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Introduction: Bleeding severity in severe haemophilic patients, with low thrombin generation (TG) capacity, can vary widely between patients, possibly reflecting differences in tissue factor pathway inhibitor (TFPI) level., Aim: To compare free TFPI (fTFPI) levels in patients with severe haemophilia A (sHA) and severe haemophilia B (sHB) and to investigate in these patients as a whole the relationships between bleeding and TG potential, between TG potential and fTFPI level and between fTFPI level and bleeding tendency., Methods: Data on bleeding episodes retrospectively recorded during follow-up visits over 5-10 years were collected and used to calculate the annualised joint bleeding rate (AJBR). fTFPI levels and basal TG parameters were determined in platelet-poor plasma (PPP) and platelet-rich plasma (PRP) using calibrated automated tomography (CAT)., Results: Mean fTFPI levels did not differ significantly between sHA (n = 34) and sHB (n = 19) patients. Mean values of endogenous thrombin potential (ETP) and thrombin peak (peak) in PPP and PRP were two-fold higher when fTFPI levels < 9.4 versus > 14.3 ng/mL. In patients treated on demand, ETP and peak in PRP were doubled when AJBR was ≤ 4.9 $ \le 4.9$ , AJBR being halved in patients with a low fTFPI level (9.4 ng/mL). In patients on factor prophylaxis, no association was found between TG parameters and either fTFPI level or AJBR., Conclusion: In patients treated on demand, bleeding tendency was influenced by fTFPI levels, which in turn affected basal TG potential. In patients on prophylaxis, bleeding tendency is probably determined primarily by the intensity of this treatment., (© 2024 The Authors. Haemophilia published by John Wiley & Sons Ltd.)

Long-term efficacy and safety of the extended half-life recombinant factor IX Fc fusion protein (rFIXFc) has been established among previously treated patients with severe hemophilia B in 2 phase 3 trials (B-LONG [#NCT01027364] and Kids B-LONG [#NCT01440946]) and a long-term extension study (B-YOND [#NCT01425723]). In this study, we report post hoc analyses of pooled longitudinal data for up to 6.5 years for rFIXFc prophylaxis. In the B-LONG study, subjects ≥12 years received weekly dose-adjusted prophylaxis (WP; starting dose, 50 IU/kg), individualized interval-adjusted prophylaxis (IP; initially, 100 IU/kg every 10 days), or on-demand dosing. In the Kids B-LONG study, subjects <12 years received 50 to 60 IU/kg every 7 days, adjusted as needed. In the B-YOND study, subjects received WP (20-100 IU/kg every 7 days), IP (100 IU/kg every 8-16 days), modified prophylaxis, or on-demand dosing; switching between treatment groups was permitted. A total of 123 subjects from B-LONG and 30 from Kids B-LONG study were included, of whom 93 and 27, respectively, enrolled in the B-YOND study. The median cumulative duration of treatment was 3.63 years (range, 0.003-6.48 years) in B-LONG/B-YOND and 2.88 years (range, 0.30-4.80 years) in Kids B-LONG/B-YOND group. Annualized bleed rates (ABRs) remained low, annualized factor consumption remained stable, and adherence remained high throughout treatment. Low ABRs were also maintained in subjects with dosing intervals ≥14 days or with target joints at baseline. Complete resolution of evaluable target joints and no recurrence in 90.2% of baseline target joints during follow-up were observed. rFIXFc prophylaxis was associated with sustained clinical benefits, including long-term bleed prevention and target joint resolution, for severe hemophilia B., (© 2023 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

Background: The disease-causative variant remains unidentified in approximately 0.5% to 2% of hemophilia B patients using conventional genetic investigations, and F9 deep intronic variations could be responsible for these phenotypes., Objectives: This study aimed to characterize deep intronic variants in hemophilia B patients for whom genetic investigations failed., Methods: We performed whole F9 sequencing in 17 genetically unsolved hemophilia B patients. The pathogenic impact of the candidate variants identified was studied using both in silico analysis (MaxEntScan and spliceAI) and minigene assay., Results: In total, 9 candidate variants were identified in 15 patients; 7 were deep intronic substitutions and 2 corresponded to insertions of mobile elements. The most frequent variants found were c.278-1806A>C and the association of c.278-1244A>G and c.392-864T>G, identified in 4 and 6 unrelated individuals, respectively. In silico analysis predicted splicing impact for 4 substitutions (c.278-1806A>C, c.392-864T>G, c.724-2385G>T, c.723+4297T>A). Minigene assay showed a deleterious splicing impact for these 4 substitutions and also for the c.278-1786&#95;278-1785insLINE. In the end, 5 variants were classified as likely pathogenic using the American College of Medical Genetics and Genomics guidelines, and 4 as of unknown significance. Thus, the hemophilia B-causing variant was identified in 13/17 (76%) families., Conclusion: We elucidated the causing defect in three-quarters of the families included in this study, and we reported new F9 deep intronic variants that can cause hemophilia B., (Copyright © 2022 International Society on Thrombosis and Haemostasis. Published by Elsevier Inc. All rights reserved.)

The incidence of FIX inhibitors in severe hemophilia B (SHB) is not well defined. Frequencies of 3-5% have been reported but most studies to date were small, including patients with different severities, and without prospective follow-up for inhibitor incidence. Study objective was to investigate inhibitor incidence in patients with SHB followed up to 500 exposure days (ED), the frequency of allergic reactions, and the relationship with genotypes. Consecutive previously untreated patients (PUPs) with SHB enrolled into the PedNet cohort were included. Detailed data was collected for the first 50 ED, followed by annual collection of inhibitor status and allergic reactions. Presence of inhibitors was defined by at least two consecutive positive samples. Additionally, data on factor IX gene mutation was collected. 154 PUPs with SHB were included; 75% were followed until 75 ED, and 43% until 500 ED. Inhibitors developed in 14 patients (7 high-titre). Median number of ED at inhibitor manifestation was 11 (IQR 6.5-36.5). Cumulative inhibitor incidence was 9.3% (95%CI 4.4-14.1) at 75 ED, and 10.2% (5.1-15.3) at 500 ED. Allergic reactions occurred in 4 (28.6%) inhibitor patients. Missense mutations were most frequent (46.8%) overall but not associated with inhibitors. Nonsense mutations and deletions with large structural changes comprised all mutations among inhibitor patients and were associated with an inhibitor risk of 26.9% and 33.3%, respectively. In an unselected, well-defined cohort of PUPs with SHB, cumulative inhibitor incidence was 10.2% at 500 ED. Nonsense mutations and large deletions were strongly associated with the risk of inhibitor development. The PedNet Registry is registered at clinicaltrials.gov; identifier: NCT02979119.

Introduction: Recombinant factor IX Fc fusion protein (rFIXFc) has demonstrated efficacy for treatment of haemophilia B in the Phase 3 B-LONG and Kids B-LONG studies. However, long-term rFIXFc safety and efficacy data have not yet been reported., Aim: To report long-term rFIXFc safety and efficacy in subjects with haemophilia B., Methods: B-YOND (NCT01425723) was an open-label extension for eligibl previously treated subjects who completed B-LONG or Kids B-LONG. Subjects received ≥1 treatment regimen: weekly prophylaxis (WP), individualized interval prophylaxis (IP), modified prophylaxis or episodic treatment. Subjects could switch regimens at any time. The primary endpoint was inhibitor development., Results: Ninety-three subjects from B-LONG and 27 from Kids B-LONG (aged 3-63 years) were enrolled. Most subjects received WP (B-LONG: n = 51; Kids B-LONG: n = 23). For subjects from B-LONG, median (range) treatment duration was 4.0 (0.3-5.4) years and median (range) number of exposure days (EDs) was 146 (8-462) EDs. Corresponding values for paediatric subjects were 2.6 (0.2-3.9) years and 132 (50-256) EDs. No inhibitors were observed (0 per 1000 subject-years; 95% confidence interval, 0-8.9) and the overall rFIXFc safety profile was consistent with prior studies. Annualized bleed rates remained low and extended-dosing intervals were maintained for most subjects. Median dosing interval for the IP group was approximately 14 days for adults and adolescents (n = 31) and 10 days for paediatric subjects (n = 5)., Conclusions: B-YOND results confirm the long-term (up to 5 years, with cumulative duration up to 6.5 years) well-characterized safety and efficacy of rFIXFc treatment for haemophilia B., (© 2020 The Authors. Haemophilia published by John Wiley & Sons Ltd.)

Introduction:  A phase 3b extension study evaluated the long-term safety and efficacy of a recombinant fusion protein-linking coagulation factor IX (FIX) with albumin (rIX-FP) for the routine prophylaxis and on-demand treatment of bleeding in pediatric hemophilia B patients., Methods:  Previously treated patients aged <12 years with moderate to severe hemophilia B enrolled in a 3-year extension study following a phase 3 pivotal study in which they received weekly rIX-FP prophylaxis. In the extension study, they could maintain or extend their prophylaxis interval to every 10 or 14 days if they were well controlled on the 7-day regimen., Results:  Compared with their initial regimen, by the end of the study, dosing intervals were the same, extended, and shortened in 16, 4, and 4 patients, respectively. Very low annualized spontaneous bleeding rates (AsBRs) were observed; median AsBR was 0.0 for the 7- and 10-day regimens, and 1.1 for the 14-day regimen. The 7- and 14-day regimens were comparable in preventing spontaneous bleeds; mean (95% confidence interval) difference in AsBR of -1.2 (-2.6 to 0.3) bleeding episodes/year/subject. Overall, 96% of bleeding episodes were successfully treated with one or two injections of rIX-FP. Patients on a 14-day regimen maintained a mean steady-state trough FIX level of >7.2 IU/dL. No patient developed an inhibitor., Conclusion:  This extension study demonstrated the long-term safety and efficacy of weekly rIX-FP in pediatric patients. Additionally, it showed that adequate bleed protection can be achieved with 10- or 14-day rIX-FP regimens in selected pediatric patients while maintaining safety., Competing Interests: G.K.: Research grant support from Alnylam, BPL, Bayer, Baxalta, CSL Behring, Opko biologics, Pfizer, Shire; consultant for Alnylam, Bayer, Opko biologics, Pfizer, Shire, Roche; honoraria/speakers bureau for Bayer, CSL, Pfizer, Roche. H.C.: Research support from CSL Behring, LFB, Novo Nordisk, Octapharma, Shire/Takeda, SOBI; honoraria from Bayer, LFB, Octapharma, Pfizer, Roche, SOBI; travel support from Bayer, LFB, Octapharma, Pfizer, Roche, Sobi; C.M.: Research support from Bayer, Biotest, CSL Behring, Shire/Takeda; honoraria from Bayer, Biotest, CSL Behring, Novo Nordisk, Pfizer, Roche, Takeda; travel support from Biotest, Bayer, CSL Behring, Novo Nordisk. S.H.: received honoraria for speaking from Bayer Healthcare, Baxalta Innovation, Biotest, CSL Behring, Novartis Pharma, Novo Nordisk, Octapharma, Pfizer; research grants from Bayer Healthcare, Baxalta, Biotest, CSL Behring, Novo Nordisk, Octapharma, Pfizer; T.L.: Research grant support and honoraria from Bayer, CSL Behring, Novo Nordisk, Octapharma, Pfizer, Roche, Shire, SOBI; honoraria from Uniqure; Y.L. and W.S. are employees of CSL Behring; E.S.: Research grant support from CSL Behring; honoraria for speaking and/or for consulting from Bayer, Bioverativ, CSL Behring, Grifols, Kedrion, Novo Nordisk, Octapharma, Pfizer, Roche, Shire/Takeda, SOBI, Spark, Uniqure., (Georg Thieme Verlag KG Stuttgart · New York.)

The thrombin generation (TG) assay evaluates haemostatic balance, which is influenced by the levels of many coagulation factors and inhibitors. Our objective was to identify the determinant factors of TG in haemophilia A (HA) and haemophilia B (HB) patients and to compare them to those in healthy controls. Coagulation factor and inhibitor levels, and TG, were measured in platelet-poor plasma from 40 patients with HA, 32 patients with HB and 40 healthy subjects. Data were analysed using multiple regression models. In HA patients, factor VIII was a positive determinant of endogenous thrombin potential (ETP) and peak, whereas tissue factor pathway inhibitor (TFPI) and factor V were negative determinants of ETP and peak. In HB patients, FIX was a positive determinant of ETP and peak, FVII being a positive determinant of peak. Antithrombin and protein S (PS) were negative determinants of ETP while FX was a negative determinant of peak. Above all, in HB patients, TFPI was a negative determinant of ETP and peak. In healthy subjects, FVIII was a positive determinant of ETP and peak, whereas FX and protein S were negative determinants of these parameters. TFPI was not a negative determinant of either peak or ETP. In haemophilic patients, the determinant factors of TG are all implicated in FXa generation and inhibition, the crucial determinant factor being TFPI whatever the type of haemophilia, A or B. These findings contribute to the rationale that recently place TFPI as a target for innovative therapies of haemophilia., (© 2019 John Wiley & Sons Ltd.)

Introduction: A room temperature stable formulation of recombinant activated factor VII (NovoSeven ® ), allowing convenient storage and therefore improved treatment access, has been developed. Bioequivalence to the previous NovoSeven ® was demonstrated in healthy humans, leading to European approval (2008). Although no confirmed cases of neutralising antibodies to rFVIIa in patients with haemophilia A or B have been observed with the original formulation, changes in formulation or storage condition may alter immunogenicity., Aim: SMART-7™ was designed to investigate the safety of NovoSeven ® in a real-world setting in patients with haemophilia A or B with inhibitors., Methods: Study medication was not provided by the sponsor, and treatment was at the discretion of the treating physician, in accordance with the local label. Patient baseline information was collected at enrolment. Information on safety, drug exposure and bleeding episodes was collected and FVII antibody screening was encouraged at baseline and performed at the investigator's discretion., Results: Fifty-one patients were enrolled and 31 completed the study. Forty-one adverse events (AEs) were reported in 23 patients; 25 AEs in 14 patients were serious. No thromboembolic events were observed. Although four cases of reduced therapeutic response were reported, FVII antibody screening was negative. Forty-eight patients experienced 618 bleeding episodes and 93.4% of 609 evaluated bleeds were stopped by treatment. Of the 538 bleeding episodes treated with NovoSeven ® monotherapy, 94.2% stopped by end of treatment., Conclusion: Data collected during the SMART-7™ study revealed no treatment-related safety issues and no FVII-binding antibodies for patients treated with NovoSeven ® under real-world conditions., (© 2017 John Wiley & Sons Ltd.)

A global phase 3 study evaluated the pharmacokinetics, efficacy and safety of a recombinant fusion protein linking coagulation factor IX with albumin (rIX-FP) in 27 previously treated male children (1-11 years) with severe and moderately severe haemophilia B (factor IX [FIX] activity ≤2 IU/dl). All patients received routine prophylaxis once every seven days for up to 77 weeks, and treated any bleeding episodes on-demand. The mean terminal half-life of rIX-FP was 91.4 hours (h), 4.3-fold longer than previous FIX treatment and clearance was 1.11 ml/h/kg, 6.4-fold slower than previous FIX treatment. The median (Q1, Q3) annualised spontaneous bleeding rate was 0.00 (0.00, 0.91) and was similar between the <6 years and ≥6 years age groups, with a weekly median prophylactic dose of 46 IU/kg. In addition, patients maintained a median trough level of 13.4 IU/dl FIX activity on weekly prophylaxis. Overall, 97.2 % of bleeding episodes were successfully treated with one or two injections of rIX-FP (95 % CI: 92 % to 99 %), 88.7 % with one injection, and 96 % of the treatments were rated effective (excellent or good) by the Investigator. No patient developed FIX inhibitors and no safety concerns were identified. These results indicate that rIX-FP is safe and effective for preventing and treating bleeding episodes in children with haemophilia B with weekly prophylaxis. Routine prophylaxis with rIX-FP at treatment intervals of up to 14 days are currently being investigated in children with severe and moderately severe haemophilia B. Clinicaltrials.gov (NCT01662531)., Competing Interests: G.K., H.C., C.M., T.L., S.H., T.C., M.E.M, J.C. and E.S. received research support from CSL Behring to conduct the study. G.K. received honoraria for speaking and/or for consulting from Opko Biologics, Alnylam, Bayer, Pfizer, Novo Nordisk and research grants from BPL, Baxalta, Pfizer, Opko Biologics. H.C. received honoraria for speaking and/or for consulting from CSL Behring, Bayer Healthcare, Baxter Biosciences, LFB, Novo Nordisk and Pfizer. C.M. has received honoraria for speaking and travel support from Baxter, Bayer, Biotest, CSL Behring, Novo Nordisk and Pfizer. T.L. has received honoraria for speaking and/or for consulting from Baxalta, Bayer, Biogen Ipsen, CSL Behring, LFB, Novo Nordisk, Octapharma, Pfizer and Roche. S.H. received research grant and speakers honorarium from Bayer Healthcare GmbH, Baxalta Innovations GmbH, Biotest AG, CSL Behring GmbH, LFB GmbH, Novartis Pharma GmbH, Novo Nordisk Pharma GmbH, Octapharma GmbH and Pfizer Pharma GmbH. M.E.M. received speaker and consulting fees from CSL Behring, Bayer Healthcare, Pfizer, Baxalta, Novo Nordisk and Sobi/Biogen Idec. J.C. received honoraria for speaking and/or for consulting from CSL Behring, Baxter Biosciences, Biogen Idec and Novo Nordisk. E.S. received honoraria for speaking and/or for consulting from CSL Behring, Bayer, Baxter/Baxalta, Pfizer, NovoNordisk, Roche, Sobi/Biogen Idec, Biotest, Kedrion, Octapharma and Grifols and received unrestricted research grants from NovoNordisk and Pfizer. C.V., Y.L. and I.J. were employed at CSL Behring.

Background: EQOFIX is a medicoeconomic study that analyzed the health-related quality of life (HRQoL) and costs of care of the moderate and severe forms of hemophilia B, treated on demand or by prophylaxis with either plasma-derived Factor IX (pdFIX) or recombinant FIX (rFIX)., Study Design and Methods: The primary objectives were evaluations of the impact of hemophilia B on HRQoL and of the costs associated with its management. The secondary objectives were evaluations of the clinical efficacy and costs of care of pdFIX and rFIX. In this observational study we included and followed for 1 year severe and moderate hemophilia B patients without inhibitor. HRQoL was evaluated through generic and disease-specific questionnaires. Information on the health resources consumed was collected every 3 months., Results: The EQOFIX cohort was composed of 155 patients, including 51 children and 104 adults, with 114 having severe disease and 41 having moderate disease. The regimens were prophylactic for 61 and on demand for 94. Altogether, 78 were treated with rFIX and 77 with pdFIX. There was no difference in the QoL between the pdFIX and rFIX treatments. The extra cost of prophylaxis was €22,605 per bleeding event prevented. The consumption of FIX was 1.4-fold higher for the patients treated with rFIX than for the patients treated with pdFIX., Conclusion: Our findings in a cohort composed of 25% of the French population of moderate and severe hemophilia B patients show, with similar clinical and HRQoL results, that treatment with rFIX is more expensive than treatment with pdFIX., (© 2015 The Authors. Transfusion published by Wiley Periodicals, Inc. on behalf of AABB.)

In the phase 3 B-LONG (Recombinant Factor IX Fc Fusion Protein [rFIXFc] in Subjects With Haemophilia B) study, rFIXFc demonstrated a prolonged half-life compared with recombinant factor IX (rFIX), and safety and efficacy for prophylaxis and treatment of bleeding in subjects with moderately-severe to severe haemophilia B. In this B-LONG sub-analysis, rFIXFc was evaluated for efficacy in subjects requiring major surgery. Dosing was investigator-determined. Assessments included dosing, consumption, bleeding, transfusions and haemostatic response. A population pharmacokinetics model of rFIXFc was used to predict FIX activity. Twelve subjects underwent 14 major surgeries (including 11 orthopaedic surgeries); most subjects (11/12) received rFIXFc prophylaxis before surgery (range, ~2 weeks-12 months). Investigators/surgeons rated haemostatic responses as excellent (n = 13) or good (n = 1). In most surgeries (85·7%), haemostasis from the pre-surgical dose until the end of surgery was maintained with a single rFIXFc infusion. Blood loss was consistent with similar surgeries in subjects without haemophilia. The strong correlation (R(2) = 0·9586, P < 0·001) between observed and population pharmacokinetic model-predicted FIX activity suggests surgery did not impact rFIXFc pharmacokinetics. No unique safety concerns or inhibitors were observed. In conclusion, rFIXFc was safe and efficacious, with prolonged dosing intervals and low consumption, when used perioperatively in haemophilia B. Surgery did not appear to alter rFIXFc pharmacokinetics., (© 2014 Biogen Idec. British Journal of Haematology published by John Wiley & Sons Ltd.)

Lymphomas or hepatocarcinomas related to blood-borne transmitted diseases are well-known malignancies in persons with haemophilia (PWH). However, rising life expectancy has increased the number of PWH suffering from other malignancies. This study aimed to collect cancer occurrence data in PWH followed in five European haemophilia treatment centres (Brussels, Geneva, Marseille, Montpellier and Paris-Bicêtre) over the last 10 years and to analyse some particular features of cancer occurring in PWH. In total, 45 malignancies were diagnosed in 1067 PWH. The most common malignancies were hepatocellular carcinoma (12/45) and urogenital tract tumours (9/45). Bleeding at presentation or changes in bleeding pattern was indicative of cancer in four patients. Three patients with mild haemophilia developed anti-factor VIII inhibitors after intensive substitution therapy prior to surgery or invasive procedures. There was no bleeding associated with chemotherapy or radiotherapy. A few bleeding complications occurred following invasive (3/39) or surgical procedures (2/27) as a result of insufficient hemostatic coverage or in spite of adequate substitution. No bleeding was noted after liver or prostate biopsies. Following cancer diagnosis, five patients were switched from on-demand to prolonged prophylaxis substitution. In the majority of cases, the standard cancer treatment protocol was not modified on account of concomitant haemophilia. Thus, oncological treatments are not contraindicated and should not be withheld in PWH assuming that adequate haemostasis correction is undertaken. As shown by our study results, a change in bleeding pattern in adult PWH should raise suspicion of a malignancy. Intensive substitution must be considered a risk factor for inhibitor development., (© 2013 John Wiley & Sons Ltd.)

Improvements in the management of haemophilia have led to a significant increase in the life expectancy of haemophilia patients, which is now close to the life expectancy in the general male population. Therefore, age-related conditions, especially cardiovascular disease (CVD), have become increasingly common in these patients. The management of CVD, especially that of coronary artery disease (CAD), acute coronary syndrome (ACS) and atrial fibrillation (AF), is particularly challenging in patients with haemophilia due to the need to find an adequate balance between bleeding and ischemic risk, requiring close coordination between cardiologists and haemophilia specialists. However, specific recommendations and relevant literature and data are scarce. Therefore, we propose pragmatic and practical therapeutic suggestions, based on the available literature and our own experience, for the management of ACS, stable angina and AF in patients with haemophilia. Overall, evidence and experience suggest that they should be treated much in the same way as the general CVD population, following standard guidelines, while choosing available treatment options known to be associated with low rates of bleeding complications. Treatments advocated for patient with haemophilia include antiplatelet therapy (aspirin and P2Y12 inhibitors), antithrombin therapy such as heparin or bivalirudin, glycoprotein IIb/IIIa inhibitors (GPIIb/IIIa inhibitors), transradial cardiac catheterization, and use of bare metal (BMS) or drug-eluting stents (DES). Antithrombotic agents with shorter half-lives that are reversible or have an antidote offer a safer choice in this setting. In addition, optimal clotting factor replacement therapy should be tailored to the increased risk of bleeding associated with invasive procedures and antithrombotic therapies, particularly during the acute phase of ACS., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Objectives: To evaluate the impact of the 2002 guidelines on the current status of prophylaxis in French children with severe hemophilia A or B., Study Design: Clinical information was captured, in a prospective way, using FranceCoag Network. We retrospectively studied 291 patients with severe (<1 IU/dL) hemophilia A and B, with no history of inhibitors., Results: Our results demonstrate that the availability of national medical guidelines has improved clinical practice in France. In the past decade, the proportion of children with severe hemophilia undergoing prophylaxis has shown a significant 2- to 3-fold increase: ∼80% of these children>3 years of age are now receiving prophylaxis. In severe hemophilia A and B, the age at which prophylaxis commences has significantly decreased: 4.0 and 6.1 years for the period 1996-1999 as opposed to 1.8 and 1.4 years for the period 2004-2007 (P=.0001)., Conclusions: Long-term clinical and physical evaluations of patients will be necessary to establish the benefits of this increase in prophylactic treatment on the prevention of hemophilic arthropathy., (Copyright © 2013 Mosby, Inc. All rights reserved.)

During the last decades, long-term prophylaxis has become the gold standard for the treatment of children with severe haemophilia A or B. Prophylactic replacement regimens modify the natural history of the disease by aiming at the prevention of haemarthrosis, target joints and arthropathy. This treatment represents a constraint and an enhanced exposure to anti-haemophilic concentrates, which means potential increase of related risks and significant additional cost. The context of crisis of confidence due to the blood borne infections in the 1980s, may have delayed prophylaxis as an universal gold standard.In the early 2000s, the French group CoMETH proposed recommendations based on the review of the international experience. At first, specific guidelines of long-term prophylaxis were dedicated to children with severe haemophilia A or B, aged 3 years or less, with no history of target joint or arthropathy. The main concerns of this regimen consist in the early start and the escalating intensification of the treatment. In the French haemophilia care centres, the diffusion of these guidelines has apparently induced a significant turning point in therapeutic practices for haemophilia children. In 2006, more comprehensive recommendations were diffused to take into account all the children with severe haemophilia, whatever the bleeding history and joint status. The analysis of their impact, jointly with the National cohort "France Coag Network", will first assess the widespread implementation of the recommendations and the observance of the prophylactic regimen and identify factors associated to the compliance.

Although most surgical and invasive procedures can be performed safely in patients with haemophilia, the optimal level and duration of replacement therapy required to prevent bleeding complications have not been established conclusively. For providing more insight into optimal therapy during invasive procedures, a literature review of surgical procedures in patients with haemophilia was conducted. Concomitantly, current practice was surveyed in 26 European Haemophilia Comprehensive Care Centres, representing 15 different countries. The review identified 110 original papers published between 1965 and 2007. Of these, only two studies were randomized controlled trials. Target levels and the duration of replacement therapy in the published studies were as follows. For major orthopaedic surgery: preoperative targets were 80-90%; postoperative targets showed a high degree of variation, with trough levels ranging from 20% to 80%, duration 10-14 days; for liver biopsy, 70-100%, 1-7 days; tonsillectomy: 90-100%, 5-11 days; indwelling venous access device insertion: 100%, 3-10 days; circumcision: 50-60%, 2-4 days; dental surgery: 30-50%, single treatment. With the exception of dental surgery, current practice in Europe, as assessed by the survey, was largely in agreement with published data. In conclusion, this study provides both a comprehensive review and a large survey of replacement therapy in patients with haemophilia undergoing invasive procedures; these data have informed the consensus practical treatment recommendations made in this paper. This study highlights the need for better-designed studies in order to better define minimal haemostatic levels of replacement therapy and optimal treatment duration.

In March 2007, the European Medicines Agency (EMEA) approved the use of single-dose recombinant activated factor VII (rFVIIa; NovoSeven, Novo Nordisk, Bagsvaerd, Denmark) 270 microg/kg for the treatment of mild-to-moderate bleeding episodes in patients with hemophilia A or B with inhibitors. The prospective, observational ONE Registry was recently established to describe "real world" use of the standard multiple-dose (3 x 90 microg/kg) and new single-dose (270 microg/kg) regimens, and to compare their safety, effectiveness, and effects on both quality of life and patient satisfaction with treatment. Enrollment started at the beginning of 2008, with a planned recruitment period of 18 months, and it is expected that approximately 100 patients will be enrolled from up to 30 European hemophilia centers. The primary efficacy outcome is global treatment response, based on subjective measures of bleeding cessation and pain relief. Secondary outcome measures include treatment satisfaction, time to hemostasis and pain relief, and quality of life assessment using the Haemo-QoL questionnaire; details of all adverse events also will be recorded. Interim results are expected by December 2008. It is hoped that the ONE Registry will raise awareness of the new single-dose rFVIIa treatment schedule, aggregate experience, and accelerate learning, fostering confidence in its use.

Haemophilia management is not uniform among countries, even within western Europe, that have close economic, social and cultural relationship. The European Paediatric Network PedNet aims to share experiences in the field of the care of boys with haemophilia. In 1998, a PedNet survey has shown significant disparities in 20 centres from 16 countries, particularly as regards the implementation of prophylaxis regimen. This survey has been updated in 2003 to describe the current status of haemophilia management in 22 centres and the changing pattern of care of boys with severe haemophilia in western Europe. Regular, continuous long-term prophylaxis is provided in all PedNet centres, more than 50% and 80-100% of boys being treated this way in 20/22 and 15/22 centres respectively. Twenty of the 22 centres (91%) recommend continuous prophylaxis (primary or secondary A) for a new patient. The use of recombinant factor VIII concentrates was already widespread in 1998 and a further expansion of recombinant products has been observed over the last 5 years. Recombinant FVIII is now used exclusively in nine centres and for more than 80% of boys with haemophilia A in nine other centres. The use of recombinant and plasma derived FIX is more balanced: among 18 centres where boys with haemophilia B are treated, 14 use recombinant FIX, and nine administer it to a majority of patients. Other modifications of practice have been stressed in this survey, such as more targeted use of central venous devices in the youngest boys and more extensive characterisation of genetic mutations.

A survey was made of the current status of treatment of haemophilic boys at 20 centres in 16 European countries and includes approximately 1500 of the estimated 6500 haemophiliacs in the participating countries. Many mild haemophiliacs are not seen, or seen infrequently, at haemophilia centres and this requires study. Nine of 18 centres provide continuous prophylaxis to 80-100% of their patients, five centres provide it to 55-80% and the remaining four centres to 15-40% of the boys. The median dose given was 6240 U kg-1 year-1 (range 3120-7800). Four centres administered only recombinant concentrates to children with severe haemophilia A, while seven centres administered recombinant concentrates to 75-90% and the remaining centres to less than 50% of the boys (two centres < 10%). When asked for the choice of concentrate for a newly diagnosed boy with severe haemophilia A, all but one centre preferred recombinant concentrate. Most boys below 6 years received concentrates via a peripheral vein but three centres preferred a central venous line for 80-100% of the boys. Thirteen of 18 centres applied home treatment to 84-100% of the boys and the remaining five centres to 57-77% of the boys.

A double blind randomized cross-over multi-center study has been conducted to compare the pharmacokinetic and coagulation activation markers of high-purity factor IX concentrate subjected to both solvent/ detergent (SD) treatment and 15 nm-filtration (FIX-SD-15) with the licensed product subjected only to solvent-detergent (FIX-SD). This filtration process allows the elimination of small particles, such as non-enveloped viruses (i.e., hepatitis A and parvovirus B19). Eleven severe hemophilia B patients (FIX coagulant activity <2 IU/dl) received one infusion of 60 IU/kg of FIX-SD and one infusion of 60 IU/kg of FIX-SD-15 at least at 10 days interval. Blood samples were obtained before and at various time up to 72 h after infusion. The decay curves of factor IX (FIX:C and FIX:Ag) were evaluated by a model independent method. Bioequivalence was found between the two concentrates using the Schuirmann test. The mean FIX:C and FIX:Ag recovery of FIX-SD-15 was 1.08 and 0.89 IU/dl/IU/kg respectively with a mean half-life of 33.3 h for FIX:C and 25.6 h for FIX:Ag. Six months after initial enrollment, pharmacokinetic parameters were similar in the 7 patients tested. There was no significant variation of prothrombin fragment 1+2 and thrombin-antithrombin complexes measured up to 6 h after infusion, indicating that there was no activation process after administration of FIX. In conclusion, these data demonstrate that the introduction of a 15 nm filtration does not alter the pharmacokinetic profile of a well characterized SD FIX concentrate while providing additional viral safety.