Recent Advances in the Treatment of Hemophilia: A Review

Elevated memory T-cell conversion in a preclinical mouse model of hemophilia A

One of the major challenges in the choice of the best therapeutic approach for the treatment of patients affected by hemophilia A (HA) is the definition of criteria predicting the formation of factor VIII (FVIII) neutralizing antibodies, called inhibitors. Both genetic and environmental elements influencing the immune response toward FVIII have been identified but still not all the factors causing the pathological rejection of FVIII have been identified. Since there is a connection between coagulation and inflammation, here we assessed the role played by the FVIII deficiency in shaping the humoral and cellular response toward an antigen other than FVIII itself. To this aim, we challenged both HA and wild-type (WT) mice with either FVIII or ovalbumin (OVA) and followed antigen-specific antibody level, immune cell population frequency and phenotype up to 9 weeks after the last antigen booster. The activation threshold was evaluated in vitro by stimulating the murine T cells with a decreasing dose of α-CD3. The humoral response to FVIII was similar between the two groups while both the in vivo and in vitro experiments highlighted an antigen-independent sensitivity of HA compared with WT T cells causing an increase in memory T-cell conversion and proliferation capability.

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.

Delivery of DNA-Based Therapeutics for Treatment of Chronic Diseases

Gene therapy and its role in the medical field have evolved drastically in recent decades. Studies aim to define DNA-based medicine as well as encourage innovation and the further development of novel approaches. Gene therapy has been established as an alternative approach to treat a variety of diseases. Its range of mechanistic applicability is wide; gene therapy has the capacity to address the symptoms of disease, the body's ability to fight disease, and in some cases has the ability to cure disease, making it a more attractive intervention than some traditional approaches to treatment (i.e., medicine and surgery). Such versatility also suggests gene therapy has the potential to address a greater number of indications than conventional treatments. Many DNA-based therapies have shown promise in clinical trials, and several have been approved for use in humans. Whereas current treatment regimens for chronic disease often require frequent dosing, DNA-based therapies can produce robust and durable expression of therapeutic genes with fewer treatments. This benefit encourages the application of DNA-based gene therapy to manage chronic diseases, an area where improving efficiency of current treatments is urgent. Here, we provide an overview of two DNA-based gene therapies as well as their delivery methods: adeno associated virus (AAV)-based gene therapy and plasmid DNA (pDNA)-based gene therapy. We will focus on how these therapies have already been utilized to improve treatment of chronic disease, as well as how current literature supports the expansion of these therapies to treat additional chronic indications in the future.

The Evolution of Hemophilia Therapeutics: An Illustrated Review

Hemophilia is a rare genetic bleeding disorder historically associated with high morbidity and mortality. Some individuals with hemophilia suffer associated chronic joint disease, chronic pain, and other physical and mental health challenges. In the last 50 years, a better understanding of the pathophysiology of the disease has resulted in extraordinary therapeutic advances leading to enhanced quality of life and increased life expectancy. We present an illustrated review of the evolution of hemophilia treatment from the development of non-factor therapies to gene therapy.

Noninterventional study assessing joint health in persons with hemophilia A after switching to turoctocog alfa pegol: design of pathfinderReal

Background

Joint damage affects the quality of life of persons with hemophilia A. The long-term safety and efficacy of turoctocog alfa pegol (N8-GP) prophylaxis in persons with hemophilia A has been investigated in pivotal phase 3 trials in children, adolescents, and adults (pathfinder program). However, there is a lack of data on joint health in adult persons with hemophilia A treated with N8-GP.

Objectives

To describe the design of the ongoing pathfinderReal study investigating the joint health status in adult persons with hemophilia A after switching to N8-GP.

Methods

pathfinderReal is a multicountry, noninterventional, single-arm study (NCT05621746) of joint health in adult (≥18 years) male persons with hemophilia A who have switched to N8-GP. Patients enrolled in other interventional studies and those who have previously terminated N8-GP treatment will be excluded. Approximately 124 adults with hemophilia A will be enrolled and followed up for a maximum of 24 months. Data from routine clinical assessments of patients' joint health will be collected. The primary endpoint is change in Hemophilia Joint Health Score (defined as a change in total score of ≤2) from initiation of N8-GP treatment until the end of the study. Secondary endpoints include number of bleeding episodes, number and resolution of target joints, patient-reported outcomes of problem joint score, pain score, and change in physical function levels. An exploratory endpoint is included to measure the number of patients achieving improved Hemophilia Joint Health Score from the initiation of N8-GP until the end of the study.

Conclusion

The pathfinderReal study will provide insights regarding the impact of N8-GP on joint health in persons with hemophilia A in a real-world setting.

Epidemiological profile of hemophilia A in Karbala-Iraq

Hemophilia is an X-linked congenital bleeding disorder caused by a deficiency of coagulation factor VIII (FVIII) (in hemophilia A) or factor IX (FIX) (in hemophilia B) and is one of the most important hereditary conditions in Iraq. The current study tried to provide a glimpse into the epidemiological and clinical status, as well as complications and treatment used for patients with hemophilia A in Karbala, Iraq. This retrospective research was carried out by reviewing the medical records of 90 male patients diagnosed with hemophilia A registered at the Hereditary Blood Disease Center in Karbala Teaching Hospital for children in Karbala, Iraq. The data was collected from May 10, 2023, until June 15, 2023, and included age, severity, type of bleeding, therapeutic approach, chronic viral infections including hepatitis B, hepatitis C, and human immunodeficiency virus (HIV). The median age of the patients was 15 years (18.86±14.42). In this study, one-third of patients' presentations started in the first year of life. The most common type was severe hemophilia A (factor VIII activity < 1%). Consequently, more than half of the patients were treated with factor VIII concentrate. Four patients had hepatitis C, while HIV was confirmed in one patient. The epidemiological or clinical parameters of hemophilia A patients in Karbala seem similar to those in other cities in Iraq. By considering this preliminary data, further comprehensive studies for patients with hemophilia and associated complications in other provinces or cities in Iraq are highly suggested to provide a clear perspective about the prevalence and epidemiological burdens.

Expression of the gene encoding blood coagulation factor VIII without domain B in E. coli bacterial expression system

In this article, we have demonstrated the feasibility of generating an active form of recombinant blood coagulation factor VIII using an E. coli bacterial expression system as a potential treatment for hemophilia type A. Factor VIII (FVIII), an essential blood coagulation protein, is a key component of the fluid phase blood coagulation system. So far, all available recombinant FVIII formulations have been produced using eukaryotic expression systems. Mammalian cells can produce catalytically active proteins with all the necessary posttranslational modifications. However, cultivating such cells is time-consuming and highly expensive, and the amount of the obtained product is usually low. In contrast to eukaryotic cells, bacterial culture is inexpensive and allows the acquisition of large quantities of recombinant proteins in a short time. With this study, we aimed to obtain recombinant blood coagulation factor VIII using the E. coli bacterial expression system, a method not previously explored for this purpose. Our research encompasses the synthesis of blood coagulation factor VIII and its expression in a prokaryotic system. To achieve this, we constructed a prokaryotic expression vector containing a synthetic factor VIII gene, which was then used for the transformation of an E. coli bacterial strain. The protein expression was confirmed by mass spectrometry, and we assessed the stability of the gene construct while determining the optimal growth conditions. The production of blood coagulation factor VIII by the E. coli bacterial strain was carried out on a quarter-technical scale. We established the conditions for isolation, denaturation, and renaturation of the protein, and subsequently confirmed the activity of FVIII.

Clinical applications of gene therapy for rare diseases: A review

Rare diseases collectively exact a high toll on society due to their sheer number and overall prevalence. Their heterogeneity, diversity, and nature pose daunting clinical challenges for both management and treatment. In this review, we discuss recent advances in clinical applications of gene therapy for rare diseases, focusing on a variety of viral and non-viral strategies. The use of adeno-associated virus (AAV) vectors is discussed in the context of Luxturna, licenced for the treatment of RPE65 deficiency in the retinal epithelium. Imlygic, a herpes virus vector licenced for the treatment of refractory metastatic melanoma, will be an example of oncolytic vectors developed against rare cancers. Yescarta and Kymriah will showcase the use of retrovirus and lentivirus vectors in the autologous ex vivo production of chimeric antigen receptor T cells (CAR-T), licenced for the treatment of refractory leukaemias and lymphomas. Similar retroviral and lentiviral technology can be applied to autologous haematopoietic stem cells, exemplified by Strimvelis and Zynteglo, licenced treatments for adenosine deaminase-severe combined immunodeficiency (ADA-SCID) and β-thalassaemia respectively. Antisense oligonucleotide technologies will be highlighted through Onpattro and Tegsedi, RNA interference drugs licenced for familial transthyretin (TTR) amyloidosis, and Spinraza, a splice-switching treatment for spinal muscular atrophy (SMA). An initial comparison of the effectiveness of AAV and oligonucleotide therapies in SMA is possible with Zolgensma, an AAV serotype 9 vector, and Spinraza. Through these examples of marketed gene therapies and gene cell therapies, we will discuss the expanding applications of such novel technologies to previously intractable rare diseases.

Current factor IX replacement options for hemophilia B and the challenges ahead

INTRODUCTION

Therapy for hemophilia B is aimed at replacing the congenital deficiency of coagulation factor IX (FIX). For replacement therapy, several FIX concentrates derived from donated human plasma or engineered by recombinant DNA technology are currently commercially available. The use of these products is well established and permit patients a relatively normal life. To further improve treatment efficacy, recombinant FIX products with a prolonged half-life have been developed, allowing relaxed prophylactic dosing and reducing treatment burden.

AREAS COVERED

In this review, we explore the current FIX replacement options for hemophilia B patients by analyzing the outcomes of their main clinical trials. We cover advances in the FIX molecules with extended half-life (EHL). Published literature on products for replacement of hemophilia B was retrieved using PubMed with no temporal limits.

EXPERT OPINION

The recent introduction of recombinant EHL FIX products has represented a major advance in the therapeutic management of hemophilia B patients, permitting both a reduction of treatment burden and improving patients' compliance to prophylaxis and, ultimately, quality of life.

Assessing the value of bypassing agent therapy used prophylactic versus on-demand, during immune tolerance induction for treatment of inhibitors: a retrospective chart review

BACKGROUND

Haemophilia A is a bleeding disorder caused by deficiency of coagulation factor VIII (FVIII) which leads to severe and repeated bleedings. There is a need to understand the optimal treatment pathway for FVIII inhibitors with the use of immune tolerance induction (ITI) and the role of haemostatic 'bypassing' agents (BPA) on-demand (OD) or prophylactically (Px). The aim of this study was to gain a better understanding of the real-world use of BPA therapy administered prophylactically or on-demand concomitant with ITI, for the treatment of an inhibitor to FVIII replacement therapy in patients with severe haemophilia A.

METHODS

Retrospective observational data were used to capture disease management information for patients who were aged 16 or under and had received ITI and BPA treatment for their most recent inhibitor from Jan-2015 to Jan-2019, for 47 patients in the UK and Germany. Descriptive comparisons of the clinical effectiveness and resource utilisation of Px and OD BPA therapy during ITI were conducted.

RESULTS

During ITI and BPA treatment, for an inhibitor, bleeding events averaged 1.5 and 1.2 for Px and OD treatment respectively. Compared to only BPA therapy we see 3.4 and 1.4 bleeding events for Px and OD respectively during an inhibitor.

CONCLUSION

Baseline disease characteristics differed between BPA therapy cohorts and this resulted in higher clinical effectiveness of ITI treatment alongside BPA Px than BPA OD during an inhibitor.

Surgery for chronic arthropathy in people with haemophilia

BACKGROUND

Chronic arthropathy is a potentially debilitating complication for people with haemophilia - a genetic, X-linked, recessive bleeding disorder, characterised by the absence or deficiency of a clotting factor protein. Staging classifications, such as the Arnold-Hilgartner classification for haemophilic arthropathy of the knee, radiologically reflect the extent of knee joint destruction with underlying chronic synovitis. Management of this highly morbid disease process involves intensive prophylactic measures, and chemical or radioisotope synovectomy in its early stages. However, failure of non-surgical therapy in people with progression of chronic arthropathy often prompts surgical management, including synovectomy, joint debridement, arthrodesis, and arthroplasty, depending on the type of joint and extent of the damage. To date, management of people with mild to moderate chronic arthropathy from haemophilia remains controversial; there is no agreed standard treatment. Thus, the benefits and disadvantages of non-surgical and surgical management of mild to moderate chronic arthropathy in people with haemophilia needs to be systematically reviewed.  OBJECTIVES: To assess the efficacy and safety of surgery for mild to moderate chronic arthropathy in people with haemophilia A or B.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Coagulopathies Trials Register, CENTRAL, MEDLINE, Embase, CINAHL, and two trial registers to August 2022. We also handsearched relevant journals and conference abstract books.

SELECTION CRITERIA

Randomized controlled trials (RCTs) and quasi-RCTs comparing surgery and non-surgical interventions, for any joint with chronic arthropathy, in people with haemophilia, who were at least 12 years old.

DATA COLLECTION AND ANALYSIS

The review authors did not identify any trials to include in this review.

MAIN RESULTS

The review authors did not identify any trials to include in this review.

AUTHORS' CONCLUSIONS

The review authors did not identify any trials to include in this review. Due to a lack of research in this particular area, we plan to update the literature search every two years, and will update review if any new evidence is reported. There is a need for a well-designed RCT that assesses the safety and efficacy of surgical versus non-surgical interventions for chronic arthropathy in people with haemophilia.

Early stage clinical trials for the treatment of hemophilia A

INTRODUCTION

Hemophilia A is a severe bleeding disorder affecting about 1 in 5,000 males. The gold standard for prophylaxis and treatment of acute bleeding has been factor (F) VIII concentrate. A multitude of treatment modalities are now available and under clinical investigation.

AREAS COVERED

This review discusses ongoing/recently completed early-phase clinical trials registered on ClinicalTrials.gov in patients with hemophilia A through April 2022. These new pipeline therapies are focused on addressing the safety and efficacy of new factor-related products, non-factor related products, and gene therapy options for hemophilia.

EXPERT OPINION

Current standard of care effectively prevents and treats acute bleeding and has significantly improved the quality of life in hemophilia. The biggest challenges in the improvement of care are treatment-related burden and the burden of cost in developing countries. New drugs under development are likely to enter practice by the end of this decade and address many of the unmet needs particularly of those with severe disease. Data is limited in unique populations (e.g. congenital/inherited FVIII inhibitors, non-severe hemophilia A, women/girls with hemophilia and children) which are important areas for future research; additional clinical trials and long-term outcome data are necessary prior to incorporating these new therapies in our treatment arsenal.

Emicizumab: a novel drug in hemophilia A prophylaxis - a narrative review

INTRODUCTION

Hemophilia A is a genetically conditioned disease leading to hemostatic disorders due to factor VIII (FVIII) deficiency. The treatment of hemophilia has evolved throughout the past years and has significantly changed. One of the newest drugs for prophylactic treatment is the humanized bispecific IgG antibody - emicizumab, which binds with factor IXa and factor X, bridging those factors and thus mimicking the activity of factor VIII.

AREAS COVERED

The literature search was made via PubMed database, with the emphasis on clinical trials and case reports, describing the off-label emicizumab use. This review presents an extensive summary and considers advantages and disadvantages (side-effects) of emicizumab, describing additional clinical situations, where emicizumab has been successfully used. In our review we cover information about the mechanisms of action, indications, efficacy and discuss some chosen case reports about off-label emicizumab use.

EXPERT OPINION

Its convenient administration method (subcutaneous) and frequency of injections (from once a week to once a month) makes it a more comfortable treatment, limiting injection-site reactions, hospital stays, costs of prophylaxis, and significantly increasing patients' quality of life. Adverse effects are scarce and rarely serious - the most common ones are reactions at the injection-site and upper respiratory tract infections.

The Arrival of Gene Therapy for Patients with Hemophilia A

Historically, the standard of care for hemophilia A has been intravenous administration of exogenous factor VIII (FVIII), either as prophylaxis or episodically. The development of emicizumab, a humanized bispecific monoclonal antibody mimicking activated FVIII, was a subsequent advance in treatment. However, both exogenous FVIII and emicizumab require repeated and lifelong administration, negatively impacting patient quality of life. A recent breakthrough has been the development of gene therapy. This allows a single intravenous treatment that could result in long-term expression of FVIII, maintenance of steady-state plasma concentrations, and minimization (or possibly elimination) of bleeding episodes for the recipient's lifetime. Several gene therapies have been assessed in clinical trials, with positive outcomes. Valoctocogene roxaparvovec (an adeno-associated viral 5-based therapy encoding human B domain-deleted FVIII) is expected to be the first approved gene therapy in European countries, including Italy, in 2022. Some novel challenges exist including refining patient selection criteria, managing patient expectations, further elucidation of the durability and variability of transgene expression and long-term safety, and the development of standardized 'hub and spoke' centers to optimize and monitor this innovative treatment. Gene therapy represents a paradigm shift, and may become a new reference standard for treating patients with hemophilia A.

Unsolved issues of treatment of adult patients with hemophilia A

Background. Sufficient supply of coagulation factors products has significantly improved life quality and expectancy in patients with hemophilia. Certain difficulties, however, persist when it comes to the treatment of the disease. Aim. To analyze current therapeutic approaches and identify major unsolved issues in the treatment of patients with hemophilia A. Materials and methods. An online survey of 100 adult patients with hemophilia A was held. Results. More than a half of the surveyed sample (59%) are patients aged 19 to 40 with the severe form of the disease, 73% of respondents receive a replacement therapy with plasmatic factors, 42% of patients inject drugs 3 times a week or more. More than a half of all age groups with hemophilia have persistent pain and limited joint mobility, in 70% of the patients, bleeding into the joints occurred 4 or more times within the past year, 47% of the patients with hemophilia A are partially satisfied or dissatisfied with their state of health, 92% of the patients would like to improve their quality of life. At the same time, about 1/3 of the patients would like to reduce the frequency of drug administration. More than 40% of the respondents did not visit a hematologist during the year, 85% do not conduct regular laboratory monitoring. Conclusion. The survey results demonstrate numerous areas of potential change pertaining to the approaches towards therapy and to the innovative drugs for the treatment of patients with hemophilia.

High Mutational Heterogeneity, and New Mutations in the Human Coagulation Factor V Gene. Future Perspectives for Factor V Deficiency Using Recombinant and Advanced Therapies

Factor V is an essential clotting factor that plays a key role in the blood coagulation cascade on account of its procoagulant and anticoagulant activity. Eighty percent of circulating factor V is produced in the liver and the remaining 20% originates in the α-granules of platelets. In humans, the factor V gene is about 80 kb in size; it is located on chromosome 1q24.2, and its cDNA is 6914 bp in length. Furthermore, nearly 190 mutations have been reported in the gene. Factor V deficiency is an autosomal recessive coagulation disorder associated with mutations in the factor V gene. This hereditary coagulation disorder is clinically characterized by a heterogeneous spectrum of hemorrhagic manifestations ranging from mucosal or soft-tissue bleeds to potentially fatal hemorrhages. Current treatment of this condition consists in the administration of fresh frozen plasma and platelet concentrates. This article describes the cases of two patients with severe factor V deficiency, and of their parents. A high level of mutational heterogeneity of factor V gene was identified, nonsense mutations, frameshift mutations, missense changes, synonymous sequence variants and intronic changes. These findings prompted the identification of a new mutation in the human factor V gene, designated as Jaén-1, which is capable of altering the procoagulant function of factor V. In addition, an update is provided on the prospects for the treatment of factor V deficiency on the basis of yet-to-be-developed recombinant products or advanced gene and cell therapies that could potentially correct this hereditary disorder.