How much prophylaxis is enough in haemophilia?

INTRODUCTION

Prophylaxis has become standard of care for all persons with haemophilia (PWH) with a severe phenotype. However, 'standard prophylaxis' with either factor or non-factor therapies (currently only emicizumab available) is prohibitively expensive for much of the world. We sought to address the question of 'How much prophylaxis is enough?' and 'Can it be individualized?' and specifically 'Can emicizumab be individualized?'.

METHODS

We reviewed the literature on prophylaxis in haemophilia since its inception in the 1950s to the present, the development of more and less intense factor prophylaxis regimens and their outcomes and additionally the published outcomes of prophylaxis with low dose emicizumab.

RESULTS

What these experiences collectively show is that low dose emicizumab does result in significant benefits to patients whilst being much less expensive than a "one size fits all" emicizumab prophylaxis approach. We also took note that some non-factor therapies still in development are individualized given that high doses of these can potentially put patients at risk.

CONCLUSIONS

Prophylaxis is now clearly accepted as standard of care for PWH with a severe phenotype but now in a very short time a large assortment of different treatment options for prophylaxis have become/are becoming available and the haemophilia community will need to determine how to best use these recognizing that no 'one treatment fits all'.

A post hoc analysis of previously untreated patients with severe hemophilia A who developed inhibitors in the PUPs A-LONG trial

ABSTRACT

Inhibitor development is a major therapeutic complication for people with hemophilia. The phase 3 PUPs A-LONG study evaluated the safety and efficacy of efmoroctocog alfa (a recombinant factor VIII Fc fusion protein, herein referred to as rFVIIIFc) in previously untreated patients (PUPs) with severe hemophilia A. Male PUPs <6 years old were enrolled and received rFVIIIFc; inhibitor development was the primary end point. Post hoc analyses, including patient treatment regimen patterns and timing of inhibitor development, descriptive and Kaplan-Meier analyses of time to first inhibitor-positive test by treatment regimen and by titer, and consumption, were performed to describe patients who developed inhibitors during PUPs A-LONG. We investigated patient characteristics (eg, demographics and genotype) and nongenetic risk factors (eg, intense factor exposure and central venous access device [CVAD] placement) that may predict inhibitor development and characteristics of inhibitor development (low-titer vs high-titer inhibitor). Baseline characteristics were similarly distributed for age, race, and ethnicity across both patients who were inhibitor-positive and those who were inhibitor-negative (all P > .05). High-risk F8 variants were associated with development of high-titer inhibitors (P = .028). High-titer inhibitor development was often preceded by the presence of a low-titer inhibitor. Patients whose low-titer inhibitor progressed to a high-titer inhibitor received a higher mean dose per infusion (98.4 IU/kg, n = 5) compared with those whose low-titer inhibitor resolved spontaneously (59.2 IU/kg, n = 7; P = .033) or persisted (45.0 IU/kg, n = 5; P = .047). There was no association between CVAD placement surgery and inhibitor development. Post hoc analyses suggest that F8 genotype and dose of factor are as important as inhibitor risk factors and require further investigation. This study was registered at ClinicalTrials.gov as #NCT02234323.

Eptacog beta for the management of patients with haemophilia A and B with inhibitors: A European perspective

Eptacog beta (activated), a recombinant human factor VIIa (rFVIIa), was approved by the US Food and Drug Administration (FDA) in 2020 (SEVENFACT®, LFB & HEMA Biologics) and the European Medicines Agency (EMA) in 2022 (CEVENFACTA®, LFB). In Europe, eptacog beta is indicated for the treatment of bleeds and the prevention of bleeds during surgery or invasive procedures in adults and adolescents (≥12 years old) with congenital haemophilia A or B with high-titre inhibitors (≥5 BU) or with low-titre inhibitors who are expected to have a high anamnestic response to factor VIII or factor IX, or to be refractory to increased dosing of these factors. The efficacy and safety of eptacog beta were evaluated in three Phase III clinical studies, PERSEPT 1, 2 and 3. For the EMA filing dossier, the analysis of data from PERSEPT 1 and 2 differed from the analysis used to support the filing in the US. In this review, we summarise current data regarding the mode of action, clinical efficacy and safety of eptacog beta for the management of haemophilia A and B in patients with inhibitors from a European perspective. In addition to providing a valuable summary of the analyses of the clinical data for eptacog beta conducted for the EMA, our review summarises the potential differentiators for eptacog beta compared with other current bypassing agents.

The effectiveness and safety of octocog alfa in patients with hemophilia A: up to 7-year follow-up of the real-world AHEAD international study

Background

Real-world data assessing treatment outcomes in patients with hemophilia A in routine clinical practice are limited.

Objective

To evaluate the effectiveness and safety of octocog alfa in patients with moderate/severe hemophilia A receiving treatment in clinical practice.

Design

The international Antihemophilic Factor Hemophilia A Outcome Database study is an observational, noninterventional, prospective, multicenter study.

Methods

This planned interim data read-out was conducted following 7 years of observation of patients receiving octocog alfa (cut-off, 30 June 2020). The primary endpoint was joint health status, assessed by the Gilbert Score. Secondary endpoints included annualized bleeding rates (ABRs), Hemophilia Joint Health Score (HJHS), health-related quality of life, consumption, and safety. This post hoc analysis stratified data by hemophilia severity at baseline [moderate, factor VIII (FVIII) 1-5%; severe, FVIII <1%].

Results

Of the 711 patients in this analysis, 582 (82%) were receiving prophylaxis with octocog alfa at enrollment, and 498 (70%) had severe disease. Median Gilbert Scores were higher with on-demand therapy versus prophylaxis and scores were comparable in moderate and severe disease. In patients receiving prophylaxis, there was an improvement in HJHS Global Gait Score over 7 years of follow-up overall and in patients with severe disease. ABRs and annualized joint bleeding rates were low across all 7 years. An ABR of zero was reported in 34-56% of prophylaxis patients versus 20-40% in the on-demand group. ABRs were similar in severe and moderate disease. In total, 13/702 (1.9%) patients experienced 18 treatment-related adverse events.

Conclusion

These data demonstrate the long-term effectiveness and safety of octocog alfa in patients with moderate and severe hemophilia A, especially in those receiving prophylaxis. The high number of patients receiving on-demand treatment experiencing zero bleeds could be due to selection bias within the study, with patients with less severe disease more likely to be receiving on-demand treatment.

Trial registration

ClinicalTrials.gov: NCT02078427.

Nonacog beta pegol prophylaxis in children with hemophilia B: safety, efficacy, and neurodevelopmental outcomes for up to 8 years

Background

Nonacog beta pegol (N9-GP) is an extended half-life PEGylated factor (F)IX product with established efficacy and short-term safety in persons with hemophilia B (HB). Long-term safety has been evaluated for polyethylene glycol exposure but not N9-GP.

Objectives

To assess safety, neurodevelopmental, and efficacy outcomes of children with HB receiving N9-GP prophylaxis across 2 open-label, single-arm, phase 3 studies: paradigm5 (previously treated patients [PTPs]) and paradigm6 (previously untreated patients [PUPs]) in this interim analysis.

Methods

PTPs (aged ≤12 years) and PUPs (aged <6 years) with severe/moderate (≤2% FIX level) HB were recruited to N9-GP prophylaxis (40 IU/kg once weekly) in paradigm5 and paradigm6, respectively. Safety assessments included FIX inhibitor incidence, adverse events, neurocognitive and neurologic outcomes, polyethylene glycol concentration in plasma, and medical events of special interest. Efficacy endpoints included bleeds, N9-GP hemostatic effect, and FIX consumption.

Results

Overall, 25 patients in paradigm5 and 50 patients in paradigm6 received N9-GP and were followed for up to 8 and 6 years, respectively. No inhibitory antibodies were reported in PTPs; 4 of the 50 PUPs developed inhibitors. Extensive evaluation revealed no neurocognitive or neurologic concerns with N9-GP use in children during the study period. Across both studies, few adverse events were reported as possibly related to N9-GP. High hemostatic response rate, high treatment adherence, low annualized bleeding rates, and no new target joints were reported.

Conclusion

These data provide the longest follow-up for an extended half-life FIX and confirm the long-term efficacy of N9-GP prophylaxis in children with HB with no observed neurocognitive or neurologic safety concerns.

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.

Inhibitor development according to concentrate in severe hemophilia: reporting on 1392 Previously Untreated Patients from Europe and Canada

Background

Clotting factor concentrates have been the mainstay of severe hemophilia treatment over the last 50 years. Differences in risk of neutralizing antibody (inhibitor) formation according to concentrate used remain clinically relevant.

Objectives

To assess inhibitor development according to type of clotting factor concentrate in previously untreated patients (PUPs) with severe hemophilia A and B.

Methods

The European Haemophilia Safety Surveillance (EUHASS) and Canadian Bleeding Disorders Registry (CBDR) have been monitoring adverse events overall and according to concentrate for 11 and 8 years, respectively. Inhibitors were reported quarterly, and PUPs completed 50 exposure days without inhibitor development annually. Cumulative inhibitor incidences and 95% confidence intervals (CIs) were compared without adjustment for other risk factors.

Results

Fifty-six European and 23 Canadian centers reported inhibitor development in 312 of 1219 (26%; CI, 23%-28%) PUPs with severe hemophilia A and 14 of 173 (8%; CI, 5%-13%) PUPs with severe hemophilia B. Inhibitor development was lower on plasma-derived factor (F)VIII (pdFVIII, 20%; CI, 14%-26%) than on standard half-life recombinant FVIII (SHL-rFVIII, 27%; CI, 24%-30% and odds ratio, 0.67; CI, 0.45%-0.98%; P = .04). Extended half-life recombinant FVIII (EHL-rFVIII, 22%; CI, 12%-36%) showed an intermediate inhibitor rate, while inhibitor rates for Advate (26%; CI, 22%-31%) and Kogenate/Helixate (30%; CI, 24%-36%) overlapped. For other SHL-rFVIII concentrates, inhibitor rates varied from 3% to 43%. Inhibitor development was similar for pdFIX (11%; CI, 3%-25%), SHL-rFIX (8%; CI, 3%-15%), and EHL-rFIX (7%; CI, 1%-22%).

Conclusion

While confirming expected rates of inhibitors in PUPs, inhibitor development was lower in pdFVIII than in SHL-rFVIII. Preliminary data suggest variation in inhibitor development among different SHL-rFVIII and EHL-rFVIII concentrates.

Rare case of refractory mixed autoimmune hemolytic anemia in a 6-year-old child: a case report

BACKGROUND

Mixed autoimmune hemolytic anemia (AIHA) shows combined clinical and laboratory characteristics of warm and cold AIHA. It is relatively uncommon in children. Consequently, knowledge about mixed AIHA prevalence, clinical presentation, treatment options, and prognosis in children is limited to very few case reports.

CASE PRESENTATION

We describe a six-year-old Asian girl presenting with profound anemia, blood group typing discrepancy and crossmatch incompatibility, post upper respiratory tract infection. Detection of red cell warm and cold reactive autoantibodies, led to the diagnosis of mixed AIHA. Autoantibodies with laboratory evidence of hemolysis persisted despite high dose steroid therapy. Due to the inability to wean further, the patient was subsequently commenced on mycophenolate mofetil to which she seems to be responding.

CONCLUSIONS

Mixed AIHA may be notoriously difficult to diagnose and treat. Detailed clinical and laboratory work-up is essential to establish the diagnosis. To the best of our knowledge, this is the first case report of mixed AIHA following upper respiratory tract infection. Awareness of this occurrence is important, as similar to warm AIHA, mixed AIHA should be treated immediately by early initiation of steroid therapy. In addition, prompt supportive care as well as long-term clinical follow-up are required to improve outcomes of these cases.

Simoctocog alfa (Nuwiq®) in previously untreated patients with severe haemophilia A-Final efficacy and safety results from the NuProtect study

INTRODUCTION

Simoctocog alfa (Nuwiq®) is a 4th generation recombinant FVIII with proven efficacy for the prevention and treatment of bleeding episodes (BEs) in previously treated patients with severe haemophilia A. The NuProtect study assessed the immunogenicity, efficacy and safety of simoctocog alfa in 108 previously untreated patients (PUPs). The incidence of high-titre inhibitors was 16.2% and no patients with non-null F8 mutations developed inhibitors.

AIM

To report the efficacy and safety results from the NuProtect study.

METHODS

PUPs received simoctocog alfa for prophylaxis, treatment of BEs, or as surgical prophylaxis. The efficacy of prophylaxis (during inhibitor-free periods) was assessed using annualised bleeding rates (ABRs). The efficacy in treating BEs and in surgical prophylaxis was assessed using a 4-point scale. Adverse events were recorded throughout the study.

RESULTS

Of 108 PUPs treated with simoctocog alfa, 103 received at least one prophylactic dose and 50 received continuous prophylaxis for at least 24 weeks. In patients on continuous prophylaxis, the median ABR was 0 (mean 0.5) for spontaneous BEs and 2.5 (mean 3.6) for all BEs. In 85 patients who had BEs, efficacy of BE treatment was excellent or good for 92.9% (747/804) of rated BEs; 92.3% of BEs were treated with 1 or 2 infusions. The efficacy of surgical prophylaxis was excellent or good for 94.7% (18/19) of rated procedures. There were no safety concerns and no thromboembolic events.

CONCLUSION

Simoctocog alfa was efficacious and well tolerated as prophylaxis, surgical prophylaxis and for the treatment of BEs in PUPs with severe haemophilia A.

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.

Long-term immunogenicity, efficacy and tolerability of simoctocog alfa in patients with severe haemophilia A who had completed the NuProtect study in previously untreated patients

BACKGROUND

The NuProtect study reported data on the immunogenicity, efficacy and tolerability of simoctocog alfa (Nuwiq^® ) in 108 previously untreated patients with severe haemophilia A planned to be treated for ≥100 exposure days or up to 5 years. The NuProtect-Extension study collected long-term prophylaxis data in children with severe haemophilia A.

METHODS

Patients who completed the NuProtect study according to the protocol were eligible for the NuProtect-Extension study, a prospective, multinational, non-controlled, Phase 3b study.

RESULTS

Of 48 patients who entered the extension study, 47 (median age 2.8 years) received prophylaxis with simoctocog alfa for a median of 24 months, with 82%-88% on a twice-weekly or less regimen. No patient developed FVIII inhibitors during the extension study. The median (IQR) annualized bleeding rate (ABR) during prophylaxis was 0 (0-0.5) for spontaneous bleeding episodes (BEs) and 1.00 (0-1.95) for all BEs. ABRs estimated using a negative binomial model were .28 (95% CI: .15, .53) for spontaneous and 1.62 (95% CI: 1.09, 2.42) for all BEs. During the median follow-up of 24 months, 34 (72%) patients had zero spontaneous BEs and 46 (98%) had zero spontaneous joint BEs. Efficacy in treating BEs was excellent or good for 78.2% of rated BEs, and efficacy of surgical prophylaxis was excellent for two rated surgeries. No treatment-related adverse events were reported.

CONCLUSION

No FVIII inhibitors developed during long-term prophylaxis in the NuProtect-Extension study. Prophylaxis with simoctocog alfa was efficacious and well-tolerated, and is therefore an attractive long-term option for children with severe haemophilia A.

Recombinant factor VIII Fc fusion protein for first-time immune tolerance induction: final results of the verITI-8 study

Inhibitor development remains a major challenge in factor VIII (FVIII) replacement therapy. verITI-8 is the first prospective study of a recombinant FVIII Fc fusion protein (rFVIIIFc; efmoroctocog alfa) for first-time immune tolerance induction (ITI) in males with severe hemophilia A and high-titer inhibitors (historical peak ≥5 Bethesda units [BU]/mL). In this single-arm, open-label, multicenter study, screening was followed by ITI (rFVIIIFc 200 IU/kg per day until tolerization or maximum of 48 weeks). Those who achieved ITI success entered a tapering period, returning to standard prophylaxis, and then entered follow-up. Primary end point was time to tolerization with rFVIIIFc defined by inhibitor titer <0.6 BU/mL, incremental recovery (IR) ≥66% of expected IR (IR ≥1.32 IU/dL per IU/kg), and half-life (t½) ≥7 hours within 48 weeks. Sixteen patients received ≥1 rFVIIIFc dose. Twelve (75%), 11 (69%), and 10 patients (63%), respectively, achieved negative inhibitor titers, an IR ≥66%, and a t½ ≥7 hours (ie, tolerance) within 48 weeks. Median times in weeks to achieve these markers of success were 7.4 (interquartile range [IQR], 2.2-17.8), 6.8 (IQR, 5.4-22.4), and 11.7 (IQR, 9.8-26.2), respectively. All patients experienced ≥1 treatment-emergent adverse event (TEAE), and 1 reported ≥1 related TEAE (injection site pain). Nine patients experienced ≥1 treatment-emergent serious AE. No thrombotic events, discontinuations because of AEs, or deaths were reported during the study. As the first extended half-life rFVIII with prospective data in ITI, rFVIIIFc offered short time to tolerization with durable responses in almost two-thirds of patients and was well tolerated. This trial was registered at www.clinicaltrials.gov as #NCT03093480.

Determinants of successful immune tolerance induction in hemophilia A: systematic review and meta-analysis

Background

Immune tolerance induction (ITI) aims to eradicate anti-factor VIII (FVIII) antibodies (inhibitors) in persons with hemophilia A. However, this burdensome treatment fails in 10% to 40%. To estimate the chance of ITI success in clinical decision making, it is important to identify the predictors of ITI success.

Objectives

We performed a systematic review and meta-analysis to summarize the current evidence on determinants of ITI outcome in persons with hemophilia A.

Methods

A literature search was conducted to identify randomized controlled trials, cohort, or case-control studies reporting on the predictors for ITI outcome in persons with hemophilia A. The main outcome was ITI success. Methodological quality was assessed using an adapted Joanna Briggs Institute checklist, rating as high if ≥11 of 13 criteria were met. Pooled odds ratios (ORs) for ITI success were calculated for each determinant. ITI success was defined as negative inhibitor titer (<0.6 BU/mL), FVIII recovery ≥66% of expected, and FVIII half-life ≥6 hours in 16 (59.3%) studies.

Results

We included 27 studies, involving 1,734 participants. Methodological quality of 6 (22.2%) studies (418 participants) was rated as high. Twenty different determinants were assessed. Historical peak titer ≤100 BU/mL (compared with >100 BU/mL, OR, 1.7; 95% CI, 1.4-2.1), pre-ITI titer ≤10 BU/mL (compared with >10 BU/mL, OR, 1.8; 95% CI, 1.4-2.3), and peak titer during ITI ≤100 BU/mL (compared with >100 BU/mL, OR, 2.7; 95% CI, 1.9-3.8) were associated with a higher chance of ITI success.

Conclusion

Our results suggest that determinants related to the inhibitor titer are associated with ITI success.

Defining vascular anomaly phenotypes in children based on a systematic literature search: A critical step in developing a single severity score for interventional clinical trials

INTRODUCTION

Genetically targeted drugs in vascular anomalies (VA) are used despite the absence of a validated severity score. The aim of this study was to evaluate the feasibility of grouping phenotypic VA clinical characteristics into a single severity score.

METHODS

A systematic literature review including children treated with sirolimus accompanied by a detailed description of phenotype and management was conducted. Demographic data and clinical features were extracted to define distinct categories of phenotypes.

RESULTS

Children with VA display two main phenotypes regardless of VA subtype, which may overlap. A systemic phenotype results from direct invasion and compression of vital structures generally leading to hospitalization and aggressive management in infancy. A functional phenotype is associated with chronic pain and disability manifesting mainly during early adolescence and managed in the outpatient setting.

CONCLUSION

The two distinct phenotypes described could be the basis for developing a unified scoring system for VA severity assessment.

Thromboelastography and thrombin generation assessments for pediatric severe hemophilia A patients are highly variable and not predictive of clinical phenotypes

Background

Severe hemophilia A (SHA) patients vary in severity of bleeding, arthropathy, and requirements for replacement factor VIII (FVIII). Baseline hemostatic activity assays using calibrated automated thrombography (CAT) and thromboelastography (TEG) may offer insights into the physiological basis of clinical heterogeneity.

Objectives

Use CAT and TEG to measure baseline hemostatic activity in a cohort of 30 pediatric SHA patients with available clinical data. Determine effect of contact activation inhibition with corn trypsin inhibitor (CTI). Assess heterogeneity among patients for baseline hemostatic activity and examine correlations between assay results and clinical parameters including FVIII dosing regimen, von Willebrand factor level, and Pettersson arthropathy score.

Methods

SHA blood after FVIII washout was subjected to TEG, and platelet‐rich (PRP) and platelet‐poor plasma was used for CAT assays. Varying concentrations of tissue factor (TF) were used. Statistical analysis examined relationships between assay results, and clinical parameters.

Results

CTI treatment was required to obtain TEG and CAT results representative of baseline hemostatic activity. Weak activity was observed in assays with low TF concentrations (0.5–2 pM), and most but not all samples approached normal activity levels at high TF concentrations (10–20 pM). A significant positive correlation was observed between results of TEG and CAT‐PRP assays. Correlations were not detected between hemostatic assay results and clinical parameters.

Conclusions

In vitro hemostatic assay results of samples containing platelets showed concordance. Assay results were not predictive of FVIII requirements or correlated with other clinical parameters. SHA patient heterogeneity is influenced by factors other than baseline hemostatic activity.

How I approach: The workup and management of patients with progressive transformation of the germinal center

Progressive transformation of the germinal center (PTGC) is a common and underrecognized cause of pediatric lymphadenopathy. PTGC may be associated with numerous systemic medical conditions that require further workup and management, including malignancy, autoimmune conditions, lymphoproliferative conditions, immunodeficiency, and infection. Given the breadth and rarity of the associated conditions, workup should be tailored to the individual patient and occur in a tiered approach. Patients with PTGC require ongoing follow-up, given their long-term risk of malignancy and recurrent PTGC.

Low dose prophylaxis and antifibrinolytics: Options to consider with proven benefits for persons with haemophilia

INTRODUCTION

Prophylaxis has become standard of care for persons with severe phenotype haemophilia (PWsH). However, 'standard prophylaxis' with either factor or non-factor therapies (emicizumab) is prohibitively expensive for much of the world. We sought to evaluate whether haemophilia care can be provided at a lower cost yet achieve good results using Lower dose/Lower frequency prophylaxis (LDP) and with increasing use of antifibrinolytics (Tranexamic acid and Epsilon amino caproic acid).

METHODS

We identified 12 studies that collectively included 335 PWsH using LDP. Additionally, we undertook a literature search regarding the benefits of antifibrinolytics in haemophilia care.

RESULTS

Identified studies show that LDP is far superior to no prophylaxis (On demand [OD] therapy) resulting in significant patient benefits. Patients on LDP showed (in comparison to patients OD) on average: 72% less total bleeds; 75% less joint bleeds; 91% less days lost from school; 77% less hospital admission days; and improved quality of life measures. These benefits come at similar or only slightly higher (< 2-fold greater) costs than OD therapy. Antifibrinolytics are effective adjunctive agents in managing bleeds (oral, nasal, intracranial, possibly other) and providing haemostasis for surgeries (particularly oral surgeries). Antifibrinolytics can substitute for more expensive factor concentrates or can reduce the use of such concentrates. There is evidence to show that antifibrinolytics may be used in conjunction with factor concentrates/emicizumab for more effective/less costly prophylaxis.

CONCLUSIONS

The use of LDP along with appropriate and increased use of antifibrinolytics offers less resourced countries good options for managing patients with haemophilia.

Eptacog beta efficacy and safety in the treatment and control of bleeding in paediatric subjects (<12 years) with haemophilia A or B with inhibitors

Introduction

Eptacog beta is a new recombinant activated human factor VII bypassing agent approved in the United States for the treatment and control of bleeding in patients with haemophilia A or B with inhibitors 12 years of age or older.

Aim

To prospectively assess in a phase 3 clinical trial (PERSEPT 2) eptacog beta efficacy and safety for treatment of bleeding in children <12 years of age with haemophilia A or B with inhibitors.

Methods

Using a randomised crossover design, subjects received initial doses of 75 or 225 μg/kg eptacog beta followed by 75 μg/kg dosing at predefined intervals (as determined by clinical response) to treat bleeding episodes (BEs). Treatment success criteria included a haemostasis evaluation of ‘excellent’ or ‘good’ without use of additional eptacog beta, alternative haemostatic agent or blood product, and no increase in pain following the first ‘excellent’ or ‘good’ assessment.

Results

Treatment success proportions in 25 subjects (1–11 years) who experienced 546 mild or moderate BEs were 65% in the 75 μg/kg initial dose regimen (IDR) and 60% in the 225 μg/kg IDR 12 h following initial eptacog beta infusion. By 24 h, the treatment success proportions were 97% for the 75 μg/kg IDR and 98% for the 225 μg/kg IDR. No thrombotic events, allergic reactions, neutralising antibodies or treatment‐related adverse events were reported.

Conclusion

Both 75 and 225 μg/kg eptacog beta IDRs provided safe and effective treatment and control of bleeding in children <12 years of age.

Switching to nonacog beta pegol in hemophilia B: Outcomes from a Canadian real‐world, multicenter, retrospective study

Background

The Canadian Bleeding Disorders Registry (CBDR) captures data from 24 hemophilia treatment centers and patients directly. Nonacog beta pegol (N9‐GP) was approved in Canada in 2018.

Objectives

To assess treatment outcomes following switching to N9‐GP in a real‐world setting.

Methods

CBDR data for Canadian male patients (aged 7–72 years) with hemophilia B receiving prophylactic N9‐GP for ≥6 months as of March 31, 2021, were included. To allow comparison with the previously used products, only patients for whom data were available in the CBDR for at least 6 months before the switch to N9‐GP were included in this retrospective analysis.

Results

Forty‐two patients were included in the analysis (total observation period: 148.0 patient‐years). The distribution of disease severity was 62% severe, 36% moderate, 2% mild, with 62% of patients previously receiving recombinant factor IX‐Fc‐fusion protein (rFIXFc) and 38% previously receiving standard half‐life (SHL) recombinant factor IX (rFIX). During a median follow‐up period of 2.3 years on N9‐GP prophylaxis, 232 bleeds were reported in 30 patients, 29% of patients reported zero bleeds. The median overall annualized bleeding rate on N9‐GP was 0.73 for patients switching from rFIXFc (previously 1.44) and 2.10 for patients switching from SHL rFIX (previously 6.06). Median total annualized factor consumption (IU/kg) was lower with N9‐GP than with previous SHL rFIX (2152 vs 3018) and previous rFIXFc (1766 vs 2278).

Conclusions

Results from this first real‐world study of N9‐GP in patients with hemophilia B suggest optimal bleeding control with low factor consumption after switching to N9‐GP, irrespective of the previous product.

Safety and effectiveness of recombinant factor XIII‐A 2 in congenital factor XIII deficiency: Real‐world evidence

Background

Objective

Patients/Methods

Results

Conclusions

Excess weight gain in the paediatric bleeding disorders population: Impact of the COVID-19 Pandemic

Introduction

The COVID‐19 pandemic has resulted in lifestyle changes for children. The aim of this study was to evaluate the impact of the pandemic on weight/BMI in children with severe bleeding disorders.

Methods

We conducted a retrospective review of patients age 3–18 years with severe bleeding disorders on prophylactic therapy treated at SickKids Hospital (Toronto, Canada) between February 01, 2018 and March 31, 2021. We evaluated the following pre‐ and post‐COVID variables: weight (kg), weight percentile, BMI (kg/m²), BMI percentile, HJHS score, and prophylactic dosing (units/kg).

Results

One hundred and four patients were included in the final analysis. Diagnoses were as follows:  haemophilia A (n = 92; 70.8%), haemophilia B (n = 17; 13.1%), type 3 von Willebrand disease (n = 11; 8.5%), the remainder were diagnosed with rare factor deficiencies.  Median interval time from pre‐COVID measurements to latest follow‐up was 12.4 months (IQR 10.32–14.52 months) during which there was a statistically significant increase in median weight percentile +5.75 centiles (from 63^rdcentile to 68.75^thcentile). There was a statistically significant increase in mean BMI of +1.03 kg/m²(P = < .001) while median BMI percentile increased +8.82 centiles (from 53.9^thcentile to 62.72^ndcentile) and mean BMI percentile increased 3.42 centiles (from 57.5 centile to 60.9 centile). The group that gained the most weight centiles, BMI and BMI centiles were 5–14 years old.

Conclusion

There was a trend to weight gain over the study period. More long‐term data is required to evaluate the impact of this increase in weight and BMI on children with bleeding disorders.

The impact of extended half-life factor concentrates on patient reported health outcome measures in persons with hemophilia A and hemophilia B

BACKGROUND

Recombinant factors VIII and IX Fc (rFVIIIFc/rFIXFc) were the only available extended half-life (EHL) products in Canada during 2016 to 2018.

OBJECTIVES

To evaluate if patient-reported outcome measures (PROMs) improved in Canadian persons with hemophilia who switched from standard half-life (SHL) to EHL products (rFVIIIFc/rFIXFc).

PATIENTS/METHODS

This prospective cohort study enrolled persons with moderate or severe hemophilia aged ≥6 years who switched to rFVIIIFc/rFIXFc (2016-2018) and those who remained on SHL. Health-related quality of life (HRQoL) was assessed using the Haemophilia-specific Quality of Life (Haem-A-QoL) and 36-item Short-Form Survey (SF-36) at baseline, 3-months, 12 months, and 24 months. Other PROMs included the Work Productivity and Impairment Questionnaire, chronic pain scale, partner/parent ratings of mood, International Physical Activity Questionnaire, and Treatment Satisfaction Questionnaire for Medication. We identified meaningful changes using minimally important difference for SF-36 and responder definition for Haem-A-QoL.

RESULTS

We enrolled 25 switchers (16 rFVIIIFc, 9 rFIXFc) and 33 nonswitchers. Those switched to rFVIIIFc/rFIXFc had improved overall HRQoL, and improved subscale physical activity, mental health, and social functioning at 3 months. The rFIXFc switchers had improved chronic pain and ability to engage in normal activities while the rFVIIIFc switchers had improved treatment satisfaction. There was no change in work impairment after the switch. Observed improvement disappeared by 24 months in most domains.

CONCLUSION

Switching from SHL to rFVIIIFc/rFIXFc resulted in short-term meaningful improvement in overall HRQoL and other PROMs in a small proportion. Longitudinal changes on PROMs are affected by ceiling effects and response shift, warranting further studies in instrument optimization in the era of EHL and nonfactor products.

Magnetic resonance imaging in boys with severe hemophilia A: Serial and end-of-study findings from the Canadian Hemophilia Primary Prophylaxis Study

BACKGROUND

This study examined the structural outcomes for joints of boys with severe hemophilia A receiving frequency/dose-escalated primary prophylaxis using magnetic resonance imaging (MRI), and the importance of interval MRI changes.

METHODS

Forty-six subjects (27 with interval studies) were evaluated by radiographs (X-rays) and mid- and end-of-study MRIs (using the International Prophylaxis Study Group scale), as part of the Canadian Hemophilia Prophylaxis Study. The primary outcome was the presence of MRI osteochondral findings.

RESULTS

The median (range) time on study at the end-of-study MRI examination was 9.6 (4.8-16.0) years, during which 18 of 46 subjects (39%) had osteochondral changes in at least one joint. An interval change in MRI score of at least 1 point was observed in 44% of joints (43 ankles, 21 elbows, 4 knees); at least one joint showed this change in all 27 subjects. Self-reported interval hemarthrosis was associated with a higher likelihood of interval osteochondral change (odds ratio [OR], 1.49; 95% confidence interval [CI] = 1.08-2.06). Presence of synovial hypertrophy or hemosiderin on interval MRIs was associated with an OR of 4.71 (95% CI, 1.92-11.57) and 5.25 (95% CI, 2.05-13.40) of later osteochondral changes on MRI.

DISCUSSION

MRI changes were seen in 39% of subjects. Interval index joint bleeding was associated with an increased risk of later MRI changes, and earlier soft-tissue changes were associated with subsequent osteochondral changes.

Factor product utilization and health outcomes in patients with haemophilia A and B on extended half-life concentrates: A Canadian observational study of real-world outcomes

INTRODUCTION

Recombinant factors VIII and IX Fc (rFVIIIFc/rFIXFc) became available in Canada in 2016 and were the only extended half-life (EHL) factor concentrates available in Canada until 2018.

OBJECTIVES

We aim to describe the change in product utilization in Canadians who switched to rFVIIIFc/rFIXFc.

METHODS

This prospective and retrospective cohort study enrolled males aged ≥6 years with moderate or severe haemophilia who switched to rFVIIIFc/rFIXFc and those who remained on standard half-life (SHL) between 2016 and 2018. Factor utilization and annualized bleeding rates (ABR) were collected at baseline, 1-year and 2-years. Due to low prospective enrolment (n = 25 switchers), prospective and retrospective data were pooled.

RESULTS

125 switchers (93 rFVIIIFc, 32 rFIXFc) and 33 non-switchers were included. The median age was 17 (rFVIIIFc) and 38 years (rFIXFc). Prior to switch, over 80% were on prophylaxis. There was a statistically significant reduction in the prescribed weekly prophylactic dose after the switch to rFVIIIFc/rFIXFc for all age groups, with a corresponding reduction (15-16%) in actual annualized FIX utilization in switchers (combined adults and children) to rFIXFc, and a smaller non-significant reduction in actual annualized FVIIII utilization (7%) in children who switched to rFVIIIFc. A significant reduction in the median ABR was only observed in children who switched to rFVIIIFc, but not in adults who switched to rFVIIIFc or rFIXFc.

CONCLUSION

Switching from SHL to EHL products led to a small reduction in factor utilization, while preserving a low ABR in children and adults with haemophilia. Further patient-reported outcomes data will further elucidate the role of EHL in the haemophilia landscape.

Patterns of joint damage in severe haemophilia A treated with prophylaxis

OBJECTIVE

The primary objective of this study was to assess whether there are different patterns (classes) of joint health in young boys with severe haemophilia A (SHA) prescribed primary tailored prophylaxis. We also assessed whether age at first index joint bleed, blood group, FVIII gene abnormality variant, factor VIII trough level, first-year bleeding rate and adherence to the prescribed prophylaxis regimen significantly predicted joint damage trajectory, and thus class membership.

METHODS

Using data collected prospectively as part of the Canadian Hemophilia Primary Prophylaxis Study (CHPS), we implemented a latent class growth mixture model technique to determine how many joint damage classes existed within the cohort. We used a multinomial logistic regression to predict the odds of class membership based on the above predictors. We fitted a survival model to assess whether there were differences in the rate of dose escalation across the groups.

RESULTS

We identified three distinct classes of trajectory: persistently low, moderately increasing and rapidly increasing joint scores. By multinomial regression, we found that only age at first index joint bleed predicted rapidly increasing joint scores. The rapidly increasing joint score class group moved through dose escalation significantly faster than the other two groups.

CONCLUSIONS

Using tailored prophylaxis, boys with SHA follow one of three joint health trajectories. By using knowledge of disease trajectories, clinicians may be able to adjust treatment according to a subject's predicted long-term joint health and institute cost-effective programmes of prophylaxis targeted at the individual subject level.

Measuring the impact of hemophilia on families: Development of the Hemophilia Family Impact Tool (H-FIT)

Introduction

This study aimed to assess the impact of hemophilia on families, in the context of current and emerging hemostatic therapies, and explore the need for a hemophilia‐specific tool targeted at parents of boys aged <4 years. A secondary aim was to develop and validate the new tool.

Methods

Focus groups were conducted with parents of boys with hemophilia and hemophilia health care providers at Canadian hemophilia treatment centers (HTCs) to review the relevance of the Pediatric Quality of Life Family Impact Module (PedsQL‐FIM); a novel questionnaire was developed by identifying core themes expressed. This questionnaire, the Hemophilia Family Impact Tool (H‐FIT) was validated in a sample of parents of boys with hemophilia relative to the PedsQL‐FIM.

Results

Seven focus groups were conducted at four HTCs, generating themes specific to hemophilia not covered by the PedsQL‐FIM, suggesting that a new tool be developed (the H‐FIT). In the validation phase, 54 parents completed the H‐FIT and PedsQL‐FIM. The H‐FIT had a strong correlation with the PedsQL‐FIM across all ages (r = 0.79; P < .0001) and a moderate correlation for parents of boys aged <7 years (r = 0.64; P = .0007). There was a significant difference between the mean H‐FIT scores for parents of boys using extended half‐life factor (68.1; standard deviation [SD]=14.2) compared to standard half‐life factor (54.7; SD=18.4; P = .04).

Conclusion

A novel, disease‐specific tool, the H‐FIT, has been developed to measure the impact of hemophilia on families. The H‐FIT has good preliminary measurement properties and may be responsive to changes in therapy associated with a decreased burden of administration.

Fetal therapy using rapamycin for a rapidly enlarging, obstructive, cervical lymphatic malformation: a case report

WHAT'S ALREADY KNOWN ABOUT THIS TOPIC?: Fetal lymphatic malformations (LMs) can be detected on prenatal ultrasound and until recently, therapeutic options were limited. Recently the mammalian target of rapamycin inhibitor rapamycin has emerged as a safe, effective therapy for children with LMs and multiple studies have demonstrated improved efficacy if started early. WHAT DOES THIS STUDY ADD?: We report the first in-utero therapy with rapamycin for a rapidly enlarging, obstructive, fetal cervical LM. Fetal therapy with rapamycin was safe and effective in managing this severe malformation, despite rapamycin being started only in the last 6.5 weeks of pregnancy. We speculate that had rapamycin been commenced earlier, the reduction in mass size might have been even greater.

Updating the Canadian Hemophilia Outcomes-Kids' Life Assessment Tool (CHO-KLAT) in the era of extended half-life clotting factor concentrates

INTRODUCTION

The purpose of this study was to review and update the content of the Canadian Hemophilia Outcomes-Kids' Life Assessment Tool version 2.0 (CHO-KLAT), in the context of extended half-life (EHL) factor concentrates (FCs) and to establish the validity and reliability of the updated CHO-KLAT.

METHODS

Focus groups were conducted with boys with hemophilia, their parents, and health care providers across Canada to review the CHO-KLAT v2.0 and determine if any modifications were required. The validity of the revised CHO-KLAT (version 3.0) was then determined in a sample of boys with hemophilia and their parents by calculating its correlation with the Pediatric Quality of Life Core Module (PedsQL-Core). Test-retest reliability was assessed using an intraclass correlation coefficient (ICC).

RESULTS

Thirteen focus groups at 5 pediatric hemophilia treatment centers (HTCs) (n = 71) resulted in 19 changes to the CHO-KLAT v2.0, generating a revised 40-item CHO-KLAT, the CHO-KLAT v3.0. Thirty-five boys with hemophilia (median age, 14; range, 7-17 years) and 47 parents participated in the validation of the CHO-KLAT v3.0. There was a moderate correlation between the CHO-KLAT v3.0 child self-report and PedsQL-Core (r = 0.56, P = .01), and a strong correlation between the CHO-KLAT v3.0 parent-proxy and PedsQL-Core (r = .79, P = .0007). The test-retest reliability ICC was 0.90 for the child self-report CHO-KLAT v3.0 and 0.68 for the parent-proxy CHO-KLAT v3.0.

CONCLUSION

The CHO-KLAT v3.0 is a reliable and valid child-centric tool that effectively measures health-related quality of life in boys with hemophilia who are receiving standard half-life or EHL FCs.

Simoctocog Alfa (Nuwiq) in Previously Untreated Patients with Severe Haemophilia A: Final Results of the NuProtect Study

Introduction  FVIII inhibitor development is the most serious contemporary treatment complication in haemophilia A, particularly in previously untreated patients (PUPs). No inhibitors developed in clinical trials in previously treated patients treated with simoctocog alfa (Nuwiq), a fourth-generation recombinant FVIII produced in a human cell line.

Methods  The NuProtect study investigated the immunogenicity of simoctocog alfa in PUPs. NuProtect was a prospective, multinational, open-label, non-controlled, phase III study. PUPs with severe haemophilia A (FVIII:C <1%) of any age and ethnicity were treated with simoctocog alfa for 100 exposure days or a maximum of 5 years. Patients were true PUPs without prior exposure to FVIII concentrates or blood components. Inhibitor titres were measured with the Nijmegen-modified Bethesda assay; cut-off for positivity was 0.6 BU mL ⁻¹ (≥0.6 to <5 low-titre, ≥5 high titre).

Results  A total of 108 PUPs with a median age at first treatment of 12.0 months (interquartile range: 8.0–23.5) were treated with simoctocog alfa. F8 mutation type was known for 102 patients (94.4%) of whom 90 (88.2%) had null F8 mutations and 12 (11.8%) had non-null mutations. Of 105 PUPs evaluable for inhibitor development, 28 (26.7%) developed inhibitors; 17 high titre (16.2%) and 11 low titre (10.5%). No PUPs with non-null F8 mutations developed inhibitors.

Conclusion  In the NuProtect study, the rate of inhibitor development in PUPs with severe haemophilia A treated with simoctocog alfa was lower than the rate reported for hamster-cell-derived recombinant factor VIII products in other recent clinical trials. No inhibitors were reported in PUPs with non-null F8 mutations.

Key questions in the new hemophilia era: update on concomitant use of FVIII and emicizumab in hemophilia A patients with inhibitors

Introduction: Immune tolerance induction (ITI) is the primary therapeutic strategy and only proven method to eradicate inhibitors to coagulation factor VIII (FVIII) in hemophilia A. Emicizumab, a humanized bispecific monoclonal antibody that mimics the function of activated FVIII, has expanded options to treat hemophilia A. The availability of emicizumab necessitates a revisit of recommendations for managing patients with inhibitors.Areas covered: Current evidence is reviewed about the concomitant use of emicizumab and FVIII concentrates during and after ITI. Areas where data are lacking are highlighted and ongoing studies designed to address these issues are described.Expert opinion: Inhibitor eradication remains a desirable goal. All patients with inhibitors should be offered at least one attempt at ITI. Emicizumab monotherapy is an option for inhibitor patients who are not candidates for ITI. Evidence is emerging about the use of emicizumab during ITI to prevent bleeds. Studies are currently addressing the safety, efficacy, and feasibility of concomitant emicizumab and FVIII in ITI. As evidence regarding the risk of inhibitor recurrence and need for continued FVIII to maintain immune tolerance post-ITI is limited, the role of emicizumab alone or in combination with FVIII after ITI is the subject of an upcoming study.

Illustrative Cases from the Pathfinder Clinical Trials of Patients with Hemophilia A Treated with Turoctocog Alfa Pegol (N8-GP)

PURPOSE

To illustrate the benefits of the extended half-life (EHL) recombinant factor VIII product N8-GP (Esperoct^®, turoctocog alfa pegol) by describing individual cases of patients with severe hemophilia A treated with N8-GP in the pathfinder clinical trial program.

PATIENTS AND METHODS

This manuscript presents selected patient cases from the pivotal pathfinder clinical trial program, which included a number of clinical studies in adults (pathfinder 2 and 3) and children (pathfinder 5); overall results published previously. Clinical data and outcomes described in this manuscript are more detailed and derived from several interesting patient cases (five adults from pathfinder 2 and two children from pathfinder 5), who received N8-GP as prophylaxis (PPX) for their severe hemophilia A. Three of the five adults described here also underwent multiple major surgeries (for which they moved from pathfinder 2 into pathfinder 3 and later returned to pathfinder 2). New analyses on pediatric joint health from pathfinder 5 are also summarized here. Outcomes assessed included bleeding complications, improvements in quality of life, intraoperative hemostatic response, blood loss during surgery, number of blood transfusions, and annualized bleeding rates. For the pediatric patients, target joint resolution, adverse events, and annualized joint bleeding rate were also assessed, all by the treating physician.

RESULTS

Considerable improvements in treatment adherence, bleeding rates, and overall physical activity levels were demonstrated in two adult cases from the pathfinder 2 trial. N8-GP demonstrated good or excellent hemostatic coverage in three adult patients undergoing multiple major surgeries. The benefits of N8-GP for joint health and in support of children and adolescents with evolving active lifestyles were reported for several pediatric cases.

CONCLUSION

These patient cases highlight the benefits of EHL products, such as N8-GP, for patients with severe hemophilia A. They include more challenging scenarios relating to improvements in previously poor adherence to PPX, children with active sporting lifestyles, and patients requiring multiple major surgeries.

Long-Term Safety and Efficacy of Nonacog Beta Pegol (N9-GP) Administered for at Least 5 Years in Previously Treated Children with Hemophilia B

Long-term safety and efficacy data of extended half-life factor IX (FIX) prophylaxis in children with hemophilia B (HB) are sparse. paradigm 5 is a multinational, open-label, single-arm, phase III trial assessing once-weekly (40 IU/kg) prophylactic nonacog beta pegol (N9-GP) in previously treated patients (PTPs) aged ≤ 12 years with HB (FIX activity ≤ 2%). Primary endpoint: incidence of anti-FIX inhibitory antibodies (≥ 0.6 Bethesda Units). We present a 5-year analysis (N = 25, including remaining patients with ≥ 5 years' follow-up) and compare with a 1-year analysis (≥ 52 weeks' exposure). The main phase enrolled 25 children; 22 entered the extension phase; 17 remained in trial at data cutoff. Median treatment period: 5.6 years/patient; median total number of N9-GP exposure days: 290.0/patient. No patients developed anti-FIX inhibitory antibodies. No other safety concerns, including thromboembolic events, were reported. Neurological examinations have not revealed any new abnormal findings. Sixteen (64.0%) patients remained free from spontaneous bleeds; all bleeds were mild/moderate in severity; 93.0% were controlled with 1 to 2 N9-GP injections. No intracranial hemorrhages were reported. Annualized bleeding rates (ABRs) were very low at 5 years (median/Poisson-estimated mean overall ABR: 0.66/0.99), having decreased from the 1-year analysis (1.00/1.44). Median/Poisson-estimated mean spontaneous ABRs for the 1- and 5-year analyses: 0.00/0.45 and 0.00/0.33. Mean FIX trough activity at 5 years: 17.9%. Mean polyethylene glycol plasma concentration reached steady state at 6 months, increasing slightly over time, in line with increased FIX trough activity. N9-GP administered for ≥ 5 years shows favorable long-term safety and efficacy in PTPs with HB (FIX activity ≤ 2%).

Sirolimus Treatment of an Infant With Intrathoracic Kaposiform Hemangioendothelioma Complicated by Life-threatening Pleural and Pericardial Effusions

Kaposiform hemangioendothelioma (KHE) is a rare infiltrative vascular tumor that may be associated with Kasabach-Merritt Phenomenon (KMP), which is a consumptive coagulopathy with potentially life-threatening thrombocytopenia. Management of KHE and KMP is challenging, and currently, there are no standardized validated treatment protocols. Mammalian target of rapamycin inhibitors have been shown to be effective in the treatment of KHE. We describe a term male who presented as a diagnostic dilemma with life-threatening pleural and pericardial effusions and severe thrombocytopenia. After extensive work-up the etiology for his condition was determined to be KHE with KMP. The patient was commenced on sirolimus and responded well to therapy with resolution of KMP.

Measuring the impact of changing from standard half-life (SHL) to extended half-life (EHL) FVIII prophylaxis on health-related quality of life (HRQoL) in boys with moderate/severe haemophilia A: Lessons learned with the CHO-KLAT tool

INTRODUCTION

In many countries, there is a shift from standard half-life (SHL) to extended half-life (EHL) clotting factor concentrates (CFCs).

AIM

To describe the experience of switching from SHL to an EHL FVIII CFC and the impact of this on frequency of infusions, factor consumption, bleeding rates and HRQoL using the Canadian Hemophilia Kids' Life Assessment Tool (CHO-KLAT).

METHODS

A retrospective chart review was conducted at a single haemophilia treatment centre in 2018 that included boys (ages: 4-18 years) with moderate/severe haemophilia A, without inhibitors, who switched from a SHL to an EHL FVIII CFC in the previous 2 years and for whom HRQoL data were available.

RESULTS

The study cohort comprised 38 boys [mean (SD) age: 11.0 (3.4) years] with moderate (n = 5)/severe (n = 33) haemophilia A. The switch was associated with a 33% reduction in the number of weekly infusions from a median of 3.5 to 2.3 (P < .0001) and a 17% reduction in median FVIII consumption from 103 IU/kg/wk to 85.5 IU/kg/wk (P = .004). There was no significant change in annualized joint bleed rates or in CHO-KLAT scores.

CONCLUSIONS

Despite documenting several benefits of switching to EHL FVIII (less infusions, lower factor consumption with no increase in bleeding), our study did not demonstrate any improvement in HRQoL. We conclude that either the current CHO-KLAT tool is not optimized to measure burden of treatment administration in boys with low bleed rates switching from SHL to EHL FVIII CFCs or that a reduction of 1.2 infusions/week does not result in a meaningful change in HRQoL.

Fixed doses of N8-GP prophylaxis maintain moderate-to-mild factor VIII levels in the majority of patients with severe hemophilia A

BACKGROUND

N8-GP is an extended half-life recombinant factor VIII developed for prophylaxis and treatment of bleeds in patients with hemophilia A.

OBJECTIVE

To assess pharmacokinetic (PK) characteristics of N8-GP in previously treated patients with severe hemophilia A, model the time spent at hemophilia thresholds of ≥1 and ≤5 IU/dL (moderate) or >5 IU/dL (mild) FVIII levels during N8-GP prophylaxis, and investigate the relationship between N8-GP half-life and von Willebrand factor (vWF).

METHODS

PK assessments were obtained from patients with severe hemophilia A (FVIII < 1 IU/dL) participating in 4 clinical trials: pathfinder 1 (20-60 years); pathfinder 2 (12-17 and ≥18 years); pathfinder 5 (0-11 years), and pathfinder 7 (25-71 years). All PK profiles were assessed after washout and considered single-dose PK profiles. Pre- and postdose FVIII activity at steady state was measured at all visits.

RESULTS

From 69 patients, 108 PK profiles of N8-GP 50 IU/kg were assessed. Adults/adolescents received 50 IU/kg every 4 days, achieving mean trough levels of 3.0 IU/dL (95% confidence interval, 2.6-3.5, adults) and 2.7 IU/dL (1.8-4.0, adolescents). Children received 60 IU/kg twice weekly, leading to mean trough levels of 1.2 IU/dL (0.8-1.6, 0- to 5-year-olds) and 2.0 IU/dL (1.5-2.7, 6- to 11-year-olds). PK modeling predicted children dosed every 3 days and adults/adolescents dosed every 3 to 4 days would maintain FVIII levels >5 and >1 IU/dL for >80% and 100% of the time, respectively. N8-GP half-life correlated linearly with von Willebrand factor levels in adults/adolescents, less in children.

CONCLUSIONS

Prophylaxis with fixed intervals (Q4D/twice weekly) and fixed weight-based dosing (50/60 IU/kg) ensured >1 IU/dL FVIII trough levels in both adults and children.

The changing face of immune tolerance induction in haemophilia A with the advent of emicizumab

INTRODUCTION

As a result of the new treatment paradigm that the haemophilia community will face with the availability of novel (non-factor) therapies, an updated consensus on ITI recommendations and inhibitor management strategies is needed.

AIM

The Future of Immunotolerance Treatment (FIT) group was established to contemplate, determine and recommend the best management options for patients with haemophilia A and inhibitors.

DISCUSSION AND CONCLUSIONS

Despite the considerable success of emicizumab in the management of inhibitor patients, the FIT group still sees the importance of eradicating inhibitors. However, the availability of emicizumab and other non-factor therapies in the future might impact greatly on how ITI is undertaken. Theoretically, concomitant use of emicizumab and FVIII might allow emicizumab to effectively prevent bleeding with lower dose ITI regimens. This might allow for the greater adoption of low-dose/low-frequency FVIII ITI regimens, which may result in a reduced need for central venous access devices while still maintaining a reasonable likelihood of ITI success. The FIT group proposes a new management algorithm for current ITI (without emicizumab) and a hypothetical new approach with the availability of emicizumab. As there are no published data regarding the concomitant use of emicizumab and FVIII for ITI, the FIT Expert group encourages the undertaking of properly conducted prospective studies to explore these approaches further.

Mild Hereditary Spherocytosis without Accompanying Hereditary Haemochromatosis: An Unrecognised Cause of Iron Overload

Hereditary spherocytosis (HS) is a common inherited haemolytic anaemia and has great variability in its presentation. Non-transfusion iron overload in HS has only been reported with co-inheritance of hereditary haemochromatosis (HHC). We present 4 unrelated patients of East Asian ethnicity with mild HS and significant non-transfusion iron overload in the absence of known disease-causing mutations in HHC genes. We hypothesise that, in patients with mild HS, life-long chronic haemolysis and erythropoietic drive may promote iron absorption. This suggests that mild HS may not be entirely benign, and that patients with mild HS should be monitored for iron overload.

Inhibitors: A Need for Eradication?

The development of inhibitors against factor VIII (FVIII) concentrates represents a significant treatment complication for hemophilia. Immune tolerance induction (ITI) therapy eradicates inhibitors in 60-80% of patients, resulting in a normal FVIII response. This article, based on presentations at the 6th International Coagulation Meeting, held in Barcelona, Spain, in September 2017, provides an overview of management approaches for patients with inhibitors and briefly tabulates four cases of ITI therapy (first-line or rescue ITI therapy in pediatric and adult patients) with successful outcomes. Switching FVIII product from recombinant FVIII to plasma-derived FVIII/VWF concentrate may be helpful in eradicating inhibitors. The rate of decline of inhibitor titer in the initial stages of ITI therapy is a good indicator of the success or failure of therapy, although prognostic biomarkers are needed. The development of the bispecific monoclonal antibody emicizumab, which was recently shown to reduce bleeding in inhibitor patients, offers a potential alternative therapeutic option. However, the benefits of inhibitor eradication, including a wider choice of cheaper therapeutic products for preventing and treating bleeds, suggest that at least one attempt of ITI therapy should be offered to patients who develop inhibitors.

Tailored frequency-escalated primary prophylaxis for severe haemophilia A: results of the 16-year Canadian Hemophilia Prophylaxis Study longitudinal cohort

BACKGROUND

Severe haemophilia A has high morbidity, and treatment, while effective, is very expensive. We report the 16-year follow-up of the Canadian Hemophilia Prophylaxis Study, which examined the effectiveness of tailored frequency-escalated primary prophylaxis with a focus on health outcomes within the domains of body structures and functions, and activities and participation (according to the WHO International Classification of Functioning, Disability and Health [WHO-ICF] framework) and a view to reducing consumption of costly clotting factor, which accounts for more than 90% of the cost of care of severe haemophilia.

METHODS

In this longitudinal study, boys with severe haemophilia A from 12 Canadian centres were enrolled at age 1·0-2·5 years. They were treated with standard half-life recombinant factor VIII (SHL-rFVIII), beginning as once-weekly prophylaxis with 50 IU/kg and escalating in frequency (with accompanying dose adjustments) in response to breakthrough bleeding as determined by the protocol. The primary endpoint for this analysis was joint health, as measured by the modified Colorado Child Physical Examination Scores (CCPES) at study end. All analyses were done by intention to treat. The trial is complete, and is registered with ClinicalTrials.gov, number NCT01085344.

FINDINGS

Between June 26, 1997, and Jan 30, 2007, 56 boys were enrolled. They were followed for a median of 10·2 years (to a maximum of 16·1 years). Median rFVIII usage was about 3600 IU/kg per year. The median end-of-study CCPES physical examination score was 1 (IQR 1-3; range 0-12) for the left ankle and 1 (1-2; 0-12) for the right ankle, with all other joints having a median score of 0. No treatment-related safety events occurred over the duration of the study, including central venous catheter infections. The median annualised index joint bleeding rate was 0·95 per year (IQR 0·44-1·35; range 0·00-13·43), but 17 (30%) patients had protocol-defined unacceptable breakthrough bleeding at some point during the study.

INTERPRETATION

Tailored frequency-escalated prophylaxis leads to very little arthropathy and very good health outcomes within the WHO-ICF domains, and only uses a moderate amount of expensive clotting factor as compared with standard prophylaxis protocols. Some sequelae of bleeding were observed in our cohort, and future studies should consider a more stringent protocol of escalation.

FUNDING

This study was initially funded by grants from the Medical Research Council of Canada/Pharmaceutical Manufacturers Association of Canada Partnership Fund and the Bayer/Canadian Blood Services/Hema-Quebec Partnership Fund. Subsequent renewals were funded by Bayer.

Results after laparoscopic partial splenectomy for children with hereditary spherocytosis: Are outcomes influenced by genetic mutation?

BACKGROUND

Laparoscopic partial splenectomy (LPS) theoretically maintains long-term splenic immune function for children with hereditary spherocytosis (HS). Our goal was to review our results after LPS and to determine if specific genetic mutations influence outcome.

METHODS

All children with HS undergoing LPS between 2005 and 2016 were reviewed.

RESULTS

Thirty-one children underwent LPS (16 male) at a median age of 9 (range 2-18) years. All experienced an increase in hemoglobin and decrease in reticulocyte count early after LPS and at last follow-up. Twenty-two were sent for genetic analysis. Mutations in α-spectrin, β-spectrin, and Ankyrin were identified in 6, 5, and 11 patients, respectively. Gene mutation was not correlated with complications, perioperative transfusion, length of hospital stay, or median hemoglobin, platelet, or reticulocyte counts. Three children required completion splenectomy at 10.9, 6.9, and 3.2years post-LPS, each with a different gene mutation.

CONCLUSIONS

LPS is effective in reversing anemia and reducing reticulocytosis. So far less than 10% have required completion splenectomy, and those children did benefit from delaying the risks of asplenia. In this preliminary analysis, genetic mutation did not influence outcome after LPS. A larger multicenter study is necessary to further investigate potential correlations with specific genetic mutations.

TYPE OF STUDY

Prognosis Study.

LEVEL OF EVIDENCE

IV.

Type 3 VWD and an inhibitor to VWF: Challenges in diagnosis

Developing an inhibitor to von Willebrand factor (VWF) is extremely uncommon. Consequently, patients with von Willebrand disease (VWD) tend not to be routinely evaluated for inhibitors, leading to the possibility of delay in inhibitor diagnosis. We present such an occurrence to raise awareness, with a view to avoiding such delays. A 1-year-old male with no family history of bleeding disorders or parental consanguinity presented with a tongue bleed lasting three days. Investigations confirmed a diagnosis of Type 3 VWD. Over the next few months, the patient received seven exposures to Humate-P (a plasma derived FVIII containing von Willebrand factor concentrate), but developed an anaphylactic reaction necessitating adrenalin and Benadryl (diphenhydramine). The reaction quickly abated and did not recur with further exposure to Humate-P. In 2013, due to recurrent epistaxis and tonsillar bleeding, the patient was commenced on prophylaxis receiving Humate-P 50 RCo U/kg twice weekly. Despite this regimen, he continued to experience recurrent epistaxis, leading to escalation of prophylaxis to 3/week. In November 2014, he showed persistent tonsillar bleeding, despite having received two doses of Humate-P (each 40 RCo U/kg) in the previous 12 hours. Testing revealed reduced VWF:Ag, VWF:RCo and FVIII:C recoveries. Further testing revealed an anti-VWF antibody (2.6 BU) of unspecified Ig type. Since diagnosis of the inhibitor, he has received 100 RCo U/kg daily for prophylaxis and immune tolerance. He is now bleed-free; however, monthly inhibitor testing shows that his inhibitor persists. Given the limited experience and literature on inhibitors in VWD, the prognosis for such cases is unknown.

Desmopressin in moderate hemophilia A patients: a treatment worth considering

Desmopressin increases endogenous factor VIII levels in hemophilia A. Large inter-individual variation in the response to desmopressin is observed. Patients with a lower baseline factor VIII activity tend to show a reduced response, therefore, desmopressin is less frequently used in moderate hemophilia A patients (baseline factor VIII activity 1-5 international units/deciliter), even though factor VIII levels may rise substantially in some of them. We aim to describe the response to desmopressin in moderate hemophilia A patients and to identify predictors. We selected data on 169 patients with moderate hemophilia from the multicenter Response to DDAVP In non-severe hemophilia A patients: in Search for dEterminants (RISE) cohort study. Adequate response to desmopressin was defined as a peak factor VIII level ≥ 30, and excellent response as ≥ 50 international units/deciliter after desmopressin administration. We used univariate and multiple linear regression techniques to analyze predictors of the peak factor VIII level. Response was considered adequate in 68 patients (40%), of whom 25 showed excellent response (15%). Intravenous administration, age, pre-desmopressin factor VIII activity and von Willebrand factor antigen, peak von Willebrand factor activity and desmopressin-induced rise in von Willebrand factor antigen were significant predictors of peak factor VIII level and explained 65% of the inter-individual variation. In 40% of moderate hemophilia A patients, desmopressin response was adequate, thus it is important not to with-hold this group of patients from desmopressin responsiveness. Among the six predictors that we identified for desmopressin-induced factor VIII rise, factor VIII activity and desmopressin-induced rise in von Willebrand factor antigen had the strongest effect.