Prevention of recurrent thrombotic events in children with central venous catheter-associated venous thrombosis.

Central venous catheters (CVC) are the most significant risk factor for pediatric venous thromboembolism (VTE). After an index CVC-associated VTE (CVC-VTE), the role of secondary prophylaxis for subsequent CVC placement is uncertain. Aims of this single-center retrospective study were to evaluate the efficacy of secondary prophylaxis for patients with a prior CVC-VTE and identify risk factors associated with recurrent VTE in patients less than 19 years with an index CVC-VTE between 2003 and 2013. Data collection included clinical and demographic factors, subsequent CVC placement, secondary prophylaxis strategy, recurrent VTE, and bleeding. Risk factors for recurrence and effectiveness of secondary prophylaxis were evaluated using survival and binomial models. Among 373 patients with an index CVC-VTE, 239 (64.1%) had subsequent CVC placement; 17.4% (65/373) of patients had recurrent VTE, of which 90.8% (59/65) were CVC-associated. On multivariable survival analysis, each additional CVC (hazards ratio [HR] 12.00; 95% confidence interval [CI] 2.78-51.91), congenital heart disease (HR 3.70; 95% CI 1.97-6.95), and total parenteral nutrition dependence (HR 4.02; 95% CI 2.23-7.28) were associated with an increased hazard of recurrence. Full dose anticoagulation for secondary prophylaxis was associated with decreased odds of recurrent CVC-VTE (odds ratio [OR] 0.35; 95% CI 0.19-0.65) but not prophylactic dosing (OR 0.61; 95% CI 0.28-1.30). Only 1.3% of CVCs experienced major bleeding with prophylactic or full-dose anticoagulation. In summary, children with CVC-VTE are at increased risk for recurrent VTE. Secondary prophylaxis with full-dose anticoagulation was associated with a 65% reduction in odds of thrombotic events.

Recommendations on Monitoring and Replacement of Antithrombin, Fibrinogen, and Von Willebrand Factor in Pediatric Patients on Extracorporeal Membrane Oxygenation: The Pediatric Extracorporeal Membrane Oxygenation Anticoagulation CollaborativE Consensus Conference.

OBJECTIVES: To derive systematic review informed, modified Delphi consensus regarding monitoring and replacement of specific coagulation factors during pediatric extracorporeal membrane oxygenation (ECMO) support for the Pediatric ECMO Anticoagulation CollaborativE. DATA SOURCES: A structured literature search was performed using PubMed, Embase, and Cochrane Library (CENTRAL) databases from January 1988 to May 2020, with an update in May 2021. STUDY SELECTION: Included studies assessed monitoring and replacement of antithrombin, fibrinogen, and von Willebrand factor in pediatric ECMO support. DATA EXTRACTION: Two authors reviewed all citations independently, with conflicts resolved by a third reviewer if required. Twenty-nine references were used for data extraction and informed recommendations. Evidence tables were constructed using a standardized data extraction form. DATA SYNTHESIS: Risk of bias was assessed using the Quality in Prognosis Studies tool. The evidence was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation system. A panel of 48 experts met over 2 years to develop evidence-based recommendations and, when evidence was lacking, expert-based consensus statements. A web-based modified Delphi process was used to build consensus via the Research And Development/University of California Appropriateness Method. Consensus was defined as greater than 80% agreement. We developed one weak recommendation and four expert consensus statements. CONCLUSIONS: There is insufficient evidence to formulate recommendations on monitoring and replacement of antithrombin, fibrinogen, and von Willebrand factor in pediatric patients on ECMO. Optimal monitoring and parameters for replacement of key hemostasis parameters is largely unknown.

Executive Summary: The Pediatric Extracorporeal Membrane Oxygenation Anticoagulation CollaborativE (PEACE) Consensus Conference.

OBJECTIVES: To present recommendations and consensus statements with supporting literature for the clinical management of neonates and children supported with extracorporeal membrane oxygenation (ECMO) from the Pediatric ECMO Anticoagulation CollaborativE (PEACE) consensus conference. DATA SOURCES: Systematic review was performed using PubMed, Embase, and Cochrane Library (CENTRAL) databases from January 1988 to May 2021, followed by serial meetings of international, interprofessional experts in the management ECMO for critically ill children. STUDY SELECTION: The management of ECMO anticoagulation for critically ill children. DATA EXTRACTION: Within each of eight subgroup, two authors reviewed all citations independently, with a third independent reviewer resolving any conflicts. DATA SYNTHESIS: A systematic review was conducted using MEDLINE, Embase, and Cochrane Library databases, from January 1988 to May 2021. Each panel developed evidence-based and, when evidence was insufficient, expert-based statements for the clinical management of anticoagulation for children supported with ECMO. These statements were reviewed and ratified by 48 PEACE experts. Consensus was obtained using the Research and Development/UCLA Appropriateness Method. Results were summarized using the Grading of Recommendations Assessment, Development, and Evaluation method. We developed 23 recommendations, 52 expert consensus statements, and 16 good practice statements covering the management of ECMO anticoagulation in three broad categories: general care and monitoring; perioperative care; and nonprocedural bleeding or thrombosis. Gaps in knowledge and research priorities were identified, along with three research focused good practice statements. CONCLUSIONS: The 91 statements focused on clinical care will form the basis for standardization and future clinical trials.

Rate of thrombosis in children and adolescents hospitalized with COVID-19 or MIS-C.

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is associated with thrombotic complications in adults, but the incidence of COVID-19-related thrombosis in children and adolescents is unclear. Most children with acute COVID-19 have mild disease, but coagulopathy has been associated with multisystem inflammatory syndrome in children (MIS-C), a postinfectious complication. We conducted a multicenter retrospective cohort study to determine the incidence of thrombosis in children hospitalized with COVID-19 or MIS-C and evaluate associated risk factors. We classified patients into 1 of 3 groups for analysis: COVID-19, MIS-C, or asymptomatic SARS-CoV-2. Among a total of 853 admissions (COVID-19, n = 426; MIS-C, n = 138; and asymptomatic SARS-CoV-2, n = 289) in 814 patients, there were 20 patients with thrombotic events (TEs; including 1 stroke). Patients with MIS-C had the highest incidence (9 [6.5%] of 138) vs COVID-19 (9 [2.1%] of 426) or asymptomatic SARS-CoV-2 (2 [0.7%] of 289). In patients with COVID-19 or MIS-C, a majority of TEs (89%) occurred in patients age ≥12 years. Patients age ≥12 years with MIS-C had the highest rate of thrombosis at 19% (9 of 48). Notably, 71% of TEs that were not present on admission occurred despite thromboprophylaxis. Multivariable analysis identified the following as significantly associated with thrombosis: age ≥12 years, cancer, presence of a central venous catheter, and MIS-C. In patients with COVID-19 or MIS-C, hospital mortality was 2.3% (13 of 564), but it was 28% (5 of 18) in patients with TEs. Our findings may help inform pediatric thromboprophylaxis strategies.

Treatment of venous thromboembolism in pediatric patients.

Venous thromboembolism (VTE) is rare in healthy children, but is an increasing problem in children with underlying medical conditions. Pediatric VTE encompasses a highly heterogenous population, with variation in age, thrombosis location, and underlying medical comorbidities. Evidence from pediatric clinical trials to guide treatment of VTE is lacking so treatment is often extrapolated from adult trials and expert consensus opinion. Aspects unique to children include developmental hemostasis and the major role of central venous access devices. There is an absence of information regarding the optimal target levels of anticoagulation for neonates and infants and lack of suitable drug formulations. Anticoagulants, primarily low-molecular-weight heparin and warfarin, are used to treat children with symptomatic VTE. These drugs have significant limitations, including the need for subcutaneous injections and frequent monitoring. Randomized clinical trials of direct oral anticoagulants in pediatric VTE are ongoing, with results anticipated soon. These trials will provide new evidence and options for therapy that have the potential to improve care. International collaborative registries offer the ability to study outcomes of rare subgroups of pediatric VTE (eg, renal vein thrombosis), and will be important to ultimately guide therapy in a more disease-specific manner.

A novel MBTPS2 variant associated with BRESHECK syndrome impairs sterol-regulated transcription and the endoplasmic reticulum stress response.

Ichthyosis follicularis, atrichia, and photophobia syndrome (IFAP syndrome) is a rare, X-linked disorder caused by pathogenic variants in membrane-bound transcription factor protease, site 2 (MBTPS2). Pathogenic MBTPS2 variants also cause BRESHECK syndrome, characterized by the IFAP triad plus intellectual disability and multiple congenital anomalies. Here we present a patient with ichthyosis, sparse hair, pulmonic stenosis, kidney dysplasia, hypospadias, growth failure, thrombocytopenia, anemia, bone marrow fibrosis, and chronic diarrhea found by research-based exome sequencing to harbor a novel, maternally inherited MBTPS2 missense variant (c.766 G>A; (p.Val256Leu)). In vitro modeling supports variant pathogenicity, with impaired cell growth in cholesterol-depleted media, attenuated activation of the sterol regulatory element-binding protein pathway, and failure to activate the endoplasmic reticulum stress response pathway. Our case expands both the genetic and phenotypic spectrum of BRESHECK syndrome to include a novel MBTPS2 variant and cytopenias, bone marrow fibrosis, and chronic diarrhea.

Thrombotic events in critically ill children with coronavirus disease 2019 or multisystem inflammatory syndrome in children.

PURPOSE OF REVIEW: To provide an update regarding what is known about thrombotic events and thromboprophylaxis in critically ill children with SARS-CoV-2 infection. RECENT FINDINGS: Pediatric patients with SARS-CoV-2 generally have mild illness; however, intensive care is required in about 20-30% of hospitalized children with COVID-19 and an even higher proportion in those with MIS-C. Increased rates of thrombosis have been observed in adults hospitalized with COVID-19, and clinical trials have attempted to optimize thromboprophylaxis. There is significant variability in the estimated incidence of thrombosis in pediatric patients (0-27%) because of variation in patient populations and study design. Multiple studies demonstrate an increased rate of thrombosis compared with baseline in hospitalized pediatric patients. Few studies have evaluated risk factors for thrombosis, but critical illness, older age, and other known thrombosis risk factors appear to increase the risk. Thromboprophylaxis strategies are inconsistent, with little evidence of efficacy but few reports of major bleeding. SUMMARY: Critically ill children with SARS-CoV-2-related illnesses are at increased risk of thrombosis. Thromboprophylaxis should be considered in select patients with COVID-19 or MIS-C, though the optimal strategy is not yet known. More data is required to guide practice to prevent thrombosis in this population.

Thromboembolic prevention and anticoagulant therapy during the COVID-19 pandemic: updated clinical guidance from the anticoagulation forum.

Thromboembolism is a common and deadly consequence of COVID-19 infection for hospitalized patients. Based on clinical evidence pre-dating the COVID-19 pandemic and early observational reports, expert consensus and guidance documents have strongly encouraged the use of prophylactic anticoagulation for patients hospitalized for COVID-19 infection. More recently, multiple clinical trials and larger observational studies have provided evidence for tailoring the approach to thromboprophylaxis for patients with COVID-19. This document provides updated guidance for the use of anticoagulant therapies in patients with COVID-19 from the Anticoagulation Forum, the leading North American organization of anticoagulation providers. We discuss ambulatory, in-hospital, and post-hospital thromboprophylaxis strategies as well as provide guidance for patients with thrombotic conditions who are considering COVID-19 vaccination.

Efficacy of Early Prophylaxis Against Catheter-Associated Thrombosis in Critically Ill Children: A Bayesian Phase 2b Randomized Clinical Trial.

OBJECTIVES: We obtained preliminary evidence on the efficacy of early prophylaxis on the risk of central venous catheter-associated deep venous thrombosis and its effect on thrombin generation in critically ill children. DESIGN: Bayesian phase 2b randomized clinical trial. SETTING: Seven PICUs. PATIENTS: Children less than 18 years old with a newly inserted central venous catheter and at low risk of bleeding. INTERVENTION: Enoxaparin adjusted to anti-Xa level of 0.2-0.5 international units/mL started at less than 24 hours after insertion of central venous catheter (enoxaparin arm) versus usual care without placebo (usual care arm). MEASUREMENTS AND MAIN RESULTS: At the interim analysis, the proportion of central venous catheter-associated deep venous thrombosis on ultrasonography in the usual care arm, which was 54.2% of 24 children, was significantly higher than that previously reported. This resulted in misspecification of the preapproved Bayesian analysis, reversal of direction of treatment effect, and early termination of the randomized clinical trial. Nevertheless, with 30.4% of 23 children with central venous catheter-associated deep venous thrombosis on ultrasonography in the enoxaparin arm, risk ratio of central venous catheter-associated deep venous thrombosis was 0.55 (95% credible interval, 0.24-1.11). Including children without ultrasonography, clinically relevant central venous catheter-associated deep venous thrombosis developed in one of 27 children (3.7%) in the enoxaparin arm and seven of 24 (29.2%) in the usual care arm (p = 0.02). Clinically relevant bleeding developed in one child randomized to the enoxaparin arm. Response profile of endogenous thrombin potential, a measure of thrombin generation, was not statistically different between trial arms. CONCLUSIONS: These findings suggest the efficacy and safety of early prophylaxis that should be validated in a pivotal randomized clinical trial.

Age-Dependent Heterogeneity in the Efficacy of Prophylaxis With Enoxaparin Against Catheter-Associated Thrombosis in Critically Ill Children: A Post Hoc Analysis of a Bayesian Phase 2b Randomized Clinical Trial.

OBJECTIVES: We explored the age-dependent heterogeneity in the efficacy of prophylaxis with enoxaparin against central venous catheter-associated deep venous thrombosis in critically ill children. DESIGN: Post hoc analysis of a Bayesian phase 2b randomized clinical trial. SETTING: Seven PICUs. PATIENTS: Children less than 18 years old with newly inserted central venous catheter. INTERVENTIONS: Enoxaparin started less than 24 hours after insertion of central venous catheter and adjusted to anti-Xa level of 0.2-0.5 international units/mL versus usual care. MEASUREMENTS AND MAIN RESULTS: Of 51 children randomized, 24 were infants less than 1 year old. Risk ratios of central venous catheter-associated deep venous thrombosis with prophylaxis with enoxaparin were 0.98 (95% credible interval, 0.37-2.44) in infants and 0.24 (95% credible interval, 0.04-0.82) in older children greater than or equal to 1 year old. Infants and older children achieved anti-Xa level greater than or equal to 0.2 international units/mL at comparable times. While central venous catheter was in situ, endogenous thrombin potential, a measure of thrombin generation, was 223.21 nM.min (95% CI, 8.78-437.64 nM.min) lower in infants. Factor VIII activity, a driver of thrombin generation, was also lower in infants by 45.1% (95% CI, 15.7-74.4%). Median minimum platelet count while central venous catheter was in situ was higher in infants by 39 × 103/mm3 (interquartile range, 17-61 × 103/mm3). Central venous catheter:vein ratio was not statistically different. Prophylaxis with enoxaparin was less efficacious against central venous catheter-associated deep venous thrombosis at lower factor VIII activity and at higher platelet count. CONCLUSIONS: The relatively lesser contribution of thrombin generation on central venous catheter-associated thrombus formation in critically ill infants potentially explains the age-dependent heterogeneity in the efficacy of prophylaxis with enoxaparin.

Real-world cost estimates of initiating emicizumab in US patients with haemophilia A.

INTRODUCTION: Emicizumab is the first approved non-factor therapy for haemophilia A. It provides superior prophylactic bleeding control compared to other products in both patients with and patients without inhibitors. However, there is no real-world data about the monetary consequences of starting emicizumab. AIM: To examine the estimated costs of starting emicizumab in a cohort of real-world haemophilia A patients with and without inhibitors. METHODS: The cost of haemostatic therapy for 6 months before and after initiating emicizumab for participants in a multicentre observational study was calculated based on the type of product and dosing that was used for prophylaxis and treating breakthrough bleeds, the number of treated bleeds and the participant weight. RESULTS: Ninety-two patients were included, 18 with an active inhibitor. The median age was 8.7 years. The median total cost for all patients decreased from $176,720 to $128,099 (p = .04) after initiating emicizumab, largely because of decrease in the total cost of high-cost outliers. The cost of prophylaxis and the total cost of bleeds also significantly decreased after starting emicizumab, both for patient with and patients without inhibitors. CONCLUSIONS: Starting or switching to prophylaxis with emicizumab results in decreased costs for the treatment of patients with haemophilia A. This real-world data could inform on payer decisions as well as future cost-effective analysis.

Venous Thromboembolism in Pediatric Inflammatory Bowel Disease: A Case-Control Study.

OBJECTIVES: Inflammatory bowel disease (IBD) is associated with increased risk of venous thromboembolism (VTE). Despite this recognized risk, there are limited data and no anticoagulation guidelines for hospitalized pediatric IBD patients. The objectives of this study were to characterize pediatric IBD patients with VTE and determine risk factors. METHODS: This was a nested case-control study comparing hospitalized children with IBD diagnosed with VTE to those without VTE over a decade at a large referral center. Standard descriptive statistics were used to describe the VTE group. Multivariable conditional logistic regression was used to assess risk factors. RESULTS: Twenty-three cases were identified. Central venous catheter (CVC) presence (odds ratio [OR] 77.9; 95% confidence interval [CI]: 6.9--880.6; P < 0.001) and steroid use (OR 12.7; 95% CI: 1.3--126.4; P = 0.012) were independent risk factors. Median age at VTE was 17 years (interquartile range [IQR] 13.5--18.2), and in 48%, VTE was the indication for admission. Median duration of anticoagulation was 3.8 months (IQR 2.3--7.6), and there were no major bleeding events for patients on anticoagulation. There were no patients with known sequelae from VTE, though 22% had severe VTE that required interventions. CONCLUSIONS: Pediatric patients with IBD are at risk for VTE, although the absolute risk remains relatively low. The safety and efficacy of pharmacologic thromboprophylaxis needs to be further evaluated in this population with attention to risk factors, such as steroid use and presence of CVC.

Long-Term Follow-Up of the First in Human Intravascular Delivery of AAV for Gene Transfer: AAV2-hFIX16 for Severe Hemophilia B.

Adeno-associated virus (AAV) vectors are a leading platform for gene-based therapies for both monogenic and complex acquired disorders. The success of AAV gene transfer highlights the need to answer outstanding clinical questions of safety, durability, and the nature of the human immune response to AAV vectors. Here, we present longitudinal follow-up data of subjects who participated in the first trial of a systemically delivered AAV vector. Adult males (n = 7) with severe hemophilia B received an AAV2 vector at doses ranging from 8 × 1010 to 2 × 1012 vg/kg to target hepatocyte-specific expression of coagulation factor IX; a subset (n = 4) was followed for 12-15 years post-vector administration. No major safety concerns were observed. There was no evidence of sustained hepatic toxicity or development of hepatocellular carcinoma as assessed by liver transaminase values, serum α-fetoprotein, and liver ultrasound. Subjects demonstrated persistent, increased AAV neutralizing antibodies (NAbs) to the infused AAV serotype 2 (AAV2) as well as all other AAV serotypes tested (AAV5 and AAV8) for the duration of follow-up. These data represent the longest available longitudinal follow-up data of subjects who received intravascular AAV and support the preliminary safety of intravascular AAV administration at the doses tested in adults. Data demonstrate, for the first time, the persistence of high-titer, multi-serotype cross-reactive AAV NAbs for up to 15 years post- AAV vector administration. Our observations are broadly applicable to the development of AAV-mediated gene therapy.

Real-world use of emicizumab in patients with haemophilia A: Bleeding outcomes and surgical procedures.

INTRODUCTION: Emicizumab is a recombinant humanized bispecific antibody that bridges factor IXa and factor X to mimic the cofactor function of factor VIII. It is approved to prevent bleeding in patients with haemophilia A (HA). Outside of clinical trials, there is limited data on outcomes of patients treated with emicizumab, particularly in children without inhibitors. AIM: To report our experience treating patients with emicizumab, including (a) bleeding rates pre and postemicizumab, (b) peri-procedural management and outcomes and (c) serious drug-related adverse events. METHODS: Multicentre observational study in patients with HA who started emicizumab prior to 15 May 2019. Data collection continued until 15 October 2019 and included demographics, disease history, bleeding events, invasive procedures, thrombotic events and death. Annualized bleeding rates (ABR) prior to emicizumab were compared to postemicizumab. RESULTS: Ninety-three patients (including three females) met inclusion criteria, 19 with an active inhibitor. Median age was 8.6 years; patients <12 years without inhibitors (n = 49) accounted for the majority. ABR dropped from 4.4 (inhibitors) and 1.6 (non-inhibitors) to 0.4 (both groups) on emicizumab, P = .0012 and .0025, respectively. There were 28 minor (21 port removals) and two major procedures. Three patients received 1-2 doses of unplanned factor postoperatively to treat minor bleeding events. No patient discontinued therapy, and there were no thrombotic events or deaths. DISCUSSION: Our favourable clinical experience with emicizumab is similar to that reported in the clinical trials. Notably, this is the largest cohort of patients <12 years without inhibitors treated with emicizumab.

Implantable venous access devices in children with severe hemophilia: a tertiary pediatric institutional experience.

BACKGROUND: Clotting factor replacement forms the pillar of treatment for children with hemophilia. Most children can be treated using peripheral venipuncture, but very young children and children with poor venous access might require a central venous catheter. Short-term and long-term complications of implantable venous access device placement (also known as port placement) can result in important morbidity and mortality in children with hemophilia. OBJECTIVE: The purpose of this study is to describe our experience with port placement in children and adolescents with severe hemophilia (<1% of the Factors VIII or IX). MATERIALS AND METHODS: We performed a retrospective review over a 10-year period to identify port placement in pediatric patients with severe hemophilia. We reviewed demographic and procedural information, access frequency, mechanical complications, and central-line-associated bloodstream infections (CLABSI). Eighteen males were included, with median age at insertion of 3.9 years (0.7-22.7 years). Fifteen of the 18 patients had hemophilia Type A and 3/18 had Type B. Thirteen had high neutralizing inhibitor titers. RESULTS: Technical success in port placement was achieved in 26/27 (96.3%) patients, with 1 port failure caused by venous occlusion from prior catheter placement. Port catheter size ranged from 5 French (Fr) to 7.5 Fr. All were single-lumen and placed via right (76.9%) or left (23.1%) internal jugular vein; 59.3% were placed during general anesthesia, and all had factor replacement prophylaxis. A peripherally inserted central catheter (PICC) was placed concurrently in 69.2% of the cases; per hospital policy, the port was only accessed 15 days post-placement to reduce the risk of site hematoma. Two patients were lost to follow-up. The total catheter days was 15,893. Ports were removed in 14/24 cases, most commonly because of CLABSI (7/24; 29.2%) and transition to peripheral infusion (3/24; 12.5%). Bleeding was the most common complication in the first 30 days after placement. There were nine CLABSI events (0.57 per 1,000 catheter days), all in patients with high neutralizing inhibitor titers. A higher frequency of port access (more or equal to daily vs. less than daily) correlated with higher infection rates (P=0.02). Median time from port insertion to first infection was 348 days (range 167-1,055 days). There were four fibrin-sheath-related catheter occlusions (0.25 per 1,000 catheter days): three catheters were salvaged with intra-catheter tissue plasminogen activator (tPA) instillation resulting in a salvage of an additional 1,214 catheter days, and one catheter was removed after tPA failure (0.06 per 1,000 catheter days). CONCLUSION: Port maintenance in boys with severe hemophilia is challenging given the need for long-term frequent device access that is associated with catheter-related infections. The rate of bleeding or infection did not differ in patients whether the device was accessed immediately or 15 days post placement. With appropriate pre- and post-procedural factor replacement, immediate and early term severe complications are not common.

Regional variation and cost implications of prescribed extended half-life factor concentrates among U.S. Haemophilia Treatment Centres for patients with moderate and severe haemophilia.

BACKGROUND: Extended half-life (EHL) factor VIII (FVIII) and IX (FIX) products are intended to decrease the burden of prophylaxis for patients with haemophilia A or B. Whether these newer concentrates have led to meaningful clinical practice change remains vague. AIM: To characterize the longitudinal use of standard (SHL) and EHL factor concentrates at haemophilia treatment centres (HTCs), using the ATHNdataset, a US database of 138 ATHN-affiliated HTCs. METHODS: Factor concentrate use among moderate and severe haemophilia A and B patients without inhibitors was analysed at three time points over 18 months. RESULTS: Use of EHL concentrates rose from 10% of patients to 22% during this study. EHL FVIII prophylaxis is prescribed to the minority of patients, 28%; EHL FIX now predominates for prophylaxis, 52%. Rates of prescribed EHL products varied significantly by age group and HTC region. Median prescribed prophylaxis for SHL compared to EHL products was FVIII 6240 and 5200 and FIX 6968 and FIX 3900 IU/kg/y, respectively. On-demand EHL use has grown but has minimal contribution to overall usage (2%). CONCLUSION: Haemophilia treatment centre region and patient age impact the rate of adoption of EHL products; however, EHL prescribing continues to rise nationally, particularly for EHL FIX. Careful attention to annual cost of prophylaxis is imperative as the decrease in median EHL prophylaxis consumption is not offset by the higher unit cost of these products. It is unclear how further growth in use of EHLs will be impacted by emerging non-factor replacement and gene therapies.

Efficacy and safety of voretigene neparvovec (AAV2-hRPE65v2) in patients with RPE65-mediated inherited retinal dystrophy: a randomised, controlled, open-label, phase 3 trial.

BACKGROUND: Phase 1 studies have shown potential benefit of gene replacement in RPE65-mediated inherited retinal dystrophy. This phase 3 study assessed the efficacy and safety of voretigene neparvovec in participants whose inherited retinal dystrophy would otherwise progress to complete blindness. METHODS: In this open-label, randomised, controlled phase 3 trial done at two sites in the USA, individuals aged 3 years or older with, in each eye, best corrected visual acuity of 20/60 or worse, or visual field less than 20 degrees in any meridian, or both, with confirmed genetic diagnosis of biallelic RPE65 mutations, sufficient viable retina, and ability to perform standardised multi-luminance mobility testing (MLMT) within the luminance range evaluated, were eligible. Participants were randomly assigned (2:1) to intervention or control using a permuted block design, stratified by age (<10 years and ≥10 years) and baseline mobility testing passing level (pass at ≥125 lux vs <125 lux). Graders assessing primary outcome were masked to treatment group. Intervention was bilateral, subretinal injection of 1·5 × 1011 vector genomes of voretigene neparvovec in 0·3 mL total volume. The primary efficacy endpoint was 1-year change in MLMT performance, measuring functional vision at specified light levels. The intention-to-treat (ITT) and modified ITT populations were included in primary and safety analyses. This trial is registered with ClinicalTrials.gov, number NCT00999609, and enrolment is complete. FINDINGS: Between Nov 15, 2012, and Nov 21, 2013, 31 individuals were enrolled and randomly assigned to intervention (n=21) or control (n=10). One participant from each group withdrew after consent, before intervention, leaving an mITT population of 20 intervention and nine control participants. At 1 year, mean bilateral MLMT change score was 1·8 (SD 1·1) light levels in the intervention group versus 0·2 (1·0) in the control group (difference of 1·6, 95% CI 0·72-2·41, p=0·0013). 13 (65%) of 20 intervention participants, but no control participants, passed MLMT at the lowest luminance level tested (1 lux), demonstrating maximum possible improvement. No product-related serious adverse events or deleterious immune responses occurred. Two intervention participants, one with a pre-existing complex seizure disorder and another who experienced oral surgery complications, had serious adverse events unrelated to study participation. Most ocular events were mild in severity. INTERPRETATION: Voretigene neparvovec gene replacement improved functional vision in RPE65-mediated inherited retinal dystrophy previously medically untreatable. FUNDING: Spark Therapeutics.

A survey of pediatric hematology/oncology specialists regarding management of central line associated venous thrombosis.

Central venous catheters (CVCs) account for the largest proportion of thrombotic events in pediatric patients. Questions remain regarding adequate treatment and prevention methods. We surveyed pediatric hematology/oncology specialists, using hypothetical cases to assess management strategies for acute CVC thrombosis and secondary prevention. Survey respondents varied in the use of the thrombophilia evaluation (33.3%, 41/123) and duration of treatment (6 weeks: 54.1%, 66/122). Secondary CVC prophylaxis was utilized by 36.6% (45/123) of respondents and by 24.4% (30/123) but only if there was a documented thrombophilia. This heterogeneity highlights the need for clinical studies to address these important clinical questions.