A long term outcomes analysis of severe haemophilia A boys receiving 4 years prophylaxis on the Chinese Haemophilia Individualized escalating low dose Prophylaxis (CHIPS).

BACKGROUND: The Chinese Haemophilia Individualized Prophylaxis Study (CHIPS), which was launched in 2016, reported a significant reduction in haemarthrosis over a one-year study. However, its long-term efficacy requires verification. This paper summarizes the clinical outcomes of 18 severe haemophilia A (SHA) patients who completed one year on the CHIPS and 3 more years of follow-up. METHODS: Clinical follow-up was based on the CHIPS protocol (from July 2018 to July 2021). Escalation was based on index joint bleeding, and serial ultrasound (greyscale and colour Doppler) examinations of the index joints (both sides of the ankles, knees and elbows) were conducted every 6 months via a scoring system. RESULTS: A total of 18 SHA patients completed the 3-year study. Fifteen patients dropped out due to the financial crisis during the COVID-19 pandemic in China. The median age was 5.4 (range 4.3-6.9) years. A significant reduction in haemarthrosis was achieved, with mean annual bleeding rates reduced from 18.9 ± 2.8 to 1.7 ± 0.4 (p < 0.001), annual joint bleeding rates from 3.1 ± 0.7 to1.2 ± 0.3 (p < 0.028). 5 out of 8 target joint resolved. Sixteen doses were escalated. At study exit, the heterogeneous treatment outcomes of the SHA boys were 5 at step 4 (20-25 lU/kg, every other day), 10 at step 3 (15-20 IU/kg, 3×/week), 2 at step 2 (10-15 lU/kg, 3×/week) and 1 at step 1 (10-15 lU/kg, 2×/week). The mean FVIII consumption was 2964 IU/kg/year, with savings. The quality of life improved, with Canadian Haemophilia Outcomes-Kids Life Assessment Tool (CHO-KLAT, Chinese Version 2.0) scores ranging from 68.8 to 78.8. There was no change in the ultrasound score. CONCLUSION: Our follow-up data on the 18 SHA boys after completing one year on the CHIPS verify the long-term efficacy of the CHIPS for haemarthrosis reduction, joint health preservation, improvement in the quality of life of the boys and cost savings.

Clinical and Humanistic Burden of Non-inhibitor Haemophilia A in Five European Countries: Insights from the CHESS II Study.

INTRODUCTION: Haemophilia A (HA) is a congenital bleeding disorder caused by a deficiency/absence of factor VIII (FVIII) and characterised by frequent, acute and prolonged spontaneous or traumatic bleeding events, often leading to haemophilic arthropathy and progressive joint deterioration. HA severity is characterized by endogenous FVIII activity: mild (> 5-40%), moderate (1-5%), or severe (< 1%). HA poses a substantial clinical and socioeconomic burden on people with HA (PWHA), their caregivers, and society. This analysis evaluates clinical and patient-centric outcomes of a cohort of individuals with non-inhibitor HA sampled from France, Germany, Italy, Spain, and the UK in the 'Cost of Haemophilia in Europe: A Socioeconomic Survey II' (CHESS II) study. METHODS: CHESS II was a cross-sectional burden-of-illness study collecting clinical and socioeconomic data on adult (≥ 18 years) individuals with haemophilia A or B of any severity with or without inhibitors from eight European countries. Descriptive analyses were conducted examining physician-reported demographics, clinical and health resource utilisation information. PWHA-reported health-related quality of life (HRQoL) using the EQ-5D-5L and Work Productivity and Activity Impairment (WPAI) were also examined. Outcomes were stratified by HA severity and reported at country level. RESULTS: Demographics and clinical characteristics of the cohort (N = 880) were generally consistent across countries. Individuals with severe HA experienced more frequent bleeding events and joint disease despite broad use of factor replacement therapy long-term prophylaxis. A minority of those with mild or moderate HA also experienced such challenges. HRQoL and workforce participation diminished, and chronic pain increased, with increasing HA severity. CONCLUSION: This analysis provides up-to-date insights on the impact of HA across five European countries. Increasing HA severity was generally associated with worse clinical outcomes, HRQoL and workforce participation. These findings suggest a place for continued evidence-based tailored treatment and clinical management approaches in addressing the residual burden of HA.

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.

Moving towards Normalization of haemostasis and health equity: Evolving treatment goals for haemophilia A.

BACKGROUND: Treatment options for people with haemophilia are evolving at a rapid pace and a range of prophylactic treatment options using various technologies are currently available, each with their own distinct safety and efficacy profile. TREATMENT GOALS: The access to replacement therapy and prophylaxis has driven a dramatic reduction in mortality and resultant increase in life expectancy. Beyond this, the abolition of bleeds and preservation of joint health represent the expected, but rarely attained, goals of haemophilia treatment and care. These outcomes also do not address the complexity of health-related quality of life impacted by haemophilia and its treatment. CONCLUSION: Capitalizing on the major potential of therapeutic innovations, 'Normalization' of haemostasis, as a concept, should include the aspiration of enabling individuals to live as normal a life as possible, free from haemophilia-imposed limitations. To achieve this-being supported by the data reviewed in this manuscript-the concept of haemostatic and life Normalization needs to be explored and debated within the wider multidisciplinary teams and haemophilia community.

Exploring the relationship between condition severity and health-related quality of life in people with haemophilia A across Europe: a multivariable analysis of data from the CHESS II study.

BACKGROUND: Haemophilia A (HA; Factor VIII deficiency) is a congenital X-linked bleeding disorder characterized by trauma-related or spontaneous bleeding events, most notably arising within the intraarticular space and resulting in chronic inflammation and degeneration of affected joints. Endogenous clotting factor activity relative to normal levels determines the severity of HA symptoms, as mild (> 5-40%), moderate (1-5%), or severe (< 1%). Within the current environment of rapid evolution in HA management, we seek to understand the interplay of condition severity and health-related quality of life (HRQoL) to characterise and differentiate unmet needs among people with HA (PwHA). METHODS: A generalised linear regression model (GLM) was developed to explore the relationship between HA severity and EQ-5D-5 L index score from adult HA patients sampled in the "Cost of Haemophilia across Europe - a Socioeconomic Survey II" (CHESS II) cross-sectional, retrospective burden of illness study among adults with hereditary haemophilia A or B from eight European countries. HA patients of any severity with no active inhibitors during the 12 months prior to data capture and a completeEQ-5D-5 L response were included. A base GLM model was specified with covariates for demographic and clinical characteristics (age, body mass index, country, employment, HA severity, annual bleeding rate, problem joints, and chronic pain). RESULTS: Of 381 evaluable patients, 221 (58.0%) had severe HA, 96 (25.2%) had moderate HA, and 64 (16.8%) had mild HA. Among the covariates included in the GLM model and after controlling for haemophilia-related outcomes, a significant association was observed between mild HA and higher EQ-5D-5 L index score (average marginal effects, 0.084; p = 0.016) relative to severe HA. Patient country of residence and magnitude of HA-related chronic pain were also associated with significant differences in index scores, with the latter showing a negative relationship with HRQoL outcomes. CONCLUSIONS: Condition severity and chronic pain are significant predictors of HRQoL in PwHA. Durable bleeding protection and effective management of chronic pain have the potential to address unmet treatment needs in this population.

Incidence and treatment-related risk factors of inhibitor development after intensive FVIII replacement for major orthopaedic surgery in previous treated haemophilia A.

INTRODUCTION: Haemophilia A (HA) is an X-linked recessive bleeding disorder caused by lack or deficiency of coagulation factor VIII. AIM: The aim of this study is to determine the incidence and treatment-related risk factors of inhibitor development after intensive FVIII replacement for major orthopaedic surgery in previous treated persons with HA. METHODS: A total of 151 HA who underwent 221 major orthopaedic surgical procedures after intensive FVIII treatment were reviewed. The results of inhibitor tests were collected. Potential clinical risk factors for inhibitor development were analyzed. RESULTS: 111 people were diagnosed with severe HA. Thirty-seven persons (24.5%) had history of previous intensive FVIII treatment for surgical procedure. They received a mean perioperative cumulative FVIII of 498 iu/kg within first week after surgery. Seven cases (4.6%) developed an inhibitor post-operatively in our study. Surgical procedure for pseudotumor and the group of persons who experienced postoperative complications had the higher incidence of inhibitor development (9.5%, 13.3% respectively). Only previous history for intensive FVIII exposure was considered as a significant predictor for postoperative inhibitor development after multivariate logistic regression analysis (OR: 29.5, P = 0.002). CONCLUSION: The incidence of inhibitor development in previously treated persons with HA undergoing major orthopaedic surgery was 4.6% and the history of previous intensive FVIII treatment for surgery was associated with higher risk of inhibitor development.

Humanistic burden of haemophilia A without inhibitors: A cross-sectional analysis of the HemoLIFE study.

AIM: To evaluate the impact of haemophilia A without inhibitors on humanistic outcomes in patients and caregivers. Herein, we report a cross-sectional analysis of the baseline data of persons with haemophilia (PWH) participating in the prospective study HEMOLIFE. METHODS: These data are part of a prospective, observational, and multicentre study currently being conducted in 20 hospitals in Spain by haematologists. We included subjects 12 years or older diagnosed with haemophilia. The evaluations included the Maladjustment Scale, Haemophilia-Specific Quality of Life Questionnaire for Adults (HaemoQol)/HaemoQol Short Form (Children), haemophilia-specific version of the Work Productivity and Impairment Questionnaire plus the Classroom Impairment Questionnaire (WPAI+CIQ:HS), Haemophilia Activity List (HAL)/Paediatric Haemophilia Activities List (pedHAL), visual analogue scale (VAS) for evaluating pain, Coping Pain Questionnaire-Reduced (CAD-R), and Hospital Anxiety and Depression Scale (HADS). RESULTS: A total of 81 PWH were recruited at 18 centres; 66 PWH were ≥18 years (i.e., adults), and PWH 15 were <18 years (i.e., paediatric patients). Out of the 79 evaluable subjects, 16 (20%) showed an impact of haemophilia on daily life, and the areas most affected were "leisure time" (58% showed maladjustment) and "work/studies" (47% showed maladjustment). Patients reported a higher impact of haemophilia on quality of life (mean [SD] of the transformed score) in the dimensions of "sport" (49.4 [28.6]), "physical health" (40.5 [25.8]) and "future" (37.7 [28.9]). In adults, according to HAL scores, greater impairment of function was observed in "lying/sitting/kneeling/standing," "function of legs" and "leisure activities and sports," with mean normalized scores of 64.7, 65.1 and 69.0, respectively. Productivity was mostly impacted by presenteeism. The pain was infrequent and moderate. According to the HADS scores, nine (11.5%) patients had clinical anxiety and depression. CONCLUSION: PWH without inhibitors exhibited impairments in adjustment, quality of life and functionality, especially related to leisure and sports activities, and exhibit relevant levels of anxiety and depression.

Reduced doses of emicizumab achieve good efficacy: Results from a national-wide multicentre real-world study in China.

INTRODUCTION: Reduced doses of emicizumab improve the affordability among patients in developing countries. However, the relationship between variant dose selection and efficacy in the real world of China is still unclear. AIM: This study aimed to investigate the efficacy and safety of emicizumab especially in those on reduced dose regimens in a real-world setting. METHODS: We carried out a multicentre study from 28 hospitals between June 2019 and June 2023 in China and retrospectively analysed the characteristics including demographics, diagnosis, treatment, bleeding episodes, and surgical procedures. RESULTS: In total, 127 patients with haemophilia A, including 42 with inhibitors, were followed for a median duration of 16.0 (IQR: 9.0-30.0) months. Median age at emicizumab initiation was 2.0 (IQR: 1.0-4.0) years. Median (IQR) consumption for loading and maintenance was 12.0 (8.0-12.0) and 4.2 (3.0-6.0) mg/kg/4 weeks, respectively. While on emicizumab, 67 (52.8%) patients had no bleeds, whereas 60 (47.2%) patients had any bleeds, including 26 with treated bleeds. Compared to previous treatments, patients on emicizumab had significantly decreased annualized bleeding rate, annualized joint bleeding rate, target joints and intracerebral haemorrhage. Different dosages had similar efficacy except the proportion of patients with treated spontaneous bleeds and target joints. Adverse events were reported in 12 (9.4%) patients. Postoperative excessive bleeding occurred following two of nine procedures. CONCLUSION: This is the largest study describing patients with HA receiving emicizumab prophylaxis on variant dose regimens in China. We confirmed that nonstandard dose is efficacious and can be considered where full-dose emicizumab is ill affordable.

Acquired haemophilia A in Finland: A nationwide study of incidence, treatment and outcomes.

INTRODUCTION: Acquired haemophilia A (AHA) is a bleeding disorder caused by autoantibody development against factor VIII (FVIII). Studies on AHA have mainly focused on patients treated at specialist centres. AIM: To determine the incidence, clinical characteristics and outcomes of AHA in an unselected population-based patient cohort from Finland. METHODS: This retrospective observational cohort comprised all cases diagnosed with AHA in Finland between 2006 and 2019. Patients were identified by the two central laboratories performing FVIII antibody testing in Finland, the Finnish Red Cross Blood Service and HUSLAB. Clinical details were collected from all hospitals and healthcare units where patients were treated. This study was performed in conjunction with the AHA in the Nordics study. RESULTS: The median incidence of AHA was 0.65 per million per year (range 0.19-1.27). Fifty-five patients were identified, with a median age of 76 years and an even sex ratio (51% women). When diagnosed, all had bleeding symptoms with severe bleeds in 92%. First-line immunosuppressive treatment regimens included steroid monotherapy in 31% of cases, steroids and a cytotoxic agent in 51% and a rituximab-based regimen in 16%. Clinical remission was achieved in 71% of cases, and 15% had relapses. Mortality was 13% for bleeds and 9% for treatment-related infections. Overall survival was 64% for 1 year and 56% for 2 years after diagnosis. CONCLUSIONS: In a nationwide population-based cohort study, we discovered a lower incidence of AHA than previously reported. Mortality among patients with AHA was high, calling for the consideration of updated treatment strategies.

Predicting joint involvement through tailored prophylaxis in severe haemophilia A, is it possible?

INTRODUCTION: Tailored prophylaxis is the current treatment regimen for patients with severe haemophilia A. Recently, published guidelines describe two possible approaches, based on clinical characteristics or estimation of pharmacokinetic parameters. However, both have strengths and weaknesses, and their characteristics need to be integrated to optimize treatment appropriately. In this paper, we present a model that considers together the characteristics of prophylaxis and the relevance of each. METHODS: The age at initiation of prophylaxis, number of bleeding events, treatment regimen, therapeutic adherence, FVIII trough levels, and joint status were analyzed in 59 patients followed at La Paz University Hospital between January 2000 and December 2019. RESULTS: The mean duration of primary prophylaxis of 113.37 ± 57.79 months. Eighty-three percent (n = 49) had no joint status involvement at the end of follow-up (HJHS and HEAD-US = 0). The median ABR was 0.7 (IQR 0.2 -1.0) and 54.2% presented trough levels of FVIII during follow-up >1 IU/dL. 72,9% engaged in some type of physical activity and overall adherence was over 85% in all patients evaluated. The regression analysis performed, considering all these factors, showed that the initiation of prophylaxis before 21 months of age was the most relevant protective factor against the appearance of joint involvement (OR 88.33 p.031 CI 95% 1.49-5224.40) CONCLUSION: Early initiation of prophylaxis was the most relevant factor in the protection of joint status. More comprehensive analysis models adapted to the characteristics of each population, are needed to adequately individualize treatment.

Transitioning from emicizumab prophylaxis to valoctocogene roxaparvovec gene therapy: A simulation study for individuals with severe haemophilia A.

INTRODUCTION: Valoctocogene roxaparvovec, a gene therapy evaluated in the phase 3 GENEr8-1 trial, supports endogenous factor VIII (FVIII) production to prevent bleeding in people with severe haemophilia A. Individuals receiving emicizumab, an antibody mimicking the function of activated FVIII, were excluded from GENEr8-1 enrolment since emicizumab was an investigational therapy at the time of trial initiation. AIM: Utilize pharmacokinetic simulations to provide guidance on best practices for maintaining haemostatic control while transitioning from emicizumab prophylaxis to valoctocogene roxaparvovec. METHODS: To estimate bleeding risk at weekly intervals following valoctocogene roxaparvovec infusion, a published emicizumab pharmacokinetic model was used to simulate emicizumab concentrations and merged with FVIII activity time-course data for participants in GENEr8-1. The analysis investigated three approved emicizumab dosing regimens for two transition scenarios that varied whether the last dose of emicizumab was administered on the same day or 4 weeks after valoctocogene roxaparvovec infusion. RESULTS: Simulations demonstrated administering the last emicizumab dose the day of valoctocogene roxaparvovec infusion and 4 weeks after offered similar levels of haemostatic control, and bleeding risk was similar for all emicizumab dosing regimens. An algorithm was developed to provide guidance for discontinuation of emicizumab. Theoretical cases based on GENEr8-1 participants are presented to illustrate how decisions may vary among individuals. CONCLUSION: Pharmacokinetic simulations demonstrated no clinically meaningful difference in bleeding risk caused by decaying emicizumab levels and rising gene therapy-derived endogenous FVIII for all examined emicizumab doses and dosing regimens. Therefore, multiple approaches can safely transition individuals from emicizumab prophylaxis to valoctocogene roxaparvovec.

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.

The use of Bacillus subtilis as a cost-effective expression system for production of Cholera Toxin B fused factor VIII epitope regions applicable for inducing oral immune tolerance.

Coagulation factor replacement therapy for the X-linked bleeding disorder Haemophilia, characterized by a deficiency of coagulation protein factor VIII (FVIII), is severely complicated by antibody (inhibitors) formation. The development of FVIII inhibitors drastically alters the quality of life of the patients and is associated with a tremendous increase in morbidity as well as treatment costs. The ultimate goal of inhibitor control is antibody elimination. Immune tolerance induction (ITI) is the only clinically established approach for developing antigen-specific tolerance to FVIII. This work aims to establish a novel cost-effective strategy to produce FVIII molecules in fusion with cholera toxin B (CTB) subunit at the N terminus using the Bacillus subtilis expression system for oral tolerance, as the current clinical immune tolerance protocols are expensive. Regions of B-Domain Deleted (BDD)-FVIII that have potential epitopes were identified by employing Bepipred linear epitope prediction; 2 or more epitopes in each domain were combined and cDNA encoding these regions were fused with CTB and cloned in the Bacillus subtilis expression vector pHT43 and expression analysis was carried out. The expressed CTB-fused FVIII epitope domains showed strong binding affinity towards the CTB-receptor GM1 ganglioside. To conclude, Bacillus subtilis expressing FVIII molecules might be a promising candidate for exploring for the induction of oral immune tolerance.

Long-Term Efficacy and Safety of Damoctocog Alfa Pegol Prophylaxis in Patients with Haemophilia A Aged 12-<18 Years at Enrolment into PROTECT VIII.

INTRODUCTION: The phase 2/3 PROTECT VIII study demonstrated long-term efficacy and safety of damoctocog alfa pegol (BAY 94-9027; Jivi®), a B-domain-deleted recombinant factor VIII (FVIII), site-specifically PEGylated to improve its pharmacokinetic profile. We report a post hoc assessment of bleeding and safety outcomes in the subgroup of patients, aged 12-<18 years at enrolment. METHOD: PROTECT VIII was a multicentre, open-label study of previously treated males aged 12-65 years with severe haemophilia A (FVIII <1%). Twelve patients were included in this analysis. All received damoctocog alfa pegol prophylaxis for the total time in study (median [range] time in study 4.0 [1.3-6.2] years). RESULTS: Overall median (Q1; Q3) total and joint annualised bleeding rates were 1.8 (0.4; 5.1) and 0.7 (0.2; 1.8), respectively, for the entire study. During the last 6 months of treatment, eight (66.7%) and ten (83.3%) out of 12 patients experienced zero total and joint bleeds, respectively. No patient developed FVIII inhibitors. No deaths or thrombotic events were reported. CONCLUSION: Efficacy and safety of damoctocog alfa pegol were confirmed in adolescent patients with haemophilia A, with data for up to 6 years supporting its use as a long-term treatment option in this group as they transition into adulthood.

Mutational landscape, inhibitor development, and health-care burden in non-severe haemophilia A: A single-centre Australian experience.

AIM: To characterise non-severe haemophilia A (HA) patients enrolled on the Australian Bleeding Disorders Registry (ABDR) treated through a state-wide Haemophilia Treatment Centre (HTC) with respect to their mutational profile, inhibitor risk and health-care burden. METHOD: We conducted a single-centre observational study of all non-severe HA patients treated at the Alfred Health HTC registered on the ABDR as of the 26th July 2023. Data were extracted from the ABDR and electronic medical record (EMR) regarding demographics, severity, genetic testing, treatment, inhibitors, bleeding events and procedures. Inhibitor risk was calculated as a function of exposure days (EDs) of FVIII replacement. RESULTS: There were 289 non-severe HA patients treated at the Alfred HTC registered on the ABDR as of July 2023, all of whom were adult patients aged > 18 years old. Genotyping had been performed in 228/289 (78.9%). Of the inhibitor analysis population, 14/193 (7.3%) had an inhibitor. The cumulative incidence of inhibitor development at 75 EDs was 31% (95% CI 13%-46%). The median cost of bypassing agents per inhibitor patient was $57,087.50/year. CONCLUSION: These results demonstrate a relatively high inhibitor prevalence and incidence risk in non-severe HA compared to previously published work, although this may partly reflect a smaller population size. High rates of genotyping have allowed representative mutational characterisation. The burden of care imposed by non-severe HA in terms of bleeding events, procedures and bypassing agent cost is larger than expected, particularly within the inhibitor population.

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

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

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.

Health utilities in adults with hemophilia A: A retrospective cohort study.

INTRODUCTION: Haemophilia A negatively affects a patient's quality of life. There is a limited amount of health utility data (a measure of health-related quality of life) available for patients with haemophilia A. This information is crucial for cost-effectiveness analysis for haemophilia A treatment. OBJECTIVES: The goal of this project is to elicit the health utilities and factors impacting utility values for haemophilia A patients in Canada. METHODS: This is a population-based, cross-sectional, retrospective study of health utilities in patients with haemophilia A using Patient Report Outcomes Burdens and Experiences (PROBE) components from the Canadian Bleeding Disorders Registry (CBDR). A review of the mean utilities for three severity states, defined by clotting factor VIII level, was completed. A multiple linear regression analysis was completed to examine the determinants of health utilities including age, treatment type, chronic pain status, number of limited joints, and bleed rate. RESULTS: The average utility values (and standard deviations) for patients with haemophilia A in Canada are .79(.17), .76(.20), and .77(.19) for patients with severe, moderate, and mild haemophilia. The regression showed chronic pain status and the number of additional comorbidities as major significant factors (p-value < .001) in haemophilia A utility. Haemophilia severity was shown to be a major factor with smaller p-value (p-value < .05). CONCLUSIONS: Haemophilia A patients have lower utility than the general population. Chronic pain was shown to be a significant, major factor in health-related quality of life. Our study is essential for valuing health outcomes in haemophilia A-related cost-effectiveness analysis.

Anxiety and depression among adults with haemophilia A: Patient and physician reported symptoms from the real-world European CHESS II study.

INTRODUCTION: The physical pain and disability affecting many people with haemophilia A (PwHA) are known detractors from psychological wellbeing. While psychosocial support is considered a core tenet of the haemophilia comprehensive care structure, the extent to which mental health challenges are detected and monitored by the individuals treating haematologist remains relatively unexplored. AIM: To describe prevalence of anxiety and depression in a real-world cohort of adult PwHA and evaluate the congruence in reporting of anxiety or depression (A/D) between PwHA and their treating physicians. METHODS: Data for PwHA without inhibitors was drawn from the European 'Cost of Haemophilia: A Socioeconomic Survey II' (CHESS II) study. Haematologist-indicated comorbidities of anxiety and depression were unified into a single A/D indicator. The EQ-5D-5L health status measure was used to characterise self-reported A/D, with individuals stratified into two non-mutually exclusive subgroups based on level of A/D reported (Subgroup A: 'some' or above; Subgroup B: 'moderate' or above). RESULT: Of 381 PwHA with evaluable EQ-5D-5L responses, 54% (n = 206) self-reported at least some A/D (Subgroup A) and 17% (n = 66) reported at least moderate A/D (Subgroup B). Patient-physician congruence in A/D reporting was 53% and 76% for Subgroups A and B, respectively. Descriptive analysis suggested that individuals with physician- and/or self-reported A/D experienced worse clinical outcomes (bleeding events, joint disease, chronic pain). CONCLUSION: While adverse clinical outcomes appear to correlate with A/D, self-reports of moderate-severe symptoms occasionally lacked formal recognition from treating physicians. Cross-disciplinary surveillance of mental health issues could improve both psychological and clinical outcomes among PwHA.