Three-year outcomes of valoctocogene roxaparvovec gene therapy for hemophilia A.

BACKGROUND: Valoctocogene roxaparvovec transfers a human factor (F)VIII coding sequence into hepatocytes of people with severe hemophilia A to provide bleeding protection. OBJECTIVES: To present 3-year efficacy and safety in the multicenter, open-label, single-arm, phase 3 GENEr8-1 trial. METHODS: GENEr8-1 enrolled 134 adult males with severe hemophilia A who were receiving FVIII prophylaxis. Efficacy endpoints included annualized bleeding rate, annualized FVIII utilization, FVIII activity (chromogenic substrate assay; imputed as 1 IU/dL at baseline and 0 IU/dL after discontinuation), and the Haemophilia-Specific Quality of Life Questionnaire for Adults. Safety was assessed by adverse events (AEs). RESULTS: At week 156, 131 of 134 participants remained in the study; overall, 17 of 134 resumed prophylaxis. Mean annualized bleeding rate for treated bleeds decreased from 4.8 (SD, 6.5) bleeds/y at baseline to 0.8 (SD, 2.3; P < .0001) bleeds/y after prophylaxis (prophylaxis cessation to last follow-up) and 0.97 (SD, 3.48) bleeds/y during year 3. Annualized FVIII utilization decreased 96.8% from baseline after prophylaxis and 94.2% during year 3. At week 156, mean and median FVIII activity were 18.4 (SD, 30.8) and 8.3 IU/dL, respectively. FVIII activity decrease was lower between years 2 and 3 than between years 1 and 2. At the end of year 3, clinically meaningful improvements in the Haemophilia-Specific Quality of Life Questionnaire for Adults Total Score were observed (mean change from baseline, 6.6; 95% CI, 4.24-8.87; P < .0001). Mild alanine aminotransferase elevations remained the most common AE during year 3 (23.7% of participants). A serious AE of B-cell acute lymphoblastic leukemia was considered unrelated to treatment. CONCLUSION: Hemostatic efficacy was maintained, and safety remained unchanged from previous years.

Bleeding control improves after switching to emicizumab: Real-world experience of 177 children in the PedNet registry.

INTRODUCTION: Despite the rapid uptake of emicizumab in the paediatric haemophilia A (HA) population, real-world data on the safety and efficacy is limited. AIM: To report on bleeding and safety in paediatric patients receiving emicizumab prophylaxis. METHODS: Data were extracted from the multicentre prospective observational PedNet Registry (NCT02979119). Children with haemophilia A, and ≥50 FVIII exposures or inhibitors present receiving emicizumab maintenance therapy were analysed. Data were summarized as medians with interquartile range (IQR, P25-P75). Mean (95% confidence interval (CI)), annualized (joint) bleeding rate (A(J)BR) during emicizumab and ≤2 years before emicizumab prophylaxis were modelled and compared using negative binomial regression. RESULTS: Total of 177 patients started emicizumab at median 8.6 years (IQR 4.8-13.1), most had no FVIII inhibitors (64%). Follow up before emicizumab was median: 1.68 years (IQR: 1.24-1.90) and during emicizumab: 1.32 years (IQR: .94-2.11). In patients without inhibitors, mean ABR reduced after starting emicizumab from 2.41 (CI 1.98-2.95) to 1.11 (CI .90-1.36, p < .001), while AJBR reduced from.74 (CI .56-.98) to.31 (CI .21-.46, p < .001). Concordantly, in patients with inhibitors, mean ABR reduced from 5.08 (CI 4.08-6.38) to .75 (CI .56-1.01, p < .001), while AJBR reduced from 1.90 (CI 1.42-2.58) to .34 (CI .21-.56, p < .001). Five emicizumab-related adverse events were reported (3% of the cohort), including one patient with antidrug antibodies. CONCLUSION: This study showed improved bleeding control compared to previous treatment and a favourable safety profile during emicizumab therapy in paediatric haemophilia A patients.

Venous Thromboembolism Characteristics and Outcomes Among RIETE Patients Tested & Untested for Inherited Thrombophilia.

Inherited thrombophilia (IT) workup is commonly pursued in venous thromboembolism (VTE) patients. Recent American Society of Hematology (ASH) guidelines recommend a selective approach to IT testing, nevertheless, evidence on whether thrombophilia testing can actually improve patient-important outcomes through tailored management is limited. Data from the large prospective RIETE registry was analyzed to compare VTE risk factors, management and outcomes between patients who were tested for IT and untested patients, during anticoagulant treatment and following its discontinuation. Among 103,818 patients enrolled in RIETE, 21,089 (20.3%) were tested for IT, 8,422 (8.1%) tested positive, and 82,729 (79.7%) were not tested. IT testing was more frequent in patients with VTE provoked by minor risk factors, and less common in those with major risk factors like surgery or active cancer. Choices of anticoagulant treatment did not differ based on IT testing results. Untested patients exhibited inferior outcomes across all VTE categories, with higher rates of VTE recurrence, major bleeding, mortality, and notably, cancer-related mortality. After treatment discontinuation, IT-negative patients with surgically provoked VTE showed lower recurrence rates. For immobilization-related VTE as well as in estrogen-related VTE, no significant differences in recurrence rates were observed between IT-negative and IT-positive patients. However IT-negative patients with pregnancy or postpartum-related VTE, had significantly lower recurrence rates. Patients with unprovoked VTE, particularly those testing positive for IT, had high recurrence rates post-treatment. These findings underscore the complex role of IT testing in managing VTE, supporting personalized treatment strategies that consider VTE risk factors and comorbidities.

Fitusiran prophylaxis in people with hemophilia A or B who switched from prior BPA/CFC prophylaxis (ATLAS-PPX).

Fitusiran, a subcutaneous (SC) investigational siRNA therapeutic, targets antithrombin to rebalance hemostasis in people with hemophilia A or B (PwHA/B), irrespective of inhibitor status. This Phase 3, open-label study (NCT03549871) evaluated the efficacy and safety of fitusiran prophylaxis in males aged ≥ 12 years with hemophilia A or B, with or without inhibitors, who received prior bypassing agent (BPA)/clotting factor concentrate (CFC) prophylaxis. Participants continued their prior BPA/CFC prophylaxis for 6 months before switching to once-monthly 80 mg fitusiran prophylaxis for 7 months (onset and efficacy periods). Primary endpoint was annualized bleeding rate (ABR) in the BPA/CFC prophylaxis and fitusiran efficacy period. Secondary endpoints included spontaneous ABR (AsBR) and joint ABR (AjBR). Safety and tolerability were assessed. Of 80 enrolled participants, 65 (inhibitor/non-inhibitor, n = 19/46) were eligible for ABR analyses. Observed median (IQR) ABRs were 6.5 (2.2, 19.6)/4.4 (2.2, 8.7) with BPA/CFC prophylaxis versus 0.0 (0.0, 0.0)/0.0 (0.0, 2.7) in the corresponding fitusiran efficacy period. Estimated mean ABRs were substantially reduced with fitusiran by 79.7% (P = 0.0021) and 46.4% (P = 0.0598) versus BPA/CFC prophylaxis, respectively. Forty-one participants (63.1%) experienced zero treated bleeds with fitusiran versus 11 (16.9%) with BPAs/CFCs. Median AsBR and AjBR were both 2.2 with BPA/CFC prophylaxis and 0.0 in the fitusiran efficacy period. Two participants (3.0%) experienced suspected or confirmed thromboembolic events with fitusiran. Once-monthly fitusiran prophylaxis significantly reduced bleeding events versus BPA/CFC prophylaxis in PwHA/B, with or without inhibitors and reported adverse events were generally consistent with previously identified risks of fitusiran.

Pediatric splenic infarction: Assessment of associated clinical conditions and outcome.

Pediatric splenic infarction (SI) is rare yet clinically significant. Publications regarding this complication are mostly limited to case reports. This is a retrospective study examining SI etiology, clinical presentation, management, and outcomes among children. Twenty-two patients (median age: 7.9 years) were included, mostly with pre-existing hematological diseases. Splenomegaly (72%), thrombocytopenia, and anemia were common. Most of the patients did not receive antithrombotic therapy yet only two patients experienced recurrences. During follow up 36% of patients died, however no fatalities were attributed to thrombotic or bleeding complications.

Outcomes of venous thromboembolism in patients with inherited thrombophilia treated with direct oral anticoagulants: insights from the RIETE registry.

While direct oral anticoagulants (DOACs) are frequently used to treat venous thromboembolism (VTE), the outcomes of patients with inherited thrombophilia (IT) receiving DOACs for VTE remain understudied. We used data from the international RIETE registry to compare the rates of VTE recurrences, major bleeding, and mortality during anticoagulant treatment in VTE patients with and without IT, grouped by the use of DOACs or standard anticoagulant therapy. Among 103,818 enrolled patients, 21,089 (20.3%) were tested for IT, of whom 8422 (39.9%) tested positive: Protein C deficiency 294, Protein S deficiency 726, Antithrombin deficiency 240, Factor V Leiden 2248, Prothrombin gene mutation 1434, combined IT 3480. Overall, 14,189 RIETE patients (6.2% with IT) received DOACs, and 89,629 standard anticoagulation (8.4% with IT), mostly with heparins followed by vitamin K antagonists. Proportions of patients receiving DOACs did not differ between IT-positive and IT-negative patients. Rates of VTE recurrence on anticoagulant treatment were highest in patients with AT deficiency (P < 0.01). Rates of on-treatment major bleeding and all-cause mortality were lowest among patients with Factor V Leiden (FVL) or PT G20210A mutations, compared with patients who tested negative. Patients with IT who received DOACs had lower rates of major bleeding than those receiving standard anticoagulation. Excluding FVL and Protein S deficiency, patients with IT had lower rates of VTE recurrence with DOACs than with standard anticoagulation. DOACs are equally safe and effective in VTE patients with IT, with lower bleeding rates than those on standard anticoagulation.

The value-based healthcare approach to haemophilia: Development of outcome measures for the evaluation of care of people with haemophilia.

INTRODUCTION: Considering the advances in haemophilia management and treatment observed in the last decades, a new set of value-based outcome indicators is needed to assess the quality of care and the impact of these medical innovations. AIM: The Value-Based Healthcare in Haemophilia project aimed to define a set of clinical outcome indicators (COIs) and patient-reported outcome indicators (PROIs) to assess quality of care in haemophilia in high-income countries with a value-based approach to inform and guide the decision-making process. METHODS: A Value-based healthcare approach based on the available literature, current guidelines and the involvement of a multidisciplinary group of experts was applied to generate a set of indicators to assess the quality of care of haemophilia. RESULTS: A final list of three COIs and five PROIs was created and validated. The identified COIs focus on two domains: musculoskeletal health and function, and safety. The identified PROIs cover five domains: bleeding frequency, pain, mobility and physical activities, Health-Related Quality of Life and satisfaction. Finally, two composite outcomes, one based on COIs, and one based on PROIs, were proposed as synthetic outcome indicators of quality of care. CONCLUSION: The presented standard set of health outcome indicators provides the basis for harmonised longitudinal and cross-sectional monitoring and comparison. The implementation of this value-based approach would enable a more robust assessment of quality of care in haemophilia, within a framework of continuous treatment improvements with potential added value for patients. Moreover, proposed COIs and PROIs should be reviewed and updated routinely.

A post hoc analysis of PROTECT VIII kids assessing long-term efficacy and safety of damoctocog alfa pegol in adolescents with severe haemophilia A.

INTRODUCTION: The safety and efficacy of the extended half-life factor VIII (FVIII) product damoctocog alfa pegol (BAY 94-9027, Jivi®) has been demonstrated in the PROTECT VIII Kids study (NCT01775618), where male previously-treated patients (PTPs) aged <12 years old with severe haemophilia A and ≥ 50 exposure days (EDs) were treated prophylactically. The PROTECT VIII Kids extension study assessed the long-term safety and efficacy of damoctocog alfa pegol in the same population. AIM: To evaluate the long-term impact of damoctocog alfa pegol in a post hoc subgroup analysis of adolescent patients in the PROTECT VIII Kids study and its extension from 12th birthday onwards. METHODS: The current analysis included PTPs aged ≥12 years old, who remained in the extension for ≥6 months following their 12th birthday. The observation period was defined as the time from 12th birthday to the end of the extension period; all data from this birthday were included whether in the main study or extension phase. The main efficacy variable was annualised bleeding rate (ABR) and the main safety variable was the frequency of inhibitor development. RESULTS: This subgroup analysis comprised 25 patients. Median observation time after 12th birthday was 3.2 years. Median total/joint/spontaneous ABRs in the observation period were 1.7/0.7/0.3, respectively. Safety findings were consistent with those reported for the overall study population; no confirmed FVIII inhibitors or anti-drug antibodies were reported. CONCLUSIONS: Damoctocog alfa pegol is efficacious with a favourable safety profile in adolescents with haemophilia A, supporting its long-term use in children and adolescents.

Safety of recombinant activated factor VII for treatment of breakthrough bleeds in patients with congenital haemophilia A and inhibitors receiving emicizumab prophylaxis: Review of the real-world evidence.

BACKGROUND: Emicizumab is used as a subcutaneous prophylaxis for prevention of bleeding episodes in patients with haemophilia A (HA) with and without inhibitors. While low bleeding rates were observed in clinical trials, patients still experience breakthrough bleeds (BTBs) with emicizumab in the real-world. Current guidelines recommend use of recombinant activated factor VII (rFVIIa) for treatment of BTBs in patients with inhibitors. Due to thrombotic events observed in the HAVEN 1 study, activated prothrombin complex concentrate (aPCC) should be used with caution. OBJECTIVES: The objective of this review is to identify and discuss real-world data on the frequency of BTBs and the safety of concomitant rFVIIa use in patients with inhibitors on emicizumab prophylaxis. METHODS: A search of the following databases was conducted on 15 July 2022: BIOSIS Previews® , Current Contents Search® , Embase® , MEDLINE® . Search terms included 'real world', 'haemophilia A', and 'emicizumab'. RESULTS AND CONCLUSIONS: Eleven relevant publications were identified (seven original research articles and four congress abstracts). The frequency of BTBs specifically for HA patients with inhibitors was described in three publications with 5%-56% patients on emicizumab reporting ≥1 bleeding episode. Treatment of these BTBs appeared to be managed according to relevant guidelines. Importantly, no thrombotic complications occurred during concomitant rFVIIa use. Due to the nature of real-world studies, direct comparison of the results between studies is limited. However, real-world data show that BTBs in inhibitor patients during emicizumab prophylaxis can be safely treated with rFVIIa.

Emicizumab prophylaxis in infants: Single-centre experience.

The hallmark of haemophilia A (HA) therapy is prophylaxis, aimed at spontaneous bleeding prevention. Emicizumab provides a viable alternative to intravenous factor replacement therapy. However, data on its use in infants are limited. This single-centre open arm prospective study reports on emicizumab prophylaxis in infants. We included severe HA patients under 1 year who started emicizumab prophylaxis since 2018, with longitudinal follow-up. The study collected data on demographics, clinical and laboratory variables, the occurrence of bleeding events, surgeries and treatment outcomes. Of the 27 enrolled infants, whose median age at prophylaxis initiation was 7 months, 24 primarily choose to start emicizumab therapy (3/27 switched from FVIII prophylaxis due to development of FVIII inhibitors). The median age for prophylaxis initiation decreased to 3 months in 2023. Following emicizumab initiation, the median calculated ABR decreased, and no intracranial haemorrhages were observed. Thrombin generation showed a significant improvement in peak height and endogenous thrombin potential at steady state after a loading period. Our study highlights a shift towards early prophylaxis in the era of non-replacement therapies. It underscores the need for continuous evaluation and refinement of treatment approaches, emphasizing personalized care and diligent monitoring in the evolving field of paediatric haemophilia care.

Factor XI deficiency: phenotypic age-related considerations and clinical approach towards bleeding risk assessment.

ABSTRACT: Factor XI (FXI) deficiency is a rare bleeding disorder that presents complex challenges in patient assessment and bleeding risk management. Despite generally causing mild to moderate bleeding symptoms, clinical manifestations can vary, and bleeding tendency does not always correlate with FXI plasma levels or genotype. Our manuscript delves into the age-related nuances of FXI deficiency across an individual's lifespan. We emphasize issues faced by specific groups, including neonates and females of reproductive age experiencing abnormal uterine bleeding and postpartum hemorrhage. Older patients present unique challenges and concerns related to the management of bleeding as well as thrombotic complications. The current assortment of diagnostic laboratory assays shows limited success in predicting bleeding risk in the perisurgical setting of patients with FXI deficiency. This review explores the intricate interplay between individual bleeding profiles, surgical sites, and FXI activity levels. We also evaluate the accuracy of existing laboratory assays in predicting bleeding and discuss the potential role of investigational global assays in perioperative assessment. Furthermore, we outline our suggested diagnostic approach to refine treatment strategies and decision making. Available treatment options are presented, including antifibrinolytics, replacement products, and recombinant activated FVII. Finally, we discuss promising nonreplacement therapies for the treatment of rare bleeding disorders that can potentially address the challenges faced when managing FXI deficiency-related bleeding complications.

Determinants of bleeding before and during immune tolerance in 222 boys with severe hemophilia A and inhibitors >5 BU.

ABSTRACT: Prevention of bleeding and its consequences is the main goal of hemophilia treatment and determines treatment choices for patients who develop inhibitors. To assess bleeding before and during immune tolerance induction (ITI) and its association with ITI regimen and inhibitor titer, we selected and analyzed data on patients receiving high-titer inhibitors from the international prospective PedNet cohort study. In total, 222 patients with severe hemophilia A and inhibitor titers of >5 Bethesda units (BU) were followed from the first positive to the first negative inhibitor result (median overall follow-up, 1.7 years). Mean annual (joint) bleeding rates (AJBR) and 95% confidence intervals (CIs) were compared according to treatment and inhibitor titer using multivariable negative binomial regression. Before ITI, 115 patients showed an ABR of 6.1 (5.0-7.4) and an AJBR 2.6 (2.1-3.2). Bleeding was independent of inhibitor titer. During ITI, 202 patients had an ABR of 4.4 (3.9-5.1) and an AJBR of 1.7 (1.5-2.0). AJBR during ITI increased with inhibitor titer (hazard ratio [HR] for ≥200 BU vs 5 to 39 BU [4.9; CI, 3.2-7.4]) and decreased with daily ITI infusions (HR, 0.4; CI, 0.3-0.6) or activated prothrombin complex concentrate prophylaxis (HR, 0.4; CI, 0.2-0.8), whereas ITI dose and recombinant activated factor VII prophylaxis did not independently affect bleeding. These data provide evidence for a protective effect of repeated FVIII infusions (ITI) on bleeding in patients who have developed inhibitors; these data should be used to plan ITI and/or serve as a comparator for prophylaxis with nonreplacement therapy.

Elevated International Normalized Ratio and Mortality in Hospitalized Patients Treated with Direct Oral Anticoagulants.

BACKGROUND: Direct oral anticoagulants (DOACs) are associated with a prolongation of the prothrombin time and an increased international normalized ratio (INR). The clinical significance of these changes is unclear. This study aimed to examine the association between an elevated INR on admission and in-hospital death and long-term survival in patients treated with DOACs. METHODS: Data were retrospectively retrieved from records of hospitalized patients at the Sheba Medical Center between November 2008 and July 2023. Patients were selected based on DOAC treatment, coagulation profile, and INR test done within 48 hours of hospitalization. The outcomes were in-hospital mortality and mortality in the year following hospitalization. RESULTS: The study included 11,399 hospitalized patients treated with DOACs. Patients with elevated INR had a 180% higher risk of in-hospital mortality (adjusted odds ratio 2.80; 95% confidence interval, 2.30-3.39) and a 57% increased risk of death during the following year (adjusted hazard ratio 1.57; 95% confidence interval, 1.44-1.71). Similar results were observed in subgroup analyses for each DOAC. CONCLUSIONS: An elevated INR on admission is associated with a higher risk for in-hospital death and increased risk for mortality during the first year following hospitalization in hospitalized patients treated with DOACs. This highlights that elevated INR levels in patients on DOACs should not be dismissed as laboratory variations due to DOAC treatment, as they may serve as a prognostic marker.

Bleeding phenotype and hemostatic evaluation by thrombin generation in children with Noonan syndrome: A prospective study.

BACKGROUND: This study aimed to evaluate the bleeding phenotype and to conduct a comprehensive hemostatic evaluation in individuals with Noonan syndrome (NS), a dominantly inherited disorder caused by pathogenic variants in genes associated with the Ras/MAPK signaling pathway. METHODS: Children with a genetically confirmed diagnosis of NS underwent clinical evaluation, routine laboratory tests, platelet function testing, and thrombin generation (TG) assessment. RESULTS: The study included 24 children. The most frequently reported bleeding symptoms were easy bruising and epistaxis, while bleeding complications were observed in 15% of surgical procedures. Various hemostatic abnormalities were identified, including platelet dysfunction, von Willebrand disease, and clotting factor deficiencies. Abnormal platelet function was observed in 50% of the patients, and significantly lower TG parameters were found compared to controls. However, no significant correlation was observed between bleeding symptoms and TG results. CONCLUSIONS: The study suggests that the bleeding diathesis in NS is multifactorial, involving both platelet dysfunction and deficiencies of plasma coagulation factors. The potential role of TG assay as an ancillary tool for predicting bleeding tendencies in individuals with NS undergoing surgery warrants further investigation.

Emicizumab prophylaxis in infants with hemophilia A (HAVEN 7): primary analysis of a phase 3b open-label trial.

ABSTRACT: Subcutaneous emicizumab enables prophylaxis for people with hemophilia A (HA) from birth, potentially reducing risk of bleeding and intracranial hemorrhage (ICH). HAVEN 7 (NCT04431726) is the first clinical trial of emicizumab dedicated to infants, designed to investigate the efficacy, safety, pharmacokinetics, and pharmacodynamics of emicizumab in those aged ≤12 months with severe HA without factor VIII (FVIII) inhibitors. Participants in this phase 3b trial received emicizumab 3 mg/kg maintenance dose every 2 weeks for 52 weeks and are continuing emicizumab during the 7-year long-term follow-up. Efficacy end points included annualized bleed rate (ABR): treated, all, treated spontaneous, and treated joint bleeds. Safety end points included adverse events (AEs), thromboembolic events (TEs), thrombotic microangiopathies (TMAs), and immunogenicity (anti-emicizumab antibodies [ADAs] and FVIII inhibitors). At primary analysis, 55 male participants had received emicizumab (median treatment duration: 100.3; range, 52-118 weeks). Median age at informed consent was 4.0 months (range, 9 days to 11 months 30 days). Model-based ABR for treated bleeds was 0.4 (95% confidence interval, 0.30-0.63), with 54.5% of participants (n = 30) having zero treated bleeds. No ICH occurred. All 42 treated bleeds in 25 participants (45.5%) were traumatic. Nine participants (16.4%) had ≥1 emicizumab-related AE (all grade 1 injection-site reactions). No AE led to treatment changes. No deaths, TEs, or TMAs occurred. No participant tested positive for ADAs. Two participants were confirmed positive for FVIII inhibitors. This primary analysis of HAVEN 7 indicates that emicizumab is efficacious and well tolerated in infants with severe HA without FVIII inhibitors.

Management of surgery in persons with hemophilia A receiving emicizumab prophylaxis: data from a national hemophilia treatment center.

Background: Persons with hemophilia A may require surgical procedures. Real-world data on invasive procedures in persons with hemophilia A receiving emicizumab prophylaxis are limited. Objectives: To evaluate the safety of invasive procedures in persons with hemophilia A receiving emicizumab prophylaxis and their outcomes in a longitudinally followed cohort. Methods: Data from medical records of persons with hemophilia A with and without factor VIII (FVIII) inhibitors longitudinally followed at our tertiary center, who received emicizumab prophylaxis and underwent all types of invasive procedures, were retrieved. Outcomes of interest were bleeding and thrombotic complications. Results: Overall, 35 patients underwent 56 invasive procedures, 18 (32.1%) were major. The median age was 36.3 years (IQR, 8.8-55.9 years); 12 patients (34.3%) were younger than 18 years at the time of procedure; 17 (48.6%) were patients with FVIII inhibitors. Among major procedures, orthopedic surgeries prevailed. All patients who underwent major procedures received factor replacement with either recombinant activated factor VII (patients with inhibitors) or FVIII (patients without inhibitors). Factor concentrates were administered prior to 32 (84.2%) of the minor procedures. Repeated doses were given according to international expert opinion recommendations and patients' condition.There were 7 bleeding events in 6 patients, 5 were major bleeds, including 1 patient who underwent a minor procedure without factor replacement. None of the patients experienced a thrombotic complication. Conclusion: Invasive procedures can be performed safely in patients receiving emicizumab prophylaxis with close surveillance after surgery. Factor concentrates may be advised in selected patients undergoing minor procedures.

Ocular venous occlusion in pediatrics: Should thrombophilia investigation and anticoagulant treatment be initiated?

Retinal vein occlusion (RVO) and superior ophthalmic vein thrombosis (SOVT) are rare diseases in the pediatric population; however, the ophthalmic and neurologic morbidity are significant. As published data are scarce for these conditions, we present our experience with pediatric ocular venous thrombosis in four patients, and discuss recommended management for evaluation and treatment. We suggest performing thrombophilia workup for all pediatric patients with RVO or SOVT. In patients with thrombophilia risk factors or patients with additional thrombi, we highly recommend initiating anticoagulation therapy. There is a need for more research in order to determine the optimal management strategy.

Factor VIII inhibitors in hemophilia A treated with emicizumab: longitudinal follow-up of outcomes.

Background: Using emicizumab in lieu of immune tolerance induction (ITI) for patients with hemophilia A (HA) and factor (F)VIII inhibitors has been well described. However, decisions regarding ITI initiation, regimen, and preservation of tolerance remain to be elucidated. Objectives: To study the course of FVIII inhibitors in patients with HA and a history of FVIII inhibitors receiving emicizumab prophylaxis. Methods: Patients with HA, with and without FVIII inhibitors, initiating emicizumab prophylaxis were prospectively followed up in our center. All patients with current or previous inhibitors were included in this analysis. Plasma samples for FVIII inhibitor assays were obtained every 3 to 6 months or following FVIII exposure. Patients documented annual bleeding rate and any FVIII exposure days (EDs). Results: Of 162 emicizumab-treated participants, 51 met the inclusion criteria. A decrease in annual bleeding rate was observed in all 51 participants followed up for a median of 3.3 years, with 31 breakthrough bleeding episodes reported in 22 of 51 participants. FVIII inhibitor level transiently increased following FVIII exposures in 5 of 15 failed ITI participants. Eight of 21 participants who did not undergo ITI were exposed to FVIII (1-2 EDs)), and 1 of these 8 participants demonstrated increased FVIII inhibitor levels after head trauma (following 1 ED). Among participants who underwent successful ITI, 8 of 15 patients were exposed to FVIII over a total of 13 EDs (1-2 ED(s) each) for traumatic breakthrough bleeds. In all these participants, inhibitor levels remained zero, indicating successful tolerance maintenance. Conclusion: Our longitudinal follow-up of emicizumab-treated patients with HA and FVIII inhibitors shows that occasional exposure to FVIII may induce a transient anamnestic response. Nonetheless, no FVIII inhibitor recurrence was noted following FVIII exposures in patients who underwent successful ITI.

The immunogenicity, safety, and efficacy of N8-GP in previously untreated patients with severe hemophilia A: pathfinder6 end-of-trial results.

BACKGROUND: The pathfinder6 (NCT02137850) international phase 3 trial examined immunogenicity, safety, and efficacy of the extended half-life factor VIII (FVIII) replacement product N8-GP (turoctocog alfa pegol; Esperoct) in previously untreated patients (PUPs) with hemophilia A. OBJECTIVES: We present end-of trial results for extended PUP N8-GP treatment for up to a median (range) 2.5 (0.0; 7.4) years. PATIENTS/METHODS: Longer-term N8-GP treatment in PUPs with hemophilia A was examined. The prophylaxis regimen was ∼60 IU/kg N8-GP i.v. twice weekly, or every 3 or 7 days. The primary endpoint was the incidence of FVIII inhibitors. RESULTS: Overall, 81 patients received N8-GP and were included in this analysis. The inhibitor incidence was 30.0% (15.7% high-titer [>5 BU]) for the extension phase. Patients had a median (range) 2.9 (0.1; 7.2) years of prophylaxis following the pre-prophylaxis period. During prophylaxis, the median annualized bleeding rate (ABR) (interquartile range) was 1.4 (0.6; 3.5), 13% of patients experienced no bleeding episodes, and 55.1% of patients experienced no spontaneous bleeds. The proportion of patients without any spontaneous bleeding episodes increased after the first year of prophylaxis. The hemostatic success rate in the treatment of bleeding episodes was 87.6%. No additional safety concerns were observed in patients with previously reported observation of temporarily decreased incremental recovery (IR). CONCLUSION: Long-term end-of-trial PUP N8-GP prophylaxis data indicate that PUPs respond well to long-term N8-GP treatment. The inhibitor incidence was consistent with previous results. Median ABR during prophylaxis was 1.4. There were no lasting clinical impacts or safety concerns for patients with an observation of temporarily decreased IR.

Dilemmas on emicizumab in children with haemophilia A: A survey of strategies from PedNet centres.

INTRODUCTION: Haemophilia A care has changed with the introduction of emicizumab. Experience on the youngest children is still scarce and clinical practice varies between haemophilia treatment centres. AIM: We aimed to assess the current clinical practice on emicizumab prophylaxis within PedNet, a collaborative research platform for paediatricians treating children with haemophilia. METHODS: An electronic survey was sent to all PedNet members (n = 32) between October 2022 and February 2023. The survey included questions on the availability of emicizumab, on the practice of initiating prophylaxis in previously untreated or minimally treated patients (PUPs or MTPs) and emicizumab use in patients with or without inhibitors. RESULTS: All but four centres (28/32; 88%) responded. Emicizumab was available in clinical practice in 25/28 centres (89%), and in 3/28 for selected patients only (e.g. with inhibitors). Emicizumab was the preferred choice for prophylaxis in PUPs or MTPs in 20/25 centres; most (85%) started emicizumab prophylaxis before 1 year of age (30% before 6 months of age) and without concomitant FVIII (16/20; 80%). After the loading dose, 13/28 centres administered the recommended dosing, while the others adjusted the interval of injections to give whole vials. In inhibitor patients, the use of emicizumab during ITI was common, with low-dose ITI being the preferred protocol. CONCLUSION: Most centres choose to initiate prophylaxis with emicizumab before 12 months of age and without concomitant FVIII. In inhibitor patients, ITI is mostly given in addition to emicizumab, but there was no common practice on how to proceed after successful ITI.