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Aim/objective: Understanding pharmacokinetic (PK) differences between standard and extended half-life (EHL) products is important, particularly for factor IX (FIX), where differences are more significant than for factor VIII. Two single-dose PK trials showed N9-GP achieves higher FIX levels and greater area-under-the-curve than pdFIX, rFIX, and rFIXFc through higher recovery and longer terminal half-life. In paradigm 7, N9-GP demonstrated consistently favorable PK characteristics compared with rFIXFc. Collins et al explored population PK differences between N9-GP and pdFIX/rFIX based upon paradigm 1 data. This analysis uses population PK models based upon the paradigm 7 trial. Methods: 15 patients (21–65 years) with hemophilia B received single 50-IU/kg doses of N9-GP and rFIXFc ≥21 days apart. A population PK model developed from single-dose PK profiles simulated plasma FIX activity following dosing for surgery and on-demand treatment of bleeds. Simulations explored doses and frequencies required to sustain target World Federation of Hemophilia (WFH) factor activity levels. Results: PK profiles of N9-GP and rFIXFc were described by one- and three-compartment models, respectively. Simulations predicted significantly reduced dosing frequency and consumption for N9-GP than rFIXFc. For severe bleeds, a single N9-GP dose (80 IU/kg) is sufficient to maintain WFH-recommended FIX levels, whereas multiple rFIXFc doses are required. For surgery, redosing in the first week with N9-GP is modeled at day 6 vs rFIXFc dosing at 6, 30, 54, 78, and 126 hrs. For life-threatening bleeds, N9-GP is required at days 0, 3, 6, 13, and 18 vs rFIXFc redosing after 6 hrs with 10 additional doses at 24-, 48-, and 72 hr intervals. Conclusion: PK modeling approaches based upon direct comparative studies offer insights into PK differences between EHL FIX products. Model simulations show N9-GP may allow on-demand treatment and perioperative management with 55–75% fewer injections and 65–74% lower overall factor concentrate consumption than rFIXFc. [ABSTRACT FROM AUTHOR]

Abstract: Introduction: Thrombin and plasmin are the key enzymes involved in coagulation and fibrinolysis, respectively. Plasma coagulative and fibrinolytic potentials in normal children and adults, and in representative pathologically altered hemostatic states, were evaluated via simultaneous assessment of thrombin and plasmin generation. Materials and Methods: An assay of Simultaneous Thrombin and Plasmin generation (STP) was developed to measure thrombin and plasmin in plasma using individual fluorometric substrates. Coagulation is initiated with dilute tissue factor, phospholipid, and calcium in platelet-poor plasma; fibrinolysis is accelerated via tissue plasminogen activator (tPA). Abnormal states of hemostasis were investigated. Results: STP assay reproducibility and normal adult and pediatric values for measured and calculated parameters have been established. Onset of both thrombin and plasmin generation was significantly delayed in children relative to adults (p<0.001) and the maximum amplitudes of thrombin and plasmin generation were less in children than adults (p<0.01). No significant differences were measured among pediatric age groups. The most profound impairments in thrombin generation were observed for extrinsic and common pathway factor deficiencies, with the exception of afibrinogenemia. Plasmin generation was severely impaired in deficiencies of fibrinogen and plasminogen as well as with decreased tPA reagent concentration and addition of aminocaproic acid. Plasmin generation was greatly enhanced by alpha-2-antiplasmin deficiency and excess tPA reagent. Conclusion: Simultaneous assessment of thrombin and plasmin generation in plasma shows promise for affording an enhanced understanding of overall coagulative and fibrinolytic functions in physiological and pathologically altered states of hemostasis in children and adults. [Copyright &y& Elsevier]

Introduction: Health literacy (HL) and health numeracy (HN) are underestimated barriers to treatment adherence in patients with haemophilia. Aim: To test the ability of an educational intervention to improve knowledge, HL, HN, adherence and joint health in adolescent and young adult (AYA) males with haemophilia. Methods: We performed a longitudinal pilot study of 41 participants aged 12–21 years with haemophilia A or B during two clinic visits 6–12 months apart. The first visit included a comprehensive pre‐intervention assessment: demographics, knowledge survey, Montreal Cognitive Assessment testing, 5‐question tool to assess baseline HN, assessment of HL with the Rapid Estimate of Adolescent Literacy in Medicine tool, history of adherence and Haemophilia Joint Health Score (HJHS). An educational intervention using a visual aid explained basic pharmacokinetic (PK) concepts and personal teaching regarding haemophilia treatment regimens was used during this visit. The second visit included a post‐intervention assessment: a reassessment of knowledge, HL, HN, HJHS, adherence to prescribed therapy and number of joint bleeds since the pre‐intervention visit. Results: Forty‐one males with haemophilia A or B were enrolled in the study. Of these, 33 completed the post‐intervention assessment. Knowledge (p =.002) and HN (p =.05) were significantly improved post‐intervention, although the HL, number of joint bleeds, adherence to prescribed therapy and HJHS were not. Conclusions: Participants with low HL and/or HN may benefit from alternate methods of education such as audiovisual material. Education using audiovisual materials improved knowledge and HN in this study; however, this did not affect adherence to prescribed therapy. [ABSTRACT FROM AUTHOR]

Introduction: In recent years, there has been increased focus on individualizing treatment for persons with hemophilia including pharmacokinetic‐guided (PK) dosing. Aims: In this retrospective study clinical outcomes before and after PK‐guided prophylaxis were examined. Materials and methods: Eight Haemophilia Treatment Centres from the United States participated in the study and included 132 patients classified into two cohorts: those undergoing a PK‐assessment for product switch (switchers) or to optimize treatment (non‐switchers). Subset analyses for the two most common products and patients with dosing per prescription label were included for annual bleeding rates (ABR), mean weekly consumption outcomes, and annualized cost of prophylaxis. Results: The most common products before and after index date were octocog alfa, rurioctocog alfa pegol, and efmoroctocog alfa. Seventy‐four (56%) patients were identified as switchers and 58 (44%) patients were classified as non‐switchers. The majority of patients (78.0%) experienced either a decrease in ABR post‐index or maintained 0 ABR during pre‐ and post‐index time periods, with similar proportions identified in both switchers (77.0%) and non‐switchers (79.3%) populations. Non‐switchers were identified as having no significant change in cost of therapy, while switchers experienced increased cost of therapy driven by higher price of extended half‐life products. Within subset analyses, patients receiving rurioctocog alfa pegol and efmoroctocog alfa had mean ABR under 1 after index date. Conclusion: PK‐guided prophylaxis has the potential to improve clinical outcomes without increase in cost of therapy for patients maintaining product and can aid in maintaining effective protection against bleeds in those switching product. [ABSTRACT FROM AUTHOR]