Tissue factor pathway inhibitor (TFPI) inhibits coagulation initiation, and TFPI inhibition enhances the activation of factor X by tissue factor. Shapiro et al report the results of a phase 2 study of prophylactic administration of the TFPI inhibitor concizumab for bleeding prevention in hemophilia, reporting efficacy in Factor VIII and IX deficiency even in patients with inhibitors to Factor VIII or IX.
Haemophilia A and haemophilia B are congenital X-linked bleeding disorders caused by deficiency of coagulation factor VIII (FVIII) and IX (FIX), respectively. The preferred treatment option for patients with haemophilia is replacement therapy. For patients with severe disease, prophylactic replacement of coagulation factor is the treatment of choice; this has been shown to reduce arthropathy significantly, reduce the frequency of bleeds and improve patients' quality of life. Prophylaxis with standard recombinant factor requires regular intravenous infusion at least two (FIX) to three (FVIII) times a week. Recombinant FVIII and FIX products with an extended half-life are in development, or have been recently licensed. With reported mean half-life extensions of 1.5-1.8 times that of standard products for FVIII and 3-5 times that of standard products for FIX, these products have the potential to address many of the unmet needs of patients currently treated with standard factor concentrates. For example, they may encourage patients to switch from on-demand treatment to prophylaxis and improve the quality of life of patients receiving prophylaxis. Indeed, extended half-life products have the potential to reduce the burden of frequent intravenous injections, reducing the need for central venous lines in children, promote adherence, improve outcomes, potentially allow for more active lifestyles and, depending on the dosing regimen, increase factor trough levels. Members of the Zürich Haemophilia Forum convened for their 19th meeting to discuss the practicalities of incorporating new treatments into the management of people with haemophilia. This review of extended half-life products considers their introduction in haemophilia treatment, including the appropriate dose and schedule of infusions, laboratory monitoring, patient selection, safety considerations, and the economic aspects of care.
The standard therapy for patients with haemophilia is prophylactic treatment with replacement factor VIII (FVIII) or factor IX (FIX). Patients who develop inhibitors against FVIII/FIX face an increased risk of bleeding, and the likelihood of early development of progressive arthropathy, alongside higher treatment‐related costs. Bypassing agents can be used to prevent and control bleeding, as well as the recently licensed prophylaxis, emicizumab, but their efficacy is less predictable than that of factor replacement therapy. Antibody eradication, by way of immune tolerance induction (ITI), is still the preferred management strategy for treating patients with inhibitors. This approach is successful in most patients, but some are difficult to tolerise and/or are unresponsive to ITI, and they represent the most complicated patients to treat. However, there are limited clinical data and guidelines available to help guide physicians in formulating the next treatment steps in these patients. This review summarises currently available treatment options for patients with inhibitors, focussing on ITI regimens and those ITI strategies that may be used in difficult‐to‐treat patients. Some alternative, non‐ITI approaches for inhibitor management, are also proposed.
Patients with congenital hemophilia require lifelong replacement therapy with a clotting factor concentrate: factor (F) VIII in hemophilia A and FIX in hemophilia B (1). However, patients can develop inhibitors to these exogenous factors, resulting in the most serious treatment related complication in hemophilia (2, 3). Once inhibitors have developed, it is more challenging to achieve hemostasis than in non-inhibitor patients. Furthermore , the presence of inhibitors has a major impact on patients' physical functioning, quality of life, morbidity , and mortality (4-6). In patients with high-titer inhibitors [ ‡5 Bethesda units (BU)], immune tolerance induction (ITI) aims to eradicate anamnestic inhibitors and restore normal responses to replacement therapy. The process of ITI involves regular infusion of FVIII or FIX concentrate with the goal Abstract For hemophilia patients with inhibitors, immune tolerance induction (ITI) may help to restore clinical response to factor (F) VIII or FIX concentrates. Several ITI regimens and protocols exist; however, despite 30 yr of progressive investigation, the ITI evidence base relies mainly on observational data. Expert opinion, experience, and interpretation of the available evidence are therefore valuable to support clinical decision-making. At the Sixth Zü rich Haemophilia Forum, an expert panel considered recent data and consensus to distill key practice points relating to ITI. The panel supported current recommendations that, where feasible, ITI should be offered early to children and adults (ideally £5 yr of inhibitor detection) when inhibitor titers are <10 Bethesda units (BU) and should be stopped when successful tolerance is achieved. For hemophilia A inhibitor patients, ITI can be founded on recombinant FVIII at high doses. The panel considered that patients with a high bleeding frequency should be offered additional prophylaxis with a bypassing agent. For patients with hemophilia B, there may be a benefit of genetic testing to indicate the risk for inhibitors. ITI is often less effective and associated with a greater risk of side effects in these patients. For high-titer inhibitor (‡5 BU) hemophilia B patients, the panel advised that bypassing agents could be offered on demand in addition to ITI. Within future ITI regimens, there may be a role for additional immunosuppressant therapies. Participants agreed that research is needed to find alternatives to ITI therapy that offer durable and sustained effects and reduced rates of complications.
Purpose: Congenital hemophilia A and B are bleeding disorders characterized by deficiency of factors VIII and IX, respectively. This study aimed to collect health-related quality-of-life (HRQoL) and health-utility data from hemophilia patients with differing disease severity. Methods: Individuals with hemophilia aged ≥12 years living in France or the UK completed a series of questionnaires, including the EQ-5D-3L and -5L and SF-36 version 2. Association with demographic and clinical variables was explored using linear regression, and health-utility comparison was completed using Pearson and intraclass correlation coefficients. Results: A total of 122 patients in France and 62 in the UK completed the survey. The combined sample primarily consisted of hemophilia A patients, mean age of 41 years, 70% had severe hemophilia, and 56% were on long-term prophylaxis. Similar HRQoL and utility scores were observed across the French and UK samples. The presence of more than two target joints, occurrence of joint surgery, and increased joint-pain frequency were independent predictors of lower SF-36 — physical health summary scores and lower health-utility scores. No statistically significant reductions in SF-36 — mental health summary scores were observed, except for participants with target joints. Strong correlations were observed between health- utility values derived from the three instruments ( r =0.69–0.79). Conclusion: Results of this study reinforce the importance of appropriate treatment to limit the physical burden and long-term joint damage associated with hemophilia. Further, utility values collected here reflect real-world data, and can serve as health-state weights in future cost–utility analyses.
Key content Postpartum ovarian vein thrombosis (POVT) is a rare but potentially fatal condition. Symptoms up to 4 weeks postpartum often include vague abdominal pain and pyrexia. A high index of suspicion is required to make the diagnosis. As there is no consensus regarding management, a multidisciplinary approach is advised. Learning objectives Recognise the symptoms and signs of POVT and formulate a differential diagnosis. Recognise the importance of imaging in confirming the diagnosis and involvement of the multidisciplinary team to plan management. Understand that conservative management with low‐molecular‐weight heparin is the first‐line treatment, and understand the situations that may require vena caval filter insertion or surgical intervention. Ethical issues How can we counsel women about risks of conservative and surgical management of this condition when there is no consensus for this management? Should women who have had an ovarian vein thrombosis in a previous pregnancy be counselled toward avoiding future pregnancy?
Dabigatran is an oral direct thrombin inhibitor (DTI) licensed for stroke prevention in atrial fibrillation and likely to be soon approved in Europe for treatment of venous thrombosis. Predictable pharmacokinetics and a reduced risk of intracranial haemorrhage do not negate the potential risk of haemorrhage. Unlike warfarin, there is no reversal agent and measurement of the anticoagulant effect is not ‘routine’. The prothrombin time/international normalised ratio response to dabigatran is inconsistent and should not be measured when assessing a patient who is bleeding or needs emergency surgery. The activated partial thromboplastin time (APTT) provides a qualitative measurement of the anticoagulant effect of dabigatran. Knowledge of the time of last dose is important for interpretation of the APTT. Commercially available DTI assays provide a quantitative measurement of active dabigatran concentration in the plasma. If a patient receiving dabigatran presents with bleeding: omit/delay next dose of dabigatran; measure APTT and thrombin time (consider DTI assay if available); administer activated charcoal, with sorbitol, if within 2 h of dabigatran ingestion; give tranexamic acid (1 g intravenously if significant bleeding); maintain renal perfusion and urine output to aid dabigatran excretion. Dabigatran exhibits low protein binding and may be removed by dialysis. Supportive care should form the mainstay of treatment. If bleeding is life/limb threatening, consider an additional haemostatic agent. There is currently no evidence to support the choice of one haemostatic agent (FEIBA, recombinant factor VIIa, prothrombin complex concentrates) over another. Choice will depend on access to and experience with available haemostatic agent(s).
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