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Background: Moderate-to-severe hemophilia B is treated with lifelong, continuous coagulation factor IX replacement to prevent bleeding. Gene therapy for hemophilia B aims to establish sustained factor IX activity, thereby protecting against bleeding without burdensome factor IX replacement. Methods: In this open-label, phase 3 study, after a lead-in period (≥6 months) of factor IX prophylaxis, we administered one infusion of adeno-associated virus 5 (AAV5) vector expressing the Padua factor IX variant (etranacogene dezaparvovec; 2×1013 genome copies per kilogram of body weight) to 54 men with hemophilia B (factor IX activity ≤2% of the normal value) regardless of preexisting AAV5 neutralizing antibodies. The primary end point was the annualized bleeding rate, evaluated in a noninferiority analysis comparing the rate during months 7 through 18 after etranacogene dezaparvovec treatment with the rate during the lead-in period. Noninferiority of etranacogene dezaparvovec was defined as an upper limit of the two-sided 95% Wald confidence interval of the annualized bleeding rate ratio that was less than the noninferiority margin of 1.8. Superiority, additional efficacy measures, and safety were also assessed. Results: The annualized bleeding rate decreased from 4.19 (95% confidence interval [CI], 3.22 to 5.45) during the lead-in period to 1.51 (95% CI, 0.81 to 2.82) during months 7 through 18 after treatment, for a rate ratio of 0.36 (95% Wald CI, 0.20 to 0.64; P

INTRODUCTION: As people with haemophilia (PWH) receive better treatment and live longer they are more likely to encounter cardiovascular disease (CVD) and other comorbidities. ESC guidelines for the acute management of patients presenting with acute coronary syndrome (ACS) are based on the non-haemophilia population. AIM: To review the guidelines and propose relevant adaptations for PWHA without inhibitors who are treated with prophylaxis and present with ACS. METHODS: As part of the ADVANCE Group, 20 European haemophilia experts used a modified Delphi approach to develop and gain consensus on proposed adaptations of the ESC guidelines for PWHA without inhibitors. RESULTS: Of the 32 Class I recommendations across both guidelines, adaptions were considered necessary and proposed for 15. The adaptions highlight the need to provide sufficient FVIII trough levels at the time of antithrombotic treatment in people with haemophilia A (HA) without inhibitors. Patients receiving emicizumab prophylaxis and requiring oral anticoagulation therapy or combined single antiplatelet plus oral anticoagulation therapy will require additional FVIII replacement therapy. CONCLUSION: In the absence of high-quality clinical evidence, the combined expert opinion used to develop these adaptions to the current ESC guidelines may help to guide clinicians in their treatment decisions when a PWHA presents with ACS. Free to read [see URL]

Introduction Treatment optimization in haemophilia A can be achieved by choice of FVIII product and knowledge of pharmacokinetics (PK), phenotype and adherence. A favourable PK profile of BAY 81–8973 (octocog alfa) (Kovaltry, Bayer AB) compared to other standard half-life (SHL) FVIII products has been suggested. Aim To evaluate whether the switch to BAY 81–8973, using the same dosing schedule, impact factor consumption and bleed rates, taking arthropathy and adherence into account Methods Forty patients on prophylaxis with SHL (median age 40.5 years) attending the haemophilia treatment centres in Malmö and Oslo were enrolled. The annualised bleeding rate (ABR) and joint bleeding rate (AJBR) before and after the switch to BAY 81–8973 was calculated. PK analyses were performed with WAPPS-Hemo. Joint health status and treatment adherence were assessed. Results The median ABR and AJBR was 0 before and after the switch, at both centres. The median yearly factor consumption was 3,345 IU/Kg/year in the entire study group corresponding to intermediate-intensity prophylaxis in most patients and with significantly more used in Malmö (3,862 IU/Kg/year), compared to Oslo (2,337 IU/Kg/year) (P .006). There was no correlation between arthropathy and bleeding. The median BAY 81–8973 t½ was 15.15 h (range 7.5–29 h), with significant correlation to VWF levels, and 13.4 h after exclusion of VWF outliers. Adherence to treatment was 97%. Conclusions Concentrate switch, using mainly intermediate-intensity regimens with high adherence rates, preserves excellent prophylaxis outcome using standard half-life FVIII products, indicating the value of individualized prophylaxis and close follow-up.

Introduction A second peak of inhibitors has been reported in patients with severe hemophilia A (HA) aged >50 years in the United Kingdom. The reason for this suggested breakdown of tolerance in the aging population is unclear, as is the potential impact of regular exposure to the deficient factor by prophylaxis at higher age. No data on hemophilia B (HB) have ever been reported. Aim The ADVANCE Working Group investigated the incidence of late-onset inhibitors and the use of prophylaxis in patients with HA and HB aged ≥40 years. Methods A retrospective, observational, cohort, survey-based study of all patients aged ≥40 years with HA or HB treated at an ADVANCE hemophilia treatment center. Results Information on 3,095 people aged ≥40 years with HA or HB was collected. Of the 2,562 patients with severe HA, the majority (73% across all age groups) received prophylaxis. In patients with severe HA, the inhibitor incidence per 1,000 treatment years was 2.37 (age 40–49), 1.25 (age 50–59), and 1.45 (age 60 + ). Overall, the inhibitor incidence was greatest in those with moderate HA (5.77 [age 40–49], 6.59 [age 50–59], and 4.69 [age 60 + ]) and the majority of inhibitor cases were preceded by a potential immune system challenge. No inhibitors in patients with HB were reported. Conclusion Our data do not identify a second peak of inhibitor development in older patients with hemophilia. Prophylaxis may be beneficial in older patients with severe, and possibly moderate HA, to retain a tolerant state at a higher age.

Introduction The use of pharmacokinetic assessment for optimal prophylactic dosing of factor concentrates in haemophilia has gained increasing enthusiasm over the last decade. However, blood sampling on several occasions is burdensome and limited sampling using population-based PK is appealing. Aim To compare the pharmacokinetics and dosing recommendations for prophylaxis using six-point single subject versus population-based method (WAPPS-Hemo) for simoctocog alfa (Nuwiq® ). Methods Twelve adult patients with severe haemophilia A received a factor VIII (FVIII) dose of ≈50 IU/kg, and the activity was measured pre-infusion and at 30 min, 6, 9, 24 and 48 h post-infusion. Half-life (t1 /2 ), weight-normalized AUC and time to troughs of 5%, 3% and 1% were calculated. The correlation between the PK algorithms was assessed using intraclass correlations (ICC) and dosing estimations were provided. Results WAPPS-Hemo yielded a slightly longer mean t1 /2 , but the overall correlation between the methods was good (ICC ≥0.79) The time to troughs of 5%, 3% and 1% showed ICCs ≥0.86. For all variables, the most converging limited time point was 6+48 h. Additional time points did not improve the correlation. Despite similar pharmacokinetics, the mean estimated dose for a specific trough level varied from 60% less to 20% more using the population-based approach. The time to 1% and the corresponding dose was sensitive to the baseline assumption. Conclusion Our data support the use of population-based PK for patients on simoctocog alfa prophylaxis but also indicates differences, stressing the importance of the sampling scheme and monitoring actual FVIII levels achieved.

Introduction Data on outcome in persons with haemophilia B (PwHB) are limited and mainly extrapolated from studies of haemophilia A (HA). Aim To characterize treatment outcomes in persons with severe HB in the Nordic region, with a focus on joint health, compared with matched controls with HA. Methods PwHB attending haemophilia centres in Denmark, Finland, Norway and Sweden were enrolled and matched with controls with HA. Joint assessment using Haemophilia Joint Health Score (HJHS) and ultrasound according to Haemophilia Early Arthropathy Detection protocol (HEAD-US) was conducted. Adherence was evaluated using the Validated Haemophilia Regimen Treatment Adherence Scale (VERITAS). Results Seventy-nine males with HB, with median age of 30 years (range 1-75), were enrolled. Eleven patients (14%) had a history of or current inhibitor. Twenty-nine PwHB (37%) reported joint bleeds during the prior year, and 35% had previously undergone joint surgery. Ninety-five per cent were on prophylaxis, and 70% used recombinant concentrates, with a median factor consumption of 3,900 IU/kg/year for standard half-life products. Only two patients had a VERITAS score corresponding to 'non-adherence'. Joint health, assessed with HJHS, showed a significant lower score among PwHB compared with HA controls, explained by a difference in the 18-49 age group, without observed differences in older or younger subgroups. The HEAD-US scores were overall low. Conclusion The Nordic cohort of PwHB is well treated by prophylaxis, but the goal of zero bleeds for all is not reached. Our findings suggest that patients with severe HB suffer from a milder arthropathy than patients with severe HA.

Haemophilia B (HB) is less well studied than haemophilia A (HA); despite similarities between the two inherited bleeding disorders, important differences remain that require further research.B-Natural is a multi-centre, prospective, observational study of HB, designed to increase understanding of clinical manifestations, treatment, quality-of-life (QoL), inhibitor development, immune tolerance induction (ITI) outcome, renal function and create a biorepository for future investigations.Participants include sibling pairs/groups without a current/history of inhibitors and singletons or siblings with a current/history of inhibitors followed for six months. Demographics, medical, social history and treatment were recorded. A physical examination including joint range of motion (ROM) was performed; QoL was assessed. Samples were collected for F9 gene mutation, HLA typing, non-inhibitory antibodies and renal function testing.Twenty-four centres enrolled 224 individuals from 107 families including 29 with current/history of inhibitors. Of these, 68, 30.4%, had severe (1% FIX level of normal); 114, 50.9%, moderate (1%-5%); and 42, 18.8%, mild (5-40%) disease. At enrolment, 53.1% had 50 + exposure days to exogenous FIX. Comparison of joint scores showed significant (P .05) differences between those with severe (with/without inhibitors), and those with moderate/mild disease. The majority with severe disease, 80.0% with current/history of inhibitors and 64.3% of those without, were treated with prophylaxis.B-Natural provides data supporting an increased understanding of HB and its impact throughout life. The need for optimal disease control to normalize physical and psychosocial outcomes is underscored, and further analyses will contribute to an increased understanding of critical issues in HB.

Introduction Perioperative dosing recommendations vary across Nordic haemophilia treatment centres (HTCs) for extended half-life (EHL) factor concentrates in haemophilia A/B (HA/HB) patients. Aim To summarise Nordic real-world surgical experiences with EHL recombinant factor VIII/IX Fc (rFVIIIFc/rFIXFc) fusion proteins using retrospective data from clinical records at four HTCs in Finland, Sweden and Norway. Methods Factor dosing and surgical outcomes were recorded from HA/HB patients who underwent surgery and were treated with rFVIIIFc/rFIXFc. Perioperative factor dosing regimens were clinician-determined based on local practises. Results Twenty five surgeries were performed on 20 patients, all covered by bolus injections except one minor HA surgery; eight minor surgeries were in paediatric patients. Median preoperative rFVIIIFc dose for major HA surgeries (n = 8) was 48 IU/kg (range: 35–57), with total consumption up to Day 14 of 427 IU/kg (196–568). For the two major HB surgeries (in one patient), preoperative rFIXFc doses were 50 IU/kg and 20 IU/kg; total consumption up to Day 14 was 130 IU/kg and 40 IU/kg. Median preoperative rFVIIIFc/rFIXFc bolus doses for minor HA (n = 10) and HB (n = 4) surgeries were 50 IU/kg (24–79) and 47 IU/kg (40–71), with total consumption up to Day 5 of 138 IU/kg (49–404) and 100 IU/kg (43–125), respectively. Intraoperative and postoperative haemostatic responses were rated as at least good/excellent for 24/25 surgeries, with bleeding episodes reported in only three surgeries. Conclusion Nordic real-world experiences suggest that EHL products can be used safely and effectively for peri-operative haemostasis. Further research is required to develop local dosing guidelines for optimised treatment schedules.

BACKGROUND: Inversions involving intron 22 (Inv22) of F8 are detected in approximately 45% of all severe hemophilia A patients. Diagnosis is complicated by the large size of the ~9.5 kb int22h repeated sequence which generates the inversions. Methods such as long-range PCR and inverse-shifting PCR are currently used diagnostically, but suffer from low PCR efficiencies and are difficult to standardize.OBJECTIVES: To design and validate a sensitive and robust assay for the detection of F8 int22h inversions.METHODS: Digital droplet PCR using mile-post assays was used to investigate archival DNA samples.RESULTS: The detection of linkage as a function of physical distance between loci was investigated using an anchor locus and mile-post loci located at 1, 6, 12 and 15 kb distances from the anchor locus. The proportion of linked molecules decreased with increasing distance between loci and showed 30-40% linked molecules for loci 12-15 kb apart. Mile-post assays specific for wild type and Inv22 type 1 and 2 chromosomes were then designed and optimized. All three assays showed high specificities and sensitivities, with coefficients of variation < 5% for all assays. Analysis of 106 patients and 20 carrier mothers showed complete concordance with previously known mutation status. The analysis demonstrated the robustness of the assays versus input DNA concentration (6 ng and higher) and level of fragmentation.CONCLUSIONS: Digital droplet PCR and mile-post assays can be used to detect F8 int22h inversions. The assay systems are technically simple to perform, highly efficient and robust. (Less)

Introduction: The B-Natural study is a multicentre, multinational, observational study of haemophilia B (HB) designed to increase understanding of clinical manifestations, treatment and quality of life (QoL). Aim: To characterise and compare QoL in HB across disease severity groups and individuals with inhibitors to identify gaps in treatment. Methods: A total of 224 individuals from 107 families were enrolled from a total of 24 centres in North America (n = 16), Europe (n = 7) and Asia (n = 1). Of these, 68 (30.4%) subjects had severe (5–

INTRODUCTION: Recurrent bleeding in severe haemophilia B causes painful hemarthroses and reduces capacity for physical activity. Recombinant factor IX Fc fusion protein (rFIXFc) prophylaxis results in low annualised bleeding rates, with the potential to improve patients' health-related quality of life (HRQoL). AIM: To present a post hoc analysis of data from B-LONG describing change over time in patient-reported outcomes associated with pain and physical activity. METHODS: Patients (≥12 years) who received weekly dose-adjusted or interval-adjusted rFIXFc prophylaxis and completed the Haemophilia-Specific QoL questionnaire for adolescents (Haemo-QoL) or adults (Haem-A-QoL) at baseline (BL) and end of study (EoS). Individual level changes in items of the 'Physical Health' and 'Sports and Leisure' domains, categorised as 'never/rarely/seldom' or 'sometimes/often/all the time', were analysed using McNemar's test to compare distribution of responses at EoS versus BL. RESULTS: At EoS versus BL, a significantly greater proportion of patients did not experience painful swellings (64% vs. 44%; P = .004), painful joints (44% vs. 28%; P = .003) or pain when moving (54% vs. 41%; P = .026). Additionally, at EoS versus BL, patients were less likely to avoid participating in sports like football (30% vs. 8%; P = .002), avoid sports due to their haemophilia (47% vs. 27%; P = .007), or experience difficulty walking as far as they wanted (63% vs. 43%; P = .001). The proportion of patients who played sports as much as the general population was numerically increased (52% vs. 37%; P = .033) at EoS versus BL. CONCLUSION: Results of the analysis suggest that over time, rFIXFc prophylaxis is associated with significant improvements in pain and physical functioning. This contributes to previous evidence of overall HRQoL improvements in patients with haemophilia B treated with rFIXFc.

Introduction People with haemophilia (PwH) may experience symptoms of haemophilia-related pain, depression or anxiety, which can negatively impact health-related quality of life. Aim To obtain the perspective of PwH and treaters from Sweden, Finland and Denmark on the management of haemophilia-related pain, depression and anxiety using cross-sectional survey data from the MIND study (NCT03276130). Methods PwH or their caregivers completed a survey about experiences of pain, depression and anxiety related to haemophilia, and the standard EQ-5D-5L instrument. Five investigators at haemophilia treatment centres (HTC) were sent a complementary survey containing questions about the management of pain and depression/anxiety. Results There were 343 PwH (mild: 103; moderate: 53; severe: 180; seven lacking severity information) and 71 caregiver responses. Experience of pain in the last 6 months was reported by 50% of PwH respondents and 46% of caregiver respondents. Anxiety/depression was reported by 28% of PwH respondents. Reporting of pain and anxiety/depression was associated with disease severity. Whilst 62% of PwH who had experienced pain at any time point (n = 242) felt this was adequately addressed and treated at their HTC, only 24% of those who had experienced depression/anxiety (n = 127) felt this was adequately addressed. Disease severity was negatively associated with EQ-5D-5L utility value (p < .001). In the HTC survey, 4/5 and 2/5 agreed that pain and depression/anxiety, respectively, are adequately addressed. Conclusions Pain and depression/anxiety occur more frequently with increasing haemophilia severity, with negative impacts on health-related quality of life. PwH with depression/anxiety or unaddressed pain could benefit from improved management strategies. Funding Agencies|Sobi

Despite current therapies, there remains an unmet need for treatment for patients with hemophilia. The main parts of two phase 2 trials established clinical proof-of-concept for once-daily, subcutaneous concizumab prophylaxis in patients with hemophilia A/B with inhibitors (HAwI/HBwI; explorer4) and severe hemophilia A without inhibitors (HA; explorer5). Here, we present results from extension parts of these trials, included to evaluate longer term safety and efficacy. Both trials included main (>= 24 weeks) and extension (52-102 weeks) parts, with patients receiving concizumab 0.15 mg/kg with potential dose escalation to concizumab 0.20 or 0.25 mg/kg if they experienced >= 3 treated spontaneous bleeding episodes within 12 weeks. Endpoints included annualized bleeding rate (ABR), adverse events (AEs), and occurrence of antidrug antibodies. Thromboembolic events were AEs of special interest. Thirty-six patients with HA, 15 with HAwI, and 10 with HBwI were exposed to concizumab. Estimated ABRs during the main + extension parts at last dose level were 4.8 (95% confidence interval [CI], 3.2-7.2) and 6.4 (95% CI, 4.1-9.9) in explorer4 and explorer5, respectively (spontaneous ABRs were 1.8 [95% CI, 1.2-2.6] and 2.1 [95% CI, 1.3-3.3]). Most AEs were mild, with no deaths, events leading to withdrawal, or thromboembolic events. Anti-drug antibodies developed in 25% of patients and were low titer and transient, with no observed clinical effect in most cases. Results of the main + extension parts of these trials were consistent with results of the main parts. Ongoing phase 3 trials will further evaluate concizumab as a once-daily, subcutaneous treatment across hemophilia subtypes. These trials were registered at www.clinicaltrials.gov as #NCT03196284 and #NCT03196297., Novo Nordisk A/S, The authors thank the patients, their families, and all trial investigators for their participation and support in explorer4 and explorer5, and also the external independent data monitoring committee for their assistance with these studies. These studies were funded by Novo Nordisk A/S. Medical writing support, under the direction of the authors, was provided by Ashfield MedComms GmbH (an Ashfield Health company) and was funded by Novo Nordisk A/S.

Introduction The development of inhibitory antibodies is a severe complication of clotting factor replacement therapy in patients with severe haemophilia A (HA). Current World Federation of Hemophilia (WFH) guidelines for haemophilia care indicate that eradication of inhibitors is best achieved through immune tolerance induction (ITI) therapy. Aim The European Collaborative Haemophilia Network conducted a survey to determine whether ITI is still used in the routine management of patients with HA, and whether the availability of emicizumab prophylaxis has influenced treatment decisions. Methods The survey was conducted in late 2020/early 2021 in 18 centres representing 17 countries in the Europe/Middle East region treating a total of 4955 patients, and included sections specific to patient and centre demographics, treatment protocols (both ITI and prophylactic), inhibitor development and initiation of ITI, treatment success, and the incidence of adverse events. Results While our results indicate that ITI can still be considered a mainstay of treatment for patients with HA with inhibitors, less than daily dosing of ITI in combination with emicizumab prophylaxis is becoming commonplace across the spectrum of disease severity, with initiation being guided by bleeding patterns. The most frequently cited reasons for not initiating emicizumab prophylaxis were availability or reimbursement issues. Conclusion ITI remains a mainstay for haemophilia treatment of patients with HA with inhibitors, but emicizumab has become a preferred first-line approach to protect against bleeds and represents an alternative to burdensome ITI in certain patient groups.

Jan Astermark,1 Piotr Wojciechowski,2 Samuel Aballéa,3 Zalmai Hakimi,4 Jameel Nazir,4 Robert Klamroth5 1Department of Translational Medicine, Lund University, and Department of Hematology, Oncology and Radiation Physics, Skåne University Hospital, Malmö, Sweden; 2Creativ-Ceutical, Krakow, Poland; 3Creativ-Ceutical, Rotterdam, the Netherlands; 4Swedish Orphan Biovitrum AB, Stockholm, Sweden; 5Department of Internal Medicine, Hemophilia Treatment Centre, Vivantes Klinikum im Friedrichshain, Berlin, GermanyCorrespondence: Robert Klamroth Email robert.klamroth@vivantes.dePurpose: In patients with hemophilia B, treatment with extended half-life (EHL) recombinant factor IX allows for longer dosing intervals while providing equal or superior bleeding protection compared with standard half-life products. This enables flexible, individualized treatment schedules, which reduce the burden of prophylaxis and improve patient outcomes. This analysis compared the efficacy of recombinant factor IX Fc fusion protein (rFIXFc) and recombinant factor IX albumin fusion protein (rIX-FP), two EHL therapies approved for prophylaxis and treatment of bleeding in hemophilia B.Patients and Methods: Matching-adjusted indirect treatment comparison (MAIC) was used to adjust the between-treatment differences in baseline characteristics. Individual patient data for rFIXFc (B-LONG) were matched to aggregated data for rIX-FP (PROLONG-9FP) followed by statistical comparison for estimated annualized bleeding rate (ABR) using a Poisson regression model with adjustment for over dispersion. Data were analyzed according to treatment regimen prior to study entry: prior prophylaxis (rFIXFc, n=48; rIX-FP, n=40) or prior episodic treatment (n=43 and n=19, respectively). Relative treatment effects are presented as incidence rate ratios (IRR) with 95% confidence intervals (CI).Results: After adjustment for baseline characteristics, estimated ABR observed for rFIXFc and rIX-FP was not significantly different in patients on prior prophylaxis (1.87 versus 1.58; IRR 1.18, 95% CI 0.67– 2.10) or prior episodic (2.25 versus 2.22; IRR 1.01 95% CI 0.40– 2.57) regimens.Conclusion: This MAIC analysis shows that the estimated ABR for rFIXFc-treated patients from B-LONG was similar to that of rIX-FP-treated patients from PROLONG-9FP and, therefore, indicates that the two EHL therapies provide similar efficacy when used as prophylaxis for patients with hemophilia B. Trough levels differ between the two products (1– 3% [targeted] versus 20% [observed], respectively), suggesting that trough level is not a surrogate indicator when ABR is used as a criterion for clinical efficacy when comparing these FIX products in hemophilia B.Keywords: annualized bleeding rate, comparative effectiveness research, factor IX deficiency, factor IX Fc fusion protein, rIX-FP fusion protein, treatment outcome

Background: A significant fraction of women with an impaired factor VIII or IX gene in the X chromosome, carriers of haemophilia, will have clotting factor activities corresponding to those seen in males with non-severe haemophilia, hence, experience an increased bleeding tendency. Data describing the long-term joint outcomes among carriers are limited. We compared the age at onset, frequency of joint-related diagnoses as well as joint surgery and related hospitalizations among carriers of haemophilia with sex- and birthdate-matched controls from the general population. Methods: Carriers of haemophilia born 1941-2008 were identified through the haemophilia treatment centres' (HTCs) databases and the National Patient Register of Sweden. For each carrier, we included up to five individuals using the Swedish population register as comparisons. Data for the period 1987-2008 were obtained. Results: Among 539 potential carriers identified, 213 had a known factor activity. Carriers with reduced factor activity and those with unknown factor activity had received their first joint-related diagnosis at a significantly earlier age than their comparisons. The same subgroups showed an overall 2.3- and 2.4-fold higher hazard for joint-related diagnoses compared with the general population. In addition, the hazards of joint-related outpatient hospitalization were 3.2-fold (95% CI: 1.2, 9.1) and 2.5-fold (95% CI: 1.6, 3.7). This was not observed for those with normal factor activity. Conclusion: Carriers of haemophilia suffer a significant risk for joint comorbidities. This risk seems to correlate to the factor activity. Our findings underline the importance of regular clinical follow-up of carriers at HTCs. (Less)

Introduction Monitoring replacement therapy with standard and extended half-life (EHL) products is challenging, since one-stage assay (OSA) and chromogenic substrate assay (CSA) results may differ significantly. Recent recommendations include local validation of each new product with recovery within 20-30%, depending on activity level. Aim To validate factor VIII (FVIII) activity for monitoring products in clinical use on Atellica Coag and to correlate it with thrombin generation. Methods Plasma samples spiked with Advate® , Elocta® , Adynovi® , Nuwiq® , NovoEight® and Afstyla® (0.05, 0.20, 0.50 and 0.80 IU/ml) were analysed using Atellica Coag 360 with CSA-1 (Coatest SP) and CSA-2 (FVIII chromogenic), and OSA (Actin FS). Thrombin generation was performed using two thrombin generation assays (TGA-1 (Thrombinoscope) and TGA-2 (Technothrombin). Results All products at levels above 0.05 IU/ml, except Adynovi, showed acceptable recovery using CSA-1, whereas measurements using CSA-2 gave more results outside the target level. All products, except Afstyla, showed acceptable recovery using OSA. Correlation between CSA-1 and OSA was excellent (r2 =1.0) with biases of 6-3​2%, depending on FVIII product. A clear dose-response was seen for all thrombin generation parameters and products using both methods, except at low levels for lag time using TGA-1. With CSA-1 as an independent variable, the correlations to thrombin peak (measured with TGA-2) were good (r2 = .8-.9). Conclusion Our data revealed good correlation and acceptable bias between CSA and OSA using our sets of reagents, methods and analyser in spiked samples. Thrombin generation gave good correlation to CSA-1 factor activity and is a possible complement to factor activity assays.

Introduction: MyPKFiT and the Web-Accessible Population Pharmacokinetic service—Hemophilia (WAPPS-Hemo) are web-based population-based applications developed for helping physicians individualize and optimize replacement therapy. Although MyPKFiT is intended for Octocog alfa and Rurioctocog alfa pegol use only, the WAPPS-Hemo is applicable to all factor VIII concentrates. Aim: To compare MyPKFiT and WAPPS-Hemo as dosing tools for optimizing treatment of patients with severe haemophilia A on regular prophylaxis with Octocog alfa in a real-world setting. Methods: Fourteen patients with severe haemophilia A (median age 30.8 years; range 20–71) were enrolled. The FVIII activity was measured twice after a regular dose of Octocog alfa by the chromogenic and the one-stage assays. PK analyses were performed using each tool and dosing estimations to reach trough levels of 1%, 3% or 5% after 48 h. Findings were calculated and compared. Results: The two PK algorithms yielded similar t½ independent of the type of FVIII assay used. However, there were significant differences in the time to reach 1%, 3% and 5%. The WAPPS-Hemo generated 10–12 h longer time to a trough of 1% and up to 4 h for the troughs of 3% and 5%. Accordingly, the doses estimated by WAPPS-Hemo for a daily regimen were between 28% and 100% of those proposed by MyPKFiT. Conclusions: MyPKFiT and WAPPS-Hemo provided similar half-life estimations for Octocog alfa independent of the FVIII assay used. The doses suggested by WAPPS-Hemo to reach specific troughs were overall lower, which may have implications for treatment optimization.

Aim: To assess available evidence on the use of rFVIIa in non-orthopaedic surgery including dental surgery in adult patients with congenital haemophilia with inhibitors (PWHI). Methods: A systematic literature search was performed according to a prespecified search string; prespecified criteria were used to select applicable studies including PWHI ≥18 years of age who underwent any non-orthopaedic surgery using rFVIIa. Results: Thirty-three publications met the eligibility criteria, of which 26 publications – including 46 procedures in 44 patients – were selected for the qualitative analysis. Most publications were case reports or case series (21/26). Primary authors assessed rFVIIa as effective in maintaining haemostasis during and after most major surgeries (22/32). rFVIIa dose was mainly on label, with higher doses used in 4 cases, and a lower dose in 1 case. Duration of treatment was mostly 5–10 days (range: 3 days to 1 month post-operatively). Adverse events related to rFVIIa were rare. Conclusions: Assessing non-orthopaedic surgery in this patient population is hampered by a paucity of published data; nevertheless, the current evidence indicates that rFVIIa is effective in achieving haemostasis in haemophilia patients with inhibitors undergoing elective non-orthopaedic or dental surgery. rFVIIa was generally well tolerated in these patients, with thrombotic events occurring rarely. These data, generated to help clinicians manage congenital haemophilia with inhibitors, highlight the need for more systematic reporting of rFVIIa and all other therapeutic agents in non-orthopaedic surgery and dental surgery in patients with congenital haemophilia and inhibitors. (Less)

Introduction: Inhibitors develop less frequently in haemophilia B (HB) than haemophilia A (HA). However, when present, the success of tolerization by immune tolerance induction (ITI) therapy is lower and the risk of complications higher. Aim: To evaluate the use and outcome of ITI in patients with HB and inhibitors. Methods: Subjects include singletons or siblings with a current/history of inhibitors enrolled in B-Natural—an observational study designed to increase understanding of clinical management of patients with HB. Patients were followed for 6 months and information on demographics, medical and social history, and treatment were recorded. Results: Twenty-nine patients with severe HB and inhibitors were enrolled in 24 centres. Twenty-two underwent one or more courses of ITI with or without immune suppression. Eight patients (36.4%) were successfully tolerized after the first course of ITI. One of these successes (12.5%) experienced allergic manifestations, whereas the corresponding number for the 10 treatment failures was five (50%). One of seven (14.2%) patients with large deletions and three of eight (37.5%) with nonsense mutations were tolerized at the first attempt, and all patients experiencing nephrosis either failed or were on-going. At study end, 11 (50%) were considered successfully tolerized after one or more ITI courses, three were unsuccessful, and eight were still undergoing treatment. Conclusion: Our data underscore the possibilities and difficulties of achieving tolerization in patients with HB with inhibitors. The type of mutation and complications appear to correlate with ITI outcome, but more accurate definitions of successful ITI are warranted.

Background F8 int1h inversions (Inv1) are detected in 1-2% of severe hemophilia A (HA) patients. Long-range polymerase chain reaction (PCR) and inverse-shifting PCR have been used to diagnose these inversions. Objectives To design and validate a sensitive and robust assay for detection of F8 Inv1 inversions. Methods Archival DNA samples were investigated using mile-post assays and droplet digital PCR. Results Mile-post assays for Inv1 showing high specificities and sensitivities were designed and optimized. Analysis of four patients, two carrier mothers and 40 healthy controls showed concordance with known mutation status with one exception. One patient had a duplication involving exons 2-22 of the F8 gene instead of an Inv1 mutation. DNA mixtures with different proportions of wild type and Inv1 DNA correlated well with the observed relative linkage for both wild type and Inv1 assays and estimated the limit of detection of these assays to 2% of the rare chromosome. Conclusions The mile-post strategy has several inherent control systems. The absolute counting of target molecules by both assays enables determination of template quantity, detection of copy number variants and rare variants occurring in primer and probe annealing sites and estimation of DNA integrity through the observed linkage. The presented Inv1 mile-post analysis offers sensitive and robust detection and quantification of the F8 int1h inversions and other rearrangements involving intron 1 in patients and their mothers.

Introduction Detection of early arthropathy is crucial for the management of haemophilia, but data on moderate haemophilia are limited. Therefore, we evaluated joint health and treatment modalities in Nordic patients with moderate haemophilia A (MHA) and B (MHB). Aim To explore and compare the Haemophilia Early Arthropathy Detection with Ultrasound (HEAD-US) and Haemophilia Joint Health Score (HJHS) to detect early arthropathy in moderate haemophilia. Methods A cross-sectional, multicentre study covering Nordic patients with MHA and MHB. Arthropathy was evaluated by HEAD-US and HJHS 2.1. Results We assessed 693 joints in 118 patients. HEAD-US scores (medians [interquartile ranges]) were as follows: elbows 0 points (0-0), knees 0 (0-0) and ankles 0 (0-1). Respectively, by HJHS: elbows 0 (0-1), knees 0 (0-1) and ankles 0 (0-1). Cartilage (14%) and bone (13%) were most commonly affected by HEAD-US. Frequent HJHS findings were crepitus on motion in knees (39%), and loss of flexion (23%) and extension (13%) in ankles. HEAD-US correlated strongly with HJHS (elbows r = .70, knees r = .60 and ankles r = .65), but 24% had discordant scores. Joints with HJHS zero points, 5% captured HEAD-US >= 1 point. Moreover, 26% had HJHS findings without HEAD-US pathology. Notably, 31% of knees had crepitus on motion and normal HEAD-US. Conclusion Overall, the joints attained low scores implying good joint health. HEAD-US correlated strongly with HJHS. In 5%, HEAD-US detected subclinical pathology. Crepitus on motion was frequently reported despite normal HEAD-US, thus not necessarily reflecting arthropathy. HEAD-US therefore improves the joint assessment in moderate haemophilia.

Background: The occurrence of mosaicism in hemophilia A (HA) has been investigated in several studies using different detection methods. Objectives: To characterize and compare the ability of AmpliSeq/Ion Torrent sequencing and droplet digital polymerase chain reaction (ddPCR) for mosaic detection in HA. Methods: Ion Torrent sequencing and ddPCR were used to analyze 20 healthy males and 16 mothers of sporadic HA patients. Results: An error-rate map over all coding positions and all positions reported as mutated in the F8-specific mutation database was produced. The sequencing produced a mean read depth of >1500X where >97% of positions were covered by >100 reads. Higher error frequencies were observed in positions with A or T as reference allele and in positions surrounded on both sides with C or G. Seventeen of 9319 positions had a mean substitution error frequency >1%. The ability to identify low-level mosaicism was determined primarily by read depth and error rate of each specific position. Limit of detection (LOD) was 1% require repeated testing and mononucleotide repeats with more than four repeat units need an alternative analysis strategy. Mosaicism was detected in 1 of 16 mothers and confirmed using ddPCR. Conclusions: Deep sequencing using an AmpliSeq/Ion Torrent strategy allows for simultaneous identification of disease-causing mutations in patients and mosaicism in mothers. ddPCR has high sensitivity but is hampered by the need for mutationspecific design.

Background Monitoring hemophilia treatment with extended half-life products is challenging for coagulation laboratories since factor assays may show substantial differences between results obtained with the one-stage assay (OSA) and the chromogenic substrate assay (CSA). Objectives The aim of this study was to evaluate and compare different factor assays and global coagulation methods. Methods Factor VIII (FVIII) and IX (FIX) activities and global assay parameters were analyzed in pre- and postinfusion samples (5 patients 2 samples/product/method). Results Samples containing FVIII products (NovoEight, Elocta, and Nuwiq) gave higher levels when measured with CSA compared to OSA. The correlation was excellent (r 2 ≥ .97) while biases of 42%-72% of mean (CSA-OSA) were obtained. With FVIII (OSA) as independent variable, the correlations to kaolin clot time (CT) and thrombin generation assay (TGA) peak were modest (r2 = .71-.72 and .64-.65, respectively), except for Nuwiq for which there was a poor correlation to TGA peak (r 2 = .08). Samples containing Alprolix, a FIX product, gave a smaller difference between activity levels (CSA-OSA), and the correlation was excellent (r 2 = .96). With FIX (CSA) as independent variable for both Alprolix and Refixia, the correlations to Innovin CT and TGA peaks were weak (r 2 = .33-.45 and .44-.76, respectively). Conclusions Our data show that factor activity assays differ between methods used and agents. These discrepancies indicate the value of having more than one type of assay available in the coagulation laboratory when monitoring hemophilia treatment with extended half-life products. Global assays gave complementary information indicated by the modest correlations to factor activities.

Introduction: The prevalence of arthropathy in moderate haemophilia A (MHA) and B (MHB) is not well known. Aim: We evaluated joint health in Nordic patients in relation to their treatment modality. Methods: A cross-sectional, multicentre study covering MHA and MHB in Sweden, Finland and Norway. Arthropathy was evaluated by ultrasound (HEAD-US) and Haemophilia Joint Health Score (HJHS). Results: We report on 145 patients: median age 28 years (IQR 13-52) and 61% MHA. Baseline factor VIII/factor IX activity (FVIII/FIX:C) was 2 IU/dL (median) (IQR 2-4): lower for MHB (2 IU/dL, IQR 1-2) than MHA (3 IU/dL, IQR 2-4) (P

Background Persons with severe haemophilia require lifelong replacement therapy, prophylaxis, to prevent bleeding. Data describing long-term outcomes of prophylactic treatment are scarce. The aim of this study was to investigate joint surgery and survival among persons with severe haemophilia with special attention to access to prophylaxis in the early years of life. Methods Eligible participants had severe haemophilia A or B and were treated at the Malmo centre from the 1960s onward. Time from birth until joint surgery was analysed for participants negative for factor inhibitor and alive in 2000. We compared survival among the entire cohort with severe haemophilia treated at the Malmo centre with the general male population of Sweden and a sample of persons with severe haemophilia from the United Kingdom (UK). Results Overall, 167 participants were included, 106 (63.5%) of whom had complete data on joint surgery. Among those born before 1970, 1970-1979 and ≥1980 approximately 37%, 21% and 0% had their first joint surgery by age 30, respectively. There were no second joint surgeries reported in cohorts born ≥1970. Persons with severe haemophilia and negative for HIV treated in Malmo have attained approximately similar survival to that of the general male population in Sweden and live slightly longer than persons with severe haemophilia from the UK. Discussion and conclusion Prophylaxis in Sweden, although costly, has markedly improved survival and joint outcomes for persons with severe haemophilia. This study highlights the importance of early start of replacement therapy to prevent or postpone serious joint damage.

Introduction Assay discrepancy in factor VIII activity between the one-stage and the chromogenic assays has been described in approximately one third of patients with non-severe haemophilia A. Whether assay discrepancy may also occur in patients with haemophilia B remains unknown. Aim This study compared the results from the one-stage and the chromogenic assays in patients with haemophilia B. Methods Plasma samples from patients with haemophilia B attending the haemophilia centre in Malmo, Sweden, were collected after a wash-out period of more than 7 days and analysed with both assays. Results Fifty samples from 36 patients were analysed. No discrepancy was found in patients with severe haemophilia B. Among the 44 plasma samples from patients with non-severe disease, 15 showed a twofold or greater difference between the results of the two methods, with the chromogenic method presenting the higher value (mean FIX:Cone-stage 0.02 vs. FIX:Cchromo 0.06 IU mL−1). Of these 15 samples, 14 were from seven individuals from five families with the same mutated amino acid at the N-terminal cleaving site of the activation peptide (FIX: c.572G>A; p.Arg191His or FIX: c.571C>T; p.Arg191Cys). These mutations were not observed in any patients with non-discrepant results. The reported bleeding frequency for these patients was low and indicative of a mild bleeding phenotype. Conclusion Our findings imply that assay discrepancy occurs for factor IX activity and that both type of assays are needed for a correct diagnosis and classification of haemophilia B. The underlying mechanism by which the mutation influences the assays remains to be determined.

Data on the prevalence of hypertension and cardiovascular diseases (CVD) among persons with haemophilia (PWH) vary. Sweden has a long tradition of maintaining population-based data registries, and there is extensive follow-up of haemophilia patients due to the use of prophylaxis over decades. We evaluated the prevalence of these diseases among Swedish PWH compared to matched controls using a longitudinal study design.Data were obtained from the National Patient Registry and linked to records of persons with haemophilia enrolled in the haemophilia centres. For each subject, five gender and age matched controls were identified.We identified 193 (19.7%) diagnoses of hypertension in PWH born in 1978 or earlier over ≥30 years compared with 550 (11.2%) among controls. The median ages and interquartile ranges were 60.0 (42.8, 69.9) and 57.2 (42.6, 70.6) years. The hazard rate (HR) for hypertension, PWH vs. controls, was 2.1, 95% CI: [1.8; 2.5], p 0.001. The findings were similar in subgroup analyses of patients with non-severe and severe haemophilia with or without HIV and/or viral hepatitis. Angina pectoris was diagnosed in 69 (4.8%) of patients censored at age 75 compared with 311 (4.3%) in controls, and myocardial ischemia in 84 (5.9%) compared with 442 (6.2%). As a cause of death, the HR for myocardial ischemia, comparing PWH and controls, was 0.58, 95% CI: [0.42, 0.80], p = 0.001.Our data support an increased prevalence of hypertension among persons with haemophilia. The prevalence of CVD seems to be similar to that of controls, but with lower mortality.

Mutations are not identified in ~5% of hemophilia A and 10-35% of type 1 VWD patients. The bleeding tendency also varies among patients carrying the same causative mutation, potentially indicating variants in additional genes modifying the phenotype that cannot be identified by routine single-gene analysis. The F8, F9 and VWF genes were analyzed in parallel using an AmpliSeq strategy and Ion Torrent sequencing. Targeting all exonic positions showed an average read depth of >2000X and coverage close to 100% in 24 male patients with known disease-causing mutations. Discrimination between reference alleles and alternative/indel alleles was adequate at a 25% frequency threshold. In F8, F9 and VWF there was an absolute majority of all reference alleles at allele frequencies >95% and the average alternative allele and indel frequencies never reached above 10% and 15%, respectively. In VWF, 4-5 regions showed lower reference allele frequencies; in two regions covered by the pseudogene close to the 25% cut-off for reference alleles. All known mutations, including indels, gross deletions and substitutions, were identified. Additional VWF variants were identified in three hemophilia patients. The presence of additional mutations in 2 out of 16 (12%) randomly selected hemophilia patients indicates a potential mutational contribution that may affect the disease phenotype and counseling in these patients. Parallel identification of disease-causing mutations in all three genes not only confirms the deficiency, but differentiates phenotypic overlaps and allows for correct genetic counseling.

61st Annual Meeting and Exposition of the American-Society-of-Hematology (ASH) -- DEC 07-10, 2019 -- Orlando, FL, WOS:000577160405077, [No Abstract Available], Amer Soc Hematol