Muscle function deterioration in patients with haemophilia: Prospective experience from Costa Rica.

INTRODUCTION: In haemophilia, recurrent joint bleeds are responsible for the development of chronic joint damage, because blood induces biochemical changes in joint structures. Joint degeneration is a long process, and structural damage is often preceded by joint dysfunction, which is represented by quantitative and qualitative changes in the contraction pattern of muscles around the joints. Muscle function in patients with haemophilia is still poorly investigated. AIM: The aim of this 2-year prospective study was to assess the changes in muscle function of lower limbs in a group of patients affected with haemophilia in San José, Costa Rica. METHODS: Muscle function of lower limbs was assessed by means of surface electromyography (sEMG) accomplished at study enrolment and after 2 years of follow-up. Gluteus medius, vastus medialis, biceps femoris, gastrocnemius and tibialis anterior were examined. All patients underwent concurrent clinical examination using Haemophilia Joint Health Score (HJHS). RESULTS: Sixty patients aged 2-43 years with severe haemophilia underwent clinical and sEMG evaluation. Thirty-two patients (53%) had target joints. sEMG parameters were altered in all patients and were not correlated to the presence of target joints and/or an abnormal HJHS. Muscle function deterioration was observed after 2 years of follow-up despite an unmodified HJHS. CONCLUSIONS: Muscle function of lower limbs as detected by means of sEMG was impaired in patients with haemophilia irrespective of the presence of overt joint damage. sEMG is a simple and sensitive assessment tool able to detect muscle dysfunction and so favouring the implementation of early rehabilitation therapy.

Women with congenital factor VII deficiency: clinical phenotype and treatment options from two international studies.

INTRODUCTION: A paucity of data exists on the incidence, diagnosis and treatment of bleeding in women with inherited factor VII (FVII) deficiency. AIM: Here we report results of a comprehensive analysis from two international registries of patients with inherited FVII deficiency, depicting the clinical picture of this disorder in women and describing any gender-related differences. METHODS: A comprehensive analysis of two fully compatible, international registries of patients with inherited FVII deficiency (International Registry of Factor VII deficiency, IRF7; Seven Treatment Evaluation Registry, STER) was performed. RESULTS: In our cohort (N = 449; 215 male, 234 female), the higher prevalence of mucocutaneous bleeds in females strongly predicted ensuing gynaecological bleeding (hazard ratio = 12.8, 95% CI 1.68-97.6, P = 0.014). Menorrhagia was the most prevalent type of bleeding (46.4% of patients), and was the presentation symptom in 12% of cases. Replacement therapies administered were also analysed. For surgical procedures (n = 50), a receiver operator characteristic analysis showed that the minimal first dose of rFVIIa to avoid postsurgical bleeding during the first 24 hours was 22 µg kg(-1) , and no less than two administrations. Prophylaxis was reported in 25 women with excellent or effective outcomes when performed with a total weekly rFVIIa dose of 90 µg kg(-1) (divided as three doses). CONCLUSION: Women with FVII deficiency have a bleeding disorder mainly characterized by mucocutaneous bleeds, which predicts an increased risk of ensuing gynaecological bleeding. Systematic replacement therapy or long-term prophylaxis with rFVIIa may reduce the impact of menorrhagia on the reproductive system, iron loss and may avoid unnecessary hysterectomies.

Experience of a new high-purity factor X concentrate in subjects with hereditary factor X deficiency undergoing surgery.

INTRODUCTION: Maintaining haemostasis in surgery is challenging for hereditary rare bleeding disorders in which multi-coagulation-factor concentrates are the only therapeutic option. Hereditary factor X (FX) deficiency affects 1:500 000 to 1:1 000 000 individuals, and no specific replacement FX concentrate has been available. A high-purity, plasma-derived FX concentrate (pdFX) has been developed for patients with hereditary FX deficiency. AIM: Our objective was to assess the safety and efficacy of pdFX in subjects with FX deficiency undergoing surgery. METHODS: Subjects with hereditary mild-to-severe FX deficiency (basal plasma FX activity [FX:C] <20 IU dL(-1) ) undergoing surgery received pdFX preoperatively to raise FX:C to 70-90 IU dL(-1) and postoperatively to maintain levels >50 IU dL(-1) until the subject was no longer at risk of bleeding due to surgery. Efficacy of pdFX was assessed by blood loss during surgery, requirement for blood transfusion, postoperative bleeding from the surgical or other sites, and changes in haemoglobin levels. Safety was assessed by adverse events (AEs), development of inhibitors, and clinically significant changes in laboratory parameters. RESULTS: Five subjects (aged 14-59 years) underwent seven surgical procedures (four major and three minor). Treatment duration was 1-15 days. For each procedure, pdFX treatment was assessed as "excellent" in preventing bleeding and achieving haemostasis. No blood transfusions were required, no AEs related to pdFX were observed, and no clinically significant trends were found in any laboratory parameters. CONCLUSION: These data demonstrate that pdFX is safe and effective as replacement therapy in five subjects with mild-to-severe FX deficiency undergoing surgery on seven occasions.

The EPIC study: a lesson to learn.

INTRODUCTION: Inhibitory antibodies to factor VIII occur in about 30% of previously untreated patients (PUPs) and are the most serious complication of haemophilia A. It is unclear why some patients develop inhibitors and others do not. AIMS: The Early Prophylaxis Immunologic Challenge (EPIC) study was designed to test the hypothesis that inhibitor incidence in PUPs with severe or moderately severe haemophilia A could be reduced when a once-weekly FVIII prophylaxis starts with 25 IU kg(-1) rAHF-PFM before 1 year of age and immunological danger signals are minimized. METHODS: These signals were minimized by avoiding: surgery; the first FVIII infusion during severe bleeding or an infection; central venous access devices and administering vaccinations intramuscularly 3-4 days before or after FVIII. RESULTS: Eight of the 19 treated subjects (42.1%) developed confirmed inhibitors. Eleven of the 19 treated subjects were PUPs without any prior exposure to FVIII. Three of them (27.3%) developed a confirmed inhibitor together with FVIII-binding antibodies. The study was stopped because the likelihood to reach the primary objective was minimal, a decision endorsed by the data safety monitoring board. CONCLUSION: Because of early termination, the EPIC study hypothesis could not be corroborated. Nonetheless, our data analyses indicate that the current definition of an inhibitor only based on plasma inhibitor activity ≥0.6 BU mL(-1) may not always reflect the presence of FVIII-neutralizing antibodies. The findings of this study teach us that low-level inhibitor activity results need in addition a confirmatory test and/or the assessment of the therapeutic response.

Treatment of children with severe haemophilia A and inhibitors: a health economic evaluation for Germany.

BACKGROUND: Decision makers request increasingly for high levels of evidence when allocating resources in medical care. This is hardly feasible for rare diseases. The objective was to analyze clinical and economic aspects of different immune tolerance induction (ITI) strategies for children with severe haemophilia A and inhibitors. METHODS: A decision model, time frame 18 years (base case: 2 year old boy), was constructed from a German statutory health insurance (SHI) perspective. Compared were high-dose (HD) ITI, low-dose (LD) ITI, 'ITI with risk assessment', on-demand (OD) treatment with bypassing agents. Clinical data were derived from structured literature research and expert opinion. Sensitivity analyses were conducted for parameters with wide statistical ranges. RESULTS: Base case analysis: total costs for HD ITI amounted to €3.4 million with 40.9% ITI costs, 51 joint bleeds, 36 hospital days; LD ITI, €2.4 million with 21.4% ITI costs, 74 joint bleeds, 52 hospital days; 'ITI with risk assessment', €2.7 million with 27.6% ITI costs, 53 joint bleeds, 37 hospital days; OD treatment, €1.7 million, 146 joint bleeds, 104 hospital days. Incremental costs per bleed avoided with HD ITI decreased from €1 million to €0.15 million with increase of joint bleeds from 3 to 20 per year, when compared to 'ITI with risk assessment' in sensitivity analysis. CONCLUSION: 'ITI with risk assessment' is cost-saving with comparable outcomes to HD ITI. However, patient-related factors like bleeding frequency have to determine treatment decisions in individual patients. More clinical data is needed to increase the significance of model -calculations.

Novel coagulation factor concentrates: issues relating to their clinical implementation and pharmacokinetic assessment for optimal prophylaxis in haemophilia patients.

Prophylaxis is considered the optimal treatment regimen for patients with severe haemophilia, and may be especially important in the prevention of joint disease. Novel coagulation factor concentrates with prolonged half-lives promise to improve patient treatment by enabling prophylaxis with less frequent dosing. With the call to individualize therapy in haemophilia, there is growing awareness of the need to use pharmacokinetic (PK) assessments to tailor prophylaxis. However, for new factor concentrates, it is not yet known which PK values will be most informative for optimizing prophylaxis. This topic was explored at the Eighth Zurich Haemophilia Forum. On the basis of our clinical experience and a discussion of the literature, we report key issues relating to the PK assessment of new coagulation factors and include suggestions on the implementation of PK data to optimize therapy. As both inter- and intra-individual variability in factor half-life have been reported, we suggest that frequent PK assessments should be conducted. However, to diminish the burden of more frequent sampling, sparser sampling strategies and the use of population modelling should be considered. Guidelines on how to assay new factor concentrates, and which PK parameters should be measured, are needed. Concerns were raised regarding the possibility of breakthrough bleeding, and current thinking on how to prevent breakthrough bleeding may no longer be appropriate. Finally, as treatment adherence may be more important to ensure that a therapeutic level of a new coagulation factor concentrate is maintained, behavioural techniques could be implemented to help to improve treatment adherence.

No inhibitor development after continuous infusion of factor concentrates in subjects with bleeding disorders undergoing surgery: a prospective study.

Inhibitor development against von Willebrand factor, factor VIII or factor IX is one of the most severe complications of treating patients with von Willebrand's disease (VWD), haemophilia A or haemophilia B respectively. Continuous infusion of factor concentrate has been implicated as a risk factor for inhibitor development. This prospective study investigated inhibitor development after continuous infusion of factor concentrate for surgical procedures in subjects with VWD or a severe form of haemophilia (factor activity <1%). Observations were made on the occurrence of inhibitor formation, adverse events and virus seroconversions. Main inclusion criteria comprised a negative history of inhibitors to replacement factor concentrate, ≥ 50 exposure days to factor concentrate and anticipated surgery requiring replacement factor coverage for ≥ 3 days. Therapy began with a bolus dose of 30-50 IU kg(-1) body weight of factor concentrate followed by continuous infusion with 3-4 IU kg(-1) h(-1) . Continuous infusion dose of factor concentrate was adjusted based on factor levels measured at least once daily. In 46 subjects included in the study to date, no inhibitors have been identified at discharge or follow-up (3-4 weeks after surgery), and no thrombotic events or postoperative wound infections occurred. All subjects underwent surgery without major blood loss, and hemostatic efficacy was generally rated 'excellent'. The results of the current study are promising, although the number of subjects is too small to make a definitive statement about the incidence of inhibitor development during continuous infusion of factor concentrate. Therefore, this study will be continued.

[Analysis of muscle function with kinetic superficial EMG in children with haemophilia - recognizing subclinical changes, establishing individual therapy, quality control]. / Muskelfunktionsmessung mit kinetischem Oberflächen-EMG bei Kindern mit Hämophilie. Erkennung subklinischer Veränderungen, Etablierung individueller Therapie, Qualitätskontrolle.

UNLABELLED: Electromyography (EMG) measures muscle electricity. It depends on muscle contraction and central motor control. Muscles react very sensitive on external signals (e. g. bleeding), The resulting changes can be shown in EMG. PATIENTS, METHODS: A first study included 51 children and young adults from Costa Rica. They underwent a clinical examination and EMG of the hip, knee and ankle joints. Resting muscle tone, maximal isometric contraction and three typical isotonic movements of the joints were measured. First step of analysis was to characterize typical pathogenic changes in the muscles and to find a corresponding physical therapy to minimize these changes. RESULTS: It showed that EMG is a good marker for muscle condition. It helps to individualize therapy and improve effectivity of physical and physiotherapeutic treatment of the locomotive system of children and young adults with hemophilia. It can help to recognize early subclinical changes and to control the outcome of therapeutic modalities.

When should prophylaxis therapy in inhibitor patients be considered?

Currently, patients with severe haemophilia can expect to lead a relatively normal life including prevention of disabling arthropathy as a result of the development of factor replacement therapy and advances in the understanding of the use of such therapy given prophylactically. Unfortunately, a subset of patients develops neutralizing antibodies termed inhibitors rendering such therapy ineffective. These patients frequently develop recurrent joint bleeding resulting in arthropathy. Until recently, prophylactic therapy was not considered for patients with inhibitors because of the perceived lack of an effective therapeutic agent. However, an accumulation of case reports and a recent prospective study have suggested that prophylaxis with the currently available bypassing agents could be effective and appears to be safe in selected cases. This report will review the current data on prophylaxis with bypassing agents and suggest specific situations in which prophylaxis in inhibitor patients could be considered.

[Inhibitor development after early high exposure and cerebral haemorrhage. Costs and factor demand for a successful immunotolerance induction therapy]. / Inhibitorentwicklung nach früher hoher Exposition und Hirnblutung. Kosten einer erfolgreichen Immuntoleranztherapie.

Severe haemophilia A was diagnosed postpartum in a newborn. The mother was known as a conductor (intron 22 inversion) and an uncle had a persistently high titer inhibitor after failed ITI. Due to a cephalhaematoma, a high-dose pdFVIII substitution was given within the first days after birth. At the age of six month a severe cerebral haemorrhage occurred, making a high-dose pdFVIII substitution and neurosurgical intervention necessary. Several days later a porth-a-cath-system was implanted. The development of a high titer inhibitor occured six days later, an ITI was started according to the Bonn Protocol. Initially rFVIIa was given in addition to the pdFVIII substitution. Seven days after the beginning of treatment the inhibitor was no longer detectable. At monthly intervals the FVIII dosage was reduced until the dosage complied with a prophylaxis in severe haemophilia A. The duration of the ITI was nine months. A total of 30 mg rFVIIa and 276000 IU pdFVIII were used; costs in total: 280173.60 Euro.

New early prophylaxis regimen that avoids immunological danger signals can reduce FVIII inhibitor development.

SUMMARY: The most problematic complication of haemophilia A treatment is the development of inhibitors to FVIII. The highest risk of developing inhibitors is during the first 20 exposure days (EDs). If the patient can be brought through this high risk period without inhibitor development, the subsequent risk is low. Therefore, as a pilot project, we developed a prophylaxis regimen for the first 20-50 EDs specifically designed to induce tolerance to the administered FVIII and to minimize inhibitor development by avoiding immunological danger signals. Twenty-six consecutive previously untreated patients (PUPs) with severe haemophilia A were treated with the new prophylaxis regimen and the incidence of inhibitor development in this group was compared with that in a historical control group of 30 consecutive PUPs treated with a standard joint protection prophylaxis regimen (40-50 IU kg(-1), three times a week). There were no significant differences between the study and control groups in patient-related inhibitor risk factors such as ethnicity (all Caucasian), severity of haemophilia (all <1% FVIII), severity of FVIII gene mutation (P < 0.0006) nor in some treatment-related factors such as product type, age at first exposure, vaccination regimen or the need for surgery. 14 of 30 subjects given standard prophylaxis but only one of the 26 subjects given the new regimen developed an inhibitor (P = 0.0003, odds ratio 0.048, 95% CI: 0.001-0.372). Our results indicate that minimizing danger signals during the first 20 EDs with FVIII may reduce the risk of inhibitor formation. These results should be confirmed in a larger prospective clinical study.

Paediatric haemophilia with inhibitors: existing management options, treatment gaps and unmet needs.

Development of inhibitors is a severe complication of haemophilia posing many management challenges. While a long-term goal in inhibitor patients is eradication of inhibitors through immune tolerance induction, bypassing agents such as recombinant activated factor VII (rFVIIa) and activated prothrombin complex concentrate (aPCC) are essential for control of bleeding episodes. Paediatric patients with haemophilia and inhibitors are at particular risk of recurrent haemarthroses, and management of these patients should seek to avoid joint damage and support the child's full social and physical development. Current options for management of bleeding complications include on-demand treatment of acute bleeding episodes, secondary prophylaxis to avoid recurrent bleeds and surgery to treat affected joints. There is also a rationale for adopting prophylactic approaches to prevent bleeding in inhibitor patients, allowing this group similar opportunities for protection against arthropathy development as are given to non-inhibitor patients. This paper, based on a roundtable meeting of haematology experts at the first Zürich Haemophilia Forum in May 2008, reviews the current evidence supporting more intense and prophylactic approaches to manage bleeding risk in paediatric haemophilia patients with inhibitors, and highlights the need for investigations of primary prophylaxis in this vulnerable patient group, to support best long-term outcome.

Haemophilia care in children--benefits of early prophylaxis for inhibitor prevention.

Haemophilia therapy is aimed at treating and preventing bleeding episodes and related complications and clinical studies have shown that regular prophylaxis, started at an early age, is able to reduce physical impairment from haemophilic arthropathy. Today, the development of anti-Factor VIII (FVIII) inhibitors is the most serious treatment-related complication of haemophilia therapy and a number of genetic and environmental risk factors have been identified in the past years. Clinical data show that early start of prophylaxis and the avoidance of intensive treatment periods may protect patients from inhibitor development. The mechanisms are not completely understood; yet, recent experimental data suggest that pro-inflammatory or 'danger signals' may be involved in inducing tolerance vs. an effector immune response. So, exposure to a factor concentrate by itself may not be enough to trigger an immune response, while an intensive exposure to FVIII in the presence of such 'danger signals' can activate antigen-presenting cells, up-regulating co-stimulatory signals for T lymphocytes and ultimately enhancing antibody production. The 'optimal' regimen for primary prophylaxis is still not identified and barriers to prophylaxis implementation remain relevant. Key issues include the optimal age at prophylaxis onset, the optimal dosage/schedule, the proper clinical and laboratory monitoring and patients' compliance. Practical approaches to early prophylaxis as implemented in the haemophilia centres in Milan and Bremen are discussed in this respect.

Factor VII deficiency: clinical manifestation of 717 subjects from Europe and Latin America with mutations in the factor 7 gene.

The congenital FVII deficiency (FVIID) is a rare haemorrhagic disorder with an autosomal recessive pattern of inheritance. Data on phenotype and the genotype from 717 subjects in Central Europe (six countries), Latin America (Costa Rica, Venezuela) and United States, enrolled in the Greifswald Registry of FVII Deficiency were analysed. We detected 131 different mutations in 73 homozygous, 145 compound heterozygous and 499 heterozygous subjects. Regional differences were observed in the mutation pattern and the clinical profile of the evaluated patients. Seventy-one per cent of homozygous and 50% of compound heterozygous subjects were symptomatic. The clinical manifestations of the homozygous subjects were characterized by intracranial haemorrhage (2%), gastrointestinal bleeding (17%), haemarthrosis (13%), epistaxis (58%), gum bleeding (38%), easy bruising (37%), haematoma (15%), haematuria (10%) and menorrhagia (19 of 26 females, 73%). The clinical variability and genotype-phenotype correlation was evaluated in the homozygous subjects. The pattern of bleeding symptoms among compound heterozygous patients was severe and similar to that of the homozygous patients. The large-scale analysis of 499 heterozygous subjects shows that 93 (19%) presented with spontaneous bleeding symptoms such as haemarthrosis (4%), epistaxis (54%), gum bleeding (14%), easy bruising (38%), haematoma (23%), haematuria (5%) and menorrhagia (19 of 45 females; 42%). The severe haemorrhages - intracranial and gastrointestinal - were not reported in heterozygous subjects. The clinical variability and the regional differences in the mutation pattern are discussed regarding care and treatment.

Haemate P/Humate-P for the treatment of von Willebrand disease: considerations for use and clinical experience.

von Willebrand disease (VWD) is a heterogeneous bleeding disorder with symptoms in affected patients ranging from mild effects to potentially devastating haemorrhagic events. Desmopressin (DDAVP) and von Willebrand factor/factor VIII (VWF/FVIII) concentrates are the principal treatments. Haemate P/Humate-P is an intermediate-purity VWF/FVIII concentrate with extensive clinical experience in VWD. This concentrate has been shown to correct haemostatic defects of VWD, with efficacy ratings of good/excellent in nearly all patients treated for bleeding or surgical events. Haemate P/Humate-P has a high content of the high molecular weight (HMW) VWF multimer fraction, which has been shown to be very effective in achieving haemostasis. The HMW VWF multimer pattern in Haemate P/Humate-P is more similar to that of normal human plasma (94% for Haemate P/Humate-P vs. 100% for normal human plasma) than that of other VWF/FVIII concentrates and correlates with functional VWF activities including ristocetin cofactor activity (VWF:RCo) and collagen-binding activity. The recommended dosing of Haemate P/Humate-P is based preferentially on VWF:RCo activity, which is approximately twice that of FVIII:C (2.4:1). Haemate P/Humate-P has been shown to be safe; no serious adverse events or cases of thrombosis have been observed in clinical trials and no documented cases of viral transmission in nearly three decades of clinical use. While DDAVP is effective in a large proportion of VWD patients, it may not provide adequate haemostasis in all situations. In such cases, Haemate P/Humate-P is an effective replacement concentrate for all types of VWD in both adult and paediatric patients.

Pharmacokinetics, efficacy and safety of IMMUNATE solvent/detergent (IMMUNATE S/D) in previously treated patients with severe hemophilia A: results of a prospective, multicenter, open-label phase III study.

BACKGROUND: IMMUNATE Solvent/Detergent (S/D) is a plasma-derived, human factor VIII (FVIII)/von Willebrand factor (VWF) complex subjected to S/D and vapor heat treatment. METHODS: This prospective clinical study evaluated the pharmacokinetics (PK) (compared to IMMUNATE), efficacy and safety of IMMUNATE S/D in 56 previously treated patients with severe hemophilia A. Subjects received IMMUNATE S/D either on-demand (47/56), as a prophylactic regimen (49/56), or both (40/56). RESULTS: IMMUNATE and IMMUNATES/D were equivalent with respect to the FVIII and VWF PK parameters assessed. Bleeding episodes (623) were reported in 47/56 subjects. For 89% of episodes, subjects required only 1 infusion with a mean dose of 29.6 IU/kg and 96% of episodes had an excellent or good response. The duration of prophylaxis ranged from 0.1 to 5.2 months. The median number of bleeds per month in subjects on prophylaxis was 0 (range 0-10). No FVIII inhibitory antibodies were observed in 56 subjects after 2,646 treatment exposure days. No related serious adverse events were reported. CONCLUSION: The introduction of S/D treatment did not alter the PK characteristics and function of VWF and FVIII molecules in IMMUNATE S/D which is effective and safe for treatment of bleeding episodes, management of surgical procedures and prophylaxis.