Recent advances in developing specific therapies for haemophilia

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.

The value-based healthcare approach to haemophilia: Development of outcome measures for the evaluation of care of people with haemophilia

INTRODUCTION

Considering the advances in haemophilia management and treatment observed in the last decades, a new set of value-based outcome indicators is needed to assess the quality of care and the impact of these medical innovations.

AIM

The Value-Based Healthcare in Haemophilia project aimed to define a set of clinical outcome indicators (COIs) and patient-reported outcome indicators (PROIs) to assess quality of care in haemophilia in high-income countries with a value-based approach to inform and guide the decision-making process.

METHODS

A Value-based healthcare approach based on the available literature, current guidelines and the involvement of a multidisciplinary group of experts was applied to generate a set of indicators to assess the quality of care of haemophilia.

RESULTS

A final list of three COIs and five PROIs was created and validated. The identified COIs focus on two domains: musculoskeletal health and function, and safety. The identified PROIs cover five domains: bleeding frequency, pain, mobility and physical activities, Health-Related Quality of Life and satisfaction. Finally, two composite outcomes, one based on COIs, and one based on PROIs, were proposed as synthetic outcome indicators of quality of care.

CONCLUSION

The presented standard set of health outcome indicators provides the basis for harmonised longitudinal and cross-sectional monitoring and comparison. The implementation of this value-based approach would enable a more robust assessment of quality of care in haemophilia, within a framework of continuous treatment improvements with potential added value for patients. Moreover, proposed COIs and PROIs should be reviewed and updated routinely.

Delivery of gene therapy in haemophilia treatment centres in the United States: Practical aspects of preparedness and implementation

INTRODUCTION

Haemophilia treatment centres (HTCs) and healthcare providers (HCPs) will need to adapt to a new treatment paradigm with the emergence of adeno-associated virus (AAV)-based gene therapy for the treatment of haemophilia in adults.

AIM

This review examines the upcoming patient and institutional journeys, along with practical aspects of preparedness for clinical delivery of gene therapy by HTCs.

METHODS

Based on our clinical experience and examination of published literature, we explored the parallel journeys for patients and treatment centres to navigate before, during, and after administration of gene therapy.

RESULTS

The patient journey includes: information gathering; decision making; comprehensive patient assessment; preparation for the infusion itself; short- and long-term monitoring; lifestyle modifications; and the possible need for immunosuppressive treatment. Informed decision-making may require patient education with extensive discussions and an understanding that not all people with haemophilia will choose or be eligible for gene therapy, although eligibility criteria continue to evolve. The institutional journey includes: consideration of biosafety procedures; planning for product procurement, handling, storage, and administration; development of detailed protocols and guidance documents; contingency planning for immunosuppressive and haemostatic management; consideration of clinical capabilities and staff training needs; coordination of efforts by the full multidisciplinary team; and collaboration between referring, dosing, and follow-up treatment centres. Documented protocols and guidance documents are pivotal for this complex therapy to ensure safe handling, optimal delivery, and post-infusion management and follow-up.

CONCLUSION

Successful implementation of this new treatment modality will require communication and collaboration among multiple stakeholders.

Haemophilia B in Algeria: Realities and therapeutic perspectives

INTRODUCTION

Haemophilia B is a debilitating hereditary coagulation disorder characterized by prolonged or spontaneous episodes of bleeding caused by a deficiency of endogenous factor IX. In Algeria, even though many studies are being carried out to evaluate the prevalence and management of haemophilia B, there is a paucity of locally published literature that can be used to understand the most recent information on the disease's epidemiology, diagnostic techniques and treatment options.

AIMS

The aim of this manuscript is to raise awareness among patients and family clinicians about current practices, recent developments and unmet needs related to haemophilia B in Algeria.

METHODS

A comprehensive literature search was conducted through online scientific databases to review publications regarding haemophilia B in Algeria. Exclusions of the review include case studies, interregional comparisons, abstract-only papers and studies outside the range of 2012-2022.

RESULTS

The findings discussed relate to the epidemiology of haemophilia B in Algeria, the clinical diagnostic process, disease symptoms, the benefits of molecular and genetic testing, advancements in prophylactic care, as well as unmet needs hindering the progression of optimal haemophilia B management.

CONCLUSION

These findings are crucial to encourage the maintenance of national registries with updated epidemiological data, facilitate early and timely detection of disease symptoms, improve the provision of diagnostic facilities and enhance the overall treatment landscape for better patient outcomes.

Prevalence of cardiovascular diseases and risk factors in adult patients with haemophilia: a cross-sectional study in a tertiary care hospital clinic in Sri Lanka

Background

Management of cardiovascular disease (CVD) in patients with haemophilia is extremely challenging. Therefore, knowing the prevalence of CVD and risk factors in this population is imperative.

Methods

All consented patients ≥ 18 years of age attending the haemophilia clinic at a tertiary care centre were recruited to the study. Data were collected using a pretested, investigator administered questionnaire. Seated blood pressure, anthropometric measurements and blood samples were obtained using standard techniques. Lipid profile and fasting plasma glucose were estimated. Prevalence of risk factors for CVD was compared with those of age matched males in the general population. P values < 0.05 were considered significant.

Results

Of the total 109 participants, 92 (84.4%) had haemophilia A. The median age of the study group was 36 years. Three (2.8%) had at least one cardiovascular disease. There were 10 (9.2%), 30 (27.5%), 13 (11.9%) and 4 (3.7%) participants with diabetes, hypertension, current smoking and obesity (Body Mass Index (BMI) ≥ 30 kg/m²) respectively. 32 (29.4%) and 37 (33.9%) participants had waist circumference ≥ 90 cm and waist hip ratio ≥ 0.9 respectively. 38 (34.9%) had total cholesterol ≥ 200 mg/dl, 43 (39.5%) had low density lipoprotein (LDL) cholesterol ≥ 130 mg/dl, 25 (22.9%) had triglycerides (TG) ≥ 150 mg/dl and 58 (53.2%) had High density lipoprotein (HDL) cholesterol < 40 mg/dl. Diabetes was significantly associated with factor levels below 5% (p = 0.038). BMI, waist circumference and dyslipidaemia in the study were significantly higher compared to the general population.

Conclusion

The study signifies an increased prevalence of risk factors for CVD among patients with haemophilia and the need for preventive measures.

Prevalence and Interference of Chronic Pain Among People With Hemophilia: A Systematic Review and Meta-Analysis

Chronic pain is a common condition among people with hemophilia (PWH), associated with joint deterioration due to repeated joint bleeds. This systematic review and meta-analysis aimed to determine the prevalence of chronic pain due to haemophilia and to analyze its interference in the lives of patients. A systematic search was performed in May and June 2019 and updated in February 2021, using PubMed, EMBASE, Web of Science and SciElo. The search included terms related to hemophilia, pain, pain prevalence and pain interference. Studies were included if they reported data referring to hemophilia-related chronic pain among adult males (age ≥18). From 3,258 identified studies, 11 met the inclusion criteria. Three studies used a proposed definition for hemophilia-related chronic pain and 8 used direct questions developed by the authors. For the global samples, prevalence ranged from 17% to 84%. The random-effects meta-analysis including all studies demonstrated a pooled prevalence of chronic pain of 46% (95% Confidence Interval, CI = 34%-58%). Subgroup analysis of samples including all disease severities or including only severe patients revealed a pooled prevalence of 48% (95% CI = 29%-67%) and 53% (95% CI = 38%-69%), respectively. High heterogeneity between studies was observed in all models. Information concerning chronic pain interference was retrieved from 1 study, reporting a mean interference of 3.7 (0-10 numerical rating scale from the Brief Pain Inventory). This systematic review revealed a wide prevalence range of hemophilia-related chronic pain across studies, varying methodologies and sample characteristics. Research in the hemophilia field should clearly distinguish between acute and chronic pain and provide complete characterization of study samples. PERSPECTIVE: Pain is a central issue in the lives of people with hemophilia, posing a significant challenge for healthcare providers. A clear picture of chronic pain due to hemophilia is precluded by high heterogeneity among studies and various definitions used to investigate its prevalence.

Variability of treatment modalities and intensity in patients with severe haemophilia A on prophylaxis: Results from the Italian national registry

BACKGROUND

A shift from a standard to a personalized prophylaxis has been increasingly adopted in patients with severe haemophilia A (SHA). This approach has raised the likelihood of a significant variability in the prophylactic approaches and the relative Factor VIII (FVIII) consumptions. The aim of our study was to assess the treatment variability of SHA patients without inhibitors and on prophylaxis regimen in Italy.

MATERIAL AND METHODS

Data reported in the National Registry of Congenital Coagulopathies (NRCC) were analysed to assess treatment distribution within SHA patients without inhibitors, focussing on FVIII consumption in 2017, associated with prophylaxis regimen. The analysis was stratified based on age groups and Italian regions to describe the variability of FVIII consumption in Italy.

RESULTS

In 2017, the Registry reported the therapeutic plans of 1068 SHA patients without inhibitors on prophylaxis. The mean (95% CI) individual consumption ranges from 123 127 IU (99 736-146 518) in the age group 0-6 years to 345 000 IU (336 000-354 000) in the age group >20 years. A significant FVIII consumption variability was identified within the adult population. Regions with less than 50 patients reported the higher variability in mean FVIII consumption per patient-year within the different age groups. Similar difference in FVIII consumption variability was reported also in the age groups comparing "low," "middle" and "high" patient volume regions.

DISCUSSION

A reliable estimation of FVIII consumption for patients' treatment is necessary to manage and plan the appropriate budget and keep treatment's costs affordable. However, without the implementation of a methodology aiming to assess the overall value produced by these FVIII consumptions, the scenario will keep driven by FVIII consumptions, its costs and the budget available. An effort by haemophilic community, haemophilia treatment centres and institutions is required to develop and share this cultural shift in improving haemophilia management and assessment.

Fusion of engineered albumin with factor IX Padua extends half-life and improves coagulant activity

The short half‐life of coagulation factor IX (FIX) for haemophilia B (HB) therapy has been prolonged through fusion with human serum albumin (HSA), which drives the neonatal Fc receptor (FcRn)‐mediated recycling of the chimera. However, patients would greatly benefit from further FIX‐HSA half‐life extension. In the present study, we designed a FIX‐HSA variant through the engineering of both fusion partners. First, we developed a novel cleavable linker combining the two FIX activation sites, which resulted in improved HSA release. Second, insertion of the FIX R338L (Padua) substitution conferred hyperactive features (sevenfold higher specific activity) as for FIX Padua alone. Furthermore, we exploited an engineered HSA (QMP), which conferred enhanced human (h)FcRn binding [dissociation constant (K_D) 0·5 nM] over wild‐type FIX‐HSA (K_D 164·4 nM). In hFcRn transgenic mice, Padua‐QMP displayed a significantly prolonged half‐life (2·7 days, P < 0·0001) versus FIX‐HSA (1 day). Overall, we developed a novel FIX‐HSA protein with improved activity and extended half‐life. These combined properties may result in a prolonged functional profile above the therapeutic threshold, and thus in a potentially widened therapeutic window able to improve HB therapy. This rational engineering of both partners may pave the way for new fusion strategies for the design of engineered biotherapeutics.

The Possible Non-Mutational Causes of FVIII Deficiency: Non-Coding RNAs and Acquired Hemophilia A

Hemophilia type A (HA) is the most common type of blood coagulation disorder. While the vast majority of cases are inherited and caused by mutations in the F8 gene, recent data raises new questions regarding the non-heritability of this disease, as well as how other molecular mechanisms might lead to the development of HA or increase the severity of the disease. Some data suggest that miRNAs may affect the severity of HA, but for some patients, miRNA-based interference might cause HA, in the absence of an F8 mutation. A mechanism in HA installation that is also worth investigating and which could be identified in the future is the epigenetic silencing of the F8 gene that might be only temporarily. Acquired HA is increasingly reported and as more cases are identified, the description of the disease might become challenging, as cases without FVIII autoantibodies might be identified.

Safety and efficacy of nonacog alfa for the treatment of haemophilia B in children younger than 6 years of age in a routine clinical care setting: the EUREKIX registry study

INTRODUCTION

European regulatory authorities request postmarketing safety and efficacy data for factor IX (FIX) products.

AIM

Collect additional clinical data from routine nonacog alfa use in children aged <6 years with haemophilia B.

METHODS

The EUREKIX registry included retrospective and prospective data collection phases. Safety was assessed via adverse drug reactions (ADRs)/adverse events (AEs) and events of special interest (ESIs) as the primary objective; efficacy was evaluated via annualised bleeding rates (ABRs).

RESULTS

The retrospective phase comprised 37 subjects. Of these, 25 had severe haemophilia B. One subject experienced 2 ADRs; another experienced 4 ESIs of hypersensitivity. Median ABR in subjects receiving a predominantly on-demand regimen (prophylaxis <50% of time; n = 11) was 2.0; median ABR was 3.8 in those receiving predominantly prophylactic treatment (prophylaxis ≥50% of time; n = 24). Joint bleeding was infrequent (median ABR, 0.4; n = 35). The prospective phase included 26 subjects, with 17 continuing from the retrospective phase. A total of 20 subjects had severe haemophilia B. Three subjects experienced 7 treatment-related AEs; 3 experienced 4 ESIs. Median ABR was 4.5 and 1.1 in subjects who received predominantly on-demand (n = 5) or prophylactic treatment (n = 19), respectively; the overall median ABR for joint bleeding events was 0.0.

CONCLUSIONS

Overall, nonacog alfa treatment effectively controlled bleeding events, with no new safety signals identified. These data support the safety and efficacy of nonacog alfa in routine clinical settings in children aged <6 years.

Continuous infusion factor replacement in haemophilia B during and after cardiac surgery: the better choice?

A 57-year-old man with mild haemophilia B was admitted for coronary artery bypass graft surgery. His factor IX (FIX) activity was 15% on admission. Our goal was to maintain his FIX activity at 80%-100% for post-op days (PODs) 0-3, and at 60%-80% for PODs 4-14. Preoperatively, the patient was given recombinant FIX (rFIX) bolus using the formula:Dosage needed=%(desired FIX level-current level of FIX)×weight (kg)×1.3.This increased his activity to 100%. One IU of rFIX increased FIX activity by 0.8%; the half-life of rFIX is 18-24 hours. The rFIX infusion was started intraoperatively and continued after surgery to maintain target FIX activity. He was discharged on POD 9 on rFIX bolus dosing of 5000 IU every 12 hours for an additional 5 days. Using continuous factor infusion, we managed to decrease the amount rFIX used by >60% while maintaining steady state FIX activity level.

Hemophilia gene therapy-New country initiatives

Gene therapy is an opportunity for haemophilia patients to receive a one-time treatment and have lasting factor levels for years or decades instead of dependence on repeated administration within short intervals and on sustained supply of drug. Great strides have been made in the development of gene therapy for haemophilia in the last decade. Adeno-associated virus (AAV) vector-mediated gene transfer in haemophilia A and B has entered the phase III trial stage. Gene transfer by lentiviral vector or gene editing technologies using factor VIII (FVIII) or IX (FIX) genes are now entering clinical evaluation. It is expected that the first FVIII and FIX gene therapy products will soon be approved and distributed in major markets. Global access to gene therapy is a critical goal. This review presents new and ongoing efforts towards this goal in countries other than North America and Europe. In Japan, researchers, regulators and funders have established a promising gene therapy development platform for multiple diseases including haemophilia. Decades of scientific and clinical research in haemophilia gene therapy in China have led to a recently registered clinical trial of AAV-mediated gene therapy for haemophilia B. Other countries are in earlier phases of building gene therapy programmes or participate in international trials. A phase 2 feasibility trial of AAV-mediated FIX gene therapy in low- and middle-income countries aims to demonstrate that gene therapy could become available in resource-constrained socio-economic settings. The different strategies for establishing gene therapy provide opportunities for closing the global gap in haemophilia care.

Factor VIII: the protein, cloning its gene, synthetic factor and now - 35 years later - gene therapy; what happened in between?

The foundation of haemophilia A therapy in the last 35 years has been critically dependent on isolation of the Factor VIII (FVIII) protein and discovery of the cDNA sequence of the FVIII gene, published in 1984. Identification of the FVIII sequence resulted in a new era of recombinant concentrates and led to significant improvements in safety, set against the tragedy of widespread HIV and hepatitis infections in haemophilia patients from contaminated plasma-based products. We chronicle the scientific methods and race leading up to the publication of the FVIII DNA sequence and the legacy that follows through to revolutionary gene therapy treatment in clinical trials today.

Effectiveness of hypnosis for pain management and promotion of health-related quality-of-life among people with haemophilia: a randomised controlled pilot trial

Joint deterioration and associated chronic pain are common among people with haemophilia (PWH), having an impact on quality-of-life. Though non-pharmacological strategies are recommended, psychological interventions to promote pain control and quality-of-life have scarcely been tested in haemophilia. This randomised controlled pilot trial aimed to assess feasibility, acceptability and effectiveness of hypnosis for pain management and promotion of health-related quality-of-life (HRQoL) among PWH. Twenty adults were randomised either to four weekly hypnosis sessions plus treatment-as-usual (experimental group; EG) or treatment-as-usual only (control group; CG). Participants completed sociodemographic and clinical assessment, measures of pain, HRQoL and emotional distress before (T1) and after (T2) intervention. Changes were analysed by calculating the differences between T1 and T2, and the groups were compared through independent-sample t tests (or chi-squared). Retention rates (90%) and analysis of patient satisfaction showed good acceptability and feasibility of the intervention. The EG (n = 8) had a higher reduction on pain interference than the CG (n = 10) (d = −0.267). A higher improvement on HRQoL (EQ-5D index: d = 0.334; EQ-5D VAS: d = 1.437) and a tendency towards better haemophilia-related quality-of-life (A36-Hemofilia QoL) were also evident in the EG. This is the first study showing the effectiveness of hypnosis to reduce pain interference and promote HRQoL among PWH.

Extended Half-Life Coagulation Factors: A New Era in the Management of Hemophilia Patients

Despite effective factor replacement and various treatment schedules, there remain several challenges and unmet needs in the prophylactic treatment of hemophilia limiting its adoption and thereby posing an increased risk of spontaneous bleeding. In this regard, extended half-life (EHL) recombinant factor VIII (rFVIII) and factor IX (rFIX) products promise optimal prophylaxis by decreasing the dose frequency, increasing the compliance, and improving the quality of life without compromising safety and efficacy. EHL products might lead to higher trough levels without increasing infusion frequency, or could facilitate the ability to maintain trough levels while reducing infusion frequency. This paper aims to provide a comprehensive review of the rationale for developing EHL coagulation factors and their utility in the management of hemophilia, with special emphasis on optimal techniques for half-life extension and criteria for defining EHL coagulation factors, as well as indications, efficacy, and safety issues of the currently available EHL-rFVIII and EHL-rFIX products. Potential impacts of these factors on quality of life, health economics, and immune tolerance treatment will also be discussed alongside the challenges in pharmacokinetic-driven prophylaxis and difficulties in monitoring the EHL products with laboratory assays.

Hemophilia trials in the twenty-first century: Defining patient important outcomes

Treatment for hemophilia has advanced dramatically over the past 5 decades. Success of prophylactic therapy in preventing bleeding and decreasing associated complications has established a new standard of care. However, with the advent of gene therapy and treatments that effectively mimic sustained coagulation factor replacement, outcome measures that worked well for assessing factor replacement therapies in past clinical trials need to be reassessed. In addition, while therapies have advanced, so has the science of outcome assessment, including recognition of the importance of patient important and patient reported outcomes. This manuscript reviews strengths and limitations of outcome measures used in hemophilia from both a provider and patient perspective.

Advances in the Treatment of Hemophilia: Implications for Laboratory Testing

BACKGROUND

Until recently, clinical laboratories have monitored hemophilia treatment by measuring coagulation factors before/after infusion of human-derived or recombinant factors. Substantial changes are expected in the near future based on new therapeutic approaches that have been or are being developed.

CONTENT

Hemophilia treatment includes replacement therapy with human-derived/recombinant factors or treatment with bypassing agents for patients without or with inhibitors, respectively. Accordingly, laboratory methods for monitoring include one-stage clotting or chromogenic assays meant to measure either factor VIII/IX or global coagulation tests to measure the effect of bypassing agents. Recently, modified long-acting coagulation factors have been introduced for which discrepant results may be expected when measurement is performed with one-stage clotting or chromogenic assays. Currently, novel drugs not based on coagulation factors are under development and are being tested in clinical studies. These drugs do require new methods and therefore laboratory evaluation of hemophilia will undergo dramatic changes in the near future.

SUMMARY

From the analysis of the current practice and literature, we draw the following conclusions: (a) Thrombin generation or thromboelastometry are the logical candidate assays to monitor bypassing agents. (b) Considerable differences are expected when measuring modified long-acting coagulation factors, depending on whether one-stage or chromogenic assays are used. Although no definitive conclusions can presently be drawn, chromogenic assays are probably more suitable than one-stage clotting. (c) Novel drugs not based on coagulation factors such as emicizumab, fitusiran, or concizumab that are entering the market do require alternative methods that are not yet well established.