The use of prophylaxis in 2663 children and adults with haemophilia: results of the 2006 Canadian national haemophilia prophylaxis survey

Summary. Prophylaxis is standard of care for boys with severe haemophilia A. Indications for prophylaxis in adulthood, non‐severe haemophilia A, haemophilia B and haemophilia with inhibitors are less well defined. This survey, conducted in 2006, aimed to describe prophylaxis use in patients of all ages and severities with haemophilia A or haemophilia B in Canada. Data on 2663 individuals (2161 haemophilia A; 502 haemophilia B), including 78 inhibitor‐positive patients, were returned by 22/25 Canadian haemophilia treatment centres. This represented 98% of the Canadian haemophilia population. Frequency of prophylaxis use, defined as infusion of factor VIII/IX concentrate at least once weekly for ≥45 weeks of the year, was highest in individuals with severe haemophilia A (69%). It was lower in individuals with severe haemophilia B (32%), moderate haemophilia A (18%) or B (5%) and mild haemophilia A (1%) or B (1%). Among individuals with severe haemophilia A, the frequency of prophylaxis use was 84% in children (≤18 years) and 55% in adults (>18 years). Thirteen per cent of inhibitor‐positive individuals were receiving prophylaxis with bypassing agents. Comparison with data obtained from a 2002 Canadian survey showed a greater use of prophylaxis in children ≤5 years of age with severe haemophilia A (73% vs. 49%). Prophylaxis is no longer confined to children with severe haemophilia A, but is used in a significant proportion of adults with severe haemophilia A and individuals with severe haemophilia B or moderate haemophilia A. Prophylaxis is being started earlier in boys with severe haemophilia A.     

Treatment trends for haemophilia A and haemophilia B in the United States: results from the 2010 practice patterns survey

Frequent evaluation of haemophilia treatment is necessary to improve patient care. The 2010 Practice Patterns Survey (PPS) investigated current trends in haemophilia treatment in the United States, as reported by nurses. The aim was to document practice patterns for haemophilia A and haemophilia B Survey questionnaires were sent to nurses at haemophilia treatment centres (HTCs) across the United States. Seventy-one of 126 HTCs (56%) responded to the survey. Factor dosage across treatment modalities ranged from 20 to 50 IU kg(-1) for severe haemophilia A. Dosage for severe haemophilia B was more variable (<40 to >100 IU kg(-1)). On-demand dosing regimens were inconsistent for haemophilia A and more so for haemophilia B. Rates of adherence to prescribed treatment were similar for both haemophilia types (～80%). The main barrier to adherence was identified as inconvenience. More bleeding episodes occurred in adults (16.6 bleeding episodes per year) with severe haemophilia A than in younger patients (11.3 bleeding episodes per year) before switching patients to prophylaxis. For both haemophilia types, most patients who switched from prophylaxis to on-demand treatment were aged 13-24 years; these patients also had the lowest adherence (60-71%). More paediatric patients with severe haemophilia A and inhibitors (53%) received prophylactic bypassing therapy than their haemophilia B counterparts (38%). Adults with severe haemophilia A faced challenges in relation to co-morbidities and long-term care. This PPS provides insights into previously unexplored aspects of haemophilia care that will serve to increase awareness and promote discussion of current issues affecting haemophilia patient care.     

Prevalence of IgG antibodies to human parvovirus B19 in haemophilia children treated with recombinant factor (F)VIII only or with at least one plasma-derived FVIII or FIX concentrate: results from the French haemophilia cohort

Human parvovirus B19 (B19) has been transmitted by some brands of virally attenuated plasma-derived factor VIII (FVIII) or IX (FIX) concentrates. To quantify the differences of human parvovirus B19 risk transmission between albumin-stabilized recombinant factor and plasma-derived factor, we studied the prevalence of IgG antibodies to B19 (anti-B19) in 193 haemophiliac children between 1 and 6-years of age who had previously been treated with albumin-stabilized recombinant FVIII only (n = 104), and in children previously treated with solvent/detergent high-purity non-immunopurified and non-nanofiltered FVIII or IX concentrates (n = 89). Association between the prevalence of anti-B19 and the treatment group was analysed using multivariate logistic regression. Age, severity and type of haemophilia, number of cumulative days of exposure to factor VIII or IX, previous history of red blood cells or plasma transfusion were considered as potential confounding variables. A higher prevalence of anti-B19 was found in children previously treated with solvent/detergent high-purity non-immunopurified and non-nanofiltered FVIII or IX concentrates than in children treated with albumin- stabilized recombinant FVIII only (OR: 22.3; CI: 7.9-62.8), independently of the other factors studied.     

Factor VIII prophylaxis for adult patients with severe haemophilia A: results of a US survey of attitudes and practices

Summary.  The emergence of a population of relatively healthy adults with severe haemophilia A presents a unique challenge for haemophilia care in the 21st century. Understanding how best to continue, restart, initiate or modify prophylaxis in younger and older adult patients is essential to optimizing their care. To elucidate practice and outcome data, a survey was sent to 23 US hemophilia treatment centers (HTCs); 10 centers responded, providing data concerning up to 145 adults (mean age of 34 years). Forty-eight patients (33%) were on regular prophylaxis when first seen at the HTC; the prophylactic regimen was modified for 22/48 (46%), often because of breakthrough bleeding. Five of 21 patients (24%) for whom data were available discontinued prophylaxis. Three of those five patients (60%) experienced increased bleeding episodes and the other two (40%) subsequently resumed regular prophylactic infusions because of the increased bleeding. Of the 77 patients not initially receiving prophylaxis for whom data were available, prophylaxis was started or resumed in all. The prophylactic regimen was modified in 57/77 patients (74%) at some point during treatment, often because of breakthrough bleeding. Of the 55 patients whose prophylactic regimens were modified for whom data were available, 22 (40%) discontinued prophylaxis. Thirteen of 20 patients (65%) for whom data were available experienced an increase in bleeding episodes and 7/18 patients (39%) who had discontinued prophylaxis and for whom data were available subsequently resumed regular prophylactic infusions because of bleeding. These findings suggest that prophylaxis prevents bleeding in adults with severe haemophilia A and that discontinuation of the prophylactic regimen is associated with increased bleeding events.     

Forum on: the role of recombinant factor VIII in children with severe haemophilia A

Summary. The development of recombinant FVIII (rFVIII) products, fuelled by the need for improved safety of treatment arising from the dramatic widespread blood‐borne virus transmission in the 1970–1980s revolutionized the care of children with haemophilia A over the last two decades. The larger availability of perceived safer replacement therapy associated with the introduction of rFVIII products reassured the haemophilia community and there was a strong push in some Western countries to treat haemophilic children only with rFVIII. Moreover, this significantly contributed in the 1990s to the diffusion outside Northern Europe of prophylactic regimens implemented at an early age to prevent bleeding and the resultant joint damage (i.e. primary prophylaxis), together with the possibility of home treatment. These changes led to a substantial improvement of the quality of life of haemophilic children and of their families. The general agreement that primary prophylaxis represents the first‐choice treatment for haemophilic children has been recently supported by two randomized controlled trials carried out with rFVIII products, providing evidence on the efficacy of early prophylaxis over on‐demand treatment in preserving joint health in haemophilic children. However, the intensity and optimal modalities of implementation of prophylaxis in children, in particular with respect to the issue of the venous access, are still debated. A number of studies also supports the role of secondary prophylaxis in children, frequently used in countries in which primary prophylaxis was introduced more recently. With viral safety now less than an issue and with the more widespread use of prophylaxis able to prevent arthropathy, the most challenging complication of replacement therapy for children with haemophilia remains the risk of inhibitor development. Despite conflicting data, there is no evidence that the type of FVIII concentrate significantly influences the complex multifactorial process leading to anti‐FVIII alloantibodies, whereas other treatment‐related factors are likely to increase (early intensive treatments due to surgery or severe bleeds) or reduce (prophylaxis) the risk. Although the optimal regimen is still uncertain, eradication of anti‐FVIII antibodies by immune tolerance induction (ITI), usually with the same product administered at inhibitor detection, should be the first‐choice treatment for all patients with recent onset inhibitors. This issue applies particularly to children, as most patients undergo ITI at an early age, when inhibitors usually appear. The availability of a stable and long‐lasting venous access represents a leading problem also in this setting. These and other topics concerning rFVIII treatment of haemophilic children were discussed in a meeting held in Rome on 27 February 2008 and are summarized in this report.     

Treatment of children with haemophilia in Europe: a survey of 20 centres in 16 countries.

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

Achieving the unimaginable: Health equity in haemophilia

Historically, treatment based on the availability of clotting factor replacement has resulted in an arcane guideline for the correction of factor deficiencies in people with haemophilia (PwH). While all other disease entities seek to restore function to a normal level, PwH are restricted to factor nadirs still equivalent to mild or moderate disease, resulting in continued risk of bleeding. A new treatment paradigm is needed based on the defined needs of PwH. A treatment model was developed by a panel of haemophilia providers, patient advocates and health economists to establish specific treatment milestones and targeted outcomes. The panel defined a series of treatment milestones to characterize the activity and outcomes linked to level of factor deficiency correction. All agreed that the ultimate goal should be ‘functional cure’ and ‘health equity’. Seven levels to achieving a functional cure were identified, (a) Sustain life; (b) Minimal joint impairment; (c) Freedom from any spontaneous bleeds; (d) Attainment of ‘normal’ mobility; (e) Able to sustain minor trauma without additional intervention; (f) Ability to sustain major surgery or trauma; and (g) Normal haemostasis. A parallel set of patient‐reported outcomes to achieve health equity was identified. These guidelines are now comparable with other disorders where the goal is to replace missing proteins to attain normal activity levels. As we are no longer limited by plasma supply due to the manufacture of recombinant factors, mimetics, and the early success of gene therapy, health equity is now achievable.     

Acquired haemophilia: management of bleeds and immune therapy to eradicate autoantibodies

Acquired haemophilia is a rare, but often severe bleeding disorder caused by autoantibodies against a coagulation factor, usually factor VIII (FVIII). Between 1997 and 2004 we observed 14 patients (mean age of 78 years) with acquired haemophilia. The aim of the present study was to investigate the effect of activated prothrombin complex concentrate (aPCC) for bleeds and the response to corticosteroids and cyclophosphamide to eradicate the offending autoantibodies. The most common clinical presentations were severe profuse bruising (12) and haematuria (5). Ten patients were classified as idiopathic. At the time of diagnosis all patients had a very low FVIII level, and one patient also showed factor IX < 1%. High levels of antibodies to FVIII varying from 10 to 1340 Bethesda units (BU) and prolonged activated partial thromboplastin time were disclosed in all patients. Eight severe bleeds were treated with aPCC (FEIBA) at a dosage of 70 IU kg(-1) every 8 h until haemostasis. Ten patients received corticosteroids and cyclophosphamide as immunomodulatory therapy. Effective haemostasis was achieved in all bleeds after aPCC. Ten of 11 patients responded either completely or partially to the immunomodulatory regime within 6 months. Five patients achieved complete response (CR) whereas partial responses were seen in five patients. The anti-CD20 monoclonal antibody rituximab was given to two patients in conventional doses and a CR was seen in one patient. aPCC is effective in treating acute bleeds in patients with acquired haemophilia with high inhibitor levels. The combination of oral corticosteroids and cyclophosphamide seems to be effective to eradicate the inhibitor.     

Prevalence of factor IX inhibitors among patients with haemophilia B: results of a large-scale North American survey

Summary. This survey provides new information on the severity of factor IX deficiencies among patients being treated for haemophilia B and on the prevalence of factor IX inhibitors in this population. A questionnaire was sent to 150 haemophilia treatment centres in the United States and Canada. 82 centres responded and provided data on 1967 patients with haemophilia B. 37% of these patients had severe haemophilia B (<1% of the normal level of factor IX), 33% had moderate haemophilia B (1–5% of the normal level of factor IX), and 30% had mild haemophilia B (>5% of the normal level of factor IX). Only 29 (1.5%) of the patients had factor IX inhibitors; 28 of these patients (96.6%) had severe haemophilia B, and one of these patients (3.4%) had moderate haemophilia B. Factor IX inhibitor titres were 0.6–1 Bethesda unit (BU) in seven patients, > 1–5 BU in four patients, > 5–10 BU in one patient, and > 10 BU in 17 patients. Factor IX inhibitors are much less common in patients with haemophilia B than in patients with haemophilia A.     

Should prophylaxis be used in adolescent and adult patients with severe haemophilia? An European survey of practice and outcome data

A survey of 21 haemophilia doctors, throughout Europe, who care for a total of approximately 5000 patients with bleeding disorders addressing practice and opinions regarding prophylaxis in patients aged 16-24 years and adults aged over 50 years, is presented. The outcome of adolescent patients who reduced or stopped prophylaxis was recorded. Eighteen of 19 respondents would consider modification of established prophylaxis in the adolescent age group, principal considerations being avoidance of risks of further concentrate exposure, predicted poor compliance and treatment costs. The preferred age for modification was 16-20 years, but there was very little consensus on the particular prophylactic regime recommended. Approximately, half of a cohort of 218 patients with severe haemophilia successfully reduced or stopped prophylaxis when they reached adolescence. Only 26 of 92 (28%) of the patient cohort who stopped prophylaxis, required reintroduction of a prophylactic regime and 12 of 59 (20%) of those who reduced the intensity of prophylaxis had to reintroduce a more intensive regime. A majority of respondents would consider starting prophylaxis in those over 50 years. There was no consensus as to indications for this practice or the nature of the prophylaxis protocol. We conclude that there is an absence of consensus on the management of patients with severe haemophilia, as they pass through adolescence and young adulthood, and reach the age of 50. Aggregate outcome data suggest a significant proportion of patients in the 18-22 years age range may be able to reduce or stop prophylaxis. A substantial number of older patients are on prophylaxis.     

Intracranial haemorrhage in the Italian population of haemophilia patients with and without inhibitors

Summary. Intracranial haemorrhage (ICH) is the most serious bleeding symptom in haemophiliacs, resulting in high rates of mortality and disabling sequelae. The Association of Italian Haemophilia Centres carried out a retrospective survey (1987–2008) of ICH occurring in haemophiliacs with the goals to establish: (i) incidence, location of bleeding, death rate and disabling sequels; (ii) risk factors for ICH; and (iii) treatment used during the acute phase of ICH and for recurrence prevention. A total of 112 ICH episodes had occurred in 88 patients (78 haemophilia A, 10 haemophilia B), 24 of whom experienced recurrences. The cumulative hazard of ICH for the whole cohort over the entire follow‐up period was 26.7 per 1000 patients, and the annualized rate of ICH was 2.50 events per 1000 patients (95% CI 1.90–3.31). The risk of ICH was higher in the youngest children (24.4 per 1000, 95% CI 12.7–47.0 in the first year of age and 14.9, 95% CI 7.1–31.4 in the second year of age) and then progressively rose again after the age of 40. Univariate, bivariate (age‐adjusted) and multivariate analysis investigating the effects of patient characteristics on ICH occurrence showed that haemophilia severity and inhibitor status were strongly associated with ICH [severe vs. mild, HR 3.96 (2.39–6.57); inhibitor vs. non‐inhibitor 2.52 (1.46–4.35)]. HCV infection was also associated with the risk of ICH [HR 1.83 (1.25–2.69)]. Therapeutic suggestions based upon our experience to control ICH recurrence are provided.     

A postmarketing surveillance study of the safety and efficacy of ReFacto® (St Louis-derived active substance) in patients with haemophilia A

This clinical trial evaluated the safety and efficacy of ReFacto (St Louis-derived active substance) in patients with severe or moderately severe haemophilia A over a period of 6 months or 50 exposure days (EDs), whichever occurred first. Sixty patients, 58 previously treated and two previously untreated, were enrolled into this study. This was an open-label, multicentre, postmarketing surveillance study in which patients received prophylaxis or on-demand treatment as determined by their doctor. Surgical prophylaxis was evaluated in seven patients requiring elective surgery. Thirty-two patients aged <1 to 66 years (median 19.5) received prophylaxis and 28 patients, aged 1-71 years (median 33.5), received on-demand treatment. The majority of patients had severe haemophilia A (FVIII:C < 2%): 84.4% in the prophylaxis group and 85.7% in the on-demand group. Prophylaxis with ReFacto was associated with a median of 6.7 bleeds per year (range: 0-37). The investigator's assessment of final outcome for prophylactic treatment was excellent or effective for 93.1% of patients. ReFacto resolved 92.8% of bleeds with one or two infusions. The investigator's assessment was excellent or good for 98.2% of bleeds treated with ReFacto. Haemostasis was achieved for all seven surgical cases and ReFacto gave an excellent or good response for each. The nature and incidence of adverse events was as expected and no new safety concerns emerged. One previously treated patient (PTP) developed a high-titre inhibitor (maximum 75 BU) and one minimally treated patient (MTP) developed a low-titre inhibitor while on the study but eventually achieved high titres (maximum 30 BU) after immune tolerance therapy was initiated with a plasma-derived FVIII product. One previously untreated patient (PUP) developed a transient low-titre inhibitor (0.4 BU). Other serious adverse events (SAEs) were unrelated to study treatment. There were no allergic events. The results of this study are consistent with the previously published ReFacto pivotal studies.     

A survey of adherence to haemophilia therapy in six European countries: results and recommendations

Summary. Very few studies have addressed the question of adherence of haemophiliacs to their treatment. The aim of our study was to compare their levels of adherence to therapy and also to provide recommendations. Professionals of an international research company performed individual interviews with 30 patients in each of six European countries (France, Germany, Italy, Spain, Sweden and UK) resulting in a total of 180 patients. Twenty‐eight interviews with haemophilia physicians and specialist nurses were also undertaken. Overall adherence to treatment was high (80–87% in each country). There was a positive correlation between greater adherence and younger age, prophylactic treatment, time spent with a haemophilia treatment centre (HTC) and the quality of the relationship with the haematologist and nurse. The four leading reasons for not using the prescribed amount of clotting factor or skipping the administration interval were reduction, fluctuation or disappearance of symptoms, forgetfulness, lack of time for treatment and convenience. These reasons differed according to the country and the age of the patient. The main suggestions made by patients to improve adherence related to HTC, environment and factor concentrates. Patients considered also that internet and electronic patient diaries were likely to improve adherence. In this selected group of European haemophilia patients, adherence to treatment appears higher than for most patients with other chronic diseases. However, it remains important to be aware of the possibility of non‐adherence given the serious implications, particularly when considering a differently selected group of patients.     

Thrombotic adverse events to coagulation factor concentrates for treatment of patients with haemophilia and von Willebrand disease: a systematic review of prospective studies

Thrombotic adverse events (AEs) after clotting factor concentrate administration are rare but the actual rate is unknown. A systematic review of prospective studies (1990-2011) reporting safety data of factor concentrates in patients with haemophilia A (HA), haemophilia B (HB) and von Willebrand disease (VWD) was conducted to identify the incidence and type of thrombotic AEs. In 71 studies (45 in HA, 15 HB, 11 VWD) enrolling 5528 patients treated with 27 different concentrates (20 plasma-derived, 7 recombinant), 20 thrombotic AEs (2 HA, 11 HB, 7 VWD) were reported, including two major venous thromboembolic episodes (both in VWD patients on prolonged replacement for surgery). The remaining thrombotic AEs were superficial thrombophlebitis, mostly occurring at infusion sites in surgical patients and/or during concentrate continuous infusion. The overall prevalence was 3.6 per 10(3) patients (3.6 per 10(4) for severe AEs) and 1.13 per 10(5) infusions, with higher figures in VWD than in haemophilia. Thrombotic AEs accounted for 1.9% of non-inhibitor-related AEs. Thrombosis-related complications occurred in 10.8% of patients with central venous access devices (CVADs) reported in six studies, the risk increasing with time of CVAD use. Data from prospective studies over the last 20 years suggest that the risk of thrombotic AEs from factor concentrate administration is small and mainly represented by superficial thrombophlebitis. These findings support the high degree of safety of products currently used for replacement treatment.