Prophylaxis in the haemophilia population

Cost-effectiveness analysis of low-dose prophylaxis versus on-demand treatment for moderate-to-severe hemophilia A in India

AIM

Hemophilia A (HA) is an inherited bleeding disorder caused by a deficiency of clotting factor VIII in the blood. In resource-limited settings like India, affordability is a significant challenge in managing patients with severe HA. This study aims to assess the cost-effectiveness of intermediate-dose prophylaxis versus on-demand factor therapy in adult and pediatric populations with moderate-to-severe congenital HA without inhibitors in India.

METHOD

We conducted a prospective cost-effectiveness analysis from a societal perspective, categorizing patients into a base state and a joint disease state (patients with Hemophilia suffering extensive bleeds leading to chronic joint disease). Using targeted literature search and primary market research, we developed a Markov model measuring the total cost of Hemophilia treatment and health outcomes, including life-years (LYs), quality-adjusted life-years (QALYs), incremental cost-utility ratio (ICUR), and incremental cost-effectiveness ratio (ICER). The model extended over a lifetime horizon of 70 years with a one-year cycle length. Sensitivity analyses assessed study robustness.

RESULTS

Low-dose prophylactic therapy was cost-effective for adults (>18 years) and pediatric populations (<18 years), yielding better health outcomes (adults: 0.15 LYs and 2.43 QALYs gained; pediatric: 0.40 LYs and 3.12 QALYs gained). Intermediate-dose prophylaxis showed positive net monetary benefits in terms of Quality-Adjusted Life Years (QALYs) for both adult and pediatric populations, with dominant ICER and ICUR values in both cases.

CONCLUSION

Using intermediate-dose prophylactic factor VIII therapy is a cost-effective approach that improves clinical outcomes compared to on-demand therapy in the Indian adult and pediatric HA populations without inhibitors.

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

Background

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

Methods

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

Results

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

Conclusion

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

Dosing for Personalized Prophylaxis in Hemophilia A Highly Varies on the Underlying Population Pharmacokinetic Models

BACKGROUND

Model-informed personalized prophylaxis with factor VIII (FVIII) replacement therapy aimed at higher trough levels is becoming indispensable for patients with severe hemophilia A. This study aimed to identify the most suitable population pharmacokinetic (PK) models for personalized prophylaxis using various FVIII products and 2 clinical assays and to implement the most suitable one in open-access software.

METHODS

Twelve published population PK models were systematically compared to predict the time above target (TaT) for a reference dosing occasion. External validation was performed using a 5-point PK data from 39 adult patients with hemophilia A with FVIII measured by chromogenic substrate (CSA) and 1-stage assays (OSAs) using NONMEM under 3 different conditions: a priori (with all FVIII samples blinded), a posteriori (with 1 trough sample), and general model fit (with all FVIII samples including the reference dosing occasion provided).

RESULTS

On average, the baseline covariate models overpredicted TaT (a priori; bias -3.8 hours to 49.6 hours). When additionally including 1 previous trough FVIII sample before the reference dosing occasion (a posteriori), only 50% of the models improved in bias (-1.0 hours to 36.5 hours) and imprecision (22.4 hours and 60.7 hours). Using all the time points (general model fit), the models accurately predicted (individual TaT less than ±12 hours compared with the reference) 62%-90% and 33%-74% of the patients using CSA and OSA data, respectively. Across all scenarios, predictions using CSA data were more accurate than those using the OSA data.

CONCLUSIONS

One model performed best across the population (bias: -3.8 hours a priori, -1.0 hours a posteriori , and 0.6 hours general model fit ) and acceptably predicted 44% (a priori) to 90% ( general model fit ) of the patients. To allow the community-based evaluation of patient-individual FVIII dosing, this model was implemented in the open-access model-informed precision dosing software "TDMx."

Twice Weekly Vs. Thrice Weekly Low-Dose Prophylactic Factor VIII Therapy in Children with Hemophilia A: An Open Label Randomized Trial

INTRODUCTION

Low dose factor VIII prophylactic therapy in hemophilia has not been well established till date. This randomized controlled trial compared the efficacy of twice vs. thrice weekly schedule of low dose prophylactic factor VIII in children with hemophilia A as evaluated by the bleeding rate and clinico-radiological evaluation.

METHODS

Thirty-three children with severe hemophilia A (≤18 years) were randomized into two groups. Baseline evaluation included detailed history, clinical (HJHS 2.1 score and FISH score) and radiological examination (Pettersson score and ultrasound score). Group 1 received twice weekly factor VIII prophylaxis while group 2 received thrice weekly factor VIII prophylaxis, the dose being 10 U/kg in both groups. All participants were followed up over next 6 months to one year. Data regarding acute bleeding episodes and repeat clinico-radiological assessment at the end of follow up were recorded.

RESULTS

We analyzed 14 children in twice weekly prophylaxis group and 16 children in thrice weekly prophylaxis group. Statistically insignificant difference was found between the bleeding rates in both the groups after prophylaxis with the median values of monthly bleeding rate being 0.17 and p-value of 0.79. The differences between the initial and final clinical and radiological scores within each group were found to be statistically significant. There was no significant difference in the clinical and radiological scores in between the groups.

CONCLUSION

Twice weekly FVIII therapy is effective, easily administered prophylactic schedule to prevent long-term complications of hemophilia A. Lay summaryHemophilia A is one of the most common congenital coagulation factor deficiencies. Low dose factor VIII prophylaxis is recommended for hemophilia in resource-poor settings to reduce the bleeding episodes and improve the quality of life, although the optimal schedule for the same has not been well established. A randomized controlled trial on 33 children with hemophilia A (≤18 years) was done to compare the efficacy of twice versus thrice weekly schedule of prophylactic factor VIII. Group 1 received twice weekly factor VIII prophylaxis while group 2 received thrice weekly factor VIII prophylaxis, the dose in both groups being 10 U/kg. They were evaluated by the bleeding rate and clinical (HJHS 2.1 score and FISH score) and radiological scores (Pettersson score and ultrasound score). All participants were followed up over next 6 months to one year. Data regarding acute bleeding episodes and repeat clinico-radiological assessment at end of follow up were recorded. When analyzed, statistically insignificant difference was found between the bleeding rates after the two prophylaxis regimes. There was a significant improvement between initial and final clinical and radiological scores in both the groups and no difference was recorded in between the groups. To conclude, twice weekly FVIII therapy is effective, easily administered prophylactic schedule to prevent long-term complications of hemophilia A.

Managing Severe Hemophilia A in Children: Pharmacotherapeutic Options

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

Impact of the HEAD-US Scoring System for Observing the Protective Effect of Prophylaxis in Hemophilia Patients: A Prospective, Multicenter, Observational Study

Objective:

This study aimed to observe the preventive effect of prophylactic treatment on joint health in people with hemophilia (PwH) and to investigate the importance of integration of ultrasonographic examination into clinical and radiological evaluation of the joints.

Materials and Methods:

This national, multicenter, prospective, observational study included male patients aged ≥6 years with the diagnosis of moderate or severe hemophilia A or B from 8 centers across Turkey between January 2017 and March 2019. Patients were followed for 1 year with 5 visits (baseline and 3^rd, 6^th, 9^th, and 12^th month visits). The Hemophilia Joint Health Score (HJHS) was used for physical examination of joints, the Pettersson scoring system was used for radiological assessment, point-of-care (POC) ultrasonography was used for bilateral examinations of joints, and the Hemophilia Early Arthropathy Detection with Ultrasound (HEAD-US) score was used for evaluation of ultrasonography results.

Results:

Seventy-three PwH, of whom 62 had hemophilia A and 11 had hemophilia B, were included and 24.7% had target joints at baseline. The HJHS and HEAD-US scores were significantly increased at the 12^th month in all patients. These scores were also higher in the hemophilia A subgroup than the hemophilia B subgroup. However, in the childhood group, the increment of scores was not significant. The HEAD-US total score was significantly correlated with both the HJHS total score and Pettersson total score at baseline and at the 12^th month.

Conclusion:

The HEAD-US and HJHS scoring systems are valuable tools during follow-up examinations of PwH and they complement each other. We suggest that POC ultrasonographic evaluation and the HEAD-US scoring system may be integrated into differential diagnosis of bleeding and long-term monitoring for joint health as a routine procedure.

A Preconditioning Strategy to Augment Retention and Engraftment Rate of Donor Cells During Hepatocyte Transplantation

BACKGROUND

Hepatocyte transplantation has been extensively investigated as an alternative to orthotopic liver transplantation. However, its application in routine clinical practice has been restricted because of low initial engraftment and subsequent repopulation.

METHODS

Using mice as a model, we have developed a minimally invasive and nontoxic preconditioning strategy based on preadministration of antibodies against hepsin to increase donor hepatocyte retention and engraftment rate.

RESULTS

Liver sinusoid diameters decreased significantly with antihepsin pretreatment, and graft cell numbers increased nearly 2-fold in the recipients' liver parenchyma for 20 days after hepatocyte transplantation. Postoperative complications such as hepatic ischemia injury or apparent immune cell accumulation were not observed in recipients. In a hemophilia B mouse model, antihepsin preconditioning enhanced the expression and clotting activity of coagulation factor IX (FIX) to nearly 2-fold that of immunoglobulin G-treated controls and maintained higher plasma FIX clotting activity relative to the prophylactic range for 50 days after hepatocyte transplantation. Antihepsin pretreatment combined with adeno-associated virus-transduced donor hepatocytes expressing human FIX-Triple, a hyperfunctional FIX variant, resulted in plasma FIX levels similar to those associated with mild hemophilia, which protected hemophilia B mice from major bleeding episodes for 50 days after transplantation. Furthermore, antihepsin pretreatment and repeated transplantation resulted in extending the therapeutic period by 30 days relative to the immunoglobulin G control.

CONCLUSIONS

Thus, this antihepsin strategy improved the therapeutic effect of hepatocyte transplantation in mice with tremendous safety and minimal invasion. Taken together, we suggest that preconditioning with antihepsin may have clinical applications for liver cell therapy.

Safety and efficacy of nonacog alfa for the treatment of haemophilia B in children younger than 6 years of age in a routine clinical care setting: the EUREKIX registry study

INTRODUCTION

European regulatory authorities request postmarketing safety and efficacy data for factor IX (FIX) products.

AIM

Collect additional clinical data from routine nonacog alfa use in children aged <6 years with haemophilia B.

METHODS

The EUREKIX registry included retrospective and prospective data collection phases. Safety was assessed via adverse drug reactions (ADRs)/adverse events (AEs) and events of special interest (ESIs) as the primary objective; efficacy was evaluated via annualised bleeding rates (ABRs).

RESULTS

The retrospective phase comprised 37 subjects. Of these, 25 had severe haemophilia B. One subject experienced 2 ADRs; another experienced 4 ESIs of hypersensitivity. Median ABR in subjects receiving a predominantly on-demand regimen (prophylaxis <50% of time; n = 11) was 2.0; median ABR was 3.8 in those receiving predominantly prophylactic treatment (prophylaxis ≥50% of time; n = 24). Joint bleeding was infrequent (median ABR, 0.4; n = 35). The prospective phase included 26 subjects, with 17 continuing from the retrospective phase. A total of 20 subjects had severe haemophilia B. Three subjects experienced 7 treatment-related AEs; 3 experienced 4 ESIs. Median ABR was 4.5 and 1.1 in subjects who received predominantly on-demand (n = 5) or prophylactic treatment (n = 19), respectively; the overall median ABR for joint bleeding events was 0.0.

CONCLUSIONS

Overall, nonacog alfa treatment effectively controlled bleeding events, with no new safety signals identified. These data support the safety and efficacy of nonacog alfa in routine clinical settings in children aged <6 years.

Total hip arthroplasty for a woman with hemophilia A -case report

Hemophilia A is a congenital bleeding disorder caused by an X-linked hereditary pattern. Female hemophilia A carriers are usually asymptomatic, although some have far lower levels of clotting factor because more X chromosomes with the normal gene are switched off, a phenomenon referred to as "lyonization.” During a medical checkup at our hospital, a 56-year-old Japanese woman with coxalgia was also diagnosed as an obligate hemophilia A carrier based on World Federation of Hemophilia criteria. She underwent total hip arthroplasty using blood product coagulation factor VIII to address her hemophilia. Immediate female relatives (mother, sisters, daughters) of a person with hemophilia should have their clotting factor levels checked, especially prior to any invasive intervention or childbirth, or if any symptoms occur.

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We report a case of total hip arthroplasty for a woman with hemophilia A.

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Some female hemophilia A carriers have far lower levels of clotting factor.

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Immediate female relatives of a person with hemophilia should have their clotting factor level checked.

Design of a prospective observational study on the effectiveness and real-world usage of recombinant factor VIII Fc (rFVIIIFc) compared with conventional products in haemophilia A: the A-SURE study

INTRODUCTION

Haemophilia A is a rare bleeding disorder caused by coagulation factor VIII (FVIII) deficiency. This is treated with factor VIII, conventionally using products with a half-life of 8-12 hours typically administered every 2-3 days. Recombinant FVIII Fc (rFVIIIFc) represents a new generation of products with an extended half-life allowing higher FVIII levels and longer dosing interval. The efficacy and safety of rFVIIIFc have been established in clinical studies and several years of postmarketing use. However, there remains a need to compare treatment outcome with conventional products in routine clinical use.

METHODS AND ANALYSIS

A-SURE is an ongoing, non-interventional European study with the primary objective to compare the clinical effectiveness of rFVIIIFc with conventional factor products used for haemophilia A prophylaxis. Data covering a 24-month prospective period and a 12-month retrospective period will be collected. Three primary endpoints: bleeding rate, injection frequency and factor consumption will be used to evaluate treatment outcomes. Enrolment of 175 patients on rFVIIIFc and 175 on conventional products is planned. All eligible patients from participating centres will be invited to participate. Visits and treatments follow routine clinical practice. Bias will be reduced by patient matching for age at baseline and the last weekly prophylaxis dose of a conventional product prior to baseline. Propensity scores will be calculated based on prognostic factors and potential confounders assessed at baseline and adjusted for in the estimation of the treatment effect.

ETHICS AND DISSEMINATION

Study approval was obtained by local independent ethics committees and/or authorities, and informed consent from patients or their legal representative is a requirement for participation. Names of ethical committees and approval numbers are provided as supplementary information. The study results will be submitted for publication in a peer-reviewed scientific journal and presented at scientific conferences.

TRIAL REGISTRATION NUMBER

NCT02976753, Pre-results.

Telehealth Videoconferencing for Children With Hemophilia and Their Families: A Clinical Project

Telehealth is the use of electronic information and telecommunications technologies to support long-distance health care. It supports quality health care that is accessible, and time- and cost-effective. Telehealth videoconferencing may enhance the care for hemophilia patients who are experiencing a bleed by supporting real-time detailed assessment including appearance, range of motion, and ambulation in addition to the traditional phone methods of verbal description of appearance, pain, and function. The aim of this clinical project was to evaluate the feasibility of using telehealth videoconferencing in children with severe hemophilia in the home setting. Twelve patients with severe hemophilia ages 2to 18 years, who had more than 2 breakthrough bleeds in the past year, and had Internet access with a computer camera were included. The incidence of bleeding was low; however, videoconferencing was effective for 3 patients who completed 4 video appointments. Patients and staff reported that videoconferencing improved communication and satisfaction. Telehealth videoconferencing is a feasible tool for managing bleeding disorders in the home setting.

Optimal management of hemophilic arthropathy and hematomas

Hemophilia is a hematological disorder characterized by a partial or complete deficiency of clotting factor VIII or IX. Its bleeding complications primarily affect the musculoskeletal system. Hemarthrosis is a major hemophilia-related complication, responsible for a particularly debilitating chronic arthropathy, in the long term. In addition to clotting factor concentrates, usually prescribed by the hematologist, managing acute hemarthrosis and chronic arthropathy requires a close collaboration between the orthopedic surgeon and physiotherapist. This collaboration, comprising a coagulation and musculoskeletal specialist, is key to effectively preventing hemarthrosis, managing acute joint bleeding episodes, assessing joint function, and actively treating chronic arthropathy. This paper reviews, from a practical point of view, the pathophysiology, clinical manifestations, and treatment of hemarthrosis and chronic hemophilia-induced arthropathy for hematologists, orthopedic surgeons, and physiotherapists.

Pharmacokinetics of plasma-derived vs. recombinant FVIII concentrates: a comparative study

Only very few pharmacokinetic (PK) studies comparing plasma derived FVIII (pd-FVIII) against recombinant FVIII (rFVIII) concentrates are available. The studies have been generally conducted to demonstrate the bioequivalence of a new product with an old one. The switch from a plasma-derived FVIII (pd-FVIII) to a rFVIII concentrate is a good moment to enrol the patients in a comparative PK study. To achieve information on the PK characteristics of two different classes of FVIII concentrates, according to two different designs: a 10 FVIII concentration/time point design and a reduced 4-point design. A single dose PK comparing pd- and rFVIII concentrates has been performed in four Haemophilia Centres of Italy. Seventeen haemophilia A patients underwent two subsequent single dose PK studies at the moment of switching. Two-compartment- and Non-compartment-analysis did not show significant differences between the outcomes of PK of pd-FVIII and rFVIII, due to inter-patient variability. In vivo recovery (IVR) of rFVIII was slightly higher than that of pd-FVIII and rFVIII/pd-FVIII AUC ratio was 1.37 in 11/17 patients. The difference is only due to the initial distribution phase because after the first 10 h from the end of the infusion, the two decay curves are overlapping. The elimination half-life of the concentrates was very similar even though a complete bioequivalence was not demonstrated because of a higher AUC of rFVIII concentrates, limited to the distribution phase. The higher Cmax and IVR of rFVIII may be due to the presence of heterodimers activated forms of the recombinant molecules.

Prophylaxis in adult patients with severe haemophilia A

Primary prophylaxis is the standard of care for children and adolescents with severe haemophilia; however, its role in adults is less well defined. To establish to which extent prophylaxis is currently being used in adults with severe haemophilia A, we conducted a systematic review of the literature by searching MEDLINE using the terms "prophylaxis", "adult", "severe" and "haemophilia A". Evidence-based guidelines and national studies relating to the use of prophylaxis in adults with severe haemophilia A were identified and reviewed. One published evidence-based guideline and three published studies fulfilled our inclusion criteria. A combined analysis of published data suggests that almost 45% of adult patients with severe haemophilia A are being treated with prophylaxis. Withdrawal of prophylaxis is attempted relatively infrequently; however, when attempted, around 27% of adolescents and adults with severe haemophilia do not experience an increase in bleeding tendency over a specific treatment period. Prophylaxis (primary and secondary) is an important part of haemophilia treatment that should be granted to all patients depending on their clinical presentation. Further studies are needed to better define this treatment strategy in adults.

Adherence to clotting factors among persons with hemophilia A or B

OBJECTIVE

Evaluate adherence to clotting factor treatment and associated outcomes for patients with hemophilia using an integrated delivery database.

METHODS

This was a retrospective, observational study tracking patients between 2006 and 2011. Patients with diagnosis codes for hemophilia were identified. Bleeding and complication rates were annualized over the study period. Medication adherence was assessed using prescription claims for clotting factors by examining sequential time periods of 180 days for each patient's continuous enrollment. Adherence within the time period was calculated using the 'days supply' field divided by 180 days. Under the assumption that severe patients should be treated prophylactically, patients were considered adherent within the time period if the ratio of 'days supply' to observed days was 60% or greater.

RESULTS

A total of 207 patients (74.9 and 25.1% hemophilia A and B, respectively) met the inclusion/exclusion criteria. There were 101 (48.8%) mild, 32 (15.5%) moderate, and 74 (35.7%) severe patients with hemophilia. The percentage of time periods where adherence to clotting factors was 60% or greater was 14% (SD = 28%) for mild disease, 21% (SD = 32%) for moderate disease, and 51% (SD = 36%) for severe disease. Among patients with severe disease, 27 (36.5%) were adherent ≤ 30% of time periods, 22 (29.7%) adherent 31-70% of the time periods, and 25 (33.8%) were adherent ≥ 71% of time periods. Joint bleeding episodes and hospitalizations were uncommon events among the three groups.

CONCLUSIONS

Among patients with severe disease, the majority (66.2%) were adherent <70% of the time.

Beriate® P in the treatment of patients with haemophilia A: results of a long-term pharmacovigilance study

BACKGROUND

The German Beriate(®) P pharmacovigilance study started in 2003 and is planned to run until December 2013.

MATERIALS AND METHODS

This analysis included data from 84 haemophilia A patients treated with the high-purity, plasma-derived coagulation factor VIII concentrate Beriate(®) P. Prior to study start, 69 of the 80 patients for whom data were available had received previous treatment with Beriate(®) P (mean treatment period 7.1 ± 5.4 years). The mean study duration from the start of pharmacovigilance was 43.3 ± 30.3 months (median 43.5 months; range 0-101.9months). The most common treatment at the last visit was prophylaxis (65.7% of patients), which was most commonly administered at a frequency of three infusions/week in 47.3% of patients.

RESULTS

Most patients experienced up to six minor bleeds/year. For 1,311 bleeding episodes, a median of one infusion/bleed was administered (mean 2.8 ± 4.7; range 0-83). The clinical response to Beriate(®) P was rated "excellent"/"good" in 94% of 32 visits of patients with major bleeding. The clinical response for patients with minor bleeding was rated "excellent"/"good" in 98.5% of 377 visits. One clinically relevant inhibitor in a previously untreated patient was documented during the study course. There were no reports of virus transmissions suspected to be caused by Beriate(®) P prior to the study start or during the study.

CONCLUSIONS

These findings confirm the excellent efficacy, safety, and tolerability of Beriate(®) P in the treatment of a wide spectrum of previously untreated patients up to adult patients with haemophilia A.

Turning severe into moderate haemophilia by prophylaxis: are we reaching our goal?

BACKGROUND

Since the introduction of prophylaxis, physicians have tried to convert the clinical phenotype of severe haemophilia (SH) into that of moderate haemophilia (MH), but the outcome of patients with SH has never been compared to that of patients with MH.

MATERIAL AND METHODS

The outcome of 80 patients with SH on long-term, intermediate dose prophylaxis was compared to that of 40 patients with MH in a single-centre study. Data on treatment history, activities (assessed by the IPAQ and HAL), quality of life (assessed by the SF-36 and EQ5D), and 5-year bleeding and clotting factor consumption were collected for patients born between 1970-1995.

RESULTS

The median age of the patients was 24 years (IQR 18-30). All patients with SH received long-term prophylaxis, which was started at a median age of 4.8 years (IQR 3.2-6.2). Among the patients with MH, ten (25%) received prophylaxis, starting at a median age of 10.8 years (IQR 3.8-13.8). The annual number of bleeds, including joint bleeds, was significantly higher in patients with SH (median 2.0 joint bleeds/year, IQR =0.8-3.7) than in patients with MH (median 0.8 joint bleeds/year, IQR =0-1.2). Due to greater use of prophylaxis, the annual clotting factor consumption of SH patients (median 2,120 IU/kg; IQR 1,514-2,768), was higher than that of MH patients (median 133 IU/kg; IQR 49-468). Patients with SH showed slightly but significantly more loss of clinical function (assessed by the Haemophilia Joint Health Score): a median of 8 points (IQR 3-15) vs a median of 2 points, IQR 0-6). Quality of life, as measured by the SF-36, EQ5D and physical activity, was similar between patients with disease of different severity, as well as compared to that of the general population.

DISCUSSION

When comparing unselected cohorts, the bleeding pattern of patients with SH does not appear to be fully converted to that of the milder bleeding pattern of MH by long-term, intermediate-dose prophylaxis, although activities and quality of life were similar.

Consequences of switching from prophylactic treatment to on-demand treatment in late teens and early adults with severe haemophilia A: the TEEN/TWEN study

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.

Enhancing the pharmacokinetic properties of recombinant factor VIII: first-in-human trial of glycoPEGylated recombinant factor VIII in patients with hemophilia A

BACKGROUND

N8-GP is a recombinant factor VIII (FVIII) with a site-directed glycoPEGylation for the purpose of half-life prolongation.

OBJECTIVES

To evaluate the safety and pharmacokinetic profiles of N8-GP in comparison with those of the patients' previous FVIII products.

PATIENTS/METHODS

This dose-escalation trial included previously treated patients with severe hemophilia A who received one of three dose levels (25, 50 or 75 U kg(-1) ) of N8-GP and FVIII product. Each dose escalation was preceded by safety and pharmacokinetic assessment. The trial was registered at www.clinicaltrials.gov (NCT01205724).

RESULTS

Twenty-six patients each received one dose of their previous FVIII product followed by the same, single dose of N8-GP. N8-GP, at any tested dose, was well tolerated, with a low frequency of adverse events. No new inhibitors against FVIII or N8-GP and no binding antibodies against N8-GP developed during the trial. The pharmacokinetics of N8-GP were dose-linear. The incremental recovery of N8-GP was 0.025 [(U mL(-1) )/(U kg(-1) )]. The clearance was 1.79 mL(-1)  h(-1)  kg(-1) . The estimated time from dosing of 50 U kg(-1) N8-GP to a plasma activity of 1% was 6.5 days (range: 3.6-7.9 days). The mean terminal half-life of N8-GP was 19.0 h (range: 11.6-27.3 h), 1.6-fold longer than that of the patients' previous products.

CONCLUSIONS

A single dose of up to 75 U kg(-1) N8-GP was well tolerated in patients with hemophilia A, with no safety concerns. N8-GP had a prolonged half-life, and FVIII:C activity remained at > 1% for longer than the patient's previous product. These results indicate that N8-GP has the potential to reduce dosing frequency during prophylaxis.

Hemophilia clinical gene therapy: brief review

Genetic correction of hemophilia A and B was long considered amenable to the available gene transfer technologies. This assumption has come to fruition with the recent results of a phase I/II trial for hemophilia B. Here we review the clinical application of gene therapy for the hemophilia's as a paradigm of the evolution of gene transfer science and technology. This review is not intended as comprehensive but rather to highlight current clinical developments of gene therapy for the hemophilias.

The history and evolution of the clinical effectiveness of haemophilia type a treatment: a systematic review

First evidence of cases of haemophilia dates from ancient Egypt, but it was when Queen Victoria from England in the 19th century transmitted this illness to her descendants, when it became known as the "royal disease". Last decades of the 20th century account for major discoveries that improved the life expectancy and quality of life of these patients. The history and evolution of haemophilia healthcare counts ups and downs. The introduction of prophylactic schemes during the 1970s have proved to be more effective that the classic on-demand replacement of clotting factors, nevertheless many patients managed with frequent plasma transfusions or derived products became infected with the Human Immunodeficiency Virus (HIV) and Hepatitis C virus during the 1980s and 1990s. Recombinant factor VIII inception has decreased the risk of blood borne infections and restored back longer life expectancies. Main concerns for haemophilia healthcare are shifting from the pure clinical aspects to the economic considerations of long-term replacement therapy. Nowadays researchers' attention has been placed on the future costs and cost-effectiveness of costly long-term treatment. Equity considerations are relevant as well, and alternative options for less affluent countries are under the scope of further research. The aim of this review was to assess the evidence of different treatment options for haemophilia type A over the past four decades, focusing on the most important technological advances that have influenced the natural course of this "royal disease".

Population pharmacokinetic modeling for dose setting of nonacog beta pegol (N9-GP), a glycoPEGylated recombinant factor IX

BACKGROUND

nonacog beta pegol (N9-GP) is a glycoPEGylated recombinant factor IX (rFIX) molecule with a prolonged half-life.

OBJECTIVES

To provide information on potential dose regimens for N9-GP for phase 3 pivotal and surgery trials.

METHODS

A population pharmacokinetic model was developed from single-dose data derived from the first human-dose trial with N9-GP in hemophilia B patients, and was used to extrapolate to steady-state conditions for different N9-GP dose regimens for prophylaxis. The model was also used to compare prophylaxis using N9-GP with standard prophylactic regimens using rFIX or plasma-derived (pd) FIX (40 IU kg(-1) every third day). Plasma activity following dosing with N9-GP, rFIX and pdFIX for surgery and on-demand treatment of bleeds was also simulated.

RESULTS

A linear two-compartmental model best described the pharmacokinetic profiles of N9-GP, rFIX and pdFIX. A prophylactic regimen of 10 U kg(-1) N9-GP once weekly predicted mean peak and trough levels of 18 and 4.2 U dL(-1) , while 40 U kg(-1) once weekly predicted values of 72 and 17 U dL(-1) , respectively. Standard prophylactic regimens with rFIX and pdFIX predicted mean peak and trough levels of 34 and 3.9 IU dL(-1) for rFIX, and mean values of 43 and 2.1 IU dL(-1) for pdFIX. Additional simulations predicted significantly reduced dosing frequency and factor concentrate consumption for N9-GP vs. rFIX and pdFIX for surgery and the treatment of bleeds.

CONCLUSIONS

N9-GP may allow prophylaxis, surgical dosing regimens and on-demand treatment of bleeding episodes with less frequent injections and lower factor concentrate consumption; this possibility is being investigated in prospective clinical trials.

Pharmacokinetics and pharmacodynamics of turoctocog alfa and N8-GP in haemophilia A dogs

The objective of the present study was to evaluate the pharmacokinetic (PK) and pharmacodynamic (PD) profiles of the new recombinant FVIII compound turoctocog alfa and a Glyco-PEGylated FVIII derivative thereof (N8-GP) in Haemophilia A dogs. Six haemophilic dogs divided into two groups were included in the study. Each dog was administered a dose of 125 U kg(-1) , blood samples were collected at predetermined time points for both pharmacokinetic (FVIII measured by one-stage aPTT assay) and pharmacodynamic [whole blood clotting time (WBCT)] evaluations. After intravenous administration to haemophilic dogs, the plasma concentration at the first sampling point was comparable for turoctocog alfa and N8-GP, and the clearance was estimated to be 6.5 and 3.9 mL h(-1) kg(-1) for turoctocog alfa and N8-GP respectively. Both turoctocog alfa and N8-GP were able to reduce the WBCT time to normal levels (<20 min), however, the reduced clearance was reflected in the WBCT, which returned to baseline at a later time point for N8-GP as compared with dogs dosed with turoctocog alfa. The clearance was 40% reduced for N8-GP as compared with turoctocog alfa. Simulations of a multiple dosing regimen in dogs, suggest that to maintain WBCT <20 min N8-GP can be dosed at reduced intervals, e.g. with 4 days between doses, whereas turoctocog alfa will have to be dosed with 2½ day between doses. Data thereby supports N8-GP as an alternative to standard rFVIII replacement therapy, with a more convenient dosing regimen.

Haemophilia care in Europe: the ESCHQoL study

The aim of this study was to determine the clinical conditions of patients with haemophilia within Europe as recommended by the European Commission. In this multicentre, cross-sectional, ambispective study, conducted within 21 European countries patients' clinical data were collected, amongst others haemophilia type, severity, treatment pattern, use of factor products, bleeding, orthopaedic joint scores and infections. A total of 1400 patients, 84.3% with haemophilia A and 15.7% with haemophilia B were enrolled by 42 centres between 2004 and 2006. Thereof, 417 were children (30.0%) and 983 were adults (70.0%). About 70% of patients had severe factor deficiency (<1%). More than half of the adults were carriers of chronic infections (12.6% HIV, 55.8% HCV), compared to only 3.8% children (no HIV, 2.9% HCV). Patients were grouped according to per capita amount of clotting factor used in patients' region of residence in 2005: region 1: >5 IU; region 2: 2-5 IU; region 3: <2 IU. Paediatric and adult patients in region 3 had median numbers of three and eight joint bleeds, respectively, with worse joint scores compared to region 1 with zero and one bleed. Prophylactic therapy was used in only 31.3% children and 8.9% adults with severe haemophilia in region 3 compared to 93.7% and 54.1%, respectively, in region 1. Statistical analysis revealed that residence in areas with low factor consumption/availability is the most prominent risk factor for joint disease. Access of European patients with haemophilia to optimal care with safe factor VIII concentrates is limited and depends on the region of residence.

Safety and prolonged activity of recombinant factor VIII Fc fusion protein in hemophilia A patients

Current factor VIII (FVIII) products display a half-life (t(1/2)) of ∼ 8-12 hours, requiring frequent intravenous injections for prophylaxis and treatment of patients with hemophilia A. rFVIIIFc is a recombinant fusion protein composed of a single molecule of FVIII covalently linked to the Fc domain of human IgG(1) to extend circulating rFVIII t(1/2). This first-in-human study in previously treated subjects with severe hemophilia A investigated safety and pharmacokinetics of rFVIIIFc. Sixteen subjects received a single dose of rFVIII at 25 or 65 IU/kg followed by an equal dose of rFVIIIFc. Most adverse events were unrelated to study drug. None of the study subjects developed anti-rFVIIIFc antibodies or inhibitors. Across dose levels, compared with rFVIII, rFVIIIFc showed 1.54- to 1.70-fold longer elimination t(1/2), 1.49- to 1.56-fold lower clearance, and 1.48- to 1.56-fold higher total systemic exposure. rFVIII and rFVIIIFc had comparable dose-dependent peak plasma concentrations and recoveries. Time to 1% FVIII activity above baseline was ∼ 1.53- to 1.68-fold longer than rFVIII across dose levels. Each subject showed prolonged exposure to rFVIIIFc relative to rFVIII. Thus, rFVIIIFc may offer a viable therapeutic approach to achieve prolonged hemostatic protection and less frequent dosing in patients with hemophilia A. This trial was registered at www.clinicaltrials.gov as NCT01027377.

Enhanced pharmacokinetic properties of a glycoPEGylated recombinant factor IX: a first human dose trial in patients with hemophilia B

Replacement therapy with factor IX (FIX) concentrates is the recommended treatment for patients with hemophilia B, an X-linked bleeding disorder occurring in 1:25 000 male births. N9-GP is a recombinant FIX molecule with a prolonged half-life which is obtained by site-directed glycoPEGylation where a 40-kDa polyethylene glycol molecule is attached to the activation peptide of FIX. This first human dose trial in patients with hemophilia B investigated the safety and pharmacokinetic properties of a single IV dose of N9-GP. Sixteen previously treated patients received one dose of their previous FIX product followed by one dose of N9-GP at the same dose level (25, 50, or 100 U/kg). None of the patients developed inhibitors. One patient developed transient hypersensitivity symptoms during administration of N9-GP and was excluded from pharmacokinetic analyses. In the remaining 15 patients, N9-GP was well-tolerated. The half-life was 93 hours, which was 5 times higher than the patient's previous product. The incremental recovery of N9-GP was 94% and 20% higher compared with recombinant and plasma-derived products, respectively. These results indicate that N9-GP has the potential to reduce dosing frequency while providing effective treatment of bleeding episodes with a single dose. The trial was registered at www.clinicaltrials.gov as NCT00956345.

Successful renal replacement therapy for a patient with severe hemophilia after surgical treatment of intracranial hemorrhage and hydrocephalus

A 21-year-old Japanese male with severe hemophilia A was developed end-stage renal failure. He was placed on combination therapy with peritoneal dialysis (PD) and hemodialysis (HD). Eight months later, he developed a hypertensive cerebral hemorrhage. After emergency surgery, he was managed with PD without HD to avoid cerebral edema. One month later, his renal replacement therapy was switched to HD (three times a week) from PD, since a ventriculoperitoneal shunt catheter was placed to treat his hydrocephalus. HD could be performed safety without anticoagulant agents on condition that factor VIII is given after every HD.