The complex, confusing and poorly understood immune responses to AAV-mediated gene transfer in haemophilia-Is more or less immunosuppression required?

Attempts to achieve a functional cure or amelioration of the severe X linked bleeding disorders haemophilia A (factor VIII deficiency) and haemophilia B (factor IX deficiency) using AAV-based vectors have been frustrated by immune responses that limit efficacy and durability. The immune responses include adaptive and innate pathways as well as cytokine mediated inflammation, especially of the target organ cells-hepatocytes. Immune suppression has only been partly effective in clinical trials at ameliorating the immune response and the lack of good animal models has delayed progress in identifying mechanisms and developing more effective approaches to controlling these effects of AAV gene transfer. Here we discuss the arguments for and against more potent immunosuppression to improve factor expression after AAV-mediated gene therapy.

The benefits of gene therapy in people with haemophilia.

Haemophilia is an inherited bleeding disorder which causes significant morbidity and mortality, especially in the severe form. Prophylaxis with factor replacement has high efficacy in reducing bleeding but is limited by the need for frequent intravenous infusion and fluctuations in haemostasis between doses. Additional prophylaxis therapies are being developed which may overcome some of the current treatment barriers. Gene therapy (GT) is being developed to provide a functional cure such that there is sustained factor expression and minimal to no need for additional haemostatic therapy. There are now two approved gene therapies for haemophilia which may be transformative for many individuals. Benefits of GT should go beyond increasing factor activity and reducing bleeding as persons with haemophilia aim to achieve a 'haemophilia-free mind' and health equity with optimal health and well-being.

Management strategies in persons with inherited haemophilia requiring antithrombotic therapy: A scoping review.

BACKGROUND: Thromboembolic events are increasingly reported in the aging haemophilia population. The purpose of this study was to understand current practices and identify knowledge and research gaps in the management of persons with haemophilia requiring antithrombotic therapy for cardiovascular disorders (CVD) or venous thromboembolism (VTE). METHODS: We searched MEDLINE, EMBASE and Scopus for studies reporting on more than two patients with inherited haemophilia A or B, without inhibitors, requiring antithrombotic therapy for CVD or VTE. Data were extracted by two independent reviewers and analysed using descriptive statistics and narrative synthesis. RESULTS: We included 32 studies reporting on 432 persons with haemophilia. Three themes described the observed practice variation: (1) Difficulty weighing competing bleeding and thrombotic risks; (2) Tensions in providing standards of care and minimizing bleeding risk; (3) Advocacy for individualized strategies and multidisciplinary care. Different management strategies were used to treat persons with haemophilia in the setting of thromboembolic events, such as avoiding or choosing lower intensity antithrombotic therapy, or procedural alternatives to antithrombotic therapy. Initiation or alteration in haemostatic therapies along with antithrombotic therapy were common strategies and reported in 30 studies. However, data on target factor levels and bleeding and thrombotic events were largely missing. DISCUSSION: Our scoping review highlights unmet needs in the management of an aging population of persons with haemophilia with increasing prevalence of CVD and VTE. Management is inconsistent and divergent from those of non-haemophilic patients. Prospective data are needed to inform optimal and evidence-based management strategies of CVD and VTE in persons with haemophilia.

Force-sensing treadmill gait analysis system can detect gait abnormalities in haemophilia patients without arthropathy.

BACKGROUND: Joint damage in patients with haemophilia (PwH) is commonly assessed by imaging, but few reports have described how structural changes in joints, for example, haemophilic arthropathy (HA)-affect gait ability. OBJECTIVES: We evaluated gait function among PwH with HA, PwH without HA, and people without haemophilia (non-PwH) using a Zebris FDM-T treadmill (FDM-T), an easy-to-use gait assessment instrument with a force sensor matrix. METHODS: The following gait parameters were collected: centre of pressure trajectory intersection (COPi) anterior/posterior variability, COPi lateral variability, COPi anterior/posterior symmetry, COPi lateral symmetry, single-limb support line (SLSL) length, and SLSL variability. Participants walked at their typical gait speed. The physical function of the PwH was assessed by the Hemophilia Joint Health Score (HJHS). Parameters were compared among the three groups. RESULTS: Twelve PwH with HA, 28 PwH without HA, and 12 non-PwH were enrolled. Gait speed significantly differed between groups (non-PwH, 3.1 ± 0.7; PwH without HA, 2.0 ± 0.7; PwH with HA; 1.5 ± 0.4). The COPi anterior/posterior variability, COPi lateral variability, SLSL length, and SLSL variability were greater in the PwH groups than in the non-PwH group. The COPi lateral symmetry differed between PwH with HA and the other groups. The HJHS was not correlated with gait parameters among PwH with HA. CONCLUSIONS: Gait parameters and speed were abnormal in both PwH with HA and PwH without HA. The FDM-T can be used to identify early stages of physical dysfunction that cannot be detected by conventional functional assessments such as the HJHS.

Health-related quality of life and physical activity in Nordic patients with moderate haemophilia A and B (the MoHem study).

INTRODUCTION: The impact of moderate haemophilia on health-related quality of life (HRQoL) and physical activity (PA) is not well known. In previous studies, persons with factor VIII/factor IX activity (FVIII/FIX:C) below 3 IU/dL were associated with a more severe bleeding phenotype than predicted. AIM: To explore HRQoL and PA in patients with moderate haemophilia A (MHA) and B (MHB). METHODS: A cross-sectional, multicentre study covering patients with MHA and MHB in Sweden, Finland, and Norway. HRQoL was assessed with the EuroQoL 5-Dimensions (EQ-5D) form and PA with the International Physical Activity Questionnaire among participants aged ≥15 years. RESULTS: We report on 104 patients aged 15-84 years from the MoHem study. Overall, EQ-5D utility was .85 (median) (Q1-Q3 0.73-1.0) with corresponding visual analogue scale (VAS) 80 (70-90), which were similar regardless of treatment modality, FVIII/FIX:C, and MHA or MHB. Pain and mobility were most frequently affected dimensions. Utility (r = -.54), VAS (r = -.42), and PA (r = -.32) correlated negatively with arthropathy (HJHS). Only patients aged 41-50 years displayed lower utility (p = .02) and VAS (p < .01) than the Norwegian population norm. Patients on prophylaxis aged 35-54 years reported higher PA than those treated on-demand (p = .01). CONCLUSION: Haemophilic arthropathy had negative impact on HRQoL and PA in Nordic patients with moderate haemophilia. Middle-aged patients captured lower utility and VAS than observed in the general population. Tailored prophylaxis and improved joint health may influence positively on HRQoL and PA also in moderate haemophilia.

Indirect treatment comparisons of the gene therapy etranacogene dezaparvovec versus extended half-life factor IX therapies for severe or moderately severe haemophilia B.

INTRODUCTION: Etranacogene dezaparvovec gene therapy for haemophilia B demonstrated superior efficacy at 24 months in reducing bleeds versus a ≥6-month lead-in period of prophylaxis with FIX products in the phase 3 trial, HOPE-B. In the absence of head-to-head comparisons of etranacogene dezaparvovec versus FIX products, indirect treatment comparisons (ITC) can be used. AIM: To compare the efficacy of etranacogene dezaparvovec versus rIX-FP, rFIXFc and N9-GP using ITC, and support HOPE-B results. METHODS: Data were leveraged from Phase 3 pivotal trials: HOPE-B, PROLONG-9FP, B-LONG and Paradigm 2. Annualised bleeding rates (ABR), spontaneous (AsBR) and joint (AjBR) bleeding rates, percentage of patients with no bleeds, and FIX consumption were assessed using inverse probability of treatment weighting and matching adjusted indirect comparisons. RESULTS: Etranacogene dezaparvovec demonstrated statistically significantly lower bleeding rates versus all comparators. Rate ratios for ABR, AsBR and AjBR versus rIX-FP were 0.19 (p < .0001), 0.08 (p < .0001) and 0.09 (p < .0001), respectively. Rate ratios for ABR, AsBR and AjBR versus rFIXFc were 0.14 (p < .0001), 0.13 (p = .0083) and 0.15 (p = .0111), respectively. Rate ratios for ABR and AsBR, versus N9-GP were 0.24 (p = .0231) and 0.13 (p = .0071), respectively. Etranacogene dezaparvovec demonstrated significantly higher percentage of patients with no bleeds versus rIX-FP and rFIXFc; odds ratios: 17.60 (p < .0001) and 5.65 (p = .0037), respectively. Etranacogene dezaparvovec resulted in significantly lower FIX consumption than all comparators. CONCLUSIONS: ITC suggests that etranacogene dezaparvovec offers patients with haemophilia B (≤2% of normal FIX expression) a single dose treatment that can significantly reduce bleeding rates and eliminate routine infusions associated with FIX therapies.

Effect of etranacogene dezaparvovec on quality of life for severe and moderately severe haemophilia B participants: Results from the phase III HOPE-B trial 2 years after gene therapy.

INTRODUCTION: For people with haemophilia B (PwHB), bleeding may occur despite prophylaxis, negatively affecting health-related quality of life (HRQoL). The pivotal phase 3 HOPE-B trial investigating the adeno-associated virus gene transfer product, etranacogene dezaparvovec (EDZ), demonstrated sustained factor IX (FIX) activity and bleed protection in PwHB with baseline FIX levels ≤2%. AIM: Assess how EDZ affects HRQoL in HOPE-B trial participants. METHODS: HRQoL was evaluated using generic and disease-specific patient reported outcomes (PROs) including the EQ-5D-5L and the Hem-A-QoL questionnaires. Mean domain and total scores were compared 6 months pre- and the first 2 years post-EDZ administration using repeated measures linear mixed models. The percentage of participants with minimal clinically important improvements in HRQoL was also evaluated. RESULTS: Two years post-EDZ, there were nominally significant increases in the least squares (LS) mean score for the EQ-5D-5L Index Value (.04; p = .0129), reflecting better HRQoL. Nominally significant decreases in the LS mean scores, reflecting better HRQoL, were also found for the Hem-A-QoL total score (-6.0; p < .0001) and the Treatment (-13.94; p < .0001), Feelings (-9.01; p < .0001), Future (-6.45; p = .0004) and Work/School (-5.21; p = .0098) domains. The percentage of participants with ≥15-point improvement ranged from 45.83% (95% CI: 31.37%, 60.83%) for Treatment to 13.89% (95% CI: 4.67%, 29.50%) for Family Planning. Results were similar for Year 1. CONCLUSION: In conclusion, gene therapy with EDZ improved HRQoL in the first and second years in several Hem-A-QoL domains, including Treatment, Feelings, Work/School and Future domains, whereas improvement in other aspects of HRQoL were not demonstrated.

Origin of pathogenic variant and mosaicism in families with a sporadic case of haemophilia B.

INTRODUCTION: Of newly diagnosed cases of haemophilia B, the proportion of sporadic cases is usually 50% of severe cases and 25% of moderate/mild cases. However, cases presumed to be sporadic due to family history may not always be sporadic. Few case reports have been published on mosaicism in haemophilia B. AIM: The present study aimed to trace the origin of the pathogenic variant in a well-defined cohort of sporadic cases of haemophilia B by haplotyping markers. It also aimed to determine the frequency of mosaicism in presumed non-carrier mothers. METHODS: The study group was 40 families, each with a sporadic case of haemophilia B analysed in two-to-three generations by Sanger sequencing, haplotyping and using the sensitive droplet digital polymerase chain reaction (ddPCR) technique. RESULTS: In 31/40 (78%) of the families, the mother carried the same pathogenic variant as her son, while Sanger sequencing showed that 9/40 (22%) of the mothers did not carry this variant. Of these variants, 2/9 (22%) were shown to be mosaics by using the ddPCR technique. 16/21 carrier mothers, with samples from three generations available, had a de novo pathogenic variant of which 14 derived from the healthy maternal grandfather. CONCLUSION: The origin of the pathogenic variant in sporadic cases of haemophilia B is most often found in the X-chromosome derived from the maternal grandfather or, less often, from the maternal grandmother. Mosaic females seem to be found at the same frequency as in haemophilia A but at a lower percentage of the pathogenic variant.

Haemophilia care in Asia: Learning from clinical practice in some Asian countries.

BACKGROUND: The healthcare systems in Asia vary greatly due to the socio-economic and cultural diversities which impact haemophilia management. METHODS: An advisory board meeting was conducted with experts in haemophilia care from Asia to understand the heterogeneity in clinical practices and care provision in the region. FINDINGS: The overall prevalence of haemophilia in Asia ranges between 3 and 8.58/100,000 patients. Haemophilia A was more prevalent as compared to haemophilia B with a ratio of around 5:1. There is under-diagnosis in the region due to lack of diagnosis, registries and/or lack of appropriate facilities in suburban areas. Most patients are referred to the haematologists by their families or primary care physicians, while some are identified during bleeding episodes. Genetic testing faces obstacles like resource constraints, services available at limited centres and unwillingness of patients to participate. Prophylaxis is offered for people with haemophilia (PWH) with a severe bleeding phenotype. Recombinant factors are approved in most countries across the region and are the preferred therapy. The challenges highlighted for not receiving a high standard of care include patients' reluctance to use an intravenous treatment, poor patient compliance due to frequency of infusions, budget constraints and lack of funding, insurance, availability and accessibility of factor concentrates. Prevalence of neutralizing antibodies ranged from 5% to 20% in the region. Use of immune tolerance induction and bypassing agents to treat inhibitors depends on their cost and availability. CONCLUSION: Haemophilia care in Asia has evolved to a great extent. However, some challenges remain for which a strategic approach along with multi-stakeholder involvement are needed.

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.

Real-world effectiveness of eptacog beta in patients with haemophilia and inhibitors: A multi-institutional case series.

INTRODUCTION: The management of bleeding events (BEs) in haemophilia A (HA) and B (HB) patients with inhibitors necessitates the use of bypassing agents. The recombinant factor VIIa bypassing agent eptacog beta has demonstrated efficacy at treating BEs and managing perioperative bleeding in adults in phase three clinical studies. AIM: To provide real-world descriptions of eptacog beta use for BE treatment in patients on emicizumab or eptacog beta prophylaxis. METHODS: This is a retrospective case series of 14 patients who received eptacog beta at seven haemophilia treatment centres, with HA (n = 11) or HB (n = 3) and inhibitors or anaphylaxis to factor replacement. RESULTS: Twenty-four spontaneous and traumatic BEs are described (muscle hematomas, joint hemarthroses, port site, and epistaxis) involving 11 subjects. Eptacog beta was effective for acute bleed treatment as both first-line therapy and for treatment of BEs refractory to eptacog alfa in 23/24 events. When eptacog beta was used for prophylaxis, 2/3 patients reported a decreased frequency of breakthrough BEs compared with prophylactic eptacog alfa and one patient experienced a similar frequency of breakthrough BEs compared with prophylactic activated prothrombin complex concentrate. Eptacog beta provided effective bleed control for three subjects who underwent minor surgical procedures. Treatment with eptacog beta was estimated to be 46%-72% more cost-effective than eptacog alfa. No safety concerns or adverse events were reported. CONCLUSIONS: In this case series, eptacog beta was safe, effective, and economical as first-line therapy, treatment of refractory BEs, management of perioperative bleeding, or prophylaxis in haemophilia patients with inhibitors.

Current and emerging gene therapies for haemophilia A and B.

INTRODUCTION: After decades of stumbling clinical development, the first gene therapies for haemophilia A and B have been commercialized and have normalized factor (F)VIII and factor (F)IX levels in some individuals in the long term. Several other clinical programs testing adeno-associated viral (AAV) vector gene therapy are at various stages of clinical testing. DISCUSSION: Multiyear follow-up in phase 1/2 and 3 studies showed long-term and sometimes curative but widely variable and unpredictable efficacy. Liver toxicities, mostly low-grade, occur in the 1st year in at least some individuals in all haemophilia A and B trials and are poorly understood. Wide variability and unpredictability of outcome and slow decline of FVIII levels are a major disadvantage because immune responses to AAV vectors preclude repeat dosing, which otherwise could improve suboptimal or restore declining expression, while overexpression may predispose to thrombosis. Long-term safety outcomes will need lifelong monitoring because AAV vectors infused at high doses integrate into chromosomes at rates that raise questions about potential oncogenicity and necessitate vigilance. Alternative gene transfer systems employing gene editing and/or non-viral vectors are under development and promise to overcome some limitations of the current state of the art for both haemophilia A and B. CONCLUSIONS: AAV gene therapies for haemophilia have now become new treatment options but not universal cures. AAV is a powerful but imperfect gene transfer platform. Biobetter FVIII transgenes may help solve some problems plaguing gene therapy for haemophilia A. Addressing variability and unpredictability of efficacy, and delivery of gene therapy to ineligible patient subgroups may require different gene transfer systems, most of which are not ready for clinical translation yet but bring innovations needed to overcome the current limitations of gene therapy.

Relationship between plasma tissue Factor Pathway Inhibitor (TFPI) levels, thrombin generation and clinical risk of bleeding in patients with severe haemophilia A or B.

INTRODUCTION: Bleeding severity in severe haemophilic patients, with low thrombin generation (TG) capacity, can vary widely between patients, possibly reflecting differences in tissue factor pathway inhibitor (TFPI) level. AIM: To compare free TFPI (fTFPI) levels in patients with severe haemophilia A (sHA) and severe haemophilia B (sHB) and to investigate in these patients as a whole the relationships between bleeding and TG potential, between TG potential and fTFPI level and between fTFPI level and bleeding tendency. METHODS: Data on bleeding episodes retrospectively recorded during follow-up visits over 5-10 years were collected and used to calculate the annualised joint bleeding rate (AJBR). fTFPI levels and basal TG parameters were determined in platelet-poor plasma (PPP) and platelet-rich plasma (PRP) using calibrated automated tomography (CAT). RESULTS: Mean fTFPI levels did not differ significantly between sHA (n = 34) and sHB (n = 19) patients. Mean values of endogenous thrombin potential (ETP) and thrombin peak (peak) in PPP and PRP were two-fold higher when fTFPI levels < 9.4 versus > 14.3 ng/mL. In patients treated on demand, ETP and peak in PRP were doubled when AJBR was ≤ 4.9 $ \le 4.9$ , AJBR being halved in patients with a low fTFPI level (9.4 ng/mL). In patients on factor prophylaxis, no association was found between TG parameters and either fTFPI level or AJBR. CONCLUSION: In patients treated on demand, bleeding tendency was influenced by fTFPI levels, which in turn affected basal TG potential. In patients on prophylaxis, bleeding tendency is probably determined primarily by the intensity of this treatment.

Value contribution of etranacogene dezaparvovec gene therapy in moderately severe and severe haemophilia B through multi-criteria decision analysis.

INTRODUCTION: The value of gene therapies for haemophilia needs to be assessed holistically. AIM: To determine the value of etranacogene dezaparvovec (ED) compared to current extended half-life (EHL) recombinant factors (rFIX), using multi-criteria decision analysis (MCDA). METHOD: MCDA EVIDEM methodology adapted to orphan drugs was used, with nine quantitative criteria and four contextual criteria. The MCDA framework was rated by 28 multidisciplinary experts. Descriptive statistics were performed for quantitative and qualitative criteria. RESULTS: Haemophilia B (HB) was considered a severe disease (mean ± SD: 4.3 ± 0.7) with some unmet needs (mean ± SD 3.3 ± 0.9). Experts found ED more effective (mean ± SD 2.0 ± 2.3) and provide better quality of life (QoL) (mean ± SD: 1.8 ± 1.5) than the comparative HB treatments but with safety uncertainties (mean ± SD -1.2 ± 1.8). ED could lead to medical cost and non-medical cost savings over time (mean ± SD: 1.6 ± 2.0 and 2.0 ± 1.5, respectively). The quality of the evidence was high (mean ± SD: 3.9 ± 0.9). ED was considered aligned with the priorities of the National Health System (NHS) and the specific interests of patients. ED's value contribution was 0.45 (+1 = highest value). CONCLUSIONS: ED brings added value in the treatment of moderately severe and severe HB (sHB) compared to current EHL rFIX, addressing the severity of the disease and increasing efficacy and patients' QoL especially related to the single dose and low bleeding rate. Concerns about long-term safety need to be addressed.

Genetic variant detection in a South African haemophilia B population.

BACKGROUND: Haemophilia B is characterised by a deficiency of factor IX (FIX) protein due to genetic variants in the FIX gene (F9). Genetic testing may have a vital role in effectively managing haemophilia B. However, in many developing countries, comprehensive genetic variant detection is unavailable. This study aimed to address the lack of genetic data in our country by conducting genetic variant detection on people affected by haemophilia B in our region. METHODS: Twenty-one participants were screened with a direct Sanger sequencing method to identify variants in the F9 gene. The identified variants were then compared to previously published variants and/or to a reference database. RESULTS AND DISCUSSION: A total of ten F9 genetic changes were detected, with five of them being novel. These identified variants were distributed across different domains of the FIX protein. Only one participant had a history of inhibitor formation against FIX replacement therapy. Notably, this participant had two distinct genetic changes present adjacent to each other. Thus, we hypothesise that the presence of multiple variants within the same functional region of the gene may increase the risk for inhibitor development. CONCLUSION: The discovery of novel pathogenic variations in the F9 gene highlights the importance of genetic analysis in specific geographical regions. The possible link between a complex variant and inhibitor formation illustrates the potential role that genetic screening has as a pre-treatment tool in predicting treatment reactions and outcomes.

Use of crushed tranexamic acid tablets in water for paediatric patients with bleeding disorders.

BACKGROUND: Ε-Aminocaproic acid oral solution (EACA OS) is the only commercially available antifibrinolytic for patients who cannot swallow tablets. Insurance denials and high costs remain barriers to its use. OBJECTIVES: To determine the safety and efficacy of crushed tranexamic acid tablets in water (cTXAw) for children with bleeding disorders. METHODS: We retrospectively reviewed records of children (<10 years) with bleeding disorders who received cTXAw or EACA OS from 1 December 2018, through 31 July 2022, at Mayo Clinic (Rochester, Minnesota). Bleeding outcomes were defined according to ISTH criteria. RESULTS: Thirty-two patients were included (median age, 3 years; male, n = 23). Diagnoses were VWD (n = 17), haemophilia (n = 5), FVII deficiency (n = 3), inherited platelet disorder (n = 4), ITP (n = 2), and combined FV and FVII deficiencies (n = 1). Thirty-two courses of cTXAw (monotherapy 24/32; mean duration 6 days) and fifteen courses of EACA (monotherapy 12/15; mean duration 5 days) were administered. No surgical procedures (n = 28) were complicated by bleeding. Of the 19 bleeding events, 16 had effective haemostasis, two had no reported outcome, and one had no response. cTXAw and EACA were equally effective in preventing and treating bleeding (p value > .1). No patients had adverse effects. Eight of 19 patients (42%) who were initially prescribed EACA OS did not receive it because of cost or insurance denial. The estimated average wholesale price of one treatment was $94 for cTXAw and $905 for EACA OS. CONCLUSIONS: CTXAw appears to be an effective, safe, and low-cost alternative option to EACA OS for young children with bleeding disorders.

Disease and treatment burden of patients with haemophilia entering the explorer6 non-interventional study.

OBJECTIVES: We aimed to characterise baseline disease and treatment burden in a large population with haemophilia A/B, both with (HAwI/HBwI) and without (HA/HB) inhibitors. METHODS: The prospective, non-interventional explorer6 study included patients ≥12 years old with severe HA, severe/moderate HB or HAwI/HBwI of any severity, treated according to local standard of care (excluding previous/current exposure to concizumab or emicizumab). Baseline characteristics and historical clinical data were collected and patient-reported outcomes, including treatment burden, were assessed. RESULTS: The explorer6 study enrolled 231 patients with haemophilia (84 HAwI/HBwI) from 33 countries. At baseline, patients with HA/HB treated with prophylaxis had the lowest median annualised bleeding rates (ABRs; 2.0), irrespective of haemophilia type; of these patients, 27.5% (HA) and 31.4% (HB) had target joints. Patients with HAwI/HBwI treated episodically reported the highest treatment burden. Of these patients, 28.5% (HAwI) and 25.1% (HBwI) performed sports activities in the month before screening. CONCLUSION: Despite receiving routine clinical care, historical and baseline information from patients enrolled in explorer6 showed that patients with HA/HB treated episodically and patients with HAwI/HBwI had higher ABRs, higher treatment burden and participated in sports less than those with HA/HB treated with prophylaxis. Emerging treatments could be beneficial in addressing these unmet medical needs.

Prophylaxis with recombinant factor IX Fc fusion protein reduces the risk of bleeding and delays time to first spontaneous bleed event in previously untreated patients with haemophilia B: A post hoc analysis of the PUPs B-LONG study.

OBJECTIVES: Haemophilia B (HB), characterised by deficient factor IX (FIX), leads to spontaneous bleeds. Severe cases require prophylactic FIX replacement. This post hoc analysis assessed the first spontaneous bleeds among previously untreated patients (PUPs) with HB treated with recombinant FIX Fc fusion protein (rFIXFc) (NCT02234310) to identify factors influencing bleeds. METHODS: Subjects included paediatric PUPs with HB (≤2 IU/dL endogenous FIX). Analyses described treatment patterns (on demand [OD] vs. prophylaxis) and prophylaxis type (started on vs. switched to prophylaxis). Kaplan-Meier analyses assessed the time to first spontaneous bleed, including median time to event and fitting models with predictors for treatment regimen and/or baseline age. RESULTS: PUPs B-LONG enrolled 33 subjects. Baseline age did not influence the time to first spontaneous bleed for any rFIXFc regimen. Those who started on prophylaxis with rFIXFc (n = 11), compared with those treated OD (n = 22), had an extended time to first spontaneous bleed. Starting prophylaxis afforded a 93% reduced risk of first spontaneous bleed versus starting OD (hazard ratio [95% confidence interval]: 0.071 [0.009-0.592]) (p = .015). CONCLUSION: rFIXFc prophylaxis, particularly starting early, reduced the risk of bleeding and delayed time to first spontaneous bleed compared with rFIXFc OD. Hence, initial treatment regimens impact bleed patterns in paediatric PUPs.

Pattern of use and clinical outcomes with rIX-FP in pediatric/adolescent patients with haemophilia B in Italy: Results from IDEAL real-world study.

OBJECTIVES: To evaluate pattern of use and clinical outcomes in pediatric/adolescent patients enrolled in the IDEAL study. METHODS: This post-hoc analysis of IDEAL retrospective-prospective observational study focused on patients <18 years, 100% on prophylaxis during the entire observation period. RESULTS: Thirteen subjects (median age 10.0 years; 61.5% ≤ 11 years) were analyzed. The infusion frequency changed from 2/week in 84.6% (N = 11) of patients with previous rFIX, to less than 1/weekly in 76.9% (N = 9) with rIX-FP and the annualized number of infusions reduced of 57% (p = .002), from a mean ± SD of 95.1 ± 22.77 to 40.4 ± 6.79, respectively. Annualized mean consumption decreased of about 56% (p = .001), from 3748.4 ± 1155.40 IU/kg with previous rFIX, to 1656.8 ± 456.63 IU/kg of rIX-FP. Mean FIX trough level changed from 3.0% ± 1.98% to 10.92% ± 3.6%. Low mean Annualized Bleeding Rate was maintained across all prophylaxis regimens (0.8 ± 1.69 vs. 0.3 ± 0.89) and zero bleeding patients moved from 69.2% (N = 9) with previous rFIX to 84.6% (N = 11) with rIX-FP (p = .63). Two adverse events, none related to rIX-FP, occurred in two patients. No inhibitors development was reported. CONCLUSIONS: The results in this pediatric/adolescent subgroup support rIX-FP prophylaxis may reduce infusion frequency, while providing high FIX trough levels, stable annualized bleeding rate and a good safety profile.

Adherence and Quality of Life in Adult Patients With Haemophilia A, Haemophilia B and Von Willebrand Disease: A National Cross-Sectional Survey.

BACKGROUND: New treatments for patients with bleeding disorders (PWB) have emerged, including products with extended half-life and subcutaneous administration. These less frequent treatments can potentially enhance quality of life (QoL), but adherence becomes critically important. AIM: To investigate adherence and QoL among PWB and explore the correlation between treatment adherence and QoL in adult patients with haemophilia A (HA), haemophilia B (HB) and Von Willebrand disease (vWD) in Denmark. METHOD: This survey used disease-specific patient-reported questionnaires: Veritas-PRO and Veritas-PRN to measure adherence, and Haemo-A-QoL and VWD-QoL to assess QoL. RESULTS: Responses were obtained from 149 patients with HA, 32 with HB and 118 with vWD. Adherence was reported by 87.1% of patients on prophylaxis and 71.2% of patients treated on demand, according to Veritas-PRO and Veritas-PRN cut-off scores. High QoL was generally reported, decreasing with age in HA and HB, but not in vWD. CONCLUSION: Danish patients with HA, HB and vWD reported high QoL and high adherence to prescribed treatments. There was no correlation between treatment adherence and QoL among the different patient groups. These findings highlight the need for further research to better understand adherence behaviours and identify opportunities to further improve QoL in PWB.