Optimizing bleed prevention throughout the lifespan: Womb to Tomb.

The focus of care providers, patients and families is the ability to tailor care for persons with haemophilia (PWH) across the lifespan. Care requires knowledge of the bleeding disorder and age-related complications, risk of therapeutic interventions, and evaluation of individual characteristics that contribute to outcomes. The ultimate goal is to live a normal life without the burden of bleeding, for PWH and carriers. A wide range of therapeutic options is required to achieve personalized care. Over the last decade, substantial therapeutic advantages have been achieved in the treatment of haemophilia that include the development of a robust array of factor concentrates, novel haemostatic agents, and increased knowledge and awareness of disease associated outcomes and risk factors. Significant strides on the road to accessible gene therapy have been realized. This increased range of therapeutic modalities provides options for development and implementation of care plans for each patient at each stage of life that are more flexible compared to prior care regimens. Paradigms for management of haemophilia are changing. As a community, we must work together to use these resources wisely, to learn from outcomes with new therapies and diagnostic tools, to assure all patients can achieve improved care and outcomes regardless of disease state or country of origin.

Treatment of bleeding episodes with recombinant factor VIII Fc fusion protein in A-LONG study subjects with severe haemophilia A.

INTRODUCTION: The Phase 3 A-LONG study demonstrated the safety and efficacy of rFVIIIFc for the control and prevention of bleeding episodes in severe haemophilia A. AIM: To describe the treatment of bleeding episodes with rFVIIIFc in the A-LONG study. METHODS: A-LONG subjects (<1 IU dL-1 endogenous FVIII) were treated with individualized prophylaxis (Arm 1), weekly prophylaxis (Arm 2) or episodic treatment (Arm 3). Information recorded for each bleeding episode included type, location and dose to treat the episode. RESULTS: During A-LONG, 757 bleeding episodes occurred during the efficacy period; the majority [456 (60%)] occurred in Arm 3 (episodic treatment). Of 93 subjects in the prophylaxis arms who entered the study with target joints, 43 (60%) in Arm 1 and 11 (52%) in Arm 2 did not experience a target joint bleed. Overall, 98% of bleeding episodes (and 98% of bleeds involving a target joint) resolved with one or two infusions; the median dose per infusion to treat a bleed was 27 IU kg-1 (27 IU kg-1 for target joints). Using population pharmacokinetic simulations, FVIII activity levels were predicted to be below the upper limit of normal (150 IU dL-1 ) in most patients in the event that rFVIIIFc is used to treat a bleeding episode in close proximity to a prophylactic dose. CONCLUSIONS: These findings demonstrate the efficacy of rFVIIIFc for the treatment of acute bleeding episodes in subjects with severe haemophilia A, regardless of treatment regimen.

Complications of haemophilia in babies (first two years of life): a report from the Centers for Disease Control and Prevention Universal Data Collection System.

AIM: To describe the prevalence and complications in babies ≤2 years with haemophilia. METHODS: We used a standardized collection tool to obtain consented data on eligible babies aged ≤2 years with haemophilia enrolled in the Centers for Disease Control and Prevention Universal Data Collection System surveillance project at US Hemophilia Treatment Centers (HTCs). RESULTS: Of 547 babies, 82% had haemophilia A, and 70% were diagnosed within one month of birth. Diagnosis was prompted by known maternal carrier status (40%), positive family history (23%), bleeding (35%) and unknown 2%; 81% bled during the first two years. The most common events were bleeding (circumcision, soft tissue, oral bleeding) and head injury. There were 46 episodes of intracranial haemorrhage (ICH) in 37 babies (7%): 18 spontaneous, 14 delivery related, 11 traumatic, 2 procedure related and 1 unknown cause. Of the 176 central venous access devices (CVADs) in 148 (27%) babies, there were 137 ports, 22 surgically inserted central catheters and 20 peripherally inserted central catheters. Ports had the lowest complication rates. Inhibitors occurred in 109 (20%) babies who experienced higher rates of ICH (14% vs. 5%; P = 0.002), CVAD placement (61% vs. 19%; P < 0.001) and CVAD complications (44% vs. 26%; P < 0.001). The most common replacement therapy was recombinant clotting factor concentrates. CONCLUSION: Bleeding events in haemophilic babies ≤2 years were common; no detectable difference in the rates of ICH by the mode of delivery was noted. Neonatal factor exposure did not affect the inhibitor rates. Minor head trauma, soft tissue and oropharyngeal bleeding were the leading indications for treatment.

Integrated analysis of safety data from 12 clinical interventional studies of plasma- and albumin-free recombinant factor VIII (rAHF-PFM) in haemophilia A.

INTRODUCTION: Antihaemophilic factor (recombinant), plasma/albumin-free method (rAHF-PFM) is a human recombinant full-length factor VIII (FVIII) approved worldwide for the control and prevention of bleeding episodes, routine prophylaxis and perioperative management in adults and children with haemophilia A. AIM: To evaluate rAHF-PFM safety [including adverse events (AEs) and inhibitor incidence] from 12 interventional studies spanning >10 years. METHODS: The study population comprised 418 treated patients (median age = 18.7 years) with FVIII levels ≤2% of normal, including 55 previously untreated or minimally treated patients (PUPs/MTPs) from all rAHF-PFM phase I-IV studies, excluding observational safety studies. RESULTS: Most AEs were non-serious; only 93 AEs in 45 patients (10.8%) were related to rAHF-PFM. A total of 106 serious AEs (SAEs) occurred in 69 patients (16.5%); the most common were FVIII inhibitors (4.1%), device-related infection (1.0%) and pyrexia (0.7%). The 17 SAEs considered related to treatment consisted of FVIII inhibitors in 1 previously treated patient (PTP) (≤5 Bethesda Units [BU]) and 16 PUPs/MTPs [7/55 high titre (>5 BU), 12.7%; 9/55 low titre (≤5 BU), 16.4%]. Overall, the incidence of FVIII inhibitors was 0.36% in PTPs and 29.1% in PUPs/MTPs. No deaths or cases of hypersensitivity related to rAHF-PFM occurred. CONCLUSION: This integrated safety analysis evaluated the safety and tolerability of rAHF-PFM in children and adults with moderately severe or severe haemophilia A in all interventional studies completed to date. It was important to review consolidated evidence as some AEs are rare. There were no new safety signals in a wide variety of clinical settings.

The obstetric, gynaecological and fertility implications of homozygous PAI-1 deficiency: single-centre experience.

Complete plasminogen activator inhibitor type 1 (PAI-1) deficiency is an exceedingly rare autosomal recessive bleeding disorder previously identified and reported in a large Old Order Amish (OOA) kindred in Indiana [Fay et al. Blood 1997; 90: 204]. Mouse models suggest that proteolysis via the plasminogen activator/plasmin system plays a crucial role in reproduction including degradation of the follicular wall during ovulation, fertilization, embryo implantation and embryogenesis [Leonardsson et al., Proc Natl Acad Sci USA 1995; 92: 12446]. We report the obstetric, gynaecological and fertility histories of OOA individuals with homozygous PAI-1 deficiency. In this family, there are 10 affected members identified to date ranging in age between 10 and 32 years, including seven female patients and three male patients. To date, two women have achieved pregnancies without difficulty; however, they experienced antenatal bleeding and preterm labour. The early initiation and continuation of antifibrinolytic agents, Epsilon-aminocaproic acid or tranexamic acid, during the pregnancy and in the postpartum period, was believed to be successful in preventing major bleeding complications in our patients with complete PAI-1 deficiency.

Safety of recombinant activated factor VII (rFVIIa) in patients with congenital haemophilia with inhibitors: overall rFVIIa exposure and intervals following high (>240 µg kg⁻¹) rFVIIa doses across clinical trials and registries.

Recombinant activated factor VII (rFVIIa) is indicated for treatment of bleeding in congenital haemophilia with inhibitors (CHwI) using 90 µg kg(-1) every 2-3 h (EU and US) or a single 270 µg kg(-1) dose (EU only) with ~90% efficacy reported for both regimens. Dosing of rFVIIa varies, and home treatment makes assessment of frequency of doses >90 µg kg(-1), the intervals before additional treatment, and the risk for thromboembolic events (TEs) more difficult. This post hoc analysis assessed the safety and distribution of rFVIIa dosing in CHwI and the impact of >240 µg kg(-1) dosing on subsequent bypassing agent (BPA) dosing interval and frequency. Data regarding on-demand or prophylactic rFVIIa dosing, TE incidence and subsequent BPA dosing after high rFVIIa doses were compiled from multiple sources incorporating safety surveillance. A total of 61 734 rFVIIa doses were reported in 481 patients treated for 3947 bleeds and for 43 135 prophylaxis days. Over half (52%) exceeded 120 µg kg(-1), 37% exceeded 160 µg kg(-1) and 15% exceeded 240 µg kg(-1). Subsequent doses of BPA(s) were administered after 38% of initial and 49% of any rFVIIa dose >240 µg kg(-1), and were most frequently administered ≥24 h after initial (40%) or any (53%) doses >240 µg kg(-1). No TEs were reported. The findings of this analysis show that rFVIIa doses >90 µg kg(-1) are utilized for 'real-world' treatment of children and adults. When additional BPA was administered following an rFVIIa dose >240 µg kg(-1), reported intervals were prolonged, often ≥24 h. No safety issues were identified in the 61,734 doses analysed.

Variability in platelet- and collagen-binding defects in type 2M von Willebrand disease.

Type 2M von Willebrand disease (VWD) includes qualitative defects in von Willebrand factor (VWF) function, with normal multimer distribution but a defect in VWF activity with respect to platelet or collagen binding. We characterized novel VWF gene mutations found in type 2M VWD subjects enrolled in the Zimmerman Program for the Molecular and Clinical Biology of VWD. Subjects were enrolled based on a pre-existing diagnosis of type 2M VWD. Testing included full-length gene sequencing, VWF antigen (VWF:Ag), VWF ristocetin cofactor activity (VWF:RCo), VWF collagen binding and multimer distribution. Recombinant VWF variants were synthesized using site-directed mutagenesis and expressed in HEK293T cells. Platelet binding was measured by flow cytometry with fixed platelets and ELISA with recombinant glycoprotein Ibα (GPIbα). Four novel VWF A1 domain mutations were found in individuals with type 2M VWD: S1358N, S1387I, S1394F and Q1402P. All subjects had a history of bleeding, VWF:RCo < 40 IU dL(-1) , VWF:RCo/VWF:Ag ratios <0.6 and normal multimer distribution. No defect in expression, secretion, or multimerization was found for any of the mutations. All showed decreased binding to intact platelets, and decreased or absent binding to a mutant GPIbα construct with spontaneous VWF binding. 1387I had decreased binding to all collagen types tested. 1402P had reduced binding exclusively to type VI collagen. Type 2M VWD is a heterogeneous category comprised of both collagen- and platelet-binding defects. Understanding the precise defect for each mutation may ultimately lead to better diagnosis and treatment.

F8 haplotype and inhibitor risk: results from the Hemophilia Inhibitor Genetics Study (HIGS) Combined Cohort.

Ancestral background, specifically African descent, confers higher risk for development of inhibitory antibodies to factor VIII (FVIII) in haemophilia A. It has been suggested that differences in the distribution of FVIII gene (F8) haplotypes, and mismatch between endogenous F8 haplotypes and those comprising products used for treatment could contribute to risk. Data from the Hemophilia Inhibitor Genetics Study (HIGS) Combined Cohort were used to determine the association between F8 haplotype 3 (H3) vs. haplotypes 1 and 2 (H1 + H2) and inhibitor risk among individuals of genetically determined African descent. Other variables known to affect inhibitor risk including type of F8 mutation and human leucocyte antigen (HLA) were included in the analysis. A second research question regarding risk related to mismatch in endogenous F8 haplotype and recombinant FVIII products used for treatment was addressed. Haplotype 3 was associated with higher inhibitor risk among those genetically identified (N = 49) as of African ancestry, but the association did not remain significant after adjustment for F8 mutation type and the HLA variables. Among subjects of all racial ancestries enrolled in HIGS who reported early use of recombinant products (N = 223), mismatch in endogenous haplotype and the FVIII proteins constituting the products used did not confer greater risk for inhibitor development. Haplotype 3 was not an independent predictor of inhibitor risk. Furthermore, our findings did not support a higher risk of inhibitors in the presence of a haplotype mismatch between the FVIII molecule infused and that of the individual.

Patient/caregiver-reported recombinant factor VIIa (rFVIIa) dosing: home treatment of acute bleeds in the Dosing Observational Study in Hemophilia (DOSE).

Patients with congenital haemophilia with inhibitors experience acute bleeds managed with bypassing agents, such as recombinant FVIIa (rFVIIa). Home-based treatment and dosing patterns in the US remain poorly described. This study aimed to assess the prescribed and actual rFVIIa dosing in frequently bleeding inhibitor patients (≥4 bleeds in 3 months) prescribed first-line therapy with rFVIIa. Patients or caregivers recorded daily diaries, including the details of all bypassing agent infusions for 3-6 months. Median (range) initial rFVIIa dose prescribed for joint, muscle and other bleeds was 167.5 (61.0-289.0) mcg kg(-1). Additional rFVIIa doses prescribed were 90 (61-270) mcg kg(-1) at an interval of 2.5-3 (1-24) h. The actual initial rFVIIa dose reported by patients/caregivers for 158 bleeds was 212 (59-400) mcg kg(-1), with total dose per episode of 695 (74-21257) mcg kg(-1). Patient/caregiver-reported average dose per bleed was 146 (40-400) mcg kg(-1) across 5 (1-106) infusions. The initial rFVIIa dose was higher for haemarthrosis (223 [59-400] mcg kg(-1)) than muscle bleeds (148 [74-300] mcg kg(-1); P = 0.07). Initial and mean dose per day changed as treatment progressed. The DOSE study indicates that frequently bleeding inhibitor patients are prescribed and use higher rFVIIa dosing for all bleed types than recommended in the package insert (90 mcg kg(-1)). The rFVIIa dosing was highly variable within and across bleed types, with higher initial doses used for joint bleeds than muscle and other bleed types, particularly in the first days of treatment. This suggests that patients/caregivers have adopted home treatment strategies based on physician discretion and individual responses and experience.

Multidisciplinary management of patients with haemophilia with inhibitors undergoing surgery in the United States: perspectives and best practices derived from experienced treatment centres.

Since the 1980s, major surgical interventions in patients with congenital haemophilia with inhibitors have been performed utilizing bypassing agents for haemostatic coverage. While reports have focused on perioperative management and haemostasis, the US currently lacks consensus guidelines for the management of patients with inhibitors during the surgical procedure, and pre- and postoperatively. Many haemophilia treatment centres (HTCs) have experience with surgery in haemophilia patients, including those with inhibitors, with approximately 50% of these HTCs having performed orthopaedic procedures. The aim of this study was to present currently considered best practices for multidisciplinary care of inhibitor patients undergoing surgery in US HTCs. Comprehensive haemophilia care in the US is provided by ~130 federally designated HTCs staffed by multidisciplinary teams of healthcare professionals. Best practices were derived from a meeting of experts from leading HTCs examining the full care spectrum for inhibitor patients ranging from identification of the need for surgery through postoperative rehabilitation. HTCs face challenges in the care of inhibitor patients requiring surgery due to the limited number of surgeons willing to operate on this complex population. US centres of excellence have developed their own best practices around an extended comprehensive care model that includes preoperative planning, perioperative haemostasis and postoperative rehabilitation. Best practices will benefit patients with inhibitors and allow improvement in the overall care of these patients when undergoing surgical procedures. In addition, opportunities for further education and outcomes assessment in the care of this patient population have been identified.

Prevalence and risk factors of cardiovascular disease (CVD) events among patients with haemophilia: experience of a single haemophilia treatment centre in the United States (US).

The primary objective of the study was to examine the prevalence of cardiovascular disease (CVD) events and their known risk factors among persons with haemophilia (PWH). This cross-sectional study, covering a 5-year period, included PWH aged ≥35 years who were cared for at a single haemophilia treatment centre in the United States. Medical records were extensively reviewed to collect the information about CVD events and their risk factors such as obesity, hypertension, diabetes, hypercholesterolemia and smoking. Prevalence rates were compared with national population estimates and associations between risk factors and CVD events were examined using logistic regression. The study cohort comprised 185 PWH (102 haemophilia A and 83 haemophilia B). Lifetime prevalence of a CVD event was 19.5% (36/185, 95% confidence interval [CI] 13.8-25.2%). CVD mortality was 5.4% (10/185, 95% CI 2.7-8.1). Compared with US non-Hispanic White males (NHWH), PWH had about twice the prevalence of coronary artery disease, stroke and myocardial infarction. The prevalence of CVD risk factors for PWH was similar to that for US NHWM with 39.5% of PWH exposed to two or more of these risk factors. Both hypertension and smoking were associated significantly with CVD events, with odds ratios of 4.9 and 6.3, respectively. In conclusion, this study revealed that both CVD events and its risk factors were at least equally prevalent among PWH and might have been even higher than among the US NHWM in the United States. Therefore, it is imperative to implement strategies for CVD prevention among PWH.

VERITAS-PRN: a new measure of adherence to episodic treatment regimens in haemophilia.

Episodic treatment of bleeding disorders is defined as utilization of clotting factor concentrates in response to acute bleeding episodes to achieve haemostasis. Non-adherence to prescribed episodic regimens can limit treatment effectiveness and result in target joint formation, pain and disability. Evaluation of and interventions to promote adherence may improve health outcomes. The purpose of this study was to validate a new adherence scale developed for individuals with bleeding disorders treated on episodic infusion regimens, entitled VERITAS-PRN [Validated Hemophilia Regimen Treatment Adherence Scale - PRN]. Participants were recruited from the Indiana Hemophilia and Thrombosis Center patient population. Participants completed the scale for psychometric development and analysis. Subjective ratings of adherence from participants and providers were used for validation. The study sample included 51 male and three female patients. Twenty-seven participants (50.0%) were diagnosed with FVIII deficiency, 21 (38.9%) with FIX deficiency and six (11.1%) with von Willebrand's disease (VWD). Internal consistency reliability for the total VERITAS-PRN score and the majority of subscales was good-to-excellent, with the one exception being the 'Plan' subscale. Test-retest reliability correlations were good-to-excellent for the total scale and all subscales. The VERITAS-PRN total scale had moderate-to-strong and statistically significant correlations with validity measures. The VERITAS-PRN is a reliable and valid measure of adherence to episodic treatment regimens for bleeding disorders. This tool may be utilized as a standard measure of adherence to increase sensitivity to adherence problems and promote targeted interventions to enhance adherence and health outcomes.

The prospective Hemophilia Inhibitor PUP Study reveals distinct antibody signatures prior to FVIII inhibitor development.

Preventing factor VIII (FVIII) inhibitors following replacement therapies with FVIII products in patients with hemophilia A remains an unmet medical need. Better understanding of the early events of evolving FVIII inhibitors is essential for risk identification and the design of novel strategies to prevent inhibitor development. The Hemophilia Inhibitor Previously Untreated Patients (PUPs) Study (HIPS; www.clinicaltrials.gov #NCT01652027) is the first prospective cohort study to evaluate comprehensive changes in the immune system during the first 50 exposure days (EDs) to FVIII in patients with severe hemophilia A. HIPS participants were enrolled prior to their first exposure to FVIII or blood products ("true PUPs") and were evaluated for different immunological and clinical parameters at specified time points during their first 50 EDs to a single source of recombinant FVIII. Longitudinal antibody data resulting from this study indicate that there are 4 subgroups of patients expressing distinct signatures of FVIII-binding antibodies. Subgroup 1 did not develop any detectable FVIII-binding immunoglobulin G (IgG) antibodies. Subgroup 2 developed nonneutralizing, FVIII-binding IgG1 antibodies, but other FVIII-binding IgG subclasses were not observed. Subgroup 3 developed transient FVIII inhibitors associated with FVIII-binding IgG1 antibodies, similar to subgroup 2. Subgroup 4 developed persistent FVIII inhibitors associated with an initial development of high-affinity, FVIII-binding IgG1 antibodies, followed by IgG3 and IgG4 antibodies. Appearance of FVIII-binding IgG3 was always associated with persistent FVIII inhibitors and the subsequent development of FVIII-binding IgG4. Some of the antibody signatures identified in HIPS could serve as candidates for early biomarkers of FVIII inhibitor development.

Lysosome biogenesis requires Rab9 function and receptor recycling from endosomes to the trans-Golgi network.

Newly synthesized lysosomal enzymes bind to mannose 6-phosphate receptors (MPRs) in the TGN, and are carried to prelysosomes, where they are released. MPRs then return to the TGN for another round of transport. Rab9 is a ras-like GTPase which facilitates MPR recycling to the TGN in vitro. We show here that a dominant negative form of rab9, rab9 S21N, strongly inhibited MPR recycling in living cells. The block was specific in that the rates of biosynthetic protein transport, fluid phase endocytosis and receptor-mediated endocytosis were unchanged. Expression of rab9 S21N was accompanied by a decrease in the efficiency of lysosomal enzyme sorting. Cells compensated for the presence of the mutant protein by inducing the synthesis of both soluble and membrane-associated lysosomal enzymes, and by internalizing lysosomal enzymes that were secreted by default. These data show that MPRs are limiting in the secretory pathway of cells expressing rab9 S21N and document the importance of MPR recycling and the rab9 GTPase for efficient lysosomal enzyme delivery.