Cardiovascular disease in hereditary haemophilia: The challenges of longevity.

The development of effective and safe treatments has significantly increased the life expectancy of persons with haemophilia (PWH). This has been accompanied by an increase in the comorbidities of ageing including cardiovascular disease, which poses particular challenges due to the opposing risks of bleeding from haemophilia and antithrombotic treatments versus thrombosis. Although mortality secondary to coronary artery disease in PWH is less than in the general population, the rate of atherosclerosis appears similar. The prevalence of atrial fibrillation in PWH and risk of secondary thromboembolic stroke are not well established. PWH can be safely supported through acute coronary interventions but data on the safety and efficacy of long-term antithrombotics are scarce. Increased awareness and research on cardiovascular disease in PWH will be crucial to improve primary prevention, acute management, secondary prevention and to best support ageing PWH.

A single centre, open label, pilot study evaluating the effect of intra-articular hyaluronic acid injection on pain and functionality when injected into the ankle (tibio-talar and sub-talar) joint in patients with haemophilic arthropathy.

AIMS: Ankle arthropathy commonly affects persons with haemophilia (PWH). Joint damage causes loss of movement, pain and reduced function. Current treatments are limited. Viscosupplementation has been used to treat other patient groups with joint damage. Viscosupplements serve to augment or act as a substitute for synovial fluid and may ameliorate the effects of cartilage loss by cushioning joints and reducing pain. This study evaluated intra-articular Ostenil Plus™ (HA) for ankle arthropathy in PWH. Reduction in pain was the primary outcome. METHODS: A single centre open label pilot study. PWH and significant ankle arthropathy, according to MRI scores, were recruited. Participants received intra-articular HA injections at baseline and 6 months. Follow up assessments were completed three-monthly for 1 year. Pain was assessed by the Visual Analogue Scale (VAS). Participant perceptions of overall changes to pain, function and quality of life were sought. RESULTS: Twenty-four participants were recruited, three withdrew. Twenty-six joints were injected. Twenty participants had severe haemophilia. Mean age 35 years. Participants reported significant reduction in pain over the study. VAS baseline: 5.62; 6 month 3.92; 12-month 3.42, P < .0001. Joint function improved together with ankle HJHS. No change was seen for EQ-5D-5L. Sixteen participants reported reductions in ankle pain and stiffness and greater confidence in undertaking physical activities. No significant adverse reactions were reported. CONCLUSION: Ostenil Plus™ treatment improves pain, function and patient perception of functional ability in PWH and ankle arthropathy. This study supports the use of HA as a safe treatment in PWH.

Gynaecological management of women with inherited bleeding disorders. A UK Haemophilia Centres Doctors' Organisation Guideline.

Women with inherited bleeding disorders (IBDs) may present to healthcare professionals in a variety of ways and commonly will be encountered by either haematology or gynaecology services. Heavy menstrual bleeding is very often the first manifestation of an IBD. There is a wide variation in severity of bleeding for women with IBD and diagnosis and subsequent management of their condition requires multidisciplinary specialised care which is tailored to the individual and includes excellent cross-specialty communication between gynaecology and haematology teams. This guideline is intended for both haematologists and gynaecologists who are involved in the diagnosis and management of women with bleeding disorders. It sets out recommendations about how to investigate heavy menstrual bleeding (HMB), the commonest presentation for women with IBD to hospital services, to guide physicians about how to diagnose an IBD and covers the management of women with known IBD and HMB. The second section sets out recommendations for patients known to have IBD and covers management of patients with IBD in the setting of gynaecological surgery and management for all other non-surgical gynaecological situations.

Germline mutations in the transcription factor IKZF5 cause thrombocytopenia.

To identify novel causes of hereditary thrombocytopenia, we performed a genetic association analysis of whole-genome sequencing data from 13 037 individuals enrolled in the National Institute for Health Research (NIHR) BioResource, including 233 cases with isolated thrombocytopenia. We found an association between rare variants in the transcription factor-encoding gene IKZF5 and thrombocytopenia. We report 5 causal missense variants in or near IKZF5 zinc fingers, of which 2 occurred de novo and 3 co-segregated in 3 pedigrees. A canonical DNA-zinc finger binding model predicts that 3 of the variants alter DNA recognition. Expression studies showed that chromatin binding was disrupted in mutant compared with wild-type IKZF5, and electron microscopy revealed a reduced quantity of α granules in normally sized platelets. Proplatelet formation was reduced in megakaryocytes from 7 cases relative to 6 controls. Comparison of RNA-sequencing data from platelets, monocytes, neutrophils, and CD4+ T cells from 3 cases and 14 healthy controls showed 1194 differentially expressed genes in platelets but only 4 differentially expressed genes in each of the other blood cell types. In conclusion, IKZF5 is a novel transcriptional regulator of megakaryopoiesis and the eighth transcription factor associated with dominant thrombocytopenia in humans.

Haemophilia Carriers Experience Study (CARES): A mixed method exploration into the experience of women who are carriers of Haemophilia.

INTRODUCTION: Haemophilia research has traditionally focused on patients diagnosed with haemophilia and although research priorities are rapidly changing, there is still a lot more we need to understand about the experiences and psychosocial issues facing women who are diagnosed as carriers of haemophilia (Haemophilia, https://doi.org/10.1111/hae.14043). One study noted that the understanding of carriers' experience of bleeding by healthcare professionals is limited and that many women have had negative experiences of healthcare (Haemophilia, 17, 2011, 237). The carrier population does not typically receive much support for themselves as individuals as they are often not registered at Haemophilia Centres in their own right. AIM: This study aimed to look at the emotional wellbeing of carriers in more detail. METHOD: This was initially investigated through the use of focus groups and individual interviews with 16 participants (Stage 1) and then widening the study using an online questionnaire battery developed from the themes identified from these interviews (Stage 2). The questionnaire battery was completed by 226 participants. RESULTS: Descriptive statistics are reported on the endorsement of themes identified in Stage 1 and around participants' experiences of their carriership and healthcare. Results demonstrated that the participants have had a number of difficulties with accessing helpful information and support during key times in their lives, for example, at diagnosis and when deciding whether to start a family. They also showed that although participants endorsing a higher number of bleeding symptoms scored statistically significantly higher in measures of depression, anxiety and negative affect, this difference was not clinically significant. CONCLUSION: These results lend support to the growing evidence base that women who are carriers of haemophilia have a distinct set of (currently unmet) needs that need assessing and treating.

Next-generation sequencing for the diagnosis of MYH9-RD: Predicting pathogenic variants.

The heterogeneous manifestations of MYH9-related disorder (MYH9-RD), characterized by macrothrombocytopenia, Döhle-like inclusion bodies in leukocytes, bleeding of variable severity with, in some cases, ear, eye, kidney, and liver involvement, make the diagnosis for these patients still challenging in clinical practice. We collected phenotypic data and analyzed the genetic variants in more than 3,000 patients with a bleeding or platelet disorder. Patients were enrolled in the BRIDGE-BPD and ThromboGenomics Projects and their samples processed by high throughput sequencing (HTS). We identified 50 patients with a rare variant in MYH9. All patients had macrothrombocytes and all except two had thrombocytopenia. Some degree of bleeding diathesis was reported in 41 of the 50 patients. Eleven patients presented hearing impairment, three renal failure and two elevated liver enzymes. Among the 28 rare variants identified in MYH9, 12 were novel. HTS was instrumental in diagnosing 23 patients (46%). Our results confirm the clinical heterogeneity of MYH9-RD and show that, in the presence of an unclassified platelet disorder with macrothrombocytes, MYH9-RD should always be considered. A HTS-based strategy is a reliable method to reach a conclusive diagnosis of MYH9-RD in clinical practice.

Pilot study to evaluate hypercoagulation and inflammation using rotational thromboelastometry and calprotectin in COVID-19 patients.

INTRODUCTION: Abnormal coagulation and inflammation are hallmarks of SARs-COV-19. Stratifying affected patients on admission to hospital may help identify those who at are risk of developing severe disease early on. Rotational Thromboelastometry (ROTEM) is a point of care test that can be used to measure abnormal coagulation and calprotectin is a measure of inflammation. AIM: Assess if ROTEM can measure hypercoagulability on admission and identify those who will develop severe disease early on. Assess if calprotectin can measure inflammation and if there is a correlation with ROTEM and calprotectin. METHODS: COVID-19 patients were recruited on admission and ROTEM testing was undertaken daily for a period of 7 days. Additionally inflammatory marker calprotectin was also tested for the same period. RESULTS: 33 patients were recruited to the study out of which 13 were admitted to ITU and 20 were treated on the ward. ROTEM detected a hypercoagulable state on admission but did not stratify between those admitted to a ward or escalated to ITU. Calprotectin levels were raised but there was no statistical difference (p = 0.73) between patients admitted to a ward or escalated to ITU. Significant correlations were observed between FIBA5 (r = 0.62; p<0.00), FIBCFT (r = -0.57; p<0.00), FIBMCF (r = 0.64; p<0.00) and INMCF (r = 0.57; p<0.00) and calprotectin. CONCLUSION: COVID-19 patients were hypercoagulable on admission. The correlations between ROTEM and calprotectin underline the interactions between inflammation and coagulation.

Educational needs of patients, families, and healthcare professionals to support the patient journey in haemophilia gene therapy in the UK.

With the first gene therapies for haemophilia approved by the European Commission, the US Food and Drug Administration, and the Medicines and Healthcare products Regulatory Agency, it is important to consider the remaining unmet needs and challenges that may arise throughout patients' treatment journeys. We discuss existing unmet needs and important considerations prior to, during, and following haemophilia gene therapy treatment in the UK, and propose potential next steps. Key areas for attention are education, psychological support, and guidance on implementation. Strategies are urgently required to fulfil these needs. An immediate priority for information providers should be comprehensive education for people with haemophilia (PWH) and healthcare professionals (HCPs). Greater access to resources and training in psychological services will be required throughout the treatment pathway. More specific guidance is required to define the implementation model, criteria for accreditation, and responsibilities of care centres. Furthermore, PWH may revisit discussions with HCPs multiple times pre-infusion, thus the patient journey is unlikely to be linear. Consideration of these challenges, and of potential strategies to address them, will be integral to optimising the future success of this promising therapy.

Delayed and prolonged umbilical stump bleeding in a Caucasian newborn as a presenting feature of factor XIII deficiency.

A term Caucasian neonate with an uncomplicated birth history presented with persistent umbilical stump bleeding unresponsive to extensive topical haemostatic measures initially. He subsequently developed hypovolaemic shock. Routine full blood count and basic coagulation screen were unremarkable. He received packed red cell and cryoprecipitate transfusions. Further specialist coagulation studies performed revealed factor XIII deficiency. Genetic investigations demonstrated a compound heterozygosity for the disorder. He was later started on monthly prophylactic treatment of plasma-derived factor XIII. Clinicians should have a high index of suspicion for factor XIII deficiency for newborns with abnormal umbilical stump bleeding in the presence of no bleeding risk factors and normal routine blood investigations.

Seroprevalence to adeno-associated virus type 6 in people with hemophilia B from a UK adult cohort.

Background: Gene therapy shows promise as a potential "cure" for hemophilia A and B. Adeno-associated virus (AAV) vectors are the leading platform to deliver modified genetic code of factor VIII or IX to the liver effecting endogenous production. Patient exposure to wild-type AAV leads to the formation of neutralizing factors, which can prevent successful transduction. It is thus important to establish the seroprevalence of the AAV serotypes in people with hemophilia to aid prediction of successful gene transfer. The seroprevalence of AAV6 in UK people with hemophilia B is not yet reported. Objectives: We studied the prevalence of anti-AAV6 neutralizing factors in UK people with hemophilia B (n = 49). We collected data on people's hepatitis C exposure and treatment with plasma-derived factor IX (FIX) to identify if there was correlation with AAV6 exposure. Methods: Serum samples and patient data were collected from 49 people with hemophilia B registered at UK hemophilia comprehensive care centers. The samples were tested for neutralizing factors to AAV6 using a cell-based transduction inhibition assay. Results: Thirty-one percent of patients had serum neutralization against AAV6. There was no correlation between AAV6 seropositivity and previous treatment with plasma-derived FIX products or hepatitis C exposure. Conclusion: Based on limited data, there is no evidence of association between the presence of AAV6 neutralizing factors in people with hemophilia B and exposure to contaminated plasma derivatives. The frequency of AAV6 neutralizing factors in our hemophilia B cohort is similar to UK people with hemophilia A and non-hemophilia populations.

The Hemophilia Joint Health Score version 2.1 Validation in Adult Patients Study: A multicenter international study.

Background: The Hemophilia Joint Health Score (HJHS) was developed and validated to detect arthropathy in children. Additional evidence is required to show validity in adults. We studied the convergent and discriminant construct validity of the HJHS version 2.1(HJHSv2.1) in adults with hemophilia. A secondary aim was to define age-related normative adult HJHSv2.1 reference values. Methods: We studied 192 adults with hemophilia, and 120 healthy adults in four age-matched groups-18 to 29, 30 to 40, 41 to 50, and >50 years-at nine centers. Trained physiotherapists scored the HJHS and World Federation of Hemophilia (WFH) joint score. Health history, the Functional Independence Scale of Hemophilia (FISH), Hemophilia Activities List (HAL), and Short-Form McGill Pain Questionnaire (SF-MPQ) were also collected. Results: The median age was 35.0 years. Of participants with hemophilia, 68% had severe, 14% moderate, and 18% mild disease. The HJHS correlated strongly with WFH score (Spearman's rho [rs ] = .95, P < .001). Moderate correlations were seen between the FISH (rs  = .50, P < .001) and SF-MPQ Present Pain Intensity (rs  = .50, P < .001), while a modest correlation was found with the HAL (rs  = -.37, P < .001). The HJHS significantly differentiated between age groups (Kruskal-Wallis T = 35.02, P < .001) and disease severity in participants with hemophilia. The HJHS had high internal reliability (Cronbach's α = .88). We identified duration of swelling as a redundant item in the HJHS. Conclusions: The HJHS shows evidence of strong convergent and discriminant construct validity to detect arthropathy in adults with hemophilia and is well suited for use in this population.

An overview of the pathfinder clinical trials program: Long-term efficacy and safety of N8-GP in patients with hemophilia A.

N8-GP (turoctocog alfa pegol, Esperoct® ; Novo Nordisk A/S, Bagsvaerd, Denmark) is a state-of-the-art, extended half-life factor VIII (FVIII) molecule used for prophylactic and on-demand treatment of patients with hemophilia A. The pathfinder clinical trial program, which began with the pathfinder1 trial in 2010, was developed to assess the long-term efficacy and safety of N8-GP in children, adolescents, and adults. The pivotal pathfinder2 (adolescents and adults) and pathfinder5 (children) trials were completed in late 2018, and comprehensive analyses of the end-of-trial results are published together with this article as part of an N8-GP Supplement. Furthermore, results from the pathfinder3 trial, which was designed to evaluate the safety and efficacy of N8-GP during major surgery, have also recently been finalized. Here, we provide an overview of the pathfinder clinical development program and summarize key data from the completed pathfinder trials. We also provide perspectives on the future of extended half-life FVIII molecules in the treatment of patients with hemophilia A and describe currently ongoing pathfinder trials.

Real-World Utilisation and Bleed Rates in Patients with Haemophilia B Who Switched to Recombinant Factor IX Fusion Protein (rIX-FP): A Retrospective International Analysis.

INTRODUCTION: Despite the well-documented benefits of prophylaxis, treatment burden is still a barrier to adherence in patients with haemophilia. An extended half-life fusion protein linking recombinant FIX (rFIX) with human albumin (rIX-FP) has been developed for the treatment of patients with haemophilia B and is indicated for dosing up to every 14 days. This analysis evaluated real-world outcomes in patients switching to rIX-FP from the previous FIX product in Italy, Belgium and the UK. METHODS: Anonymised chart data were collected from the pre-existing medical records of patients with haemophilia B between May and September 2018. Patients were included in the analysis if they had been treated with rIX-FP for ≥ 8 weeks. Data were compared between rIX-FP and the patient's prior FIX product. RESULTS: Twenty-three HTCs from Italy (n = 13), Belgium (n = 3) and the UK (n = 7) provided data for 84 male patients, 92.8% of which had severe haemophilia B. The majority of patients were previously on prophylactic regimens with their prior FIX product (Italy, 44/49; Belgium, 7/10; UK, 22/25). The switch to prophylaxis with rIX-FP led to reductions in mean annualised bleeding rate of 94.3% in Italy, 93.9% in Belgium and 67.7% in the UK compared with prior FIX prophylaxis. Overall, 41% of patients experienced zero spontaneous bleeds prior to switching, compared with 88% following the switch to rIX-FP. The majority of patients had a reduction in dosing frequency following the switch, with 98.6% of patients dosing once weekly or less frequently compared with 9.6% of patients dosing at this frequency with their prior FIX. Mean weekly FIX consumption was reduced compared with prior FIX prophylaxis. CONCLUSION: This retrospective review of real-world evidence demonstrated that switching to rIX-FP from prior FIX was associated with improved haemostatic efficacy and reduced factor consumption in patients with haemophilia B from Italy, Belgium and the UK.

While clinical trials provide robust evidence as to the effectiveness and safety of a new drug, they are tightly controlled and so may not reflect some of the issues that may be discovered in clinical practice. Therefore, real-world analyses are important to determine how a product performs in patients in everyday settings. This study looked at the use of an extended half-life fusion protein linking recombinant FIX (rFIX) with human albumin (rIX-FP), which was designed to allow longer dosing intervals, in patients with haemophilia B in Italy, Belgium and the UK, and compared this with the patients' previous FIX product. Anonymous patient chart data were collected from participating centres and analysed in terms of bleeding rate, factor usage and dosing frequency for rIX-FP and previous FIX product. The results showed that after switching to rIX-FP, patients experienced lower bleeding rates, lower factor usage and less frequent dosing regimens compared with their previous FIX product. This is the first analysis to assess the real-world clinical benefits of switching to prophylaxis with rIX-FP from a prior FIX product in Italy, Belgium and the UK. This study further strengthens the results seen in clinical trials with rIX-FP, confirming that the effective bleeding prevention demonstrated in clinical trials is consistent with that seen in patients in real-world clinical practice.

A Novel, Enriched Population Pharmacokinetic Model for Recombinant Factor VIII-Fc Fusion Protein Concentrate in Hemophilia A Patients.

BACKGROUND: The currently published population pharmacokinetic (PK) models used for PK-guided dosing in hemophilia patients are based on clinical trial data and usually not externally validated in clinical practice. The aim of this study was to validate a published model for recombinant factor VIII-Fc fusion protein (rFVIII-Fc) concentrate and to develop an enriched model using independently collected clinical data if required. METHODS: Clinical data from hemophilia A patients treated with rFVIII-Fc concentrate (Elocta) participating in the United Kingdom Extended Half-Life Outcomes Registry were collected. The predictive performance of the published model was assessed using mean percentage error (bias) and mean absolute percentage error (inaccuracy). An extended population PK model was developed using nonlinear mixed-effects modeling (NONMEM). RESULTS: A total of 43 hemophilia A patients (FVIII ≤ 2 IU/dL), aged 5 to 70 years, were included. The prior model was able to predict the collected 244 rFVIII-Fc levels without significant bias (-1.0%, 95% CI: -9.4 to 7.3%) and with acceptable accuracy (12.9%). However, clearance and central distribution volume were under predicted in patients <12 years, which was expected as this age group was not represented in the previous model population. An enriched population PK model was constructed, which was able to successfully characterize PK profiles of younger children. CONCLUSION: We concluded that the existing rFVIII-Fc population PK model is valid for patients ≥ 12 years. However, it is not reliable in younger patients. Our alternative model, constructed from real world patient data including children, allows for better description of patients ≥5 years.

Case 37: Neutropenia and macrocytosis in a middle-aged man.

A myelodysplastic syndrome (MDS) was suspected in a middle-aged man who presented with neutropenia and macrocytosis. The correct non-neoplastic diagnosis was not made for 5 years. It is of crucial importance to exclude treatable causes of cytopenia and dysplasia when MDS is suspected.