH while CCL2 (C-C motif ligand 2 chemokine) correlated to HIV infections in PwH (r = .313, p = .007). Correlation analyses of the markers studied also revealed many differences between PwH and controls suggesting a number of deregulations in PwH.

CONCLUSION

The altered levels of sRAGE and ß-NGF in PwH, which have not been analyzed in PwH before, may help to understand the neuroinflammatory network operative in PwH. The general inflammatory processes in PwH and the involved biomarkers in PwH remain poorly understood. PwH could benefit from new therapies against neuroinflammation which may help to reduce inflammation or also chronic pain.

A review of the rationale for gene therapy for hemophilia A with inhibitors: one-shot tolerance and treatment?

The therapeutic landscape for people living with hemophilia A (PwHA) has changed dramatically in recent years, but many clinical challenges remain, including the development of inhibitory antibodies directed against factor VIII (FVIII) that occur in approximately 30% of people with severe hemophilia A. Emicizumab, an FVIII mimetic bispecific monoclonal antibody, provides safe and effective bleeding prophylaxis for many PwHA, but clinicians still explore therapeutic strategies that result in immunologic tolerance to FVIII to enable effective treatment with FVIII for problematic bleeding events. This immune tolerance induction (ITI) to FVIII is typically accomplished through repeated long-term exposure to FVIII using a variety of protocols. Meanwhile, gene therapy has recently emerged as a novel ITI option that provides an intrinsic, consistent source of FVIII. As gene therapy and other therapies now expand therapeutic options for PwHA, we review the persistent unmet medical needs with respect to FVIII inhibitors and effective ITI in PwHA, the immunology of FVIII tolerization, the latest research on tolerization strategies, and the role of liver-directed gene therapy to mediate FVIII ITI.

Hemophilia gene therapy: first, do no harm

The introduction of adeno-associated virus-mediated, liver-directed gene therapy into the hemophilia treatment landscape brings not only great promise but also considerable uncertainty to a community that has a history punctuated by the devastating effects of HIV and hepatitis C virus. These infections were introduced into people with hemophilia through the innovation of factor concentrates in the 1970s and 1980s. Concentrates, heralded as a major advance in treatment at the time, brought devastation and death to the community already challenged by the complications of bleeding into joints, vital organs, and the brain. Over the past 5 decades, considerable advances in hemophilia treatment have improved the survival, quality of life, and participation of people with hemophilia, although challenges remain and health equity with their unaffected peers has not yet been achieved. The decision to take a gene therapy product is one in which an informed, holistic, and shared decision-making approach must be employed. Bias on the part of health care professionals and people with hemophilia must be addressed and minimized. Here, we review data leading to the regulatory authorization of valoctocogene roxaparvovec, an adeno-associated virus 5 gene therapy, in Europe to treat hemophilia A and etranacogene dezaparvovec-drlb in the United States and Europe to treat hemophilia B. We also provide an overview of the decision-making process and recommend steps that should be taken by the hemophilia community to ensure the safety of and optimal outcomes for people with hemophilia who choose to receive a gene therapy product.

The National Hemophilia Foundation State of the Science Research Summit initiative: executive summary

INTRODUCTION

The National Hemophilia Foundation State of the Science Research Summit initiative sought to unify research efforts in the US inherited bleeding disorders (BDs) community around key topics of importance to people living with inherited BDs, the lived experience experts.

AREAS COVERED

This community-led and -informed project focused on six broad areas - hemophilia A or B; von Willebrand Disease (VWD), platelet dysfunctions and other mucocutaneous inherited BDs; ultra-rare inherited BDs; the unique challenges of people with the potential to menstruate with inherited BDs; diversity, equity and inclusion, health services research, and implementation science; and facilitating research in the inherited BD community through designing an optimizied research infrastructure, enabling resources and funding, and furthering workforce capabilities required to execute the research priorities.

EXPERT OPINION

The work summarized here, and in the accompanying supplement manuscripts , has implications not only for the US population but for people globally who have inherited BDs. The information is equally relevant to people living with hemophilia, VWD, the spectrum of inherited platelet disorders, ultra-rare factor deficiencies, and all other inherited BDs as it is to the health care providers and researchers focused on the care and treatment of inherited BDs in the US and globally.

Patient-centered pharmacovigilance: priority actions from the inherited bleeding disorders community

Pharmacovigilance, the science and practice of monitoring the effects of medicinals and their safety, is the responsibility of all stakeholders involved in the development, manufacture, regulation, distribution, prescription, and use of drugs and devices. The patient is the stakeholder most impacted by and the greatest source of information on safety issues. It is rare, however, for the patient to take a central role and exert leadership in the design and execution of pharmacovigilance. Patient organizations in the inherited bleeding disorders community are among the most established and empowered, particularly in the rare disorders. In this review, two of the largest bleeding disorders patient organizations, Hemophilia Federation of America (HFA) and National Hemophilia Foundation (NHF), offer insights into the priority actions required of all stakeholders to improve pharmacovigilance. The recent and ongoing increase in incidents raising safety concerns and a therapeutic landscape on the cusp of unprecedented expansion heighten the urgency of a recommitment to the primacy of patient safety and well-being in drug development and distribution.

Plain Language Summary

Patients at the center of product safety Every medical device and therapeutic product has potential benefits and harms. The pharmaceutical and biomedical companies that develop them must demonstrate that they are effective, and the safety risks are limited or manageable, for regulators to approve them for use and sale. After the product has been approved and people are using it in their daily lives, it is important to continue to collect information about any negative side effects or adverse events; this is called pharmacovigilance. Regulators, like the United States (US) Food and Drug Administration, the companies that sell and distribute the products, and healthcare professionals who prescribe them are all required to participate in collecting, reporting, analyzing, and communicating this information. The people with the most firsthand knowledge of the benefits and harms of the drug or device are the patients who use them. They have an important responsibility to learn how to recognize adverse events, how to report them, and to stay informed of any news about the product from the other partners in the pharmacovigilance network. Those partners have a crucial responsibility to provide clear, easy-to-understand information to patients about any new safety concerns that come to light. The community of people with inherited bleeding disorders has recently encountered problems with poor communication of product safety issues, prompting two large US patient organizations, National Hemophilia Foundation and Hemophilia Federation of America, to hold a Safety Summit with all the pharmacovigilance network partners. Together they developed recommendations to improve the collection and communication of information about product safety so that patients can make well-informed, timely decisions about their use of drugs and devices. This article presents these recommendations in the context of how pharmacovigilance is supposed to work and some of the challenges encountered by the community.

Achieving access to haemophilia care in low-income and lower-middle-income countries: expanded Humanitarian Aid Program of the World Federation of Hemophilia after 5 years

Highly effective treatment of haemophilia A and B is primarily available to 15% of the world's population, in high-income countries. In low-income countries (LICs) and lower-middle-income countries (LMICs), morbidity and mortality are high because of greatly reduced access to diagnosis, care, and treatment. We report the challenges and impact after the first 5 years (mid-2015-2020) of the expanded World Federation of Hemophilia (WFH) Humanitarian Aid Program (HAP). WFH HAP donated coagulation products were used to treat more than 250 000 acute bleeding episodes, manage approximately 4000 surgeries, and establish bleeding preventive prophylaxis in about 2000 patients in 73 countries. Health-care providers worldwide learned optimal management of patients with complex needs through virtual and in-person training. In response to the programme, some governments increased investment in haemophilia care, including independent purchases of small amounts of treatment products. With unparalleled scope and complexity, and substantial benefits to people with haemophilia and society in general, the WFH HAP is an exemplar of partnership between for-profit and not-for-profit organisations advancing health-care equity in LICs and LMICs, which could be replicated by other organisations supporting people with different monogenic diseases.

Results of genetic analysis of 11 341 participants enrolled in the My Life, Our Future hemophilia genotyping initiative in the United States

BACKGROUND

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.

OBJECTIVES

My Life, Our Future (MLOF) was a multisector cross-sectional US initiative to improve our understanding of hemophilia through widespread genotyping.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Return to Sport Activities and Risk of Reinjury Following Primary Anterior Cruciate Ligament Reconstruction

This article examines the elements that affect the return to sport (RTS) and the risk and percentages of reinjury following a prior primary anterior cruciate ligament reconstruction (ACLR). The prevalence of RTS following ACLR ranges from 71% to 83%. Concerning elements affecting RTS, a limb symmetry index score of 90 or more duplicates the likelihood of RTS and triplicates it when the International Knee Documentation Committee (IKDC) score is 95 or more, irrespective of age. Other elements recognized to be preindicative of RTS at 1 year include complete rehabilitation, age ≤25, and higher IKDC scores. The prevalence of reinjury following ACLR ranges from 1.5% to 37.5% (between 9% and 29% in the majority of reports). It has been published that 1 in 5 individuals suffers reinjury to either knee, and that male individuals are more prone to reinjure following ACLR. The highest percentage of ACLR reinjury happens in younger male (<18 years), being substantially higher than in female of the same age. Passing a combination of functional tests with predetermined cut-off points utilized as RTS criteria are related diminished ACLR reinjury percentages.

Defining the Impact of Social Drivers on Health Outcomes for People with Inherited Bleeding Disorders

The ways in which the social drivers of health, also known as the social determinants of health (SDOH), affect health outcomes for people with inherited bleeding disorders (PwIBDs) is unclear. This systematic review of the published literature examines the impact of SDOH on health outcomes in PwIBDs. Articles that included the following parameters in PubMed informed this study: published in English between 2011–2021; available in free full text; study population diagnosed with an inherited bleeding disorder; and study measured at least one of the clinical/non-clinical outcome measures: bleeding frequency, chronic pain, mortality, quality of life (QOL), and/or cost. The main findings from the 13 included articles emphasized the unmet need for reducing the economic burden with sustainable population health strategies and treatment options for PwIBDs. Rural location was also a significant contributor to both delayed diagnosis and decreased access to care. Furthermore, the need for a multidisciplinary comprehensive care team to address physical, psychosocial, and emotional needs of PwIBDs was raised as a priority target in the desire for equitable and optimal health. This systematic literature review suggests that the SDOH are associated with inferior health outcomes and may influence the clinical progression of inherited bleeding disorders.

Building the blueprint: Formulating a community-generated national plan for future research in inherited bleeding disorders

Introduction

Decades of inherited bleeding disorders (BD) research transformed severe haemophilia from a childhood killer to a disorder managed across a full lifespan for many in economically developed countries. Health equity, a life unimpaired by disease complications, however, remains unimaginable for most people with an inherited BD (PWIBD).

Aim

The National Hemophilia Foundation (NHF) and American Thrombosis and Hemostasis Network (ATHN) undertook the development of a community‐driven United States (US) National Blueprint for Inherited Bleeding Disorders Research to transform the experience of all PWIBD and those who care for them.

Methods

Extensive community consultations were conducted to identify the issues most important to PWIBD and those who love and care for them. Expert multidisciplinary teams distilled these key areas of need into prioritised research questions, and identified the resources and infrastructure required to pursue them. A summit was held to gather feedback and inform the detailed blueprint.

Results

Community‐prioritised research areas fell into three broad categories: issues common across inherited BDs, those specific to individual disorders, and issues of infrastructure and capacity. NHF State of the Science Research Summit discussions of the research questions derived from the community priorities by six working groups provided important input for the drafting of the research blueprint for the coming decades.

Conclusion

The inherited BD community came together to develop the US National Blueprint for Inherited Bleeding Disorders Research dedicated to transforming the lives of all PWIBD including innovating solutions for the rarest disorders and under‐represented populations.

Big picture initiatives in bleeding disorders

INTRODUCTION

The inherited bleeding disorders (IBD) community has witnessed significant therapeutic advances recently, yet important gaps persist, particularly for those with rare disorders and historically underserved populations.

AIMS

-To create a national research blueprint agenda, led by the National Hemophilia Foundation (NHF), enhancing patient-centric principles, accelerate research progress and address important gaps in care. -To review critical gaps that remain to be addressed in women with IBDs, who face specific bleeding challenges.

METHODS

The NHF research blueprint research agenda was defined by input from across the community, including caregivers and patients who are considered subject matter experts of their IBD, research leaders, allied health professionals and specialists, and representatives of the biopharmaceutical industry. In addition, two medical experts in the field of IBDs performed a comprehensive review to address the knowledge gaps in women with IBDs.

RESULTS

Two foundational principles of the NHF blueprint are: (1) it must deliver on key issues that significantly impact the lives of those affected by IBDs, and (2) the priorities defined are relevant and actionable aimed to achieve health equity among all those affected by IBDs. A multidisciplinary approach is necessary for an optimal management of puberty, transition to adulthood and pregnancy. Even if strict guidelines are followed, recent studies show that women with IBDs are still facing a high burden.

CONCLUSION

NHF blueprint will be issued in 2022. A specific research agenda is needed in women with IBDs to further improve their management and quality of life.

Integrated Hemophilia Patient Care via a National Network of Care Centers in the United States: A Model for Rare Coagulation Disorders

Rare, chronic diseases such as hemophilia and other congenital coagulation disorders require coordinated delivery of services for optimal outcomes. Hemophilia Treatment Centers (HTCs) are specialized, multidisciplinary health-care centers providing team-based care to meet the physical, psychosocial, and emotional needs of people with hemophilia (PWH) and may serve as a model for other rare coagulation disorders. Health-care purchasers, as well as the general medical community, may not appreciate the breadth and quality of services provided by HTCs. They exemplify the acculturalization and actualization of integrated care by providing comprehensive diagnostic and treatment services that reduce morbidity, mortality, avoidable emergency room visits, hospitalizations, and overall costs, while promoting a longer lifespan and improved patient functioning and outcomes. This is accomplished by a team-based approach relying upon a shared decision-making model to effectively prevent complications and manage symptoms in PWH, who are dependent on high-cost treatments. This article provides a concise yet comprehensive description of the core components of an HTC and the regional and national networks in the United States, which together achieve their incomparable value for all stakeholders.

The intersection of vector biology, gene therapy, and hemophilia

Gene therapy is at the forefront of the drive to bring the potential of cure to patients with genetic diseases. Multiple mechanisms of effective and efficient gene therapy delivery (eg, lentiviral, adeno-associated) for transgene expression as well as gene editing have been explored to improve vector and construct attributes and achieve therapeutic success. Recent clinical research has focused on recombinant adeno-associated viral (rAAV) vectors as a preferred method owing to their naturally occurring vector biology characteristics, such as serotypes with specific tissue tropisms, facilitated in vivo delivery, and stable physicochemical properties. For those living with hereditary diseases like hemophilia, this potential curative approach is balanced against the need to provide safe, predictable, effective, and durable factor expression. While in vivo studies of rAAV gene therapy have demonstrated amelioration of the bleeding phenotype in adults, long-term safety and effectiveness remain to be established. This review discusses vector biology in the context of rAAV-based liver-directed gene therapy for hemophilia and provides an overview of the types of viral vectors and vector components that are under investigation, as well as an assessment of the challenges associated with gene therapy delivery and durability of expression.

Prophylaxis for hemophilia A without inhibitors: treatment options and considerations

INTRODUCTION

Hemophilia A is a bleeding disorder traditionally managed with standard half-life (SHL) factor (F) VIII concentrates. Extended half-life (EHL) FVIII products and emicizumab-kywh, a nonfactor therapy, are newer treatment options. Additional nonfactor agents and gene therapy are expected to reach the market in the near future.

AREAS COVERED

A PubMed (MEDLINE) search from 1962 to April 2020 related to hemophilia A, its management, and the products currently available for prophylaxis was performed to comprehensively review these topics and analyze the benefits and drawbacks of each therapeutic.

EXPERT OPINION

Prophylaxis with SHL FVIII concentrates remains the standard of care for patients with severe hemophilia A and may also be considered for selected individuals with moderate disease. Several years of real-world experience with EHL FVIII, emicizumab-kywh, and other agents in development will be necessary to determine their ultimate roles in the prevention of bleeding and its complications. Gene therapy may not provide a permanent cure for hemophilia A.

The Role of Gene Therapy in Cartilage Repair

The key principle of gene delivery to articulations by direct intra-articular injection is to release complementary DNA (cDNA)-encoding medical products that will lead to maintained, endogenous production of the gene products within the articulation. In fact, this has been accomplished for both in vivo and ex vivo gene delivery, using several vectors, genes, and cells in some animal models. Some clinical trials for rheumatoid arthritis and osteoarthritis (OA) using retrovirus vectors for ex vivo gene delivery and adeno-associated virus (AAV) for in vivo delivery have been reported. AAV is of special attention because, contrary to other viral vectors, it can enter deep within joint cartilage and transduce chondrocytes in situ. This quality is of special significance in OA, in which modifications in chondrocyte metabolism are believed to be crucial to the pathophysiology of the disease. The clinical effectiveness of TissueGene-C (TG-C), a cell and gene therapy for OA consisting of nontransformed and transduced chondrocytes (3:1) retrovirally transduced to overexpress TGF-β1 has been reported in patients with knee OA. The most common complications of TG-C were peripheral edema (9%), arthralgia (8%), articular swelling (6%), and injection site pain (5%). TG-C was associated with relevant ameliorations in function and pain. Gene therapy appears to be a viable method for the management of articular cartilage defects and OA.

Emicizumab: Review of the literature and critical appraisal

INTRODUCTION

Emicizumab-kywh (ACE910) is a recombinant, humanized, asymmetric bispecific antibody that functions to bring activated FIX (FIXa) and zymogen FX into an appropriate steric conformation to medicate the activation of FX to FXa thereby mimicking the cofactor function of FVIIIa.

AIM

The objective of this manuscript was to review the development and potential role for emicizumab in the treatment of patients with haemophilia A with and without inhibitors.

METHODS

A Cochrane Library and PubMed (MEDLINE) search focusing on emicizumab in haemophilia was conducted.

RESULTS

In total, 37 citations were retrieved and serve as the database for the literature reviewed herein. Once-weekly subcutaneous injection of emicizumab at three dose levels has been shown to be effective as prophylaxis to prevent bleeding in a majority haemophilia A patients with inhibitors to FVIII. Likewise, prevention of bleeding was also observed in more than two thirds of patients without inhibitors to FVIII. One antidrug antibody to emicizumab has been reported in over 600 treated patients, two have developed thromboembolic events and three thrombotic microangiopathy. These thrombotic complications have occurred in conjunction with FVIII-bypassing agents, and none have been observed following recommendations from the manufacturer regarding concomitant use of bypassing agents. The median annual treated bleeding rates were decreased in patients with as well as those without an inhibitor to FVIII.

CONCLUSION

The principal advantage of emicizumab is subcutaneous administration and effectiveness irrespective of the presence of inhibitors. Emicizumab could conceivably represent a new epoch in the treatment of people with haemophilia A.

Validation of the Haemophilia & Exercise Project-Test-Questionnaire (HEP-Test-Q)-An instrument for the assessment of subjective physical functioning in children with haemophilia

INTRODUCTION

Contemporary haemophilia management recommends sport and physical activity in children with haemophilia. Assessment of subjective physical functioning requires standardized and validated instruments.

AIMS

To adapt and psychometrically test the adult Haemophilia & Exercise Project-Test-Questionnaire (HEP-Test-Q) for children (aged 6-17 years).

METHODS

In discussion rounds with children, single items of the adult HEP-Test-Q were reformulated to make them understandable without changing the item concept. The validation of the child-adapted version in children with haemophilia (n = 228) included pre-testing with feasibility testing, cognitive interviewing (n = 34), pilot-testing of the revised version in the EIS Study (n = 67) and field-testing in the SO-FIT Study (n = 127).

RESULTS

Pre-testing revealed a completion time of 8.2 ± 4.1 minutes and children liked the instrument. Cognitive interviews demonstrated that most items were easy to understand; 9 items were reformulated. Pilot-testing demonstrated good psychometric characteristics in terms of reliability (α = .94 Total Score) and validity. Convergent validity testing showed moderate correlations with the Haemo-QoL (r = -.491), but low correlations with the Petrini Score (r = -.293). Known groups' validity revealed significant differences in clinical subgroups; chronic pain (P < .002) and target joints (P < .021). Field-testing confirmed psychometric characteristics; Cronbach's alpha ranged from α = .80 ("endurance") to α = .94 (Total Score). The child-adapted HEP-Test-Q showed moderate correlations with the PedHAL (r = .634, P < .0001) and the Haemo-QoL SF (r = -.575, P < .0001). Known groups' validity testing proved that the HEP-Test-Q could discriminate between clinical subgroups.

CONCLUSION

The child-adapted HEP-Test-Q is a short, practical and acceptable instrument for the assessment of subjective physical functioning. Outcomes can be compared to adults because item concepts are identical to the adult version.

Increased bone resorption in hemophilia

In patients with hemophilia, osteoporosis is frequently observed for which the etiology remains unclear. The aim of this paper is to review the available experimental evidence indicating the presence of this disorder in patients with hemophilia, explore the potential mechanisms which may lead to reduced bone mineral density (BMD) and speculate on useful interventions to circumvent it. A narrative review of the English literature up to April 2018 was performed. The available evidence demonstrates an increased rate of bone resorption and an excess of osteoporosis among patients with hemophilia. FVIII and FIX may act through at least two pathways: promoting bone formation by a thrombin-mediated mitogenic effect on osteoblasts and by cytokine-mediated osteoclast activity. Another potential indirect mechanism mediated through the RANK-RANKL pathway has been suggested but remains controversial. The role of confounders such as lack of activity and immobility must be considered.

Target plasma factor levels for personalized treatment in haemophilia: a Delphi consensus statement

BACKGROUND

Prophylactic replacement with factor concentrate is the optimal treatment for persons with severe haemophilia to avoid or minimize bleeding. This ultimately prevents or reduces joint disease and improves life expectancy and quality of life towards values matching those in the normal population. However, uncertainty still exists around the optimal regimens to be prescribed for prophylaxis. An increasing number of treating physicians and patients are showing interest in patient-tailored approaches to prophylaxis, which aim to harmonize the prophylaxis regimen with the patients' bleeding phenotype, levels of physical activity and a variety of other variables.

METHODS

A modified Delphi technique was adopted to generate consensus. The expert panel met in person to set the objectives, be trained on the Delphi technique and agree on the desired level of consensus. Three iterations were used to identify the targets, the scenarios and their combinations.

RESULTS

Twenty-eight scenarios and eight target levels were identified and used to issue recommendations. The panel reached the desired level of consensus on positive or negative recommendations. Areas where consensus was not reached were identified and proposed as areas for future research. Prospective assessment of the validity of most of the proposed targets is recommended.

CONCLUSIONS

We have generated, by expert consensus, target plasma levels of factor concentrate to be used to tailor treatment for persons with haemophilia.

Haemarthrosis model in mice: BSS - Bleeding Severity Score assessment system

INTRODUCTION

The prophylactic administration of clotting factor concentrate is currently the most effective strategy for the prevention of joint bleeding. As new agents with different mechanisms of action and administration schedules are developed, it will be important to study them in relevant preclinical models.

AIM

The aim of this study was the standardization of a mouse haemarthrosis model in a haemophilia mouse and the development and validation of a comprehensive bleeding assessment system, the Bleeding Severity Score (BSS).

METHODS AND RESULTS

Four outcome measurements were assessed, two of which, the extra-articular bleeding score and intra-articular bleeding score, were determined to be the most reliable and were summarized into a BSS which was validated using a mouse haemarthrosis variability model.

CONCLUSION

Using this model, the haemostatic effect of prospective drugs can be assessed in a clinically relevant joint bleeding model and will significantly increase the value of preclinical studies.

Orthopedic disorders of the knee in hemophilia: A current concept review

The knee is frequently affected by severe orthopedic changes known as hemophilic arthropathy (HA) in patients with deficiency of coagulation factor VIII or IX and thus this manuscript seeks to present a current perspective of the role of the orthopedic surgeon in the management of these problems. Lifelong factor replacement therapy (FRT) is optimal to prevent HA, however adherence to this regerous treatment is challenging leading to breakthrough bleeding. In patients with chronic hemophilic synovitis, the prelude to HA, radiosynovectomy (RS) is the optimal to ameliorate bleeding. Surgery in people with hemophilia (PWH) is associated with a high risk of bleeding and infection, and must be performed with FRT. A coordinated effort including orthopedic surgeons, hematologists, physical medicine and rehabilitation physicians, physiotherapists and other team members is key to optimal outcomes. Ideally, orthopedic procedures should be performed in specialized hospitals with experienced teams. Until we are able to prevent orthopedic problems of the knee in PWH will have to continue performing orthopedic procedures (arthrocentesis, RS, arthroscopic synovectomy, hamstring release, arthroscopic debridement, alignment osteotomy, and total knee arthroplasty). By using the aforementioned procedures, the quality of life of PWH will be improved.

An innovative outcome-based care and procurement model of hemophilia management

Hemophilia is a rare bleeding disorder associated with spontaneous and post-traumatic bleeding. Each hemophilia patient requires a personalized approach to episodic or prophylactic treatment, but self-management can be challenging for patients, and avoidable bleeding may occur. Patient-tailored care may provide more effective prevention of bleeding, which in turn, may decrease the likelihood of arthropathy and associated chronic pain, missed time from school or work, and progressive loss of mobility. A strategy is presented here aiming to reduce or eliminate bleeding altogether through a holistic approach based on individual patient characteristics. In an environment of budget constraints, this approach would link procurement to patient outcome, adding incentives for all stakeholders to strive for optimal care and, ultimately, a bleed-free world.

Utility of a Paediatric Bleeding Questionnaire as a screening tool for von Willebrand disease in apparently healthy children

von Willebrand disease (VWD), an inherited bleeding disorder caused by deficiency or dysfunction of von Willebrand factor (VWF) is diagnosed when a personal and often a family history of excessive mucocutaneous bleeding is present along with abnormal laboratory studies. An accurate assessment of haemorrhagic symptoms is key in suspecting VWD but presents a challenge especially in children due to overlap between normal and abnormal bleeding. Bleeding questionnaire (BQ) scores have been validated in adults and have recently been validated in children with VWD for assessing bleeding severity. However, there are limited data supporting their use prospectively in healthy children with bleeding complaints.

AIM

The objectives of this study were to obtain normative data from children and validate a paediatric BQ (PBQ) to determine the discriminative ability of its total score and its individual components for identifying children likely to have VWD.

METHODS

The PBQ was administered to 1281 multiethnic, healthy children between 30 days and 18 years of age presenting to a general paediatric office and to 35 children with VWD based on VWF antigen, activity and multimer pattern.

RESULTS

When children with total BQ scores of 3 or more were predicted to have VWD, the sensitivity was 97.2%, the specificity was 97.1%, the positive predictive value was 48.6% and the negative predictive value was 99.9%.

CONCLUSIONS

The PBQ may help discriminate a significant bleeding history from trivial bleeding, may be integrated into the primary care algorithm for evaluating children suspected with VWD.

Safety of radiation exposure after radiosynovectomy in paediatric patients with haemophilia

Many paediatric patients with haemophilia who might benefit from radiosynovectomy (RS) for the control of synovitis do not undergo the procedure as there is controversy in the literature regarding the safety of radiation exposure after two cases of acute lymphocytic leukaemia in children with haemophilia treated with (32) P RS were reported. The purpose of this review was to analyse the safety of RS in paediatric patients with haemophilia and provide a risk-benefit assessment, which practitioners could apply to their patients. Children undergoing knee RS receive a radiation dose of approximately 0.74 mSv (90 megabecquerels-MBq) and elbow and ankle RSs a dose of approximately 0.32 mSv (30-40 MBq). The radiation dose from natural sources is approximately 2 mSv and the recommended limit for patients (apart from natural sources) is 1 mSv per year. The lifetime cancer risk increases about 0.5% per 100 mSv per year. Considering the risks and benefits of RS, the authors recommend that clinicians consider this procedure in children with inhibitors or in patients without inhibitors when bleeding is recurrent and persistent despite aggressive factor replacement.

The role of Rixubis™ in the treatment of hemophilia B

Hemophilia B is an inherited coagulopathy caused by the partial or complete deficiency of factor (F) IX. Factor replacement therapy, involving the intravenous infusion of plasma-derived or recombinant (r) FIX concentrate, is the cornerstone of treatment, used to control and prevent bleeding episodes. Although several plasma-derived FIX products are available, until recently, only a single rFIX concentrate was on the market. The aim of this paper is to review the pharmacokinetics, hemostatic efficacy, and safety of Rixubis™ (Baxter Healthcare Corporation, CA, USA), a newly licensed rFIX product.

Considerations in individualizing prophylaxis in patients with haemophilia A

Prophylaxis is considered optimal care for children and adults with severe haemophilia A because of its proven ability to reduce joint and other bleeding episodes. However, a 'one size fits all' approach to prophylaxis is not ideal, potentially leading to over-treatment in some individuals and under-treatment in others. Moreover, a generic plan fails to take into account a patient's lifestyle and personal preferences. This article reviews the factors contributing to bleeding risk and joint damage and uses case studies to illustrate how these contributors can be weighed to individualize the prophylactic regimen, thereby increasing the likelihood of therapeutic success.

Multicentre, randomized, open-label study of on-demand treatment with two prophylaxis regimens of recombinant coagulation factor IX in haemophilia B subjects

Few randomized studies have reported on the use of factor IX (FIX) for secondary prophylaxis in haemophilia B patients. This study aimed to evaluate the efficacy and safety of two secondary prophylaxis regimens of recombinant coagulation FIX, nonacog alfa, compared with on-demand therapy. Male subjects aged 6-65 years with severe or moderately severe haemophilia B (FIX:C ≤ 2, n = 50) and ≥12 bleeding episodes (including ≥6 haemarthroses episodes) within 12 months of study participation were enrolled in this multicentre, randomized, open-label, four-period crossover trial. The primary measure was the annualized bleeding rate (ABR) of two prophylactic regimens vs. on-demand therapy. In the intent-to-treat group, mean ABR values were 35.1, 2.6 and 4.6 for the first on-demand period, the 50 IU kg(-1) twice-weekly period, and the 100 IU kg(-1) once-weekly period respectively. Differences in ABR between the first on-demand period and both prophylaxis regimens were significant (P < 0.0001); no significant differences were observed between prophylaxis regimens (P = 0.22). Seven serious adverse events occurred in five subjects, none related to study drug. Results demonstrated that secondary prophylaxis therapy with nonacog alfa 50 IU kg(-1) twice weekly or 100 IU kg(-1) once weekly reduced ABR by 89.4% relative to on-demand treatment. Both prophylaxis regimens demonstrated favourable safety profiles in subjects with haemophilia B.

Central venous access devices in patients with hemophilia

Hemophilia is a hereditary disorder in which the major clinical manifestation is bleeding into the joints, muscles, internal organs and the CNS, often without any obvious trauma. Bleeding can be fatal as in the case of CNS hemorrhage, or severely debilitating following repeated bleeding into joints that results in crippling arthritis. Treatment for hemophilia includes the intravenous administration of clotting factor concentrates to replace the missing or defective protein. Venous access is therefore critical to the treatment of hemophilia and the prevention of complications due to bleeding. According to the US Centers for Disease Control and Prevention, approximately half of patients less than 16 years of age and one-third of all patients with hemophilia receive regular prophylactic injections of clotting factor concentrates. Prophylaxis, or the regular scheduled administration of antihemophilic factor concentrate, is effective in preventing bleeding. Among those patients with severe disease, in the absence of prophylaxis, approximately 13 bleeds, including nine joint hemorrhages, occur annually. In contrast, when prophylaxis is administered, the annual number of total and joint bleeds decreases to five and three, respectively. One of the major barriers to the more wide-spread use of prophylaxis is venous access. While peripheral venipuncture remains the first choice for venous access, central venous access devices are frequently used to facilitate repeated and/or urgent administration of clotting factor concentrates. The advantages of central venous access devices are well recognized in certain treatment regimens such as prophylaxis and immune tolerance therapy, as well as certain patient groups such as young children in whom venipuncture is often difficult and traumatic, and adults with scarred veins. Central venous access devices also allow earlier commencement of both home treatment and prophylaxis. The goal of this review is to discuss the different types of central venous access devices and their role in the management of hemophilia to provide practitioners that care for patients with hemophilia with the necessary information to make sound therapeutic recommendations to their patients.

Phase 3 study of recombinant factor IX Fc fusion protein in hemophilia B

BACKGROUND

Prophylactic factor replacement in patients with hemophilia B improves outcomes but requires frequent injections. A recombinant factor IX Fc fusion protein (rFIXFc) with a prolonged half-life was developed to reduce the frequency of injections required.

METHODS

We conducted a phase 3, nonrandomized, open-label study of the safety, efficacy, and pharmacokinetics of rFIXFc for prophylaxis, treatment of bleeding, and perioperative hemostasis in 123 previously treated male patients. All participants were 12 years of age or older and had severe hemophilia B (endogenous factor IX level of ≤2 IU per deciliter, or ≤2% of normal levels). The study included four treatment groups: group 1 received weekly dose-adjusted prophylaxis (50 IU of rFIXFc per kilogram of body weight to start), group 2 received interval-adjusted prophylaxis (100 IU per kilogram every 10 days to start), group 3 received treatment as needed for bleeding episodes (20 to 100 IU per kilogram), and group 4 received treatment in the perioperative period. A subgroup of group 1 underwent comparative sequential pharmacokinetic assessments of recombinant factor IX and rFIXFc. The primary efficacy end point was the annualized bleeding rate, and safety end points included the development of inhibitors and adverse events.

RESULTS

As compared with recombinant factor IX, rFIXFc exhibited a prolonged terminal half-life (82.1 hours) (P<0.001). The median annualized bleeding rates in groups 1, 2, and 3 were 3.0, 1.4, and 17.7, respectively. In group 2, 53.8% of participants had dosing intervals of 14 days or more during the last 3 months of the study. In groups 1, 2 and 3, 90.4% of bleeding episodes resolved after one injection. Hemostasis was rated as excellent or good during all major surgeries. No inhibitors were detected in any participants receiving rFIXFc; in groups 1, 2, and 3, 73.9% of participants had at least one adverse event, and serious adverse events occurred in 10.9% of participants. These events were mostly consistent with those expected in the general population of patients with hemophilia.

CONCLUSIONS

Prophylactic rFIXFc, administered every 1 to 2 weeks, resulted in low annualized bleeding rates in patients with hemophilia B. (Funded by Biogen Idec; ClinicalTrials.gov number, NCT01027364.).

Hemophilia: in review

Hemophilia A (deficiency in factor [F] VIII) and hemophilia B (deficiency in FIX) are the most common serious congenital coagulation factor deficiencies. (Based on strong evidence) Hemophilia is a genetic disorder inherited in an Xlinked fashion. Both diseases cause similar bleeding diatheses, with the hallmark being hemarthroses. (Based on strong evidence) The optimal treatment is recombinant factor replacement to prevent bleeding; however, this treatment has many barriers. (Based on strong evidence) The most serious complication of treatment is the development of inhibitors to factor products. (Based on strong evidence) Care for patients with hemophilia is most appropriate in a comprehensive care setting. (Based on strong evidence).

Management of joint bleeding in hemophilia

Hemarthrosis, the hallmark of severe hemophilia, is the major cause of serious bleeding events, disability and reduced quality of life in patients with factor VIII or factor IX deficiency. Joint bleeding is one of the greatest challenges confronting individuals treating hemophilia, and its economic impact is enormous. This article reviews the current management of hemophilic joint bleeding and discusses the potential impact of novel therapies.

A randomized comparison of two prophylaxis regimens and a paired comparison of on-demand and prophylaxis treatments in hemophilia A management

BACKGROUND

Prophylaxis with factor (F)VIII is considered the optimal treatment for managing hemophilia A patients without inhibitors.

OBJECTIVES

To compare the efficacy of two prophylaxis regimens (primary outcome) and of on-demand and prophylaxis treatments (secondary outcome), and to continue the evaluation of immunogenicity and overall safety of the ADVATE Antihemophilic Factor (Recombinant), Plasma/Albumin Free Method (rAHF-PFM).

PATIENTS/METHODS

Previously on-demand-treated patients aged 7-59 years (n = 66) with FVIII levels ≤ 2% received 6 months of on-demand treatment and then were randomized to 12 months of either standard (20-40 IU kg(-1) every other day) or pharmacokinetic (PK)-tailored (20-80 IU kg(-1) every third day) prophylaxis, both regimens intended to maintain FVIII trough levels at or above 1%. Efficacy was evaluated in terms of annualized bleeding rates (ABRs). As subjects were first treated on-demand and then on prophylaxis, statistical comparisons between these treatments were paired.

RESULTS

Twenty-two (33.3%) subjects on prophylaxis experienced no bleeding episodes, whereas none treated on-demand were free from an episode of bleeding. ABRs for the two prophylaxis regimens were comparable, whereas differences between on-demand and either prophylaxis were statistically significant (P < 0.0001): median (interquartile range [IQR]) ABRs were 43.9 (21.9), 1.0 (3.5), 2.0 (6.9) and 1.1 (4.9) during on-demand treatment, standard, PK-tailored and any prophylaxis, respectively. There were no differences in FVIII consumption or adverse event rates between prophylaxis regimens. No subject developed FVIII inhibitors.

CONCLUSIONS

The present study demonstrates comparable safety and effectiveness for two prophylaxis regimens and that prophylaxis significantly reduces bleeding compared with on-demand treatment. PK-tailored prophylaxis offers an alternative to standard prophylaxis for the prevention of bleeding.

The Fourth Annual Meeting of the International Network for Pediatric Hemophilia: Current Challenges and Recommendations in the Clinical Care of Children with Hemophilia

The International Network for Pediatric Hemophilia (INPH) comprises a group of physicians committed to the unique care of and challenges facing pediatric hemophilia patients. By collaborating on an international level, extensive experience can be shared on current practice, new trends can be discussed and scientifically valid studies can be developed and performed. The three overall objectives of the group (scientific progress, education and networking) are achieved at each annual meeting starting with a round table on the members' current research and clinical activities, project reports of INPH study initiatives, followed by invited educational presentations and interactive discussions. The meetings close with proposals of new projects, future directions of the group and concluding remarks. The Fourth Annual INPH meeting, held in 2009 in Boston, MA, USA, focused on inhibitor development and hemophilic arthropathy in the clinical care of children with hemophilia.

Blood-induced joint disease: the pathophysiology of hemophilic arthropathy

Arthropathy is a frequent and serious complication of repeated joint bleeding in patients with hemophilia, resulting in pain, deformity, and disability. Although the pathogenesis of hemophilic arthropathy has not been fully elucidated, it appears to have similarities with the degenerative joint damage that occurs in osteoarthritis and the inflammatory processes associated with rheumatoid arthritis. This article reviews the potential actions of various blood constituents on joint components that culminate in the development of hemophilic arthropathy.