Advances in the management of haemophilia: emerging treatments and their mechanisms

Surgical procedures and complications in placement of totally implantable venous access port in pediatric hemophilia patients: A retrospective analysis

This retrospective study at Beijing Children's Hospital (2020-2023) analyzed surgical procedures and complications in 24 pediatric hemophilia patients undergoing Totally Implantable Venous Access Port (TIVAP) insertion, primarily in the right jugular vein (RJV). We detailed the surgical process, including patient demographics and intraoperative imaging use. The choice of the RJV for TIVAP placement was influenced by its larger diameter and superficial anatomical position, potentially reducing risks like thrombosis and infection. Our findings support the RJV as a safer alternative for port placement in pediatric patients, aligning with current literature. Statistical analysis revealed no significant correlation between complications and baseline characteristics like weight and diagnosis type. However, the length of hospital stay and implant brand were significant risk factors for catheter or port displacement and removal. The limited patient number may introduce bias, suggesting a need for further studies with larger samples. Despite a 14.7 %-33 % complication rate and 5 port removals, the advantages of TIVAP, including reliable venous access, reduced discomfort, and treatment convenience, were evident. Most complications improved with symptomatic treatment, and there were no deaths due to port-related complications, underscoring the impact of TIVAP on improving pediatric hemophilia treatment.

The Concizumab Pen-Injector is Easy to Use and Preferred by Hemophilia Patients and Caregivers: A Usability Study Assessing Pen-Injector Handling and Preference

Introduction

Concizumab is a once-daily prophylactic treatment developed for patients with hemophilia A or B (HA/HB) with or without inhibitors. It is the first treatment for hemophilia patients to be delivered subcutaneously using a pre-filled, multi-dose pen-injector with a 4 mm, 32 G needle.

Aim

To investigate patient and caregiver handling and preference for the concizumab pen-injector compared with current injection systems used to treat hemophilia.

Methods

This preference and handling study was conducted in accordance with authority guidelines for approval of new devices and included adults and adolescents with HA/HB with or without inhibitors and caregivers currently administering factor replacement therapy or factor VIII mimetic (emicizumab) therapy. All participants underwent a training session, followed by a test session during which participants independently administered a single pen-injection into an injection pad or manikin. Time to train, time to prepare and inject, and number of complete independent injections handling the pen were assessed. Participants evaluated handling and preference via the Hemophilia Device Handling and Preference Assessment Questionnaire.

Results

80 participants (44 adults, 21 adolescents, 15 caregivers) currently using factor replacement therapy (n=41, 51%) or emicizumab (n=39, 49%) participated. Average training time and time to complete an injection were 7 min 49s and 1 min 21s. In total, 98% of independent complete injections were achieved at first attempt. 98% (n=78; 95% confidence interval [CI] 91-100%) of participants assessed the pen-injector as either "easy" or "very easy" to use. 88% of participants preferred the pen-injector (n=70; 95% CI 78-94%) over their current injection system, and 9% (n=7) reported "no preference".

Conclusion

Participants found the concizumab pen-injector easy to learn and easy to use and preferred it over their current injection systems.

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.

Shifting Paradigms and Arising Concerns in Severe Hemophilia A Treatment

The management of hemophilia A has undergone a remarkable revolution, in line with technological advancement. In the recent past, the primary concern associated with Factor VIII (FVIII) concentrates was the risk of infections, which is now almost resolved by advanced blood screening and viral inactivation methods. Improving patients' compliance with prophylaxis has become a key focus, as it can lead to improved health outcomes and reduced health care costs in the long term. Recent bioengineering research is directed toward prolonging the recombinant FVIII (rFVIII) coagulant activity and synthesising higher FVIII yields. As an outcome, B-domain deleted, polyethylene glycolated, single-chain, Fc-fused rFVIII, and rFVIIIFc-von Willebrand Factor-XTEN are available for patients. Moreover, emicizumab, a bispecific antibody, is commercially available, whereas fitusiran and tissue factor pathway inhibitor are in clinical trial stages as alternative strategies for patients with inhibitors. With these advancements, noninfectious complications, such as inhibitor development, allergic reactions, and thrombosis, are emerging concerns requiring careful management. In addition, the recent approval of gene therapy is a major milestone toward a permanent cure for hemophilia A. The vast array of treatment options at our disposal today empowers patients and providers alike, to tailor therapeutic regimens to the unique needs of each individual. Despite significant progress in modern treatment options, these highly effective therapies are markedly more expensive than conventional replacement therapy, limiting their access for patients in developing countries.

florio® HAEMO: A Longitudinal Survey of Patient Preference, Adherence and Wearable Functionality in Central Europe

INTRODUCTION

florio® HAEMO is a hemophilia treatment monitoring application (app) offering activity tracking and wearable device connectivity. Its use might support everyday activities for people with hemophilia. The aim of this study was to evaluate user satisfaction, long-term usage and the impact on data entry when pairing a wearable with a hemophilia monitoring app.

METHODS

This is a follow-up of a two-part user survey conducted in Central Europe. People with hemophilia and parents/caregivers of children with hemophilia using florio HAEMO and who completed part one were invited to complete a second online questionnaire at least 4 months later.

RESULTS

Fifty participants (83.3%) who completed part one of the survey continued to use the florio HAEMO app and completed part two. Of 14 participants who chose to use the app with a wearable, more than half (57.1%) were aged between 13 and 25 years. Overall, the results demonstrated that florio HAEMO is very easy or rather easy to use, especially for individuals pairing the app with a wearable. Most people using a wearable indicated that florio HAEMO was very or rather important in bringing certainty to daily activities (85.7%). Notably, 14 of 36 (38.9%) non-wearable users indicated that they would prefer to pair the app with a wearable in the future.

CONCLUSIONS

Adherence to the florio HAEMO app is maintained over an extended period of use. Pairing the app with a wearable might enable easier access to app features, increase data entry motivation and provide more certainty about daily activities for people with hemophilia.

Preference of treatment characteristics among people with haemophilia or their caregivers, and physicians in the Japanese healthcare environment

INTRODUCTION

Studies of treatment preferences in haemophilia have been conducted in many countries. This study is the first to examine treatment characteristic preferences among people with haemophilia (PWH) and their caregivers, and physicians in Japan.

AIM

To examine current treatment preferences of PWH and their caregivers, plus those of physicians at haemophilia treatment centres (HTCs) and non-HTCs for different treatment characteristics in Japan.

METHODS

Physicians listed on a survey panel were invited to participate in the survey and to refer PWH and caregivers to participate in the survey. Web-based surveys were conducted to examine physician and PWH/caregiver background, prophylaxis background, prophylaxis goals, understanding of haemophilia treatment products, important information sources, preferences while choosing prophylaxis products, understanding of the patient's condition, and potential product switching. A discrete choice experiment exercise was included in the survey.

RESULTS

A total of 107 physicians and 44 PWH/caregivers participated in the study. Key treatment goals of physicians included optimisation of haemophilia management. PWH/caregivers were focused on quality of life and reduced treatment burden. Consistent differences in haemophilia treatment strategies at HTCs and non-HTCs were observed for prescribed treatments, preferences in choosing prophylaxis products, understanding of patients' condition, and reasons for potential product switch.

CONCLUSION

Our study utilises real-world survey data and presents preferences for haemophilia treatment characteristics among physicians, PWH and their caregivers in Japan, which could encourage improvements in individualised treatment and disease management. Alignment between treatment approaches at HTCs and non-HTCs could facilitate improvements in the quality of care for PWH across Japan.

Impact of Replacement Therapy on Pregnancy Outcomes in Hemophilia Carriers: A Historical Cohort Study in Saudi Arabia

This retrospective cohort study evaluates the safety and efficacy of replacement therapy with regard to pregnancy outcomes in hemophilia carriers. Hemophilia carriers face elevated bleeding risks during pregnancy, necessitating meticulous management, including replacement therapy with clotting factors. This research examines the records of 64 pregnant hemophilia carriers at King Fahad Medical City, Riyadh, from January 2010 to December 2023, analyzing their demographic details, hemophilia type and severity, replacement therapy specifics, and pregnancy outcomes. The study found that 62.5% of the participants had hemophilia A, with 43.8% categorized as severe. Most subjects (87.5%) received recombinant factor VIII at a median dosage of 30 IU/kg weekly. Adverse pregnancy outcomes included gestational hypertension (15.6%), preterm labor (18.8%), and postpartum hemorrhage (12.5%). The cesarean section rate was 28.1%. Neonatal outcomes were generally favorable, with median birth weights at 3100 g and mean Apgar scores of 8.2 and 9.1 at 1 and 5 min, respectively. Logistic regression analysis revealed no significant association between adverse events and therapy type or dosage, though a trend towards significance was noted with once-weekly administration (p = 0.082). The study concludes that replacement therapy is a viable method for managing hemophilia in pregnant carriers, leading to generally favorable maternal and neonatal outcomes. However, it underscores the importance of individualized treatment plans and close monitoring to effectively manage the risks associated with hemophilia during pregnancy.

In vivo LNP-CRISPR Approaches for the Treatment of Hemophilia

Hemophilia is a genetic disorder that is caused by mutations in coagulation factor VIII (hemophilia A) or IX (hemophilia B) genes resulting in blood clotting disorders. Despite advances in therapies, such as recombinant proteins and products with extended half-lives, the treatment of hemophilia still faces two major limitations: the short duration of therapeutic effect and production of neutralizing antibodies against clotting factors (inhibitor). To overcome these limitations, new hemophilia treatment strategies have been established such as gene therapy, bispecific antibody, and rebalancing therapy. Although these strategies have shown promising results, it is difficult to achieve a permanent therapeutic effect. Advances in the clustered regularly interspaced short palindromic repeat (CRISPR) technology have allowed sustainable treatment by correcting mutated genes. Since genome editing generates irreversible changes in host genome, safety must be ensured by delivering target organs. Therefore, the delivery tool of the CRISPR system is crucial for safe, accurate, and efficient genome editing. Recently, non-viral vector lipid nanoparticles (LNPs) have emerged as safer tools for delivering CRISPR systems than other viral vectors. Several previous hemophilia pre-clinical studies using LNP-CRISPR showed that sufficient and sustainable therapeutic effects, which means that LNP-CRISPR-mediated genome-editing therapy can be a valid option for the treatment of hemophilia. In this paper, we summarize the latest advancements in the successful treatment of hemophilia and the potential of CRISPR-mediated genome-editing therapy using LNPs.

Emicizumab is well tolerated and effective in people with congenital hemophilia A regardless of age, severity of disease, or inhibitor status: a scoping review

Background

With the treatment landscape continually evolving, it is vital that the hemophilia community have an overview of all published data for approved therapies, such as emicizumab, to support shared decision making.

Objectives

To bring together the clinical and real-world data for emicizumab use in people with congenital hemophilia A, regardless of age, disease severity, or factor VIII inhibitor status. Key focus areas were safety, efficacy, and quality of life (QoL).

Methods

This scoping review used citation databases (PubMed, Embase, and the Cochrane Library) and manual searches of abstract books. Publications reporting original data for emicizumab in people with hemophilia A, published in English after December 2014, and reporting select endpoints were included. This narrative synthesis focused on zero bleeds, treated annualized bleeding rate (ABR), adverse events, and QoL measures.

Results

Overall, 97 publications were included (cut-off: August 9, 2022). Treated ABR remained low (calculated mean and median treated ABRs ranged between 0.7-1.3 and 0.0-1.4, respectively), and the median percentage of people with zero treated bleeds was 66.7%. The proportion of people experiencing treatment-related adverse events ranged from 0.0% to 60.0%; most were injection-site reactions. Across 37 publications reporting on safety and enrolling >2300 individuals, 11 thrombotic events and 4 thrombotic microangiopathies were reported. Data from well-established tools show QoL benefits with emicizumab.

Conclusion

This scoping review consolidates the global published experience for emicizumab in people with hemophilia A and supports the fact that emicizumab has an acceptable safety profile, is effective and efficacious in bleed prevention, and is associated with improvements in QoL.

The current challenges faced by people with hemophilia B

Hemophilia B (HB) is a rare, hereditary disease caused by a defect in the gene encoding factor IX (FIX) and leads to varying degrees of coagulation deficiency. The prevailing treatment for people with HB (PWHB) is FIX replacement product. The advent of recombinant coagulation products ushered in a new era of safety, efficacy, and improved availability compared with plasma-derived products. For people with severe HB, lifelong prophylaxis with a FIX replacement product is standard of care. Development of extended half-life FIX replacement products has allowed for advancements in the care of these PWHB. Nonetheless, lifelong need for periodic dosing and complex surveillance protocols pose substantive challenges in terms of access, adherence, and healthcare resource utilization. Further, some PWHB on prophylactic regimens continue to experience breakthrough bleeds and joint damage, and subpopulations of PWHB, including women, those with mild-to-moderate HB, and those with inhibitors to FIX, experience additional unique difficulties. This review summarizes the current challenges faced by PWHB, including the unique subpopulations; identifying the need for improved awareness, personalized care strategies, and new therapeutic options for severe HB, which may provide future solutions for some of the remaining unmet needs of PWHB.

Construction and study of blood purification membrane modified with PDE inhibitor: Investigation of antiplatelet activity and hemocompatibility

The recent "cell-based theory" of coagulation suggests that platelets serve as the site of coagulation factor reactions, making platelets an effective target for inhibiting membrane thrombosis. Unfortunately, there is limited research on how blood purification membranes affect platelet intracellular signaling. In this study, we modified polyethersulfone (PES) membranes with the platelet phosphodiesterase (PDE) inhibitor dipyridamole (DIP) and investigated the effects of the DIP/PES (DP) membranes on platelet adhesion, activation, aggregation, and secretion, as well as the role of the PDE-cyclic adenosine monophosphate (cAMP) intracellular signaling pathway. Additionally, we evaluated the hemocompatibility and preliminary in vivo safety of DP membranes. Our results demonstrate that the modified DP membranes effectively inhibited platelet adhesion, membrane CD62P expression, and plasma soluble P-selectin activation levels. Furthermore, we confirmed that DP membranes achieved platelet aggregation inhibition and reduced platelet factor 4 and β-thromoglobulin secretion levels by inhibiting platelet intracellular PDE-cAMP signaling. Moreover, the modified DP membranes exhibited good anticoagulant and red blood cell membrane stability and complement resistance and demonstrated preliminary biocompatibility in mouse experiments. Collectively, these findings highlight the potential application of DP dialysis membranes in blood purification for critically ill patients.

Association of physical activity with bleeding events and safety in patients with haemophilia A starting emicizumab prophylaxis: an interim analysis of the TSUBASA study

INTRODUCTION

Little information exists on the relationship between bleeding outcomes and physical activity in patients with haemophilia A (PwHA).

AIM

This interim analysis of the TSUBASA study (UMIN-CTR ID: UMIN000037448) evaluated the association of physical activity with bleeding and safety in PwHA starting emicizumab.

METHODS

PwHA without factor VIII inhibitors were recruited. Physical activity and bleed data were obtained using an electronic patient-reported outcome application and wearable activity tracker. Adverse events (AEs) were documented.

RESULTS

At data cut-off (31-May-2021), 107 PwHA were enrolled, with a median (range) age of 35 (0-73) years. Physical activity data were obtained for 74 participants. Of these, 47 (63.5%) recorded a total of 396 exercise events. The most common exercise events were walking (32.4%), cycling (14.9%), and football (5.4%). Two (0.5%) exercise events in the same individual were associated with bleeding (running, weight training). The safety analysis population consisted of 106 participants treated with emicizumab (median observation period: 241.5 days). Twenty-one (19.8%) participants experienced a total of 39 AEs. Five (4.7%) experienced a serious AE, none of which was emicizumab-related, and three (2.8%) experienced an adverse drug reaction.

CONCLUSIONS

PwHA receiving emicizumab in the TSUBASA study experienced minimal bleeding associated with physical activity.

TRIAL REGISTRATION

Trial registration: UMIN-CTR ID: UMIN000037448.

Expert opinion paper on the treatment of hemophilia a with emicizumab

INTRODUCTION

Prophylaxis with emicizumab, a bispecific monoclonal antibody that mimics FVIII function, has shown encouraging results in clinical trials in terms of efficacy and safety. However, current experience is limited, and many areas of concern to clinicians have yet to be reviewed.

AREAS COVERED

This paper reviews the experience of hemophilia A patients treated with emicizumab based on the results of clinical trials and real-life studies. The authors place special emphasis on issues such as the management of these patients in situations of hemorrhage and/or surgical interventions, joint health or laboratory monitoring.

EXPERT OPINION

Treatment with emicizumab has been shown to improve joint health and reduce bleeding, of particular interest to patients with inhibitors and high bleeding rates. However, there are still concerns about its administration in neonates and previously untreated patients due to limited reported experience. Laboratory monitoring is not strictly necessary due to the stable pharmacokinetics emicizumab has been shown to exhibit, however, tests that globally assess hemostasis may be useful especially in cases of bleeding or surgery. The authors are also of the opinion that prophylaxis before minor surgery is not necessary and that major surgeries can be safely performed with additional prophylactic coagulation factor.Trial registration ClinicalTrials.gov identifier: NCT04431726..

Real-World Experience of People with Hemophilia A Receiving Turoctocog Alfa Pegol (N8-GP): Results from a Patient Experience Survey

Purpose

Turoctocog alfa pegol (N8-GP) is an extended half-life recombinant factor VIII molecule used for the treatment of hemophilia A (HA). The purpose of this study was to investigate real-world experiences of patients with HA treated with N8-GP.

Patients and Methods

A 25-minute online survey was completed by adults (≥18 years) and caregivers of adolescents (12-16 years) with HA receiving N8-GP across six countries (Germany, Italy, Portugal, Spain, UK and US). Patients were recruited using a multichannel approach through recruitment panels, referrals from healthcare professionals and patient associations. The survey comprised a questionnaire with metrics including satisfaction and preferences for N8-GP, quality of life (QoL) and long-term impact.

Results

A total of 62 participants (98% male [n=61], mean age 29 years) comprising 46 patients and 16 caregivers completed the survey. Patients (60% non-severe [n=37] and 40% severe [25]) were on N8-GP for a mean period of 1.4 years. Patients expressed satisfaction (95% vs 42%, p<0.001) and preference (91% vs 9%, p<0.001) for N8-GP vs their previous treatments. Most patients with severe HA (87%, p=0.038) and patients on prophylaxis (84%, p<0.001) stated lower frequency of injections as their main reason for satisfaction, while improved QoL drove satisfaction for non-severe patients (81%, p=0.053). Overall, patients perceived that QoL score improved (74.8 vs 65.9, p=0.01) with N8-GP treatment compared with previous treatments. Flexibility to store at room temperature was one of the key convenience factors driving satisfaction. Patients believed that N8-GP can offer a long-term impact in areas such as ability to perform day-to-day activities (68%), independence to live like a person without hemophilia (63%), ability to travel (60%) with a feeling of optimism and hopefulness (82%).

Conclusion

Lower frequency of injections, storage flexibility and improved QoL drove satisfaction and preference for N8-GP over previous treatments among patients with HA.

Pain interferes with daily activities, emotions and sleep in adults with severe, moderate and mild haemophilia: A national cross-sectional survey

INTRODUCTION

Pain is a major issue in people with haemophilia (PwH). Few studies comprehensively assessed pain in PwH using a biopsychosocial framework and studies in mild PwH are lacking.

AIM

To assess pain prevalence, pain interference and their relationship with health-related quality of life (HR-QoL) in male adults with haemophilia.

METHODS

A survey was initiated by the Belgian national member organisation. Pain in the last 24 h, pain severity (BPI-PS) and pain interference (BPI-PI) scores were obtained with the Brief Pain Inventory short-form (BPI). HR-QoL was evaluated with the EQ-5D-3L, giving the health utility index (EQ-HUI). Associations between EQ-HUI, BPI-PS and BPI-PI were analysed using Pearson's correlation test. A multiple regression analysed the relationship between HR-QoL and BPI-PS, with age and haemophilia severity as confounding factors.

RESULTS

Within 185 respondents (97, 31 and 57 respectively severe, moderate and mild PwH), 67% (118/177) reported pain. In severe, moderate and mild PwH, respectively 86% (79/92), 71% (22/31) and 32% (17/54) reported pain. Median [IQR] BPI-PS, BPI-PI and EQ-HUI scores were respectively 1.5 [.0; 4.0], 1.6 [.0; 3.6] and .81 [.69; 1.00]. PwH reported pain interference with general activity (56% (99/176)), psychosocial factors such as mood (53% (93/175)), and sleep (51% (90/177)). Moderate correlations were found between EQ-HUI, BPI-PS and BPI-PI. After adjusting for age and haemophilia severity, BPI-PS explained 14% of HR-QoL variance.

CONCLUSIONS

Pain is a major issue amongst PwH, including people with mild haemophilia. Pain interferes with activities, emotions, sleep and HR-QoL, arguing for a comprehensive biopsychosocial approach of pain.

From a bispecific monoclonal antibody to gene therapy: A new era in the treatment of hemophilia A

The treatment of hemophilia A has progressed amazingly in recent years. Emicizumab, a bispecific-humanized monoclonal antibody, is able to improve coagulation by bridging activated factor IX and factor X. Emicizumab is administered subcutaneously and much less often compared to factor VIII products. It has low immunogenicity, does not require dose adjustment, and can be administered regardless of the presence of factor VIII inhibitors. Thrombin generation assays but not factor VIII activity are indicated to guide and monitor the treatment. Emicizumab has enabled the conversion of patients with severe forms into patients with milder forms of hemophilia A. It has reduced the number of bleeding episodes compared to both on-demand and prophylactic substitution therapy and has an excellent safety profile. Gene therapy can elevate factor VIII plasma levels for many years after a single treatment course, could offer long-term protection from bleeding episodes, and minimize or eliminate the need for substitutive treatment with factor VIII concentrates. Gene therapy can provoke an immune response, manifested by an increase in common liver enzymes, that require immunotherapy. Long term monitoring is necessary to identify possible adverse effects. Future objectives are: the development of an ideal viral vector, the possibility of its re-administration, the use of gene therapy in hemophiliac children, and determining whether it can be successfully used to induce immune tolerance to factor VIII ceteri paribus. The future will determine the place of each type of treatment and group of patients for which it is indicated.

Absence of Effect of Emicizumab on D-Dimer Concentrations in Adult Patients with Severe Hemophilia A

BACKGROUND

The D-dimer (DD) assay is an essential biological test for the diagnosis and monitoring of thrombotic conditions. DD testing is usually not performed as part of the routine laboratory management of patients with hemophilia (PWH). There is an increasing concern about the risk of thrombotic complications in PWH, which is likely related to age, cardiovascular risk factors, invasive thrombogenic procedures, over-correction of Factor VIII (FVIII) or FIX, or administration of new therapeutic agents mimicking FVIII or rebalancing coagulation.

OBJECTIVE

This retrospective study sought to assess the basal DD levels in PWH treated prophylactically with FVIII, and to evaluate potential changes after switching to emicizumab.

METHOD

Patients over 18 years of age treated with emicizumab within a single center over the period 2017-2022 were included in the study.

RESULT

DD levels were measured in 40 adult PWH (37 severe/ three moderate / two with FVIII inhibitor) with a median age of 46 years (range: 19-82; Q1-Q3: 30,25-56,5), before and at least 3 months after emicizumab initiation. No significant changes were revealed, with DD median values of 257 ng/mL (range: 250-2876; Q1-Q3: 250-493,5) before and 250 ng/mL (range: 50-6205; Q1-Q3: 250-380,25) after the switch (p  =  0.9).

CONCLUSION

Most adult PWH on prophylaxis using FVIII display DD levels within the normal range, which remain unchanged after switching to emicizumab. In view of these reassuring results, monitoring of DDs at the start of emicizumab treatment does not appear necessary but could be considered when combined with other bypassing agents or high dose FVIII.

Genome editing-mediated knock-in of therapeutic genes ameliorates the disease phenotype in a model of hemophilia

Recently, clinical trials of adeno-associated virus-mediated replacement therapy have suggested long-term therapeutic effects for several genetic diseases of the liver, including hemophilia. However, there remain concerns regarding decreased therapeutic effects when the liver is regenerated or when physiological proliferation occurs. Although genome editing using the clustered regularly interspaced short palindromic repeats/Cas9 system provides an opportunity to solve this problem, low knock-in efficiency may limit its application for therapeutically relevant expression. Here, we identified a novel gene, APOC3, in which a strong promoter facilitated the expression of knocked-in genes in hepatocytes. We also investigated the effects of APOC3 editing using a small Cas9 protein derived from Campylobacter jejuni (CjCas9) in a hemophilic model. We demonstrated that adeno-associated virus-mediated delivery of CjCas9 and donor led to moderate levels of human factor 9 expression in APOC3-humanized mice. Moreover, knock-in-driven expression induced substantial recovery of clotting function in mice with hemophilia B. There was no evidence of off-target editing in vitro or in vivo. Collectively, our findings demonstrated therapeutically relevant expression using a precise and efficient APOC3-editing platform, providing insights into the development of further long-term therapeutics for diverse monogenic liver diseases.

Engineering a Therapeutic Protein to Enhance the Study of Anti-Drug Immunity

The development of anti-drug antibodies represents a significant barrier to the utilization of protein-based therapies for a wide variety of diseases. While the rate of antibody formation can vary depending on the therapeutic employed and the target patient population receiving the drug, the antigen-specific immune response underlying the development of anti-drug antibodies often remains difficult to define. This is especially true for patients with hemophilia A who, following exposure, develop antibodies against the coagulation factor, factor VIII (FVIII). Models capable of studying this response in an antigen-specific manner have been lacking. To overcome this challenge, we engineered FVIII to contain a peptide (323-339) from the model antigen ovalbumin (OVA), a very common tool used to study antigen-specific immunity. FVIII with an OVA peptide (FVIII-OVA) retained clotting activity and possessed the ability to activate CD4 T cells specific to OVA323-339 in vitro. When compared to FVIII alone, FVIII-OVA also exhibited a similar level of immunogenicity, suggesting that the presence of OVA323-339 does not substantially alter the anti-FVIII immune response. Intriguingly, while little CD4 T cell response could be observed following exposure to FVIII-OVA alone, inclusion of anti-FVIII antibodies, recently shown to favorably modulate anti-FVIII immune responses, significantly enhanced CD4 T cell activation following FVIII-OVA exposure. These results demonstrate that model antigens can be incorporated into a therapeutic protein to study antigen-specific responses and more specifically that the CD4 T cell response to FVIII-OVA can be augmented by pre-existing anti-FVIII antibodies.

The legacy of haemophilia: Memories and reflections from three survivors

Following the publication of a book of personal memories by one of us (CS^1,2), we have attempted to synthesis our joint memories of three ageing men, born in the era preceding universal access to treatment, in an attempt to describe our experience, our challenges and our reflections on the development of therapies, which have ensured that our experience of growing up with haemophilia in the 1950s and 1960s has not been mirrored by the current generation of patients. We describe our upbringing in different parts of Europe in health care systems which, while of varying standards, were all unable to offer the kind of care which developed after the development of specific therapies. We assess the effect of the contamination of these therapies by blood‐borne pathogens on our own development, and the development of our communities around us. In addition, we reflect on the lessons learnt, sometimes painfully, by our generation of people with haemophilia and how some of these enabled us to overcome substantial hurdles, survive and build productive lives. Finally, we survey the development of therapies in the past 20 years, and offer some reflections on how our experience can be integrated in a realistic expectation of what the future holds for our community, in our own affluent societies and in countries less advantaged economically. We hope that our thoughts may contribute to continued progress in the field of haemophilia care.

Expert opinion on current and future prophylaxis therapies aimed at improving protection for people with hemophilia A

The next frontier in hemophilia A management has arrived. However, questions remain regarding the broader applicability of new and emerging hemophilia A therapies, such as the long-term safety and efficacy of non-factor therapies and optimal regimens for individual patients. With an ever-evolving clinical landscape, it is imperative for physicians to understand how available and future hemophilia A therapies could potentially be integrated into real-life clinical practice to improve patient outcomes. Against this background, nine hemophilia experts from Central European countries participated in a pre-advisory board meeting survey. The survey comprised 11 multiple-choice questions about current treatment practices and future factor and non-factor replacement therapies. The survey questions were developed to reflect current unmet needs in hemophilia management reflected in the literature. The experts also took part in a follow-up advisory board meeting to discuss the most important unmet needs for hemophilia management as well as the pre-meeting survey results. All experts highlighted the challenge of maintaining optimal trough levels with prophylaxis as their most pressing concern. Targeting trough levels of ≥30-50 IU/L or even higher to achieve less bleeding was highlighted as their preferred strategy. However, the experts had an equal opinion on how this could be achieved (i.e., more efficacious non-factor therapies or factor therapy offering broader personalization possibilities such as targeting trough levels to individual pharmacokinetic data). In summary, our study favors personalized prophylaxis to individual pharmacokinetic data rather than a "one-size-fits-all" approach to hemophilia A management to maintain optimal trough levels for individual patients.

Bacteria-engineered porous sponge for hemostasis and vascularization

Background

Hemostasis and repair are two essential processes in wound healing, yet early hemostasis and following vascularization are challenging to address in an integrated manner.

Results

In this study, we constructed a hemostatic sponge OBNC-DFO by fermentation of Komagataeibacterxylinus combined with TEMPO oxidation to obtain oxidized bacterial nanocellulose (OBNC). Then angiogenetic drug desferrioxamine (DFO) was grafted through an amide bond, and it promoted clot formation and activated coagulation reaction by rapid blood absorption due to the high total pore area (approximately 42.429 m2/g measured by BET). The further release of DFO stimulated the secretion of HIF-1α and the reconstruction of blood flow, thus achieving rapid hemostasis and vascularization in damaged tissue. This new hemostatic sponge can absorb water at a rate of approximate 1.70 g/s, rapidly enhancing clot formation in the early stage of hemostasis. In vitro and in vivo coagulation experiments (in rat tail amputation model and liver trauma model) demonstrated superior pro-coagulation effects of OBNC and OBNC-DFO to clinically used collagen hemostatic sponges (COL). They promoted aggregation and activation of red blood cells and platelets with shorter whole blood clotting time, more robust activation of endogenous coagulation pathways and less blood loss. In vitro cellular assays showed that OBNC-DFO prevailed over OBNC by promoting the proliferation of human umbilical vein endothelial cells (HUVECs). In addition, the release of DFO enhanced the secretion of HIF-1α, further strengthening vascularization in damaged skin. In the rat skin injury model, 28 days after being treated with OBNC-DFO, skin appendages (e.g., hair follicles) became more intact, indicating the achievement of structural and functional regeneration of the skin.

Conclusion

This hemostatic and vascularization-promoting oxidized bacterial nanocellulose hemostatic sponge, which rapidly activates coagulation pathways and enables skin regeneration, is a highly promising hemostatic and pro-regenerative repair biomaterial.

Graphical Abstract