First-year results of an expanded humanitarian aid programme for haemophilia in resource-constrained countries.

INTRODUCTION: The gaps in haemophilia treatment around the world are enormous; approximately 60% of an estimated 475 000 individuals are not identified. Of the 187 000 diagnosed, 30% (57 000) access clotting factor replacement therapy. Since 1996, humanitarian aid distributed by the World Federation of Hemophilia (WFH) has played a minor, yet vital role providing life-saving clotting factor to countries in emergency situations. Donated amounts have been small and sporadic, often salvaging short-dated products, providing little opportunity to leverage donations with governments. In 2015, a prospective donation programme of 100 million I.U. per year of extended half-life factor VIII and IX over 10 years was established, necessitating the development of new logistics and training programmes by WFH. AIM: To measure the impact of a greatly expanded haemophilia humanitarian aid program. MATERIALS AND METHODS: In 2016, the first full year of the expanded programme, WFH, distributed products to 58 countries with factor VIII usage <1 I.U. per capita, a level incompatible with long-term survival and far below the 4 I.U. FVIII per capita minimum established in Europe. RESULTS: The scope of the programme and utilization data for 2016 indicate primarily use for acute bleeding, orthopaedic and emergency surgeries. Compared to 2014, 2016 data showed substantial increases in patients served (5.9-fold, from 2119 to 14 579), surgeries performed (37-fold) and bleeds treated (6.9-fold). Patients on prophylaxis rose from 0 to 852, including 458 children under 10 years old. DISCUSSION: The expanded humanitarian aid programme impacts an estimated 10% of individuals with haemophilia previously unable to access treatment. CONCLUSION: This programme represents an unprecedented public-private partnership to deliver medicines to individuals with no access. Further, the programme offers the prospective opportunity to engage governments to take more responsiblity for increasing training, medical management, and product supply in 58 resource constrained countries.

Clinical trials and registries in haemophilia: Opponents or collaborators? Comparison of PUP data derived from different data sources.

INTRODUCTION: The "Guideline on the clinical investigation of recombinant and human plasma-derived factor VIII products" (ClinGL) provides the requirements for the performing of clinical trials (CTs) for marketing authorization in Europe. The number of eligible previously untreated patients (PUPs) for CTs might be difficult to meet because of the concurrent development of FVIII concentrates, and additional data sources must be explored. AIM: The extent to which CTs and the PedNet registry met relevant parameters, identified in the ClinGL, as well as inhibitor incidences were investigated in patients from both sources. METHODS: Anonymized data of eight CTs in 369 PUPs performed from 1987 to 2009 were compared with each other and with 632 PUPs (born 2000-2009) from PedNet. RESULTS: Clinical trials in PUPs performed for marketing authorization were too heterogeneous in their investigated parameters; therefore, a comparison of single factor concentrates was not possible. Data collection in PedNet met relevant parameters required for PUPs in accordance with the ClinGL. The overall inhibitor incidences were comparable (CT = 30.9% vs PedNet = 30.6%) when only severe haemophilia A (HA) patients from both data sources were considered. CONCLUSIONS: Previously performed CTs in PUPs were divergent, which prevented a direct comparison of outcomes. However, this study demonstrated that data from CTs and carefully designed registries may complement each other in the establishing of sufficient safety information for single products to improve clinical insights and support regulatory decisions.

Vaccinations are not associated with inhibitor development in boys with severe haemophilia A.

BACKGROUND: Inhibitor development in previously untreated patients (PUPs) with severe haemophilia A is a multifactorial event. It is unknown whether paediatric vaccinations given in close proximity to factor VIII (FVIII) are associated with inhibitor development. OBJECTIVE: To assess whether paediatric vaccinations in close proximity to FVIII within the first 75 exposure days (EDs) are associated with inhibitor development in PUPs with severe haemophilia A. METHODS: We included 375 PUPs with severe haemophilia A (<0.01 IU/mL) from the PedNet Registry who had received vaccinations between the first and 75th ED or inhibitor development. Inhibitor risk was compared between patients who did and who did not receive vaccinations within 24, 72 or 120 hours of FVIII infusion. Unadjusted and adjusted hazard ratios were calculated for any or repeated vaccinations in close proximity to FVIII, using Cox regression. RESULTS: Inhibitor development occurred in 77 of 375 patients (20.5%). Overall inhibitor development appeared similar or lower in patients receiving vaccinations in close proximity to FVIII as compared to patients receiving vaccinations without FVIII: for 24 hours, this was 19.2% and 21.4% (P = .186), for 72 hours, 16.4% and 27.3% (P = .023) and for 120 hours, 18.3% and 25.0% (P = .085), respectively. CONCLUSION: We found no association between vaccinations given in close proximity to FVIII exposure within the first 75 EDs and inhibitor development. Our data do not support avoiding administration of FVIII at time of routine vaccinations.

Assessments of outcome in haemophilia - what is the added value of QoL tools?

INTRODUCTION: Access to treatment and especially to long-term regular replacement treatment with clotting factor concentrates (prophylaxis) have caused dramatic contrasts in the clinical picture between haemophilia populations. An individual patient with severe haemophilia age 20 years can have normal joints or can be severely crippled and unable to work. Assessment of outcome in a standardized way has therefore become essential. AIM: Discuss the relevance and utility of the different outcome assessment tools in patient groups with different access to treatment. METHODS: In the last decade new outcome assessment tools specific for haemophilia have been developed that measure all aspects of health according to the International Classification of Functioning, Disability and Health (ICF) model. These tools are directed at assessing the clinical and radiological status of joints as well as overall functioning, such as participation and psychosocial aspects, evaluating overall health-related quality of life (HRQOL). For deciding which tools to use in clinical practice or research, one needs to consider the specific context with regard to disease burden, healthcare environment and socioeconomic background of the patients being evaluated. CONCLUSION: Prospective systematic assessment of outcome in haemophilia and related bleeding disorders is important. Based upon recent literature a critical appraisal of outcome tools is described.

The growing number of hemophilia registries: Quantity vs. quality.

Registries for rare diseases provide a tool for obtaining an overview of the clinical situation and can be used to discover points of improvement and to monitor long-term safety. Registries could also become a powerful tool to provide supporting information for marketing authorization. There is an urgent need for a pan-European or global strategy that supports consistent data. Therefore, transparency in data collection, harmonization of the database structures, and the convergence of scientific approaches are required.

Improved prediction of inhibitor development in previously untreated patients with severe haemophilia A.

Treatment of previously untreated patients (PUPs) with severe haemophilia A is complicated by the formation of inhibitors. Prediction of PUPs with high risk is important to allow altering treatment with the intention to reduce the occurrence of inhibitors. An unselected multicentre cohort of 825 PUPs with severe haemophilia A (FVIII<0.01 IU mL(-1) ) was used. Patients were followed until 50 exposure days (EDs) or inhibitor development. All predictors of the existing prediction model including three new potential predictors were studied using multivariable logistic regression. Model performance was quantified [area under the curve (AUC), calibration plot] and internal validation (bootstrapping) was performed. A nomogram for clinical application was developed. Of the 825 patients, 225 (28%) developed inhibitors. The predictors family history of inhibitors, F8 gene mutation and an interaction variable of dose and number of EDs of intensive treatment were independently associated with inhibitor development. Age and reason for first treatment were not associated with inhibitor development. The AUC was 0.69 (95% CI 0.65-0.72) and calibration was good. An improved prediction model for inhibitor development and a nomogram for clinical use were developed in a cohort of 825 PUPs with severe haemophilia A. Clinical applicability was improved by combining dose and duration of intensive treatment, allowing the assessment of the effects of treatment decisions on inhibitor risk and potentially modify treatment.

Prospective observational cohort studies for studying rare diseases: the European PedNet Haemophilia Registry.

Haemophilia is a rare disease. To improve knowledge, prospective studies of large numbers of subjects are needed. To establish a large well-documented birth cohort of patients with haemophilia enabling studies on early presentation, side effects and outcome of treatment. Twenty-one haemophilia treatment centres have been collecting data on all children with haemophilia with FVIII/IX levels up to 25% born from 2000 onwards. Another eight centres collected data on severe haemophilia A only. At baseline, details on delivery and diagnosis, gene mutation, family history of haemophilia and inhibitors are collected. For the first 75 exposure days, date, reason, dose and product are recorded for each infusion. Clinically relevant inhibitors are defined as follows: at least two positive inhibitor titres and a FVIII/IX recovery <66% of expected. For inhibitor patients, results of all inhibitor- and recovery tests are collected. For continued treatment, data on bleeding, surgery, prophylaxis and clotting factor consumption are collected annually. Data are downloaded for analysis annually. In May 2013, a total of 1094 patients were included: 701 with severe, 146 with moderate and 247 with mild haemophilia. Gene defect data were available for 87.6% of patients with severe haemophilia A. The first analysis, performed in May 2011, lead to two landmark publications. The outcome of this large collaborative research confirms its value for the improvement of haemophilia care. High-quality prospective observational cohorts form an ideal source to study natural history and treatment in rare diseases such as haemophilia.

Epidemiological aspects of inhibitor development redefine the clinical importance of inhibitors.

Inhibitor development is a serious complication of treatment with coagulation products. Presently, 25-30% of all newly diagnosed patients with severe haemophilia A are diagnosed with inhibitors. An increasing number of genetic and non-genetic risk factors have been reported to be involved, although the impact of them in understanding the aetiology is still limited. Much attention has been focused on factor VIII products, but more recent studies show very little, if any, difference between class plasma and recombinant factor VIII products. More intensive treatment and higher dosing are probably more important factors. More than 10% of the inhibitors diagnosed in the last decade are of low titre. A first goal should be to understand their importance. It is argued that the impact of different risk factors should be studied in high-titre inhibitors to prevent dilution by non-significant low-titre inhibitors.

Influence of the type of F8 gene mutation on inhibitor development in a single centre cohort of severe haemophilia A patients.

The development of neutralizing antibodies against factor VIII (FVIII) is a major complication of treatment with FVIII in patients with severe haemophilia A. This study was designed to describe the relationship between the type and location of the factor 8 (F8) gene mutation and the development of clinically relevant inhibitors in patients with severe haemophilia A. We conducted a single centre cohort study among 318 consecutive patients (baseline FVIII activity level <0.01 IU mL(-1)) born between 1934 and 2007 who were treated with FVIII on at least 50 exposure days. The primary outcome was clinically relevant inhibitor development, defined as the occurrence of at least two positive inhibitor titres and a decreased recovery. Clinically relevant inhibitors were diagnosed in 14% (43) of patients (30 high-titre). The cumulative incidence of inhibitor development was 18% (35 of 200) in high-risk gene defects (67% in patients with large deletions, 30% in patients with nonsense mutations, 15% in patients with intron 1 or 22 inversions) and 7% (8 of 118) in low-risk gene defects (7% in patients with small deletions and insertions, 6% in patients with missense mutations, 8% in patients with splice site mutations). In patients with point mutations, the cumulative risk of developing inhibitors was highest in patients with mutations in the A3 and C2 domains (13% and 17% respectively). In conclusion, in agreement with earlier observations, the type and location of the F8 gene mutation were important determinants of inhibitor development in patients with severe haemophilia A.

Domain specificity of factor VIII inhibitors during immune tolerance induction in patients with haemophilia A.

INTRODUCTION: Frequent administration of high dosages factor VIII (FVIII), so-called immune tolerance induction (ITI), provides an efficient strategy to eradicate inhibitory antibodies in patients with haemophilia A. At present, our knowledge on the characteristics of inhibitory antibodies in patients undergoing ITI is limited. AIM: In this study we characterized the domain specificity of FVIII inhibitors in 11 haemophilia A patients during ITI. RESULTS: In three of six patients who were successfully tolerized, inhibitory antibodies were directed predominantly against the FVIII light chain. In two other patients within this group, a significant contribution of A2 antibodies was observed which did not change during treatment. In the sixth patient the relative contribution of A2 inhibitors declined which coincided with an increase in antilight chain antibodies. In four of five patients who failed ITI, A2 inhibitors were observed. In two patients the contribution of A2 inhibitors increased during treatment, while in two other patients the contribution of A2 inhibitor remained constant. The fifth patient had inhibitory antibodies predominantly directed against the FVIII light chain. CONCLUSION: Overall, our findings revealed changes in domain specificity of FVIII antibodies in five of 11 patients analysed. Remarkably, antibodies exclusively directed towards the light chain of FVIII were predominantly observed in patients who were successfully tolerized.