The overall effectiveness of prophylaxis in severe haemophilia

Long-term impact of primary prophylaxis on joint status in patients with severe hemophilia A

Background

Primary prophylaxis with factor VIII concentrates is the therapeutic gold standard for severe hemophilia A. Although this approach will change substantially with the use of nonsubstitutive therapies, the long-term effects of primary prophylaxis remain unclear. We present information on joint health with tailored primary prophylaxis in a consecutive series at a single center.

Methods

We retrospectively analyzed 60 patients who did not develop early inhibitors. The annual bleeding rate and annual joint bleeding rate, prophylaxis characteristics, physical activity, adherence, and development of inhibitors were compared between those with and without joint involvement at the end of follow-up. Joint involvement was defined as a Hemophilia Joint Health Score or Hemophilia Early Arthropathy Detection with an ultrasound score ≥1.

Results

Among 60 patients with median follow-up of 113 ± 6 months after starting prophylaxis, 76.7% had no joint involvement at the end of the follow-up. Those without joint involvement started prophylaxis at a younger median age (1 [IQR 1-1] year vs 3 [IQR 2-4.3] years). They also had lower annual joint bleeding rate (0.0 [IQR 0-0.2] vs 0.2 [IQR 0.1-0.5]), were more often physically active (70% vs 50%), and had lower trough factor VIII levels. Adherence to treatment was not significantly different between groups.

Conclusion

Initiation of primary prophylaxis at a younger age was the main factor associated with long-term preservation of joint status in patients with severe hemophilia A.

Early stage clinical trials for the treatment of hemophilia A

INTRODUCTION

Hemophilia A is a severe bleeding disorder affecting about 1 in 5,000 males. The gold standard for prophylaxis and treatment of acute bleeding has been factor (F) VIII concentrate. A multitude of treatment modalities are now available and under clinical investigation.

AREAS COVERED

This review discusses ongoing/recently completed early-phase clinical trials registered on ClinicalTrials.gov in patients with hemophilia A through April 2022. These new pipeline therapies are focused on addressing the safety and efficacy of new factor-related products, non-factor related products, and gene therapy options for hemophilia.

EXPERT OPINION

Current standard of care effectively prevents and treats acute bleeding and has significantly improved the quality of life in hemophilia. The biggest challenges in the improvement of care are treatment-related burden and the burden of cost in developing countries. New drugs under development are likely to enter practice by the end of this decade and address many of the unmet needs particularly of those with severe disease. Data is limited in unique populations (e.g. congenital/inherited FVIII inhibitors, non-severe hemophilia A, women/girls with hemophilia and children) which are important areas for future research; additional clinical trials and long-term outcome data are necessary prior to incorporating these new therapies in our treatment arsenal.

Managing Severe Hemophilia A in Children: Pharmacotherapeutic Options

Hemophilia A is the most common severe inherited bleeding disorder in males. Initial treatment strategies focused on the use of factor concentrates to prevent joint bleeding and the development of long-term crippling arthropathy. The current standard of care has evolved from regular replacement of factor VIII concentrates which has significantly improved the quality of life for those with severe disease to include and consider novel therapies that augment or bypass the hemostatic pathway (ie, emicizumab, Mim8). Other pipeline therapies that suppress specific natural anticoagulant pathways (ie, antithrombin, TFPI) to reestablish hemostatic balance are under Phase 3 trial investigation. These novel therapeutics have allowed providers more variety in dosing regimens and ease of administration while also maintaining effective bleeding prevention. The possibility of "curative" gene therapy is under exploration, with ongoing clinical trials in adult males.

Major cardiac surgery with recombinant FIX Fc fusion protein replacement in hemophilia B: a case report

The introduction of extended factor IX (FIX) products has significantly facilitated the treatment of hemophilia B patients. However, optimal perioperative management remains a topic of hot debate, particularly in surgeries with high bleeding risk. For the first time, we report here a patient with mild hemophilia B and degenerative aneurysms of aortic root and ascending aorta undergoing elective Bentall’s operation with full cardiopulmonary bypass, who was successfully managed with eftrenonacog alfa (Alprolix^®), a recombinant FIX Fc fusion protein (rFIXFc). rFIXFc could safely be monitored using the Pathromtin SL aPTT-reagent. No significant bleeding was noted intraoperatively despite systemic heparinization as well as postoperatively. Higher doses of rFIXFc were inevitable to reach target FIX levels intraoperatively, whereas in the post-surgery setting stable FIX concentrations were maintained with only few rFIXFc injections facilitating fast wound healing and remobilization of the patient.

Cost-Effectiveness Analysis of rFVIIIFc Versus Contemporary rFVIII Treatments for Patients with Severe Hemophilia A Without Inhibitors in the United States

BACKGROUND

A range of treatments for patients with severe hemophilia A (HA) have been developed over the last decade, allowing for reduced frequency of administration and improved outcomes (joint health and breakthrough bleeding rates). While clinically effective, the cost effectiveness of these treatments has not been established.

OBJECTIVE

This study presents a cost-effectiveness analysis of contemporary rFVIII treatments for severe HA patients without inhibitors.

METHODS

A published semi-Markov model was used to compare three different prophylaxis regimens: (1) extended half-life (EHL) recombinant Factor VIII (rFVIII) Fc-fusion protein (rFVIIIFc, Eloctate^®, Sanofi), (2) EHL PEGylated rFVIII (PEG-rFVIII, Adynovate^®, Takeda), and (3) standard half-life (SHL) rFVIII (antihemophilic factor [recombinant], Advate^®, Takeda), used as a proxy for all SHL rFVIII treatments. Acquisition costs were included based on published dosing and weight data. Benefits were incorporated through published annualized bleeding rates, rates of target joint development/resolution, and improvements in the modified hemophilia joint health score. Results were presented as total, discounted costs, and quality-adjusted life-years (QALYs).

RESULTS

rFVIIIFc was shown to provide the most QALYs (27.922) compared with both PEG-rFVIII (27.454) and SHL rFVIII (27.071), at lower costs. Discounted lifetime costs were estimated at US$18.235m (rFVIIIFc), US$20.198m (PEG-rFVIII), and US$18.285m (SHL rFVIII), and were predominantly affected by model settings related to acquisition costs, patient weight, and dosing.

CONCLUSIONS

rFVIIIFc may offer a cost-effective option for severe HA patients. Uncertainties owing to the limited evidence base is the main limitation of the study.

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.

Cost-Effectiveness Analysis of Recombinant Factor VIII Fc-Fusion Protein (rFVIIIFc) for the Treatment of Severe Hemophilia A in Italy Incorporating Real-World Dosing and Joint Health Data

BACKGROUND

Patients with severe hemophilia A (SHA) in Italy are routinely treated with standard half-life recombinant factor VIII (rFVIII) products. rFVIII Fc-fusion protein (rFVIIIFc) is an extended half-life rFVIII product that enables less frequent administration than rFVIII, which may support improved adherence. Available data indicate low breakthrough bleed rates and potentially improved long-term joint health for patients treated with rFVIIIFc prophylaxis.

OBJECTIVE

This study assessed the cost effectiveness of rFVIIIFc versus rFVIII from an Italian healthcare perspective.

METHODS

A Semi-Markov model was constructed to assess the lifetime costs and benefits of rFVIII and rFVIIIFc prophylaxis. rFVIII product acquisition costs from a published Italian database were included for both prophylaxis and the resolution of breakthrough bleeding. Clinical outcomes within the model were determined based on published annualized bleeding rates and literature regarding the development of target joints (TJs) as the incidence of bleeds and TJs is associated with impaired health-related quality of life. Cost effectiveness was assessed using cost per quality-adjusted life-year (QALY) gained.

RESULTS

Compared with rFVIII, rFVIIIFc was associated with a per-patient cost saving of approximately €1.3 million and QALY gains of 0.39 over a lifetime horizon. Sensitivity analyses considering alternative efficacy, dosing, and structural assumptions each showed that rFVIIIFc dominated rFVIII (i.e., provided more QALYs at a reduced cost).

CONCLUSIONS

This cost-effectiveness analysis demonstrated that rFVIIIFc may offer a cost-effective treatment option for patients with SHA in Italy.

Optimizing bleed prevention throughout the lifespan: Womb to Tomb

The focus of care providers, patients and families is the ability to tailor care for persons with haemophilia (PWH) across the lifespan. Care requires knowledge of the bleeding disorder and age-related complications, risk of therapeutic interventions, and evaluation of individual characteristics that contribute to outcomes. The ultimate goal is to live a normal life without the burden of bleeding, for PWH and carriers. A wide range of therapeutic options is required to achieve personalized care. Over the last decade, substantial therapeutic advantages have been achieved in the treatment of haemophilia that include the development of a robust array of factor concentrates, novel haemostatic agents, and increased knowledge and awareness of disease associated outcomes and risk factors. Significant strides on the road to accessible gene therapy have been realized. This increased range of therapeutic modalities provides options for development and implementation of care plans for each patient at each stage of life that are more flexible compared to prior care regimens. Paradigms for management of haemophilia are changing. As a community, we must work together to use these resources wisely, to learn from outcomes with new therapies and diagnostic tools, to assure all patients can achieve improved care and outcomes regardless of disease state or country of origin.

Adherence to prophylaxis in adolescents and young adults with severe haemophilia A, a qualitative study with patients

Introduction: Reported levels of adherence to prophylaxis among young people with haemophilia (YPH) vary widely and are predominately based on estimations made by healthcare professionals and parents. Reasons for (non)adherence among YPH in particular have not been evidenced.

Aim: to examine experiences in relation to prophylaxis with YPH themselves, and barriers and facilitators to their adherence.

Methods: 11 Participants were recruited in five haemophilia centres across England and Wales. All patients who met the inclusion criteria (aged 12-25, diagnosed with haemophilia, on prophylaxis) were approached during a routine check-up appointment, and all participants who agreed to take part were interviewed. Interviews were audio recorded, transcribed and analysed using Interpretative Phenomenological Analysis.

Results: Self-reported adherence to prophylaxis was good. Few participants admitted to intentionally skipping injections although they reported sometimes forgetting. However, due to the increasingly personalised and flexible approach to prophylaxis, adherence is not straightforward to define. Barriers to adherence included a busy lifestyle, dislike of the intravenous injection, venous access issues, anxiety or stress and being out of one’s normal routine. Support was an important facilitator to adherence, including support from health professionals at the haemophilia centre as well as friends. Parents appear to be very involved with their child’s haemophilia management, even after they leave home.

Conclusion: What this study adds is that the increasingly flexible and personalised approach to managing prophylaxis in haemophilia may sometimes lead to confusion around treatment frequency and dosing. This may lead to accidental non-adherence, which is distinct from both skipping and forgetting. Advice from haemophilia teams may not always be consistent and is likely to be interpreted differently by different individuals. Some additional training and education of patients and their families to increase their knowledge and skills around prophylaxis may reduce this confusion and therefore is likely to improve adherence further.

Major bleeding disorders: diagnosis, classification, management and recent developments in haemophilia

In this review, we outline the standard of care for children in the UK with the most common major bleeding disorder, haemophilia, and how exciting new developments in therapy have the potential for further improvements in quality of life and clinical outcome. The combination of comprehensive specialist medical care, safer factor concentrates, earlier introduction of prophylaxis and patient-specific education has allowed the current generation of patients with haemophilia to grow into adulthood with excellent joint function, pursuing full-time employment with a good quality of life. We are entering an exciting new phase in paediatric haemophilia as potentially life-changing products appear on the scene taking a step towards achieving better, easier and personalised prophylaxis.

Validation of the Brazilian version of the VERITAS-Pro scale to assess adherence to prophylactic regimens in hemophilia

INTRODUCTION

Prophylaxis is the treatment of choice for patients with severe hemophilia. Low adherence may limit the effectiveness of the prophylactic regimen, thereby compromising outcomes.

OBJECTIVE

The objective of this study was to validate the Brazilian version of the VERITAS-Pro prophylaxis adherence scale, originally an American questionnaire that can be answered by the individual responsible for prophylaxis as well as by an observer.

METHODS

The scale has 24 questions divided into six subscales: Routine, Dosage, Plan, Remember, Skip and Communicate. Participants were recruited at a blood center in southeastern Brazil for validation and reliability analyses. Validation measures included the results obtained using analog visual scales of adherence, interval between medication dispensed by the treatment center pharmacy and the percentage of recommended doses administered and infusions registered in the patients' logs.

RESULTS

The study included 32 individuals responsible for prophylaxis and five observers. The internal consistency was very good for the VERITAS-Pro total score, excellent for the Remember, Skip and Communicate subscales, good for the Dosage subscale, and acceptable for the Routine and Plan subscales. Twelve participants answered the questionnaire on more than one occasion to evaluate reproducibility. The intraclass correlation coefficient was excellent. Regarding convergent validity, the VERITAS-Pro scores were moderately correlated with the global adherence scale and with infusion log records, but showed a weak correlation with pharmacy dispensation records.

CONCLUSION

The Brazilian version of VERITAS-Pro is a valid and reliable instrument, enabling the understanding of specific factors related to non-adherence and allowing targeted interventions for proper treatment.

Progress in the contemporary management of hemophilia: The new issue of patient aging

The management of inherited coagulation disorders such as hemophilia A and B has witnessed dramatic progresses since the last few decades of the last century. Accordingly, persons with hemophilia (PWH) now enjoy a life expectancy at birth not different from that of males in the general population, at least in high income countries. Nowadays, a substantial proportion of PWH are aging, like their peers in the general population. This outstanding progress is accompanied by problems that are in part similar to those of any old person (multiple concomitant diseases and the resulting intake of multiple drugs other than those specific for hemophilia treatment). In addition, older PWH suffer from the consequences of the comorbidities that developed when their treatment was at the same time poorly available and unsafe. Typical hemophilia comorbidities affect the musculoskeletal system following joint and muscle bleeds, but also the liver and kidney are often impaired due to previous bloodborne infections such as viral hepatitis and HIV. Thus, the comorbidities of hemophilia superimposed on the multimorbidity and polypharmacy associated with aging create peculiar problems in the current management of these patients, that demand the coordinated holistic intervention of internists, geriatricians and clinical pharmacologists in addition to the care traditionally provided by pediatricians and hematologists.

Efficacy of standard prophylaxis versus on-demand treatment with bayer's sucrose-formulated recombinant FVIII (rFVIII-FS) in Chinese children with severe hemophilia A

In China, care of patients with severe hemophilia primarily involves insufficient dosing of on-demand treatment and secondary low-dose prophylaxis (10 IU/kg 2× /wk). We sought to evaluate 3× /wk, standard-dose prophylaxis with sucrose-formulated recombinant factor VIII (rFVIII-FS; Bayer) compared with on-demand treatment in Chinese children with severe hemophilia A. Children and adolescents aged 2-16 years with severe hemophilia A, no inhibitors, and no prophylaxis for >6 consecutive months before study entry were eligible for this 24-week, interventional, sequential-treatment study. Patients received rFVIII-FS on demand for 12 weeks followed by a 12-week prophylaxis period (25 IU/kg 3× /wk). The primary efficacy endpoint was comparison of the annualized bleeding rate (ABR) of all bleeds in the prophylaxis versus on-demand phase. Additional variables included ABR of joint bleeds, school attendance/activity, daily activity, and hemophilia Joint Health Score (HJHS). Thirty patients (median age, 12 years) were treated and analyzed. Compared with on-demand treatment, prophylaxis reduced median (quartile [Q1; Q3]) ABR of all bleeds (57.5 [44.5; 73.9] vs 0 [0; 4.0]) and joint bleeds (34.5 [26.1; 56.5] vs 0 [0; 4.0]). Median (range) total HJHS improved after both the prophylaxis and on-demand phases (8.0 [0-48.0] and 11.0 [0-55.0], respectively) compared with baseline (16.0 [0-56.0]). School attendance/activity and daily activity improved with prophylaxis versus on demand. No inhibitors or treatment-related adverse events were reported. In this first prospective, standard-dose, secondary prophylaxis study in China, rFVIII-FS prophylaxis reduced bleeding and improved health outcomes versus on-demand treatment in children with severe hemophilia A.

Treatment adherence in hemophilia

Prophylactic clotting-factor regimens reduce the occurrence of bleeding episodes and maintain joint health in individuals with moderate and severe hemophilia. However, these outcomes are only achieved with adherence to prescribed prophylaxis regimens. There are several types of barriers to adherence related to key patient, condition, treatment, health-care system, and/or socioeconomic variables. Notably, health-care professionals may not prescribe prophylaxis if they perceive that a patient will be nonadherent. Prophylactic treatment strategies should be developed with the patient and family, focused on individualized treatment goals. Personalized strategies are needed to reinforce the importance of and encourage confidence in administering the regular infusions required for prophylactic therapy. These strategies may include verbal and written information delivered by health-care professionals, peers, and inter-active media. The advent of extended half-life clotting factors requiring less frequent infusion may improve adherence.

Usefulness of a simple self-administered joint condition assessment sheet to predict the need for orthopaedic intervention in the management of haemophilic arthropathy

INTRODUCTION

Detecting signs of joint deterioration is important for early effective orthopaedic intervention in managing haemophilic arthropathy.

AIM

We developed a simple, patient self-administered sheet to evaluate the joint condition, and assessed the predictive ability of this assessment sheet for the need for an orthopaedic intervention.

METHODS

This was a single-centre, cross-sectional study. The association between the score of each of the four items of the assessment sheet (bleeding, swelling, pain and physical impairment) and the results of radiological findings and physical examinations based on Haemophilia Joint Health Score 2.1 was assessed. An optimal scoring system was explored by the area under the curve (AUC). The cut-off value for the need for surgery or physiotherapy was determined using the receiver operating characteristic curve procedure.

RESULTS

Forty-two patients were included. The 'physical impairment' item showed the highest correlation coefficient with the results of radiographic and physical examinations (range: 0.57-0.76). The AUC of finally adjusted scoring indicates good ability to discriminate between patients with and without a need for orthopaedic intervention. The positive predictive value was the highest at a cut-off value of 4 points for knees (63.0%) and ankles (70.0%), at 5 points for elbows (66.7%) and the highest predictive accuracy at the cut-off value of 4 points for all the joints. The linear trend of the need for an orthopaedic intervention was observed with an increasing score.

CONCLUSION

The joint condition assessment sheet can help clinicians assess the need for orthopaedic intervention for haemophilic arthropathy in Japanese patients with haemophilia.

Advances in the clinical management of inhibitors in hemophilia A and B

Inhibitors to factor (F)VIII or FIX are the most serious and challenging complication of hemophilia treatment, increasing morbidity and mortality because bleeds no longer respond to standard clotting factor replacement therapy. For patients with high-titer inhibitors, immune tolerance induction achieved through regular factor exposure is the only proven therapy capable of Inhibitor eradication and is almost always indicated for inhibitors of recent onset. Bypassing therapy is used to treat and prevent bleeding, but neither of the two currently available bypassing agents has the predictable hemostatic efficacy of factor replacement in hemophilia patients without inhibitors. Major research efforts are focused on the development of new, more potent therapies for the management of patients with inhibitors.

How I use bypassing therapy for prophylaxis in patients with hemophilia A and inhibitors

Inhibitor development poses a significant challenge in the management of hemophilia because once an inhibitor is present, bleeding episodes can no longer be treated with standard clotting factor replacement therapy. Consequently, patients with inhibitors are at increased risk for difficult-to-control bleeding and complications, particularly arthropathy and physical disability. Three clinical trials in patients with inhibitors have demonstrated that prophylaxis with a bypassing agent reduces joint and other types of bleeding and improves health-related quality of life compared with on-demand bypassing therapy. In hemophilia patients without inhibitors, the initiation of prophylaxis with factor (F) VIII or FIX prior to the onset of recurrent hemarthroses can prevent the development of joint disease. Whether this is also true for bypassing agent prophylaxis remains to be determined.

Recombinant long-acting glycoPEGylated factor IX in hemophilia B: a multinational randomized phase 3 trial

This multinational, randomized, single-blind trial investigated the safety and efficacy of nonacog beta pegol, a recombinant glycoPEGylated factor IX (FIX) with extended half-life, in 74 previously treated patients with hemophilia B (FIX activity ≤2 IU/dL). Patients received prophylaxis for 52 weeks, randomized to either 10 IU/kg or 40 IU/kg once weekly or to on-demand treatment of 28 weeks. No patients developed inhibitors, and no safety concerns were identified. Three hundred forty-five bleeding episodes were treated, with an estimated success rate of 92.2%. The median annualized bleeding rates (ABRs) were 1.04 in the 40 IU/kg prophylaxis group, 2.93 in the 10 IU/kg prophylaxis group, and 15.58 in the on-demand treatment group. In the 40 IU/kg group, 10 (66.7%) of 15 patients experienced no bleeding episodes into target joints compared with 1 (7.7%) of 13 patients in the 10 IU/kg group. Health-related quality of life (HR-QoL) assessed with the EuroQoL-5 Dimensions visual analog scale score improved from a median of 75 to 90 in the 40 IU/kg prophylaxis group. Nonacog beta pegol was well tolerated and efficacious for the treatment of bleeding episodes and was associated with low ABRs in patients receiving prophylaxis. Once-weekly prophylaxis with 40 IU/kg resolved target joint bleeds in 66.7% of the affected patients and improved HR-QoL. This trial was registered at www.clinicaltrials.gov as #NCT01333111.

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.

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.).

Outcome measures monitoring physical function in children with haemophilia: a systematic review

Our objective was to provide a synthesis of measurement properties for performance-based outcome measures used to evaluate physical function in children with haemophilia. A systematic review of articles published in English using Medline, PEDro, Cinahl and The Cochrane Library electronic databases was conducted. Studies were included if a performance-based method, clinical evaluation or measurement tool was used to record an aspect of physical function in patients with haemophilia aged ≤ 18 years. Recording of self-perceived or patient-reported physical performance, abstracts, unpublished reports, case series reports and studies where the outcome measure was not documented or cross-referenced was excluded. Description of outcome measures, patient characteristics, measurement properties for construct validity, internal consistency, repeatability, responsiveness and feasibility was extracted. Data synthesis of 41 studies evaluating 14 measures is reported. None of the outcome measures demonstrated the requirements for all the measurement properties. Data on validity and test-retest repeatability were most lacking together with studies of sufficient size. Measurement of walking and muscle strength demonstrated good repeatability and discriminative properties; however, correlation with other measures of musculoskeletal impairment requires investigation. The Haemophilia Joint Health Score demonstrated acceptable construct validity, internal consistency and repeatability, but the ability to discriminate changes in physical function is still to be determined. Rigorous evaluation of the measurement properties of performance-based outcome measures used to monitor physical function of children with haemophilia in larger collaborative studies is required.

Haemophilia Joint Health Score in healthy adults playing sports

To evaluate outcome of prophylactic clotting factor replacement in children with haemophilia, the Haemophilia Joint Health Score (HJHS) was developed aiming at scoring early joint changes in children aged 4-18. The HJHS has been used for adults on long-term prophylaxis but interpretation of small changes remains difficult. Some changes in these patients may be due to sports-related injuries. Evaluation of HJHS score in healthy adults playing sports could improve the interpretation of this score in haemophilic patients. The aim of this study was to evaluate the HJHS scores in a cohort of young, healthy men participating in sports. Concomitant with a project collecting MRI images of ankles and knees in normal young adults, HJHS scores were assessed in 30 healthy men aged 18-26, participating in sports one to three times per week. One physiotherapist assessed their clinical function using the HJHS 2.1. History of joint injuries was documented. MRI images were scored by a single radiologist, using the International Prophylaxis Study Group additive MRI score. Median age of the study group was 24.3 years (range 19.0-26.4) and median frequency of sports activities was three times per week (range 1-4). Six joints (five knees, one ankle) had a history of sports-related injury. The median overall HJHS score was 0 out of 124 (range 0-3), with 60% of subjects showing no abnormalities on HJHS. All joints were normal on MRI. These results suggest that frequent sports participation and related injuries are not related with abnormalities in HJHS scores.

Hemophilia A and hemophilia B: focus on arthropathy and variables affecting bleeding severity and prophylaxis

Hemophilia A (HA) and hemophilia B (HB) are X-linked, recessive disorders. Although their clinical manifestations are essentially indistinguishable, it has been suggested that bleeding episodes in patients with HA are generally more severe and occur at higher frequency than in patients with HB. Nevertheless, considerable debate remains regarding the relative severity of HA and HB. Based on the relative risk of undergoing joint arthroplasty, it appears that patients with HA have more severe joint deterioration compared with patients with HB. Although it is difficult to speculate on the factors that might modify bleeding severity in patients with hemophilia, recent observations indicate that other coagulation proteins, such as tissue factor pathway inhibitor or polymorphisms in coagulation factor genes and genetic defects associated with hypercoagulability may account for the variability in clinical phenotype among patients with hemophilia. Numerous studies have provided evidence supporting the clinical and social benefits of administration of clotting factor in prophylaxis. However, it is still unclear why this approach is more commonly utilized in patients with HA than in those with HB.

Secondary prophylaxis vs. on-demand treatment to improve quality of life in severe adult haemophilia A patients: a prospective study in a single centre

BACKGROUND

Retrospective publications show a decrease in the bleeding frequency and an improvement in the quality of life (QoL) in severe adult haemophilia A (SAHA) after switching from the on-demand treatment (DT) to secondary prophylaxis (SP). But there are no prospective studies which demonstrate, using a haemophilia-specific questionnaire, an improvement in the QoL after such treatment change. The main objective of this study is to prospectively compare the QoL and the musculoskeletal assessment after switching from DT to SP in SAHA using the A36 Hemofilia-QoL(®) . As secondary objective, we compare the haemarthrosis frequency and factor VIII consumption in DT and SP during a similar period of time (12 months) after switching.

MATERIALS AND METHODS

We have designed a prospective study including SAHA who have been under DT and were changed to a protocol, which combines SP (biweekly administration of factor VIII) with individualized physiotherapy programme.

RESULTS

Twelve months after switching to SP, the QoL was significantly improved (P = 0·005). Musculoskeletal assessment of pathologic irreversible joints and joints with a reversible alteration was generally improved, although in only a few joints, this improvement was statistically significant. Haemarthrosis was strongly reduced (12·60-1·42, P < 0·001).

CONCLUSIONS

This prospective study has demonstrated a statistically significant improvement in the QoL after 1 year from switching patients from DT to SP. The musculoskeletal assessment after 1 year was maintained similar or slightly improved. When we compared retrospective DT and prospective SP, haemarthrosis where strongly reduced requiring a slight increase in the consumption of factor VIII concentrates.

Randomized, controlled, parallel-group trial of routine prophylaxis vs. on-demand treatment with sucrose-formulated recombinant factor VIII in adults with severe hemophilia A (SPINART)

BACKGROUND

The benefits of routine prophylaxis vs. on-demand treatment with factor VIII products have not been evaluated in controlled clinical trials in older patients with hemophilia A.

OBJECTIVES

To report results from a preplanned analysis of data from the first year of the 3-year SPINART study, which compares routine prophylaxis with on-demand treatment with sucrose-formulated recombinant FVIII (rFVIII-FS).

PATIENTS/METHODS

SPINART is an open-label, randomized, controlled, parallel-group, multinational trial. Males aged 12-50 years with severe hemophilia A, ≥ 150 days of exposure to FVIII, no FVIII inhibitors, no prophylaxis for > 12 consecutive months in the past 5 years and 6-24 bleeding episodes in the preceding 6 months were randomized 1 : 1 to rFVIII-FS prophylaxis (25 IU kg(-1) , three times weekly) or on-demand treatment. The primary efficacy endpoint, number of total bleeding episodes in the intent-to-treat population, was analyzed after the last patient had completed 1 year of follow-up. A negative binomial model was used for the primary endpoint analysis; analysis of variance was used for confirmatory analysis of annualized bleeding rates.

RESULTS

Eighty-four patients were enrolled and analyzed (n = 42 per group; mean age, 30.6 years; median treatment duration, 1.7 years). The median number of total bleeding episodes and total bleeding episodes per year were significantly lower with prophylaxis than with on-demand treatment (total, 0 vs. 54.5; total per year, 0 vs. 27.9; both P < 0.0001). No treatment-related adverse events occurred, and no patients developed FVIII inhibitors.

CONCLUSIONS

Routine prophylaxis with rFVIII-FS leads to a significant reduction in bleeding as compared with on-demand treatment. Adverse events were consistent with the established rFVIII-FS safety profile.

Factors affecting the Haemophilia Joint Health Score in children with severe haemophilia

Joint damage from bleeding episodes leads to physical or functional limitations in people with haemophilia. Various factors may influence the frequency and severity of joint damage. This study examined whether age, prophylaxis, history of high-titre inhibitors (HTI) and bleeding events influenced the Haemophilia Joint Health Score (HJHS) in children. Medical and physiotherapy notes of boys with severe haemophilia, aged 4-18 years, were reviewed to identify factors associated with increased HJHS. The HJHS of 83 boys (median age: 11) ranged from 0 to 25, with 44/83 (53%) having a score of zero. The median HJHS was 0 (mean 2.6). In the non-HTI group, the HJHS for boys on late prophylaxis was 2.68 times higher than those who started early and the HJHS was on average 10% higher for every additional recent bleed. In this group the odds of having a zero score fell by 30% for every year increase in age. Boys with a history of HTI had higher HJHS scores than the non-HTI group, and age, number of recent bleeds and tolerized status were positively associated with HJHS. The score rose on average by 28% for every year of age and by 76% for non-tolerized boys. This study provides further evidence supporting early prophylaxis use and the importance of immune tolerance therapy. The HJHS is a useful tool for identifying and tracking changes in joint health with respect to therapy or disease progression. With improvements in haemophilia treatment, the disproportionate number of zero scores will continue to make interpretation of the HJHS challenging.

Musculoskeletal health of subjects with hemophilia A treated with tailored prophylaxis: Canadian Hemophilia Primary Prophylaxis (CHPS) Study

BACKGROUND

Full-dose prophylaxis is very effective at minimizing joint damage but is costly. Tailored prophylaxis has been proposed as a way of reducing costs while still protecting joints.

OBJECTIVE

To report detailed findings in index joints of 56 subjects with severe hemophilia A entered into the Canadian Hemophilia Prophylaxis Study, and treated with tailored prophylaxis, after 13 years.

METHODS

Boys with severe hemophilia A (< 2% factor) and normal joints were enrolled between the ages of 1 and 2.5 years. Initial treatment consisted of once-weekly factor infusions, with the frequency escalating in a stepwise fashion when breakthrough bleeding occurred. During the first 5 years, subjects were examined every 3 months using the modified Colorado Physical Evaluation (PE) scale; subsequently, every 6 months. The Childhood Health Assessment Questionnaire (CHAQ) was administered at each visit.

RESULTS

Median age at study entry was 19 months (range 12-30 months); median follow-up was 92 months (range 2-156). The median PE score was 2, 3 and 3 at ages 3, 6 and 10 years. Persistent findings were related to swelling, muscle atrophy and loss of range of motion. The median score for each of these items (for the six index joints) was 0 at ages 3, 6 and 10 years. The median overall CHAQ score was 0 at ages 3, 6 and 10 years, indicating excellent function.

CONCLUSIONS

Canadian boys treated with tailored primary prophylaxis exhibit minimal joint change on physical examination and minimal functional disability.

Haemophilia B: current pharmacotherapy and future directions

INTRODUCTION

Hemophilia B is a rare hereditary hemorrhagic disorder characterized by deficiency of the clotting factor IX (FIX). Hemophilia B patients experience mild to severe bleeding complications according to the degree of FIX defect. Nowadays, the most challenging complication of individuals with hemophilia B is the development of alloantibodies, which render the standard replacement therapy with FIX concentrates ineffective, exposing them to a significantly increased morbidity and mortality.

AREAS COVERED

This review summarizes the most important events leading to the development of the current FIX products available for the treatment of hemophilia B patients. In addition, it focuses on the more recent advances in the production of new FIX molecules aimed at improving the clinical management of such patients.

EXPERT OPINION

Although the availability of plasma-derived FIX concentrates has greatly improved the clinical management of hemophilia B patients, the introduction of FIX products using recombinant DNA technology has represented the most significant therapeutic progress in hemophilia B therapy, ensuring an advanced level of safety. The development of rFIX products with extended half lives will further improve the therapeutic armamentarium for hemophilia B patients.

Biomechanics of lower limb haemophilic arthropathy

Intermittent joint bleeding and potential arthropathy remain a concern for patients and those responsible for haemophilic care. Monitoring the status of haemophilic joints is a current challenge. Evaluation of bone and soft tissue with radiological imaging together with clinical joint scoring is often used to monitor haemophilic arthropathy and may not be sufficiently sensitive to early changes in joint morphology. Recently an interest in the biomechanical status of haemophilic joints has emerged. Biomechanics is defined as the interdiscipline that describes, analyses and assesses movement in relation to biological and physical principles. This review considers the biomechanical evaluation of haemophilic joint status of the lower limb with particular reference to the evaluation of muscle atrophy, muscle strength, range of motion and gait as well as the relationship to haemophilic arthropathy. In raising the need for increased clinical awareness, this review highlights the need to establish test-retest and inter-rater reliability and ensuring that comparative studies are undertaken with age-matched unaffected peer groups.

Current prescription of prophylactic factor infusions and perceived adherence for children and adolescents with haemophilia: a survey of haemophilia healthcare professionals in the United States

The primary goal of prophylaxis in patients with severe haemophilia is to convert the phenotype from severe to moderate and to prevent the development of chronic arthropathy. Prior studies have demonstrated that prophylaxis decreases episodes of joint bleeds and chronic arthropathy. Effectiveness depends on prescription of prophylaxis and adherence to the prescribed regimen. The aim of this study was to determine if prescription of prophylaxis for children with haemophilia and perceptions of adherence to prophylaxis have changed since publication of the Joint Outcome Study (JOS). A questionnaire was sent, in electronic and written formats, to health professionals who provide care to children with haemophilia at US haemophilia treatment centres (HTCs). The response rate was 56 of 128 (44%) of the targeted HTCs. There were a few missing data and denominators are provided. All responses agreed with the results of the JOS and 30/55 (55%) reported the JOS increased their prescription of prophylaxis. Nineteen of 56 (34%) physicians or HTC staff reported that they had not prescribed prophylaxis within the last year due to concerns about adherence, and 19/56 (34%) reported they had stopped prophylaxis due to concerns about adherence within the last year. Predicted adherence decreased with increasing age. Prescription of prophylaxis appears to be increasing since publication of the JOS. Strategies to improve adherence may increase the likelihood of physician prescription of prophylaxis and make prophylaxis easier to implement for individual patients, thereby improving the clinical outcome of children and adults with haemophilia.

Joint health and functional ability in children with haemophilia who receive intensive replacement therapy

Joint physical examination is an important outcome in haemophilia; however its relationship with functional ability is not well established in children with intensive replacement therapy. Boys aged 4-16 years were recruited from two European and three North American treatment centres. Joint physical structure and function was measured with the Haemophilia Joint Health Score (HJHS) while functional ability was measured with the revised Childhood Health Assessment Questionnaire (CHAQ₃₈. Two haemophilia-specific domains were created by selecting items of the CHAQ₃₈ that cover haemophilia-specific problems. Associations between CHAQ, HJHS, cumulative number of haemarthroses and age were assessed. A total of 226 subjects - mean 10.8 years old (SD 3.8) - participated; the majority (68%) had severe haemophilia. Most severe patients (91%) were on prophylactic treatment. Lifetime number of haemarthroses [median=5; interquartile range (IQR)=1-12] and total HJHS (median = 5; IQR=1-12) correlated strongly (ρ = 0.51). Total HJHS did not correlate with age and only weakly (ρ=-0.19) with functional ability scores (median=0; IQR=-0.06-0). Overall, haemarthroses were reported most frequently in the ankles. Detailed analysis of ankle joint health scores revealed moderate associations (ρ=0.3-0.5) of strength, gait and atrophy with lower extremity tasks (e.g. stair climbing). In this population, HJHS summating six joints did not perform as well as individual joint scores, however, certain elements of ankle impairment, specifically muscle strength, atrophy and gait associated significantly with functional loss in lower extremity activities. Mild abnormalities in ankle assessment by HJHS may lead to functional loss. Therefore, ankle joints may warrant special attention in the follow up of these children.

Validation of a new pediatric joint scoring system from the International Hemophilia Prophylaxis Study Group: validity of the hemophilia joint health score

OBJECTIVE

Repeated hemarthrosis in hemophilia causes arthropathy with pain and dysfunction. The Hemophilia Joint Health Score (HJHS) was developed to be more sensitive for detecting arthropathy than the World Federation of Hemophilia (WFH) physical examination scale, especially for children and those using factor prophylaxis. The HJHS has been shown to be highly reliable. We compared its validity and sensitivity to the WFH scale.

METHODS

We studied 226 boys with mild, moderate, and severe hemophilia at 5 centers. The HJHS was scored by trained physiotherapists. Study physicians at each site blindly determined individual and total joint scores using a series of visual analog scales.

RESULTS

The mean age was 10.8 years. Sixty-eight percent were severe (93% of whom were treated with prophylaxis), 15% were moderate (24% treated with prophylaxis), and 17% were mild (3% treated with prophylaxis). The HJHS correlated moderately with the physician total joint score (rs=0.42, P<0.0001) and with overall arthropathy impact (rs=0.42, P<0.0001). The HJHS was 97% more efficient than the WFH at differentiating severe from mild and moderate hemophilia. The HJHS was 74% more efficient than the WFH at differentiating subjects treated with prophylaxis from those treated on demand. We identified items on the HJHS that may be redundant or rarely endorsed and could be removed from future versions.

CONCLUSION

Both the HJHS and WFH showed evidence of strong construct validity. The HJHS is somewhat more sensitive for mild arthropathy; its use should be considered for studies of children receiving prophylaxis.

Challenges of defining reliable clinical surrogate end points in haemophilia trials: a critical review

The success of a treatment in haemophilia patients experiencing a bleeding episode is very difficult to define. A variety of efficacy assessment tools have been developed in an effort to better assess when haemostasis has been achieved. These assessment tools are particularly important for the evaluation of the efficacy of therapeutic agents whose mechanism of action is based on pharmacological activity in haemostasis rather than upon the principle of 'replacement therapy'. This review focuses on a number of efficacy measures, summarizing their methodology and discussing their validity. In addition, future developments and requirements in order to evaluate the effectiveness of haemostatic treatment are discussed. The majority of end points used for evaluation of haemostasis relate to the relief of symptoms arising from bleeds. The results of this review highlight that several efficacy end points are frequently combined in order to provide a more comprehensive assessment of efficacy. Key limitations of current methodology are the subjectivity of assessment by either the patient or clinician, and the incomparability of results between trials.