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Background: Oral gene delivery of non-viral vectors is an attractive strategy to achieve transgene expression. Although expected efficacy from non-viral delivery systems is relatively low, repeated vector administration is possible and may help to obtain durable transgene expression in a therapeutic range., Objectives: To test the principle feasibility of using factor (F) IX variants with improved function combined with an optimized oral delivery system in hemophilia B (HB) mice., Methods: FIX modifications were introduced by site-directed mutagenesis into plasmid- or minicircle-based expression cassettes. Vectors were formulated as chitosan nanoparticles for oral delivery to HB mice. Protection of vector DNA in nanoparticle constructs and transfection efficiency were characterized. HB mice received eGFP-formulated chitosan nanoparticles to confirm gene transfer in vivo. FIX expression, phenotype correction and the potential of nanoparticles to induce immunotolerance (ITI) against exogenous FIX were evaluated after repeated oral administration., Results: Transfection of HEK 293T cells or livers of FIX-knockout mice with nanoparticles resulted in GFP or functional FIX expression. Oral administration of FIX mutants resulted in exclusive FIX expression in the small intestine, as confirmed by RT-PCR and fluorescence staining. HB mice demonstrated transient FIX expression reaching > 14% of normal activity and partial phenotype correction after oral delivery of FIX mutants with high specific activity and improved tissue release., Conclusion: The feasibility of oral, non-viral delivery of FIX was established and improved by bioengineered FIX proteins and optimized vectors. Thus, these data might point the way for development of a clinically applicable oral gene transfer strategy for hemophilia B., (© 2014 International Society on Thrombosis and Haemostasis.)

From a young age patients with severe and moderately severe FIX deficiency (haemophilia B) can experience spontaneous or traumatic bleeding and joint destruction may result. The use of coagulation factor IX concentrate to prevent anticipated bleeding, as primary or secondary prophylaxis, has become a common and recommended practice in children. The current practice of using tertiary prophylaxis, in the presence of established joint arthropathy, in adults with haemophilia B is not well characterized. This observational study was conducted to gain a better understanding of the recent Canadian experience with tertiary prophylaxis in adults with severe and moderately severe haemophilia B. Data were collected from all eligible adult (≥ 18 years of age) males with baseline FIX:C ≤ 2% from seven Canadian Hemophilia Treatment centres over a 2-year observation period from 2009 to 2011. Thirty-four per cent of the 67 subjects with moderately severe haemophilia B were exposed to prophylaxis with the majority as continuous prophylaxis (≥45 weeks year(-1) ). The severe subgroup (FIX:C < 1%) demonstrated a 52% exposure rate. None had primary prophylaxis exposure in childhood. Eighty-one per cent used once or twice weekly infusion regimens and reported a median annual bleeding rate of five bleeds per year versus four bleeds per year for those using on-demand treatment. Annual median factor utilization for all subjects using prophylaxis was 196,283 U year(-1) compared to 46,361 U year(-1) for on demand. Approximately 50% of adults with severe haemophilia B are using continuous tertiary prophylaxis in Canada, a practice likely to increase which warrants further study., (© 2014 John Wiley & Sons Ltd.)

Beginning in the 1960s the care of persons with haemophilia began to improve dramatically through a series of transformative improvements in care: development of lyophilized factor concentrates, home care programmes, prophylaxis and (due to the tragedy of HIV/hepatitis) the development of virally safer plasma-derived and recombinant factor concentrates. Prophylaxis, if commenced early and given in sufficient dose/frequency has been shown to allow persons with haemophilia to maintain excellent joints and lead normal lives. Yet the relatively short half-lives of factor (F) VIII and IX concentrates leads to the need for frequent venous access. This remains a significant burden for patients with haemophilia on prophylaxis causing in many cases reduced patient adherence to prophylaxis and negative longterm outcomes. The last 5 years have witnessed a flourish of new bioengineered longer acting FVIII and IX concentrates manufactured using different technologies (pegylation or fusion to Fc/albumin). These products (especially the longer acting FIX concentrates) are likely to have profound implications on prophylaxis. With these longer acting factor concentrates prophylaxis regimens will almost certainly change. This will involve changes in what trough levels are targeted and how frequently factor is administered. It is hoped that these changes may improve patients' adherence to prophylaxis and their quality of life. These long-acting factor concentrates will undoubtedly have cost repercussions and will raise important questions regarding how decisions about choosing one longer acting concentrate over another, and whether these products are interchangeable, are made. This article will review what changes may ensue with the advent of these new longer acting factor concentrates., (© 2014 John Wiley & Sons Ltd.)

Prophylaxis has become the standard mantra of care for those individuals with severe haemophilia A and B. Primary prophylaxis is advocated to prevent the occurrence of symptomatic acute spontaneous haemarthroses and to preserve joint structure and function. Typically, twice or thrice weekly infusions of factor VIII or IX concentrates are integral to this treatment approach. Secondary prophylaxis is initiated after the relentless cycle of progressive joint damage has been triggered by prior haemarthroses and is intended to preserve existing joint health by preventing additional spontaneous bleeding events. Event-driven prophylaxis involves the administration of clotting factor concentrates to prevent acute traumatic bleeds, which are anticipated to occur in association with surgical or physical trauma. This regimen enhances the effectiveness of primary or secondary prophylaxis protocols or on-demand approaches to replacement therapy. Besides the marked reduction in the so-called annual bleed rate, prophylaxis regimens frequently increase personal self-confidence to embark on a more active and physical lifestyle; however, in reality, prophylaxis must be individualized in accordance with bleeding phenotypes, with the unique pharmacokinetic profile of administered replacement clotting factor concentrates, with the specific clinical scenario, and with the degree of intensity anticipated for any physical activity. The introduction of extended half-life replacement products will also influence how these prophylaxis regimens will be accomplished. The following scenarios will discuss how prophylaxis regimens can be implemented to protect the individual from developing spontaneous and activity-induced acute bleeding complications and to maintain an improved quality of life., (© 2014 John Wiley & Sons Ltd.)

Haemophilia therapy is experiencing an unprecedented expansion in the number and novelty of clotting factor concentrates. Every product must be licensed by regulatory authorities, primarily on the basis of its safety and efficacy profiles. The low prevalence of haemophilia, and other inherited bleeding disorders, presents a significant challenge to patient recruitment for preauthorization clinical trials, especially given the low frequency of inhibitory antibodies, the major adverse event related to clotting factor exposure. Other challenges include a lack of harmonization between the major regulatory authorities in certain key areas, the selection of laboratory monitoring methodologies and the difficulty in obtaining high-quality phase IV safety data following authorization. These aspects will be reviewed in this session, which will also highlight the roles played by the World Federation of Hemophilia and International Society on Thrombosis and Haemostasis in the promotion of these discussions., (© 2014 John Wiley & Sons Ltd.)

Spontaneous haemorrhage in patients with haemophilia is generally considered to occur randomly and without a predictable temporal or seasonal pattern; however, there is a lack of evidence in the literature on the effects of weather, temperature and atmosphere on bleeding episodes. This post hoc analysis of a multicentre, open-label crossover study examined the influence of seasonality on bleeding frequency and patient-assessed pain in patients with moderately severe and severe (FIX C ≤ 2%) haemophilia B. Fifty patients were enrolled and treated on-demand for 16 weeks; 47 were subsequently randomized to one of two prophylactic regimens (nonacog alfa 100 IU kg(-1) once weekly or 50 IU kg(-1) twice weekly) for 16 weeks. Patients then underwent an 8-week washout period of on-demand therapy before being crossed over to the other prophylactic regimen for 16 weeks. Bleeding episodes during the on-demand treatment periods were analysed. To assess for temporal trends, data were graphed as scatter plots. The primary end point was the annualized bleeding rate (ABR). Additional measures included raw and median pain scores during every joint bleeding event (spontaneous or traumatic), with pain scored using the Brief Pain Inventory (0 = 'no pain' to 10 = 'pain as bad as you can imagine'). The observed ABRs during the on-demand periods showed no distinguishable trend over time. Analysis of pain associated with joint bleeding episodes also did not demonstrate any discernible temporal trend. No apparent seasonal variation in bleeding pattern or patient-reported pain was observed in this analysis of patients with haemophilia B., (© 2013 Pfizer Inc. Haemophilia published by John Wiley & Sons Ltd.)

Factor replacement therapy for the treatment of moderate to severe haemophilia A and B can be complicated by the production of inhibitory alloantibodies to factor VIII (FVIII) or factor IX. Treatment with the nanofiltered anti-inhibitor coagulant complex, Factor Eight Inhibitor Bypassing Activity (FEIBA NF), is a key therapeutic option for controlling acute haemorrhages in patients with high-titre inhibitors or low-titre inhibitors refractory to replacement therapy. Given the high risk for morbidity and mortality in haemophilia patients with inhibitors to FVIII or FIX, we conducted this Phase 3 prospective study to evaluate whether prophylaxis with FEIBA NF is a safe and effective treatment option. Over a 1-year period, 17 subjects were treated prophylactically (85 ± 15 U kg(-1) every other day) while 19 subjects were treated on demand. The median (IQR) annualized bleeding rate (ABR) during prophylaxis was 7.9 (8.1), compared to 28.7 (32.3) during on-demand treatment, which amounts to a 72.5% reduction and a statistically significant difference in ABRs between arms (P = 0.0003). Three (17.6%) subjects (ITT) on prophylaxis experienced no bleeding episodes, whereas none treated on demand were bleeding episode-free. Total utilization of FEIBA NF for the treatment of bleeding episodes was significantly higher during on-demand therapy than prophylaxis (P = 0.0067). There were no differences in the rates of related adverse events between arms. This study demonstrates that FEIBA prophylaxis significantly reduces all types of bleeding compared with on-demand treatment, and the safety of prophylaxis is comparable to that of on-demand treatment., (© 2013 John Wiley & Sons Ltd.)

Severe haemophilia is often managed by prophylactic factor infusions in developed countries. The benefits of secondary prophylaxis in adults are currently being studied and adherence to the prescribed prophylactic factor regimen is vital to decreasing bleeding episodes. The aim of this study was to measure discrepancy between the physicians' prescription for prophylactic factor usage, and the actual factor usage obtained through infusion logs. During this method subjects with severe haemophilia A or B (FVIII or FIX ≤2%), from a single haemophilia clinic with complete medical and infusion records from July 01, 2009 to June 30, 2011, were evaluated. Continuous prophylaxis ≥4 weeks were included in the analysis. A scoring system for adherence to prescribed dosing and frequency was developed. A global scale of adherence was performed by two independent nurses using visual analogue scale. Thirty-one subjects, all with haemophilia A, with a median age of 26 years (range 18-56) were included. Results showed that the median (IQR) adherence rate to prescribed frequency and dosage, respectively, was 76% (67;85) and 93% (73;97). In multivariate analysis, only the length of time on prophylaxis during the study period showed a positive correlation with adherence whereas age, number of co-infections, number of bleeds and number of joints with chronic arthropathy did not. Global nursing assessments were in general agreement with the score. In conclusion, we observed a moderately good level of adherence based on score and by the nurse global assessment. Better adherence was found in subjects with longer exposure to prophylaxis., (© 2013 John Wiley & Sons Ltd.)

Immune tolerance induction (ITI) in patients with haemophilia B and inhibitors may be complicated by anaphylactic reactions and nephrotic syndrome with lower success rates than in haemophilia A (25% vs. 50-90%). According to case reports, immunosuppressive therapy in addition to high doses of factor IX (FIX) appears to be promising. We report an 18-year-old patient with severe haemophilia B and a FIX inhibitor with a maximum titre of 2.6 Bethesda units and allergic skin reactions to FIX infusions. At 5 years of age, this patient already had a FIX inhibitor with allergic reactions to FIX and activated prothrombin complex concentrate. ITI at 11 years of age with high-dose FIX, dexamethasone, rituximab, mycophenolate mofetil and intravenous immunoglobulins had induced a sustained response until the current presentation. The patient was restarted on the same ITI regimen with aforementioned immunosuppressants, which were initiated one week before high-dose FIX. No allergic reactions, nephrotic syndrome or serious infection occurred during ITI. The FIX inhibitor was undetectable after five weeks of treatment and remained so until 19 months of follow-up.

Total knee replacement is an operation frequently needed by hemophilia patients, which greatly improves their quality of life. This operation, however, carries a higher risk of bleeding and infection for hemophiliacs than it does for osteoarthritis sufferers. It is advisable to implant prosthetic components using antibiotic-loaded cement. It is essential to maintain a level of 100% of the replacement clotting factor for 2 weeks. Hematological treatment must be established, depending on the patient's factor levels and other pharmacokinetic parameters such as recovery and half-life, optimal doses and treatment time. It is preferable to use general anesthesia due to the risk of spinal bleeding. The lifespan of total knee replacement in hemophilic patients is shorter than in patients with osteoarthritis because of the increased risk of infection.

Baxter has developed a new recombinant factor IX (rFIX) drug product (BAX326) for treating patients with hemophilia B, or congenital FIX deficiency. An extensive preclinical program evaluated the pharmacokinetics, efficacy, and safety of BAX326 in different species. The efficacy of BAX326 was tested in three mouse models of primary pharmacodynamics: tail-tip bleeding, carotid occlusion, and thrombelastography. The pharmacokinetics was evaluated after a single intravenous bolus injection in mice, rats, and macaques. Toxicity was assessed in rats and macaques, safety pharmacology in rabbits and macaques, and immunogenicity in mice. BAX326 was shown to be efficacious in all three primary pharmacodynamic studies (P ≤ 0.0076). Hemostatic efficacy was dose related and similar for the three lots tested. Pharmacokinetic results showed that rFIX activity and rFIX antigen concentrations declined in a bi-phasic manner, similar to a previously licensed rFIX product. BAX326 was well tolerated in rabbits and macaques at all dose levels; no thrombogenic events and no adverse clinical, respiratory, or cardiovascular effects occurred. BAX326 was also shown to have a similar immunogenicity profile to the comparator rFIX product in mice. These results demonstrate that BAX326 has a favorable preclinical safety and efficacy profile, predictive of a comparable effect to that of the previously licensed rFIX in humans.

The concept of using pharmacokinetics for prophylactic dose tailoring with limited blood sampling in clinical practice has been demonstrated for factor VIII but not for factor IX. The pharmacokinetics of factor IX are more complicated than for factor VIII and also differ between plasma-derived and recombinant factor IX. Therefore, the pharmacokinetics of factor IX need to be further explored in clinical trials including comparative studies of prophylaxis with different factor IX concentrates. These are the main conclusions drawn from two of the last manuscripts written by Professor Sven Björkman and published in Haemophilia. Professor Björkman suddenly and unexpectedly died last summer. Thanks to the academic network created around his skill and through his enthusiasm for the pharmacokinetics of clotting factors and ability to convey his wisdom to others, this work will continue. Sven Björkman opened a new era in hemophilia prophylaxis., (© 2013 John Wiley & Sons Ltd.)

Intense haemostatic interventions are required to avoid bleeding complications when surgical procedures are performed on haemophilia patients. The objective of this study was to establish an appropriate protocol for perioperative haemostatic management of haemophilic mice. We assessed the prophylactic haemostatic effects of normal mouse plasma (NMP) on haemophilia B (HB) mice for both a skin flap procedure and a laparotomy. When 500 μL of NMP was administered to the mice, plasma factor IX (FIX:C) levels peaked at 15.1% immediately after intravenous (IV) administration, at 6.1% 2 h after intraperitoneal (IP) administration and at 2.7% 6 h after subcutaneous administration. Administering 500 μL of NMP via IP or IV 30 min in advance enabled the skin flap procedure to be performed safely without any complications. After the laparotomy procedure, several mice in the IP administration group exhibited lethal bleeding, but all mice survived in the IV administration group. Anti-mouse FIX inhibitors did not develop, even after repetitive administrations of NMP. However, human FIX concentrates, especially plasma-derived concentrates, elicited the anti-human FIX inhibitors. The results show that administering 500 μL of NMP via IV or IP 30 min in advance enables surgical procedures to be safely performed on HB mice, and that IV administration is more desirable than IP if the procedure requires opening of the abdominal wall., (© 2013 John Wiley & Sons Ltd.)

Posterior spinal fusion for scoliosis was planned in a 14-year-old male patient with hemophilia B. Preoperative examination showed factor IX activity of 8.4% with no inhibitor development. A perioperative dosage schedule was prepared after examining the pharmacokinetics of recombinant coagulation factor IX in order to maintain levels of perioperative factor IX activity at < or = 80% for the first 6 days (days 0-6), and > or = 40% for days 7-14 postoperatively. The dose of recombinant coagulation factor IX was adjusted to maintain factor IX activity above 80%, while measuring coagulation activity every hour during the surgery. The patient showed a favorable course without hemorrhagic tendency. We could safely manage anesthesia without requiring allogeneic blood transfusion.

The management of patients with congenital hemophilia who develop alloantibodies that neutralize coagulation factor activity is the most important challenge for hemophilia care providers because this complication renders replacement treatment with factor concentrates partially or completely ineffective, exposing the patients to an increased risk of morbidity and mortality. Development of inhibitors complicates the clinical course of severe hemophilia in up to 30% of patients with hemophilia A and up to 5% of those with hemophilia B. Although the ultimate goal of treatment of patients with alloantibodies against factors VIII and IX is eradication of the inhibitor, the control of bleeding through high doses of factor concentrates (low titer inhibitors) or bypassing agents (high titer inhibitors) is the mainstay of management of these patients. In this review, we summarize the main characteristics of the bypassing agents FEIBA and NovoSeven, briefly discussing available literature data, and in particular, focusing on comparative studies., (Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.)

Although many people with haemophilia discontinue prophylaxis in their late teens or early adulthood, the consequences of this decision are largely not known. This 18-month, observational, case-controlled, multicentre study evaluated long-term prophylaxis and the consequences of switching from prophylaxis to on-demand treatment in late teens and young adults with severe haemophilia A. Participants with haemophilia (aged 14-29 years) on prophylaxis ≥ 60% of the time for the 5 years before study entry were enrolled into 1 of 2 prospective or 1 retrospective group. Group 1 was prophylaxis, group 2 had voluntarily discontinued prophylaxis ≤ 12 months before study entry and group 3 had voluntarily discontinued prophylaxis ≥ 13 months before study entry. Assessments included bleeding frequency (primary endpoint), Haemo-QoL-A health-related quality of life (HRQoL) scores, Gilbert score, development of target joints, Haemophilia Activities List, Godin Leisure-Time, treatment satisfaction and State-Trait Anxiety Inventory (secondary and exploratory endpoints). Descriptive statistics were provided for all variables. Thirty-eight participants (group 1, n = 22; group 2, n = 5; group 3, n = 11; median age, 19.5 years) were enrolled. The median annualized number of bleeding events was 0, 4.8 and 24 in groups 1, 2 and 3 respectively. HRQoL was lower in participants who discontinued prophylaxis vs. those who remained on prophylaxis. Changes in the remaining secondary and exploratory variables were small, but were generally worse in participants who discontinued prophylaxis. Following a switch from prophylaxis to on-demand therapy, the number of bleeding events increased and HRQoL worsened in late teens and young adults with severe haemophilia A., (© 2013 John Wiley & Sons Ltd.)

The principles of pharmacokinetic (PK) dose tailoring in clinical practice, using limited blood sampling and Bayesian PK analysis, have been described for factor VIII (FVIII). This study applied the same procedure to recombinant FIX (rFIX), i.e. population PK modelling and the use of a simplified (one-compartment) model to describe only the terminal part of the coagulation factor vs. time curve. Data from a previous study on rFIX in 56 patients (4-56 years, 18-133 kg) were used to define a three-compartment population PK model. The average FIX clearance was 8.4 mL h(-1) kg(-1) . Elimination half-life ranged between 14 and 27 h. Data obtained from 24 h after the infusion were found to define the terminal phase of FIX disposition. Doses to produce a target trough FIX level (set at 0.01 IU mL(-1) ) at 72 h predicted by the Bayesian analysis, with blood sampling at either 24, 48 and 72 h or at only 24 and 48 h, were within -40% to +67% of those predicted using the three-compartment model, and within -57% to +125% for targeting a level at 96 h. These errors were lower than the overall interindividual variance in dose requirements. As three-compartment models are needed to characterize the PK of both plasma-derived FIX and rFIX, simplification to a one-compartment model is less straightforward than for FVIII, and the methodology should be investigated further before clinical application. Limited blood sampling and Bayesian analysis could still, however, be potentially useful for targeting rFIX trough levels during prophylaxis., (© 2013 John Wiley & Sons Ltd.)

Background: The rapid clearance of factor IX (FIX) necessitates frequent intravenous administration to achieve effective prophylaxis for patients with hemophilia B. Subcutaneous administration would be a preferred route of administration but is limited by bioavailability., Objectives: To improve the pharmacokinetics (PK) and bioavailability of FIX, a screen was performed to identify positions for the introduction of novel glycosylation sites with maximal effect on PK and maintenance of coagulation activity., Methods: Two hundred fifty-one variants, each containing one additional N-linked glycosylation site, were screened in vitro, and the PK profiles of selected variants mapping to spatially distinct regions of FIX were evaluated in mice. Optimal variants were combined, and their PK and efficacy were determined in mice with hemophilia B., Results: Variants that mapped to spatially distinct regions of the FIX structure exhibited different degrees of improved PK and enabled selection of optimized sites while minimizing the loss of FIX activity. Combining the most effective N-glycan sites in the same FIX molecule resulted in further improvements in PK. An optimized variant containing three novel N-glycan sites (at amino acids 103, 151, and 228), and the activity enhancing 338A variant had double the specific activity of wild-type FIX, exhibited 4.5-fold reduced clearance and 2.4-fold increased subcutaneous bioavailability, and was efficacious at a fivefold lower mass dose than wild-type FIX after subcutaneous injection in a bleeding model in mice with hemophilia B., Conclusions: Glycoengineering was used to significantly improve the subcutaneous PK and efficacy of FIX and may have advantages for subcutaneous dosing., (© 2013 International Society on Thrombosis and Haemostasis.)

Head-on comparative studies of factor IX (FIX) concentrates performed under standardized conditions are rarely conducted regardless of being a valuable instrument guiding health care providers towards better informed and cost-effective decisions. This study is an extension of a multicentre study that assessed the efficacy, safety and pharmacokinetics (PK) of AlphaNine(®) in 25 previously treated patients with severe haemophilia B (FIX:C ≤ 2%). After a washout period ≥ 7 days following the last PK performed with AlphaNine(®) after a dose of 65-75 IU kg(-1) , an identical PK study was performed with BeneFIX(®) on 22 of the same patients. Venous blood samples for analysis were taken at baseline and at 0.25, 0.5, 1, 3, 6, 9, 24, 48, 72 and 74 h post infusion. The outcomes of the comparison of the PK parameters were as follows: Mean (± SD) in vivo recovery (IVR) was 1.3 ± 0.4 IU dL(-1) per IU kg(-1) for AlphaNine(®) and 1.0 ± 0.3 IU dL(-1) per IU kg(-1) for BeneFIX(®) (P < 0.01). Mean terminal half-life, mean residence time, area under the curve, clearance and volume of distribution of BeneFIX(®) were 36.0 ± 12.8 h, 39.3 ± 13.9 h, 1631 ± 467 IU h dL(-1) , 0.046 ± 0.01 dL kg(-1) min(-1) and 1.75 ± 0.52 mL kg(-1) respectively. These values were not significantly different to those observed in AlphaNine(®), although BeneFIX(®) displayed higher than expected IVR values and lower than expected clearance values. In conclusion, AlphaNine(®) showed a comparable half-life, but an IVR significantly higher than that of BeneFIX(®). This dissimilarity may have implications on dosing requirements for on-demand treatment regimes affecting optimal resource allocation., (© 2013 John Wiley & Sons Ltd.)

The prevalence of inhibitors in haemophilia B is significantly lower than that of patients with haemophilia A. However, the peculiar occurrence of allergic reactions associated with the onset of inhibitor in haemophilia B (HB) may render immune tolerance a risky procedure. We have carried out a detailed survey among all the Italian Hemophilia Centers to analyse all the patients with HB and inhibitors. A total of eight patients were reported among 282 living patients (2.8%) with severe factor IX (FIX) deficiency (FIX < 1 U dL(-1)). In addition, two deceased patients were also identified. Six patients carried nonsense mutations while in four partial or complete gene deletions were detected. Three patients (one deceased) had history of allergic/anaphylactic reaction upon substitutive treatment, which in one case was recurrent and resolved after switching to plasma derived FIX. Immune tolerance was adopted in five patients and in four complete response was achieved while in the remaining it was partial. No nephrotic syndrome was observed. Our data confirm that inhibitors in HB occur in patients with null mutations or complete/partial gene deletion. Immune tolerance can be achieved also in HB patients, without allergic reactions or nephrotic syndrome upon replacement therapy., (© 2013 John Wiley & Sons Ltd.)

Prophylactic treatment in severe hemophilia is very effective but is limited by cost issues. The implementation of 2 different prophylactic regimens in The Netherlands and Sweden since the 1970s may be considered a natural experiment. We compared the costs and outcomes of Dutch intermediate- and Swedish high-dose prophylactic regimens for patients with severe hemophilia (factor VIII/IX < 1 IU/dL) born between 1970 and 1994, using prospective standardized outcome assessment and retrospective collection of cost data. Seventy-eight Dutch and 50 Swedish patients, median age 24 years (range, 14-37 years), were included. Intermediate-dose prophylaxis used less factor concentrate (median: Netherlands, 2100 IU/kg per year [interquartile range (IQR), 1400-2900 IU/kg per year] vs Sweden, 4000 IU/kg per year [IQR, 3000-4900 IU/kg per year]); (P < .01). Clinical outcome was slightly inferior for the intermediate-dose regimen (P < .01) for 5-year bleeding (median, 1.3 [IQR, 0.8-2.7] vs 0 [IQR, 0.0-2.0] joint bleeds/y) and joint health (Haemophilia Joint Health Score >10 of 144 points in 46% vs 11% of participants), although social participation and quality of life were similar. Annual total costs were 66% higher for high-dose prophylaxis (mean, 180 [95% confidence interval, 163 - 196] × US$1000 for Dutch vs 298 [95% confidence interval, 271-325]) × US$1000 for Swedish patients; (P < .01). At group level, the incremental benefits of high-dose prophylaxis appear limited. At the patient level, prophylaxis should be tailored individually, and many patients may do well receiving lower doses of concentrate without compromising safety.

Among 12billion injections administered annually, unsafe delivery leads to >20million infections and >100million reactions. In an emerging new concept, freeze-dried plant cells (lettuce) expressing vaccine antigens/biopharmaceuticals are protected in the stomach from acids/enzymes but are released to the immune or blood circulatory system when plant cell walls are digested by microbes that colonize the gut. Vaccine antigens bioencapsulated in plant cells upon oral delivery after priming, conferred both mucosal and systemic immunity and protection against bacterial, viral or protozoan pathogens or toxin challenge. Oral delivery of autoantigens was effective against complications of type 1 diabetes and hemophilia, by developing tolerance. Oral delivery of proinsulin or exendin-4 expressed in plant cells regulated blood glucose levels similar to injections. Therefore, this new platform offers a low cost alternative to deliver different therapeutic proteins to combat infectious or inherited diseases by eliminating inactivated pathogens, expensive purification, cold storage/transportation and sterile injections., (Copyright © 2012 Elsevier B.V. All rights reserved.)

The hemophilias are the most common X-linked inherited bleeding disorders. The challenges in children are different from that in adults and, If not properly managed, can lead to chronic disease and lifelong disabilities. Currently, inhibitors are the most severe complication and prophylaxis is emerging as the optimal preventive care strategy. Quality of life has become in the western countries the primary objective of the process of providing care, thus all the strategies (psychotherapy, physiotherapy, community life), not just the infusion of the missing factor, should be activated for the patient and family to give them the perception of being healthy.

This report describes the successful management of neurosurgical procedures with continuous infusion of recombinant factor IX (rFIX). A 1-year-old boy with severe hemophilia B was administered prophylactic therapy with rFIX after intracranial bleeding. We found the enlargement of an arachnoid cyst in a follow-up CT scan. He underwent marsupialization of the cyst under the continuous infusion of rFIX. FIX levels were examined in our hospital and the rFIX infusion rate was adjusted in an attempt to keep FIX levels above 90% intraoperatively, and 70% until his 7th post-operative day. We studied the pharmacokinetic profile of rFIX and found a half-time of 25 hours and mean in vivo recovery of 0.69 IU/dl/IU/kg. Reconstituted rFIX also retained at least 95% activity after 72 hours at room temperature. This is the first report of the perioperative management of a child undergoing a neurosurgical procedure under the continuous infusion of rFIX in Japan. Further studies are required before the routine use of this product for continuous infusion.

Hemophilia B is a severe bleeding disorder that is characterized by a deficiency or dysfunction of coagulation factor IX (FIX). Replacement therapy using recombinant or plasma-derived FIX is available, but the relatively short half-life of FIX (approximately 18 hours) necessitates administration every 2-3 days to prevent bleeding episodes. A recombinant fusion protein linking coagulation factor IX with albumin, known as rIX-FP, was developed to extend the half-life of recombinant FIX and allow for less frequent dosing. In a phase I, multicenter, dose-escalation trial (PROLONG-9FP), the safety and pharmacokinetics of rIX-FP were assessed in patients with hemophilia B. At a dose of 25-75 IU/kg, rIX-FP was well tolerated: no serious adverse events were reported and there was no evidence of hypersensitivity or immunogenic reactions. Pharmacokinetic analysis indicated enhanced properties, including a 5-fold increase in half-life, 44% higher recovery, 7-fold greater area under the curve, and 7-fold slower clearance, compared with recombinant FIX. Trough levels were maintained above 5% after 7 days when rIX-FP was administered at 25 IU/kg and after 14 days when given at 50 IU/kg, suggesting that schedules involving weekly dosing or dosing every 2 weeks are feasible. These results represent the first reported experience with rIX-FP in humans, and suggest that rIX-FP therapy is feasible and well tolerated in patients with hemophilia B. Phase II/III studies evaluating rIX-FP are underway., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Recombinant fusion protein linking coagulation factor IX with albumin (rIX-FP) is a novel recombinant albumin fusion protein designed to extend the half-life of recombinant factor IX (rFIX), which is used in the management of hemophilia B. Clinical evaluation of rIX-FP in humans is underway, including a recently completed phase I/II, open-label, multicenter, study that assessed the safety, pharmacokinetics, and efficacy of rIX-FP in patients with severe hemophilia B. A total of 17 patients received rIX-FP (25 IU/kg) as either on-demand therapy (n = 4) for 20 weeks or weekly prophylaxis (n = 13) for up to 44 weeks. Preliminary results confirm that rIX-FP has an excellent safety profile and a pharmacokinetic profile highlighted by a marked extended half-life, suggesting that weekly prophylaxis with rIX-FP at a dose of 25 IU/kg may be appropriate in patients with severe hemophilia B, and that extended dosing intervals (10-14 days) may be feasible in some patients. A phase II/III study evaluating the safety and efficacy of rIX-FP in patients with hemophilia B is underway., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Recurrent bleeding into joints initiates a sequence of events leading to a progressive joint damage in people with severe haemophilia. This is a continuous process during childhood and adolescence, therefore joint abnormalities may be minimal on physical examination in very young children - even those receiving on-demand treatment. The aim of our study was to quantify the burden of arthropathy in Lithuanian patients who had been treated exclusively by on-demand substitution and compare their physical joint health with age-matched Danish patients who received prophylaxis from an early age. Boys, aged 4-17 years, with severe haemophilia and no signs of inhibitors were included in the study. Joint outcome based on the Haemophilia Joint Health Score (HJHS) was analysed in two different treatment groups and compared within the matched pairs. In total, 32 (16 in each treatment group) patients were enroled. A total of 192 joints were evaluated. Joint status according to treatment strategy was strikingly different: 27.4 for on-demand vs. 3.3 for prophylaxis (<0.001) group. Significance of the difference in joint status comparing different treatment strategies was equally strong both in younger (4-9 years) and older (10-17 years) patient groups: 2.2 vs. 12.5 (P = 0.0002) and 3.9 vs. 36.3 (P < 0.0001) respectively. The results further demonstrate the unequivocal effect of prophylaxis on joint status and give an insight into early and late manifestations of joint impairment based on the HJHS in haemophilia patients with treatment on-demand compared with joint changes that may develop over the time with the preventative treatment., (© 2012 Blackwell Publishing Ltd.)

A number of studies have been published on the benefits of prophylactic treatment in adults with haemophilia. However, in many countries, it is considered as optional due to financial constraints. This survey was carried out to examine the long-term effects of prophylaxis and the continuing benefit of the treatment into adulthood. Self-assessed health-related data and the EQ-5D questionnaire measuring health utility were collected from 124 men (26.9 ± 4.6 years) from Canada (N = 40), France (N = 14), Ireland (N = 17), the Netherlands (N = 16), Poland (N = 24) and the UK (N = 13). The respondents were split into four groups: On-Demand, <50% life on prophylaxis, ≥ 50% life on prophylaxis, Prophylaxis. Overall, long-term prophylaxis results in lower presence of target joints (P ≤ 0.001), occurrence of serious bleeding episodes (P ≤ 0.05), recurring bleeding episodes (P ≤ 0.01) and requirement for surgical procedures (P ≤ 0.05). Furthermore, health utility (P ≤ 0.01) in the On-demand group was significantly lower (P ≤ 0.01) compared to the ≥ 50% life on prophylaxis and the Prophylaxis group. No significant differences between countries were found except between the Netherlands and Poland, with Poland showing the lowest health utility (P ≤ 0.01) and the most problems with mobility (P ≤ 0.05) and pain/discomfort (P ≤ 0.001). The Netherlands showed the highest health utility (0.915) followed by Canada (0.791), Ireland (0.786), UK (0.768), France (0.687) and Poland (0.629). The results demonstrate consistently higher quality of life of individuals who are on long-term prophylactic treatment when compared to on-demand treatment or intermittent prophylaxis and on -demand treatment., (© 2012 Blackwell Publishing Ltd.)

To prevent major hemorrhage during anticoagulation, it is quite important to manage controllable risk factors such as hypertension, diabetes mellitus, smoking habit, and too much alcohol intake. It is also important to avoid dual antithrombotic therapy as long as possible, which increases severe bleeding events. For patients with major bleeding during anticoagulation, we should stop oral medication, stop bleeding by mechanical compression or surgical interventions, and maintain circulation blood volume and blood pressure by appropriate intravenous drip infusion. When intracranial hemorrhage happens, adequate treatment to suppress blood pressure should be provided. Administration of prothrombin complex concentrate (PCC) and vitamin K is effective for urgent reversal of anticoagulation by warfarin. The PCC may be also useful for that by novel oral anticoagulants.

On-demand therapy enables stopping haemorrhages rapidly, reducing joint pain and restoring joint mobility, but does not prevent the beginning and subsequent development of haemophilic arthropathy. The main objective of this study was to identify the clinical and orthopaedic status of severe haemophilic patients with bleeding phenotype receiving on-demand treatment in Spain. We conducted an epidemiological, observational, retrospective study, recruiting 167 patients from 36 centres (92% of them with haemophilia A), median age at enrolment of 35 years. Forty per cent of the patients received a combination of on-demand and short-term prophylaxis regimen; the rest was under on-demand treatment. One hundred and forty-five patients (87%) reported at least one bleeding episode and 22 (13%) of the biologically severe patients had no bleeding phenotype. Seventy-one per cent of the studied population presented established haemophilic arthropathy, reaching 80% if we exclude patients without bleeding phenotype. Forty-three per cent of these patients had one or two joints affected, 28% of them had three or four affected joints, 20% reported five or six affected joints and 9% more than six injured joints. An increase in established haemophilic arthropathy with age was observed. Forty-six patients underwent orthopaedic surgery at least once. These data show that on-demand therapy is not effective in preventing the development of haemophilic arthropathy in severe haemophilic population with bleeding phenotype. Therefore, we suggest that the optimal treatment in these patients should be based on prophylaxis. We recommend analysing the reasons for ending prophylaxis, in case its reinstatement should be necessary., (© 2012 Blackwell Publishing Ltd.)

Background: There are situations where a pharmacokinetic (PK) study may not be possible in children, especially in neonates and infants. Under these circumstances, one would like to extrapolate PK parameters from adults or older children to neonates and infants. Allometric scaling is a method which can be used for PK extrapolation from adults to children., Objectives: The objective of this study was to evaluate the predictive performance of an allometric model for the prediction of clearance of three coagulation factors in children from adult clearance., Methods: Clearance values for three coagulation factors (rVIIa, rVIII and rIX) for adults and children were obtained from the literature. The allometric model was developed from adult data and then the model was used to predict clearance of the coagulation factors in individual child. The predicted clearance value was then compared with the observed clearance value in that child., Results: The results of the study indicated that the CL of the three coagulation factors tested in this study could be predicted with accuracy (≤30% prediction error) in most of the children from the allometric model developed from adults., Conclusions: The study indicated that allometric scaling could be applied to predict the CL of coagulation factors in children from adults with accuracy. The predicted clearance can then be used to select a dose to initiate a clinical trial (pharmacokinetics, safety and efficacy) in children., (© 2012 International Society on Thrombosis and Haemostasis.)

Background: Prophylaxis of hemophilia B, at present, requires multiple infusions of human factor (F)IX concentrates per week. A FIX molecule with a prolonged half-life has the potential to greatly improve the convenience of, and adherence to, prophylaxis., Objectives: The aim of our studies was to investigate the pharmacokinetic (PK) and pharmacodynamic (PD) profile of a recombinant fusion protein linking coagulation FIX with albumin (rIX-FP)., Methods: Cynomolgus monkeys and hemophilia B dogs received single intravenous doses of rIX-FP (50-500 IU kg(-1)). rIX-FP plasma levels were determined by an activity-based assay (dogs only) and anti-FIX ELISA methods. Additionally, activated partial thromboplastin time (APTT) was determined in hemophilia B dogs. Data were compared with a direct study comparator (recombinant FIX [rFIX]) or previously published data., Results: The terminal half-life of rIX-FP was prolonged in both species compared with FIX reference data. In hemophilia B dogs, human FIX antigen levels remained above 0.05 IU mL(-1) more than three times longer after rIX-FP (7.3 days) compared with rFIX (2.3 days), whereas respective calculations based on activity levels confirmed the observed superior profile. Prolonged PDs of rIX-FP were demonstrated with APTT<60 s sustained around four times longer with rIX-FP (5.9 days) than rFIX (1.5 days)., Conclusions: These studies indicate that the recombinant albumin fusion technology successfully improves the PK profile of FIX. Clinical studies will test whether the improved kinetics result in a significant half-life extension in patients with hemophilia B., (© 2012 International Society on Thrombosis and Haemostasis.)

Prophylaxis is the recommended treatment for people with severe haemophilia. It is unlikely that a single prophylactic regimen, for example based on weight, would be optimal for all patients and therefore each individual should have a personalized regimen, agreed between themselves and their haemophilia centre. This regimen should take into account the individual's bleeding pattern, the condition of their musculoskeletal system, level and timing of physical activity and measurement of coagulation factor in their blood. It is important to recognize that prophylactic regimens are likely to need to change with time as the circumstances of an individual change. For example, activity may change with age or with the season and an individual's factor VIII pharmacokinetics vary with age. Knowledge of a patient's pharmacokinetics is likely to help personalize prophylaxis when combined with other information. Factor VIII pharmacokinetics are simple to measure in routine clinical practice and can be adequately calculated from 2 to 3 blood samples combined with a simple to use computer program. Prophylaxis is expensive and, in countries with a limited health care budget, ways to improve its cost effectiveness need to be considered to allow increased access to this treatment. For example, increasing the frequency of prophylaxis can dramatically reduce the amount of treatment required to sustain measureable factor levels and hence reduce cost. The introduction of longer-acting coagulation factors may necessitate a change in concepts about prophylaxis because whilst these agents may sustain an apparently adequate trough level with fewer infusions, the length of time a person spends at a low level will be increased and this could increase the risk of bleeding, especially at the time of increased physical activity. There is convincing evidence that prophylaxis is the optimal therapy for severe haemophilia, optimizing treatment for each individual and increasing access to this treatment modality are important goals for the future., (© 2012 Blackwell Publishing Ltd.)

AAV virus mediated transfer of factor IX to humans is safe and effective at three dose levels. Two subjects treated at highest dose level developed immune mediated transaminitis which resolved on a short course of Prednisolone. Beneficial effects in terms of continuous elevation of factor IX level above base line was seen in all subjects, continuing for over 18 months. Further study of this treatment method is warranted., (© 2012 Blackwell Publishing Ltd.)

Long-term, continuous prophylaxis for haemophilia began at a modest scale during the 1950s and 1960s in Sweden and The Netherlands. In the face of high cost and impediments to the performance of longitudinal, well-designed studies, it was decades before prophylaxis was considered to be the best practice in countries that could afford the cost. In 2007 and 2011, the only prospective randomized studies ever performed confirmed what large cohort studies in Europe had long since shown. Today, focus is on when to start prophylaxis, dosing and when/if to stop. Retrospective comparisons of the Swedish and Dutch cohorts, where different strategies have been used, indicate that a costly, high-dose regimen improves outcome, but not dramatically. A prospective comparison is now underway. Treatment, clinical outcome, clotting factor consumption and socioeconomic parameters will be compared between the two strategies. Results are expected to provide greater insight into the long-term consequences of the different prophylactic treatment strategies. The economic justification for prophylaxis has been addressed in several studies with varying results. While the majority (implicitly) suggest that prophylaxis is not cost effective at conventional willingness to pay for additional units in health thresholds, their results vary markedly. Closer inspection suggests that the primary reasons results differ include different definitions of prophylaxis, clotting factor price, discount rates, choice of outcome measures and time horizon., (© 2012 Blackwell Publishing Ltd.)

Prophylactic infusion of clotting factor concentrates is a developing standard of care for individuals with haemophilia. The ideal schedule and techniques of prophylactic infusions remain incompletely defined. Our aim was to determine the optimal techniques and schedules for factor prophylaxis in paediatric patients. A retrospective electronic medical record review of all children treated with prophylactic factor infusions in a single Haemophilia Treatment Center was conducted. Comparison of traditional vs. Canadian dosing regimens and primary vs. secondary prophylaxis was made. Failure of prophylaxis was defined as the first serious bleed. A total of 58 children were identified for review. Five cases were excluded (four due to high titre inhibitors and one due to repeated non-compliance), thus there were 53 total cases: 46 with severe haemophilia, 2 with moderate haemophilia, 5 with mild haemophilia, 44 with haemophilia A and 9 with haemophilia B; 32 Traditional dosing and 21 Canadian dosing regimens. Patients on primary prophylaxis had a decreased failure rate (25%) compared to children treated with secondary prophylaxis (67%) regardless of technique of prophylaxis. When compared to a 'Traditional' factor prophylaxis schedule, the 'Canadian' tailored prophylaxis protocol was comparable with the exception of a decreased use of implanted venous devices in the 'Canadian' group. Ongoing bleeding (primarily joint bleeds) occurs with all prophylactic regimens. The lowest incidence of treatment failure was noted in children who began primary prophylaxis at a young age and before initial joint bleeds. Primary prophylaxis is superior to secondary prophylaxis regardless of dosing regimen. Traditional and Canadian dosing regimens were equivalent in outcome when measured over several years of follow-up., (© 2012 Blackwell Publishing Ltd.)

Purpose: Knowledge of the pharmacokinetics (PK) of plasma-derived factor IX (FIX) is still inadequate, with conflicting findings on its elimination half-life and as yet no analysis of the variance in PK between and within individuals. The aim of the study was thus to characterize the PK of plasma-derived FIX, including estimates of variance between and within patients, in adult patients and to predict the variation between individuals in dose requirement to produce a target trough level during regular prophylaxis., Methods: Plasma FIX versus time data were compiled from four published and one unpublished PK study involving a total of 26 adult patients with severe haemophilia B. The number of PK assessments per patient varied between one and eight, yielding in total 893 measured FIX levels from 80 study occasions. A population PK model was developed to describe the whole dataset. Parameter values from the model were used to calculate the dose requirement to maintain a trough level of 1% of normal FIX activity in each patient., Results: The disposition of FIX was well described by a three-compartment PK model. The median elimination half-life was 31 h, and the variation between individuals was modest both in PK and in dose requirement during twice-weekly prophylaxis., Conclusion: With twice weekly dosing, the need for PK-based dose tailoring of FIX in adult patients appears to be limited. However, monitoring FIX levels should be considered in children, in patients who do not respond satisfactorily to standard dosing, and if treatment is switched from plasma-derived to recombinant FIX.

Severe haemophilia is associated with recurrent joint bleeds, which can lead to haemophilic arthropathy. Subclinical joint bleeds have also been associated with joint damage detected using magnetic resonance imaging (MRI). We investigated the development of early changes in clinically asymptomatic joints using MRI in haemophilia A or B patients receiving prophylactic therapy. In this single-centre retrospective cohort study, patients with clinical evidence of joint damage in one ankle and one clinically asymptomatic ankle, in which we performed an MRI scan of both ankles in one session, were enrolled. MRI findings were graded using a 4-point scoring system (0 = normal findings and III = severe joint damage). Since 2000, 38 MRIs in 26 patients have been performed. Starting at a median age of 4 years, 23 patients received prophylaxis 2-3 times weekly. On-demand treatment was performed in three patients. Eight patients (31%) presented with an MRI score of 0, 12 (46%) had a score of I, four (15%) had a score of II, and two (8%) had a score of III in the clinically unaffected ankle. The six patients with MRI scores of II and III had started regular prophylaxis between the ages of 2 years and 15 years; none had developed an inhibitor or experienced a clinically evident bleed in the asymptomatic ankle. During our study, five of 26 patients had a worsening of MRI findings without experiencing a joint bleed. Early morphological changes in clinically asymptomatic ankles can be detected using MRI, despite adequate prophylaxis., (© 2011 Blackwell Publishing Ltd.)

Background: Damage control resuscitation advocates correction of coagulopathy; however, options are limited and expensive. The use of prothrombin complex concentrate (PCC), also known as factor IX complex, can quickly accelerate reversal of coagulopathy at relatively low cost. The purpose of this study is to describe our experience in the use of factor IX complex in coagulopathic trauma patients., Methods: All patients receiving PCC at our Level I trauma center over a two-year period (2008-2010) were reviewed. PCC was used at the discretion of the trauma attending for treatment of coagulopathy, reversal of coumadin, and when recombinant factor VIIa was indicated., Results: Forty-five trauma patients received 51 doses of PCC. Sixty-two per cent were male and mean Injury Severity Score was 23 (± 14.87). Standard dose was 25 units per kg and mean cost per patient was $1,022 ($504-3,484). Fifty-eight per cent of patients were on warfarin before admission. Mean international normalized ratio (INR) was decreased after PCC administration (p = 0.001). Packed red blood cell transfusion was also reduced after factor IX complex (p = 0.018). Mean INR was reduced in both the nonwarfarin (p = 0.001) and warfarin (p = 0.001) groups. Packed red blood cell transfusion was less in the nonwarfarin group (p = 0.002) however was not significant in the warfarin group. Subsequent thromboembolic events were observed in 3 of the 45 patients (7%). Mortality was 16 of 45 (36%)., Conclusion: PCC rapidly and effectively treats coagulopathy after traumatic injury. PCC therapy leads to a significant correction in INR in all trauma patients, regardless of coumadin use, and concomitant reduction in blood product transfusion. PCC should be considered as an effective tool to treat acute coagulopathy of trauma. Further prospective studies examining the safety, efficacy, cost, and outcomes comparing PCC and recombinant factor VIIa are needed.

This case report describes a term infant born by a non-traumatic, non-instrumented cesarean section that presented with respiratory failure and severe metabolic acidosis secondary to subgaleal hemorrhage (SGH). Further evaluation revealed a functional factor X deficiency that was initially treated with fresh frozen plasma infusions. This report is significant for the occurrence of a SGH in a non-traumatic delivery and emphasizes the importance of obtaining a coagulopathy evaluation in patients with similar presentations. In addition, this case suggests that the mechanism of injury that causes SGH may occur more frequently than previously thought, but does not become clinically significant in patients without an underlying coagulopathy.

Haemorrhagic manifestations in patients with haemophilia A and B are considered quite similar for comparable level of factor deficiency. We investigated the bleeding frequency and factor usage between HA and HB patients with comparable disease severities. We collected data on frequency of bleeds and factor concentrate utilization over 3 years, from January 2001 to December 2003. Information was gathered from home infusion logs recorded by patients or their parents, and treatment records from the Hemophilia Clinic or the Hospital Emergency Department. Data were available on 58 patients with severe HA (FVIII < 0.01 U mL(-1)), 10 with moderate HA (FVIII < 0.05 U mL(-1)), 15 with severe HB, and five with moderate HB who required treatment for episodic bleeds, postoperative haemostasis and for primary or secondary prophylaxis. The HA patients bled more frequently than HB patients (14.4 vs. 8.63 bleeds/patient/year), but used similar amounts of concentrate per year. HA patients underwent surgical procedures 3.2 times more frequently than HB patients to correct musculoskeletal complications. A total of 21,363,409 IU of recombinant FVIII was used by patients with HA (104,722 IU/patient/year) and 6,430, 960 IU of recombinant factor IX, by patients with HB (107,182 IU/patient/year). The difference in factor concentrate usage is not statistically significant (P > 0.05). The decrease in bleed frequency in haemophilia B indicates that the conclusions from randomized trials of prophylaxis in HA may not be accurately applied to HB., (© 2011 Blackwell Publishing Ltd.)

The current regimen of factor IX (FIX) injection is of an episodic format, which leads to limited efficacy. A sustained release dosage form is beneficial in terms of reducing the injection frequency and improving the therapeutic effectiveness. The aim of this study was to formulate a new microsphere form of a FIX-containing preparation to diminish these shortcomings. Using the water-in-oil-in-water (W/O/W) double emulsion technique, injectable long-acting FIX microspheres were prepared with transgenic recombinant human FIX (rhFIX) and poly(lactic-co-glycolic acid) (PLGA) polymer. The rhFIX microspheres prepared had diameters ranging between 25-350 μm and easily passed through a small-gauge-number needle for subcutaneous injection. In in vitro release testing, the microspheres had a sustained release profile featuring an initial burst and sustained release spanning a 5-day period. In in vivo pharmacodynamic testing, normalization of the bleeding of hemophilic mice was maintained for 5 days with microsphere injection as compared with 2 days with native rhFIX. Taken together, these results indicated that long-acting FIX microspheres were successfully prepared for potential use in hemophilic prophylaxis.