Search

Emicizumab, a bispecific humanized monoclonal antibody, bridges activated factor IX (FIX) and FX to restore the function of missing activated FVIII in hemophilia A. Emicizumab prophylaxis in children with hemophilia A and FVIII inhibitors was investigated in a phase 3 trial (HAVEN 2). Participants, previously receiving episodic/prophylactic bypassing agents (BPAs), were treated with subcutaneous emicizumab: 1.5 mg/kg weekly (group A), 3 mg/kg every 2 weeks (group B), or 6 mg/kg every 4 weeks (group C). Pharmacokinetics, safety, and efficacy (including an intraindividual comparison of participants from a noninterventional study) were evaluated. Eighty-five participants aged <12 years were enrolled. In group A (n = 65), the annualized rate of treated bleeding events (ABRs) was 0.3 (95% confidence interval [CI], 0.17-0.50), and 77% had no treated bleeding events. Intraindividual comparison of 15 participants who previously took BPA prophylaxis showed that emicizumab prophylaxis reduced the ABR by 99% (95% CI, 97.4-99.4). In groups B (n = 10) and C (n = 10), ABRs were 0.2 (95% CI, 0.03-1.72) and 2.2 (95% CI, 0.69-6.81), respectively. The most frequent adverse events were nasopharyngitis and injection-site reactions; no thrombotic events occurred. Two of 88 participants developed antidrug antibodies (ADAs) with neutralizing potential, that is, associated with decreased emicizumab plasma concentrations: 1 experienced loss of efficacy, and, in the other, ADAs disappeared over time without intervention or breakthrough bleeding. All other participants achieved effective emicizumab plasma concentrations, regardless of the treatment regimen. Emicizumab prophylaxis has been shown to be a highly effective novel medication for children with hemophilia A and inhibitors. This trial was registered at www.clinicaltrials.gov as #NCT02795767., (© 2019 by The American Society of Hematology.)

Background: Hereditary factor X (FX) deficiency (FXD) affects 1:500 000-1:1 000 000 people worldwide. A novel, high-purity plasma-derived FX concentrate (pdFX) is available in the United States and European Union as replacement therapy for FXD, but data are scarce on pdFX use in children <12 years., Aim: This prospective, open-label phase 3 study assessed the safety, efficacy and pharmacokinetics of pdFX in children <12 years with moderate/severe FXD., Methods: Subjects aged <12 years with basal plasma FX activity (FX:C) <5 IU/dL received pdFX as prophylactic and on-demand treatment, with doses adjusted to maintain FX:C > 5 IU/dL. After ≥26 weeks and ≥50 exposure days, investigators rated pdFX efficacy for preventing/decreasing bleeds. Secondary endpoints included number and severity of bleeds, trough FX:C and incremental recovery. Safety parameters were adverse events (AEs), inhibitor development and changes in laboratory parameters., Results: The study enrolled 9 subjects (0-5 years, n = 4; 6-11 years, n = 5) with severe (n = 8) or moderate (n = 1) FXD. At end of study, investigators rated pdFX efficacy excellent for all subjects. Ten bleeds occurred (n = 3 subjects; 6 major, 3 minor, 1 unassessed for severity). Trough FX:C levels remained >5 IU/dL for all subjects after the last dose adjustment study visit. Mean incremental recovery was significantly lower for younger vs older subjects (1.53 vs 1.91 IU/dL per IU/kg; P = .001). All AEs were unrelated to treatment; no inhibitor development or clinically significant changes in laboratory parameters were observed., Conclusions: These results demonstrate the efficacy and safety of pdFX for treating children <12 years with moderate/severe hereditary FXD., (© 2018 The Authors Haemophilia Published by John Wiley & Sons Ltd.)

Inherited bleeding, thrombotic, and platelet disorders (BPDs) are diseases that affect ∼300 individuals per million births. With the exception of hemophilia and von Willebrand disease patients, a molecular analysis for patients with a BPD is often unavailable. Many specialized tests are usually required to reach a putative diagnosis and they are typically performed in a step-wise manner to control costs. This approach causes delays and a conclusive molecular diagnosis is often never reached, which can compromise treatment and impede rapid identification of affected relatives. To address this unmet diagnostic need, we designed a high-throughput sequencing platform targeting 63 genes relevant for BPDs. The platform can call single nucleotide variants, short insertions/deletions, and large copy number variants (though not inversions) which are subjected to automated filtering for diagnostic prioritization, resulting in an average of 5.34 candidate variants per individual. We sequenced 159 and 137 samples, respectively, from cases with and without previously known causal variants. Among the latter group, 61 cases had clinical and laboratory phenotypes indicative of a particular molecular etiology, whereas the remainder had an a priori highly uncertain etiology. All previously detected variants were recapitulated and, when the etiology was suspected but unknown or uncertain, a molecular diagnosis was reached in 56 of 61 and only 8 of 76 cases, respectively. The latter category highlights the need for further research into novel causes of BPDs. The ThromboGenomics platform thus provides an affordable DNA-based test to diagnose patients suspected of having a known inherited BPD., (© 2016 by The American Society of Hematology.)

To facilitate early prophylaxis, step-up regimens starting prophylaxis with infusions 1× week(-1) were introduced. Choice of initial regimen may affect outcome. This study aims to classify initial prophylactic regimens and compare them on short-term outcome. From the 'European Paediatric Network for Haemophilia Management' (PedNet) registry, patients with severe haemophilia A without inhibitors, born 2000-2012, receiving prophylaxis were included. Treatment centres were classified according to the initial frequency of prophylactic infusions and the age at reaching infusions ≥3× week(-1) . Bleeding, and central venous access device (CVAD) use were compared at age 4 years. In 21 centres with 363 patients, three regimens were identified: (i) start prophylaxis with ≥3× week(-1) infusions before age three (full: 19% of centres, 18% of patients); (ii) start 1-2× week(-1) , increasing frequency as soon as possible (asap), reaching ≥3× week(-1) before age three (43% of centres, 36% of patients); (iii) start 1-2× week(-1) , increasing frequency according to bleeding (phenotype), reaching ≥3× week(-1) after age three (38% of centres, 46% of patients). Prophylaxis was started at median 1.2 years on the full and asap regimen vs 1.8 years on the phenotype regimen. Complete prevention of joint bleeds was most effective on the full regimen (32% full vs. 27% asap and 8% phenotype), though at the cost of using most CVADs (88% full vs. 34% asap and 22% phenotype). The three prophylaxis regimens identified had different effects on early bleeding and CVAD use. This classification provides the first step towards establishing the optimum prophylactic regimen., (© 2014 John Wiley & Sons Ltd.)

The bleeding phenotype has been suggested to differ between haemophilia A and B. More knowledge on the bleeding phenotype at initiation of treatment is important to optimize patient care. The aim of this study was to investigate the severity of the bleeding phenotype and the variation in bleeding in children with severe or moderate haemophilia A and B. Consecutive, previously untreated patients with severe or moderate haemophilia A and B (factor VIII or IX activity <0.01 or 0.01-0.05 IU mL(-1) respectively) born between January 1st 2000 and January 1st 2010 were included. Primary outcome was severity of bleeding tendency. Secondary outcome was variation in bleeding pattern. A total of 582 patients with severe haemophilia A and 76 with severe haemophilia B did not differ in age at first exposure to clotting factor (0.81 vs. 0.88 years, P = 0.20), age at first bleed (0.82 vs. 0.88 years, P = 0.36), and age at first joint bleed (1.18 vs. 1.20 years, P = 0.59). Patients with moderate haemophilia were older compared to patients with severe haemophilia. In patients with moderate haemophilia there were no clear differences between haemophilia A and B. Severity and variation in bleeding phenotype are similar during the early stage of treatment in patients with severe and moderate haemophilia A and B respectively. The findings imply that children with haemophilia B should be observed and treated as vigilantly as those with haemophilia A., (© 2014 John Wiley & Sons Ltd.)

The objective of this study was to examine the association of the intensity of treatment, ranging from high-dose intensive factor VIII (FVIII) treatment to prophylactic treatment, with the inhibitor incidence among previously untreated patients with severe hemophilia A. This cohort study aimed to include consecutive patients with a FVIII activity < 0.01 IU/mL, born between 2000 and 2010, and observed during their first 75 FVIII exposure days. Intensive FVIII treatment of hemorrhages or surgery at the start of treatment was associated with an increased inhibitor risk (adjusted hazard ratio [aHR], 2.0; 95% confidence interval [CI], 1.3-3.0). High-dose FVIII treatment was associated with a higher inhibitor risk than low-dose FVIII treatment (aHR, 2.3; 95% CI, 1.0-4.8). Prophylaxis was only associated with a decreased overall inhibitor incidence after 20 exposure days of FVIII. The association with prophylaxis was more pronounced in patients with low-risk F8 genotypes than in patients with high-risk F8 genotypes (aHR, 0.61, 95% CI, 0.19-2.0 and aHR, 0.85, 95% CI, 0.51-1.4, respectively). In conclusion, our findings suggest that in previously untreated patients with severe hemophilia A, high-dosed intensive FVIII treatment increases inhibitor risk and prophylactic FVIII treatment decreases inhibitor risk, especially in patients with low-risk F8 mutations.

Homozygous severe factor V (FV) deficiency has a prevalence of around one per million. Even in patients with FV levels of <0.01 IU mL(-1) there appears to be a variation in bleeding phenotype in that there is a subgroup of affected individuals who present in later childhood and have a relatively mild bleeding phenotype, but there are children who present as neonates with intracerebral bleeding events and who have a much more severe bleeding phenotype. The only available current FV replacement is in the form of fresh frozen plasma (FFP) or solvent detergent FFP. We present here our experience with surgical haemostatic cover for 13 surgeries in three children with severe FV deficiency., (© 2012 Blackwell Publishing Ltd.)

We report a prospective trial of 55 previously untreated patients (PUPs) and minimally treated patients (MTPs) with severe/moderately severe haemophilia A (baseline factor VIII [FVIII] ≤2%) treated with a single FVIII replacement product. It was the objective of this study to evaluate the immunogenicity, efficacy, and safety of rAHF-PFM (Advate®). On-demand or prophylactic treatment regimens were determined at the discretion of the investigator. rAHF-PFM was also permitted for perioperative management. There were 633 bleeding episodes (BEs), including 517 treated, and 466 rated for efficacy. Haemostatic efficacy was considered excellent/good in 93% of 466 rated treatments. Of 517 treated BEs, 463/517 (90%) were managed with one (356/517 [69%]) or two infusions (107/517 [21%]). There were 27 surgeries. Intraoperative (n=22) and postoperative (n=25) haemostatic efficacies were considered excellent or good in 100% of rated surgeries. Related serious adverse events (SAEs) were inhibitor development in 16/55 (29.1%) subjects who received at least one infusion of rAHF-PFM. Non-serious, related adverse events (AEs) were few in number (14 in eight subjects). The odds ratio (OR [95% Confidence Interval, CI]) of developing inhibitors was significantly higher in subjects with a family history of inhibitor (4.95[1.29-19.06]), non-Caucasian ethnicity (4.18, [1.18-14.82]), and intensive treatment at high dose (4.5 [1.05-19.25]) within ≤20 exposure days (EDs). In conclusion, rAHF-PFM was safe and effective for the management and perioperative coverage of PUPs/MTPs with severe/moderately severe haemophilia A. This report supports previous findings from studies in which family history of inhibitor, non-Caucasian ethnicity, and high intensity treatment were associated with high risk of inhibitor development.

Prophylaxis is increasingly prescribed in treatment of haemophilia and its benefit is believed to be most significant for the youngest patients as haemophilic arthropathy may be prevented if prophylaxis is initiated prior to recurrent haemarthroses. While clinical prophylaxis data are readily available for haemophilia A, analogous data for haemophilia B are relatively limited. A prospective clinical study of recombinant factor IX (BeneFIX; rFIX), designed to allow investigator prescribed prophylaxis according to customary practices, was conducted in children <6 years old with severe haemophilia B. Nearly all children were prescribed prophylaxis (22/25; 88%) for all or part of their study participation. Favourable efficacy and safety profiles were reported. Routine prophylaxis with 1 or 2 rFIX infusions per week over an average of greater than 6 months of therapy resulted in near complete prevention of spontaneous breakthrough haemorrhages (<1 per year), with most children (77%) having none, including seven patients (32%) who had no bleeding episodes at all. Haemorrhages in joints were less common than those outside joints (27% vs. 73% of haemorrhages). In a patient population that included children with multiple prior haemarthroses, 68% of children had no joint bleeding. Breakthrough haemorrhages resolved with 1 or 2 infusions in 89% of episodes. The absence of changes in prophylaxis infusion schedules suggests that 1 or 2 rFIX infusion(s) per week were well-tolerated by these young patients, including those with (41%) and without (59%) central venous access devices. Safety was established by the low incidence of treatment-related adverse events.

Desmopressin (1-deamino-8-D-arginine vasopressin (DDAVP)) has been shown to be an effective treatment option when administered both intravenously [1,2] and subcutaneously [3] to children with inherited bleeding disorders. We demonstrate here, both the efficacy and acceptability of a new intranasal DDAVP preparation, providing a cost effective treatment with good outcomes for children with bleed disorders.

Bruising and bleeding are commonly seen in children and are usually associated with minor injury and trauma. However, in two groups of children the bruising may be more significant than expected: those with an underlying haemostatic abnormality, such as an inherited bleeding disorder, or those who have been subjected to non-accidental injury (NAI). Diagnosing inherited bleeding disorders in children is fraught with difficulty, from venous access to interpretation of results; the possibility of NAI should be borne in mind, even in those children with proven significant bleeding disorders when the severity of the injury and the history are non-compatible. We describe the investigation of the haemostatic system in children with bruising and/or bleeding with emphasis on the key haemostatic disorders that need to be excluded.

Inherited deficiencies of platelet surface glycoproteins such as Glanzmann's thrombasthenia (GT) or Bernard-Soulier syndrome (BSS) can lead to a severe bleeding diathesis. In the past, bleeding episodes in these patients have often required platelet transfusion to secure haemostasis but recently a number of patient reports have suggested that recombinant factor VIIa (rVIIa) may also be effective. We have used rVIIa on 33 occasions in seven children with inherited platelet function disorders over a 2-year period: five had GT, one had BSS and one had storage pool disease with a severe phenotype. Bleeding ceased with rVIIa alone in 10 of 28 acute bleeding episodes, but recurred in two of these. The two features that predicted response to rVIIa were the severity of the bleeding and the delay from the onset of bleeding to treatment. Five episodes of planned surgical intervention were treated successfully with rVIIa. Eighteen out of the 28 acute episodes and none of the planned surgical episodes required blood product support. We have found variable efficacy of rVIIa for acute bleeding episodes in this small series of children with inherited platelet function defects but larger studies are warranted, particularly as rVIIa is a relatively low-risk treatment approach for these disorders.

The management of acute and surgical bleeding episodes in children with severe factor VIII or IX deficiency who develop high responding inhibitors presents a major therapeutic challenge to clinicians. Recombinant factor VIIa (rVIIa) is an effective, reliable and safe treatment that can be used to treat acute bleeding episodes prior to commencing an immune tolerance programme and to cover surgical procedures until the immune tolerance programme is successful. In a significant minority of patients, immune tolerance therapy is ineffective and an alternative haemostatic agent such as rVIIa is required for life-long treatment. The present study evaluated the use of rVIIa in a paediatric setting. Twelve children, aged 1-16 years, were treated successfully with rVIIa to prevent surgical bleeding in 20 surgical procedures (19 central venous access device insertion or removal, 1 dental extraction). Minor postoperative haematomata developed in 2 out of 20 cases after regular rVIIa therapy had been discontinued and resolved with a short course of rVIIa in both cases. Three children had six life- or limb-threatening bleeding episodes. All bleeding episodes resolved with regular rVIIa treatment although topical fibrin glue was needed in one child with a frenulum tear. One patient required two red cell transfusions for symptomatic anaemia resulting from two separate bleeding episodes. The rVIIa therapy was well tolerated and there was no evidence of treatment-related complications. We conclude that rVIIa is the treatment of choice for the management of surgery and acute life- or limb-threatening bleeding in children with haemophilia and high responding inhibitors.

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. [ABSTRACT FROM AUTHOR]

Children with von Willebrand disease ( VWD) in whom DDAVP is ineffective or contraindicated require treatment with a coagulation factor concentrate containing von Willebrand factor ( VWF) and factor VIII ( FVIII). The aim of this study was to monitor the safety, efficacy and tolerability of Wilate® (a VWF: FVIII concentrate with a 1:1 ratio) used across the North London Paediatric Haemophilia Network since May 2010. In total, 47 children (aged 0.0-17.0 years) with type 1 ( n = 28), type 2 ( n = 7), type 3 ( n = 10) and acquired VWS ( n = 2) have been treated for bleeds, surgery and/or prophylaxis using 260 000 IU Wilate®. Analysis of dose and frequency of treatment show expected responses to treatment with mean doses of 55, 50 and 50 IU kg−1 for bleeds, surgery and prophylaxis respectively. Most bleeds responded to a single treatment. Surgical procedures were covered with clinician approved dosing schedules with 95% (39/41) reported as having excellent or good efficacy. There was no accumulation of FVIII or VWF and no thromboembolic events. This case series confirms the efficacy, safety and tolerability of Wilate® in neonates, children and adolescents when used on-demand, prophylactically and in the surgical setting. [ABSTRACT FROM AUTHOR]

The development of inhibitors and the need for frequent venous access for FVIII injection are major challenges in current haemophilia treatment. Presently available recombinant FVIII (rFVIII) products produced in hamster cell lines are associated with inhibitor formation in up to 32% of previously untreated patients. The new human cell line-derived recombinant human FVIII (Human-cl rhFVIII) protein is the first native, unmodified truly human rFVIII product produced in a human cell line without additive animal proteins. The aim of using a human cell line for the production of rFVIII is the avoidance of non-human epitopes on rFVIII, thereby potentially reducing the rate of inhibitor development, avoiding allergic reactions and allowing personalized prophylaxis with the chance of fewer infusions. Studies to date show that prophylaxis with Human-cl rhFVIII prevents 96% of bleeding events in adults with severe haemophilia A when compared to on-demand treatment. Available pharmacokinetic data with a mean half-life of 17.1 h allow personalized prophylaxis with the chance of fewer infusions. Studies in previously treated children and adults indicate that Human-cl rhFVIII is efficacious and safe in the prevention and treatment of bleeding episodes and that none of the treated patients developed inhibitors or allergic reactions thus far. [ABSTRACT FROM AUTHOR]

Intracranial haemorrhages (ICH) in children with haemophilia are rare, and the outcome is variable, ranging from no apparent impairment to death. The aim of this investigation was to identify if children with haemophilia and ICH, have any long-term problems with motor function, visual motor integration or strengths and difficulties compared with a control group. A review of the Haemophilia Database at Great Ormond Street Hospital for Children NHS Trust was undertaken to identify boys with haemophilia and a history of ICH, as well as a control group of peers with no such history. Boys were born between January 1994 and December 2002. All boys were assessed using the movement Assessment Battery for Children, the Developmental Test of Visual Motor Integration and The Strengths and Difficulties Questionnaire as standardized assessments of motor competence, visual motor integration and behavioural difficulties. Six boys with haemophilia and ICH and 11 controls (mean age: 7 years; range: 4–12 years) were assessed. Children with ICH were significantly more likely to have problems with motor function and visual motor integration (Fisher’s exact: P < 0.05). In addition, they had a tendency towards more problems with strengths and difficulties than their peer group (Fisher’s exact: P = 0.06). Five of the six boys who had sustained an ICH were in mainstream schools; four requiring assistance with their education. The results of this small study suggest that ICH may signify long-term consequences for boys with haemophilia. The multidisciplinary team need to be aware of the rare but potentially important impact on motor function, visual motor integration and behaviour, which may inhibit the child from functioning optimally. An agreed comprehensive battery of assessments in collaboration with schools and healthcare workers is required to identify impairments to enable prompt interventions to be co-ordinated. [ABSTRACT FROM AUTHOR]

Desmopressin (1-deamino-8-D-arginine vasopressin (DDAVP)) has been shown to be an effective treatment option when administered both intravenously [ 1,2 ] and subcutaneously [ 3 ] to children with inherited bleeding disorders. We demostrate here, both the efficacy and acceptability of a new intranasal DDAVP preparation, providing a cost effective treatment with good outcomes for children with bleed disorders. [ABSTRACT FROM AUTHOR]

Abstract: Children may be born with an inherited coagulation disorder or can develop an acquired coagulopathy as a consequence of another disease or disorder. The correct diagnosis in either case is essential to appropriate management, to reduce the morbidity and mortality associated with inaccurate diagnosis or the incorrect treatment. The treatment of these disorders is often very expensive and there may be risks to the child associated with the administration of products used to treat coagulation disorders; these must be minimized when possible. For these reasons, the child may require referral to a tertiary specialist centre for further investigations and management. In children presenting with bruising or more severe bleeding manifestations, it is not uncommon for the first presumed diagnosis to be non-accidental injury, and it is essential that a true coagulation defect is excluded in these children. [Copyright &y& Elsevier]

Abstract: The normal haemostatic process relies on the presence of normal vascular endothelium, a normal number of functioning platelets and appropriate levels of the coagulation proteins involved in both the propagation and the limitation of clot formation. Our ability to detect abnormalities in the haemostatic process relies initially on taking a thorough bleeding history and on coagulation screening tests. It is vital to understand the limitations of these screening tests and when it is appropriate to perform further investigations and when to seek advice from a haematologist. This review outlines the haemostatic process, and discusses the relevance of abnormal coagulation screen results, the indications for diagnostic coagulation tests,and the pitfalls of bleeding disorders that are not reflected by coagulation screens. [Copyright &y& Elsevier]

Hermansky-Pudlak syndrome (HPS) is a rare disorder characterised by oculocutaneous albinism, a bleeding tendency, and lipofuscinosis. This retrospective study reviews the clinical history and haematological features of 23 cases of HPS. Information was gathered from patient notes and by direct interview. Thirteen of the 23 children were of Turkish origin, 12 being members of four kindreds from the Turkish/Kurdish border. Four children originated from Pakistan. Haemorrhage was uncommon; two experienced significant bleeding (intracranial and retinal haemorrhage in one and menorrhagia in another), and twelve minor symptoms. Results of laboratory evaluation of platelet function were not predictive of bleeding; in particular the PFA-100 analyser was not sensitive to the HPS defect. The most sensitive test of platelet fuction was quantitation of platelet nucleotides. The occurrence of Turkish and Pakistani kindreds with HPS is novel and follow up for long term complications described in Puerto Rican patients as well as genetic analysis is ongoing. [ABSTRACT FROM AUTHOR]

Presents a letter to the editor about management of neonates with inherited bleeding disorders.

The article presents the case of a 7-week-old infant who was born at term with Hermansky-Pudlak syndrome presenting with subdural hematoma and retinal hemorrhages in Great Britain. The baby was seen with bleeding from one nostril, a bulging anterior fontanelle and drowsiness. A computed tomographic scan showed an acute left occipital subdural hematoma. It was explained that the syndrome is a mild disorder that usually occur for babies who are two and twelve weeks old.