Optimal treatment strategies for hemophilia: achievements and limitations of current prophylactic regimens

Overview of Patients with Hemophilia in China: Demographics, Diseases, Treatment, and Health Status

Background

In China, there were over 65,000 hemophilia patients according to estimations requiring overall description. However, former Chinese studies related to hemophilia were based on data of relatively small sample size from single-center or selected multi-centers in specific areas.

Objective

This study is aimed to provide an overview of patients with hemophilia in China and basic information for optimized hemophilia care and policy decisions in the future.

Methods

We cooperated with the biggest patient organization of hemophilia in China, Hemophilia Home, got access to over ten thousand registered patients with hemophilia and conducted a national representative online survey in 2021. Descriptive statistics were conducted to describe the mean and standard deviation for continuous variables and numbers and proportions for categorical variables.

Results

Nine hundred and fifty patients with hemophilia aged 0-71 years were included in our analysis and divided into 538 children and 412 adults. Compared to international research, consistent results were found regarding the proportions of hemophilia types and hemophilia severity, while Chinese patients had less opportunity to receive the formal education and the lower rate to be employed or married. Although children with hemophilia had higher household income, timely treatment, and more prophylaxis treatment leading to better clinical outcomes and higher HRQoL than adults, there were still more annual bleeds, chronic pains, and lower EQ-VAS scores especially in adults than in other countries.

Conclusions and Recommendation

Our findings suggest the urgency for promoting hemophilia care and improving the social adaptation of hemophilia patients in China.

Emicizumab as a Promising Form of Therapy for Type A Hemophilia - A Review of Current Knowledge from Clinical Trials

Hemophilia is a plasma bleeding disorder characterized by a deficiency of certain blood clotting factors. The most common forms of this disease, i.e., type A and type B, affect approximately 400,000 people worldwide. Without appropriate treatment ensuring the proper coagulation cascade, this disease may lead to serious disability. Minimizing patient discomfort is possible via replacement therapy, consisting of the substitution of a missing coagulation factor via intravenous administration. Frequent medication and the risk related to factor inhibitors are significant disadvantages, necessitating the improvement of current therapies or the development of novel ones. This review examines the humanized bispecific antibody Emicizumab which ensures hemostasis by mimicking the action of the coagulation factor VIII, a deficiency of which causes type A hemophilia. The paper outlines the topic and then summarizes available clinical trials on Emicizumab in type A hemophilia. Several interventional clinical trials have found Emicizumab to be effective in decreasing bleeding episodes and raising patient satisfaction among various hemophilia A populations. Current Emicizumab-related trials are forecast to be completed between 2024 and 2030, and in addition to congenital hemophilia A, the trials cover acquired hemophilia A and patients playing sports. Providing a more comprehensive understanding of Emicizumab may revolutionize the management of hemophilia type A and improve quality of life. Conclusively, Emicizumab is a gentler therapy owing to subcutaneous delivery and fewer injections, which reduces injection-site reactions and makes therapy less burdensome, ultimately decreasing hospital visits and indirect costs.

Perspectives and perception of haemophilia gene therapy by French patients

INTRODUCTION AND AIM

A national survey was initiated by representatives of French patients with haemophilia (AFH) and the French reference centre for haemophilia, in order to appreciate the awareness and knowledge of these patients regarding haemophilia gene therapy (HGT) and understand better their position about this innovative treatment that will soon become available.

RESULTS

Of 143 answers received, 137 could be analysed, representing about 3.5% of patients with severe or moderate haemophilia over 16year-old. They were 80.3% with haemophilia A and 19.7 % with haemophilia B, with a severe form of the disease for 80.3 % of them. Curiosity for HGT was formulated by 64.2% of the participants, 33.6 % being interested by this approach as soon as it will be available and 38.7 % preferring to wait until more patients have been treated. Only 3.6 % of the participants would never consider receiving HGT. The level of awareness and knowledge was estimated to be limited by 39.5 % of the patients. More than 60 % of them declared having never or almost never discussed HGT with the team of their haemophilia centre. Before deciding to get HGT, 54.4 % of the participants considered that it will be very important to compare it with their current treatment and 53.7 % would like to be better informed by their care providers.

CONCLUSIONS

These results highlight the need for training and education for patients, but also for professionals at haemophilia centres, about HGT and the shared decision-making process. Objective, unbiased and transparent information must be available for patients about this very promising therapy which nonetheless carries more uncertainty and unknowns compared to other haemophilia treatments.

Comparison Pharmacokinetic Dosing Tools in Hemophilia A Children

Prophylaxis is the gold standard for the management of hemophilia A patients. It has been shown that prophylaxis regulated with pharmacokinetic (PK) data reduces frequency of bleeding and cost of treatment. To determine the best prophylaxis regimen, PK dosing tools using the Bayesian method have been developed. We aimed to compare two PK dosing tools. Blood samples were drawn before, 4, 24, and 48 h after FVIII infusions from patients with severe hemophilia A and inhibitor negative. FVIII levels were measured by PTT-based one-stage assay method. PK parameters obtained using WAPPS and myPKFiT, which are web-accessible PK dosing tools using Bayesian algorithm, and daily prophylaxis dose estimated by the programs were compared. Forty-two hemophilia A patients [median age 13 years (IQR 8.9-16.4)] included in the study. There was no difference between the daily dose of FVIII given for prophylaxis and the dose recommended by the myPKFiT for the 1% trough level; whereas, a significant difference was found with the WAPPS. The half-lives of FVIII did not differ between the two dosing tools; however, significant differences were found in the estimated dose, clearances, and times to 1% trough level. There was no significant difference between PK data of patients who received Advate® and those who received non-Advate® factor concentrates. Choice of PK dosing tool can affect recommended FVIII dose. However, target trough levels should be individualized according to bleeding phenotype and daily activity of patient.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12288-023-01671-0.

Personalized Prophylaxis with myPKFiTCE: A Real-World Cost-Effectiveness Analysis in Haemophilia A Patients

Background and Objectives: This study aimed to assess the effectiveness and costs associated with pharmacokinetics-driven (PK) prophylaxis based on the myPKFiT® device in patients affected by hemophilia A (HA) in Italy. Materials and Methods: An observational retrospective study was conducted in three Italian hemophilia centers. All patients with moderate or severe HA, aged ≥ 18 years, capable of having PK estimated using the myPKFiT device, and who had had a clinical visit between 1 November 2019 and 31 March 2022 were included. Differences in clinical, treatment, health resources, and cost data were assessed comparing post-PK prophylaxis with pre-PK. The incremental cost-effectiveness ratio (ICER) was estimated as cost (EUR) per bleed avoided. Results: The study enrolled 13 patients with HA. The mean annual bleeding rate decreased by -1.45 (-63.80%, p = 0.0055) after the use of myPKFiT®. Overall, the consumption of FVIII IU increased by 1.73% during follow-up compared to the period prior the use of the myPKFiT. Prophylaxis based on the myPKFiT resulted in an ICER of EUR 5099.89 per bleed avoided. Conclusions: The results of our study support the idea that the use of PK data in clinical practice can be associated with an improvement in the management of patients, as well as clinical outcomes, with a reasonable increase in costs.

IL-6, IL-1β and TNF-α regulation of the chondrocyte phenotype: a possible mechanism of haemophilic cartilage destruction

OBJECTIVE

Proinflammatory cytokines are considered to be one of the key causes of haemophilic cartilage destruction by inducing chondrocyte apoptosis and extracellular matrix degradation. However, few studies have focused on how proinflammatory cytokines regulate the phenotypic changes of chondrocytes, which may be an important factor in haemophilic cartilage degradation pathogenesis. More understanding is needed about the effect of proinflammatory cytokines on phenotypic changes of the chondrocyte. The objective of this study was to examine how IL-6, TNF-α and IL-1β regulate the chondrocyte phenotype, which may be an important factor in haemophilic cartilage degradation pathogenesis.

METHODS

HUM-iCell-s018 chondrocytes were treated with increasing concentrations of TNF-α, IL-6 or IL-1β (0, 1, 5, 10 ng/ml) for 24 h, then FGF23 and SOX9 expression was determined by qRT-PCR and WB, respectively.

RESULTS

We found that TNF-α, IL-6 and IL-1β induced FGF23 and suppressed SOX9 expression in chondrocytes in a dose-dependent manner. IL-1β had a stronger regulatory effect on FGF23, while TNF-α and IL-6 had stronger regulatory effects on SOX9.

CONCLUSIONS

These findings suggest that IL-6, IL-1β and TNF-α may be involved in haemophilic cartilage destruction pathogenesis by altering the chondrocyte phenotype through modulation of FGF23 and SOX9 gene expression.

Real-world data on the use of emicizumab in patients with haemophilia A with and without inhibitors in Singapore

Introduction

Emicizumab is a bispecific monoclonal antibody that mimics the function of factor VIII by binding to factor IXa and factor X to achieve haemostasis in haemophilia A. The long half-life and subcutaneous mode of administration makes emicizumab a compelling treatment option for bleeding prophylaxis. There is still limited real-world data on its use and management considerations, especially during surgical procedures. The objective of the study is to describe the real-world experience of emicizumab in a cohort of adult and paediatric haemophilia A patients in Singapore, including its use in the periprocedural setting.

Method

This was an observational study conducted at the 2 main haemophilia treatment centres in Singapore. All haemophilia A patients who commenced treatment with emicizumab before 1 July 2022 were recruited.

Results

A total of 18 patients with haemophilia A were included in this study. Ten (55.6%) patients had active inhibitors. The median annual bleeding rate for all patients before emicizumab use was 4.5 events (interquartile range [IQR] 2.8-8.3) compared with 0 events (IQR 0-0) after emicizumab was commenced (P=0). There were no adverse events of venous or arterial thrombosis, thrombotic microangiopathy, or death. A total of 6 procedures in 5 patients were performed during the study period with no major bleeding complications.

Conclusion

Emicizumab effectively protects against bleeding in haemophilia A patients with and without inhibitors, including in children less than 12 years old. More studies are required to address clinical nuances, such as periprocedural management and the role of immune tolerance in patients with inhibitors on emicizumab.

Hemophilia Gene Therapy: The End of the Beginning?

Extensive preclinical research over the past 30 years has culminated in the recent regulatory approval of several gene therapy products for hemophilia. Based on the efficacy and safety data in a recently conducted phase III clinical trial, Roctavian® (valoctocogene roxaparvovec), an adeno-associated viral (AAV5) vector expressing a B domain deleted factor VIII (FVIII) complementary DNA, was approved by the European Commission and Food and Drug Administration (FDA) for the treatment of patients with severe hemophilia A. In addition, Hemgenix® (etranacogene dezaparvovec) was also recently approved by the European Medicines Agency and the FDA for the treatment of patients with severe hemophilia B. This product is based on an AAV5 vector expressing a hyper-active factor IX (FIX) transgene (FIX-Padua) transgene. All AAV-based phase III clinical trials to date show a significant increase in FVIII or FIX levels in the majority of treated patients, consistent with a substantial decrease in bleeding episodes and a concomitant reduction in factor usage obviating the need for factor prophylaxis in most patients. However, significant interpatient variability remains that is not fully understood. Moreover, most patients encountered short-term asymptomatic liver inflammation that was treated by immune suppression with corticosteroids or other immune suppressants. In all phase III trials to date, FIX expression has appeared relatively more stable than FVIII, though individual patients also had prolonged FVIII expression. Whether lifelong expression of clotting factors can be realized after gene therapy requires longer follow-up studies. Further preclinical development of next-generation gene editing technologies offers new prospects for the development of a sustained cure for hemophilia, not only in adults, but ultimately in children with hemophilia too.

Treatment regimens, patient reported outcomes and health-related quality of life in children with moderate and severe hemophilia A in China: using real-world data

BACKGROUND

Prophylaxis therapy for children with moderate and severe hemophilia A (HA) is the optimal treatment regimen. The real-world treatment regimens, patient-reported outcomes, and health-related quality of life (HRQoL) in children with moderate and severe HA in China are less known.

OBJECTIVE

This study aimed to describe real-world treatment regimens and evaluate the association of treatment regimens with comprehensive patient-reported outcomes including bleeds, chronic pain, target joints, disability, and HRQoL in children under 18 years old with HA in China.

METHODS

Real-world data of a nationwide online cross-sectional survey in 2021 and patients' coagulation factor utilization data from self-management records from 2020 to 2021 were merged. 373 eligible children were included and categorized by treatment regimens according to the Chinese guideline: on-demand, short-term prophylaxis, and long-term prophylaxis treatment.

RESULTS

Currently, in China, 4.8% of children with HA are receiving full-dose long-term prophylaxis treatment. Prophylaxis treatment was a significant positive predictor of better patient-reported outcomes and HRQoL. For children with prophylaxis treatment, there were significantly fewer annual bleeds (p < 0.001), lower frequency of chronic pain(p < 0.001), and higher health utility scores(p < 0.01) and EQ-VAS scores(p < 0.05) than children with on-demand treatment.

CONCLUSION

Accessible long-term prophylaxis treatment should be promoted for children with moderate and severe HA in China and regular monitoring of their outcomes and HRQoL should be carried out.

Long-term outcomes of prophylaxis with a recombinant factor VIII Fc or recombinant factor IX Fc in patients with hemophilia previously treated on demand

Background

Prophylactic factor replacement therapy is recommended over on-demand treatment for preserving long-term joint health in hemophilia. Extended half-life products, including efmoroctocog alfa/eftrenonacog alfa (recombinant factor VIII [FVIII]/FIX Fc fusion proteins; herein rFVIIIFc/rFIXFc), have the potential to reduce treatment burden with less frequent administration and improve bleed prevention.

Objectives

We report post hoc data from patients with hemophilia A or B (HA/HB) who switched from prestudy on-demand FVIII/FIX to rFVIIIFc/rFIXFc prophylaxis at the start of A-LONG/B-LONG or start of/during ASPIRE/B-YOND phase 3 studies.

Methods

Patients with ≥6 months rFVIIIFc/rFIXFc prophylaxis were enrolled. Treatment exposure, dosing, annualized bleeding rates, joint health, and health-related quality of life (HRQoL) outcomes were assessed. Results were also stratified by age.

Results

Sixty-seven patients with HA and 50 with HB were analyzed; ≥60% were from regions outside Europe/North America, predominately those aged 12 to ‍25 years. No subjects returned to on-demand treatment postswitch.After switch to rFVIIIFc/rFIXFc prophylaxis, median annualized bleeding rates were reduced and sustained at low levels with stable factor usage across age groups (median treatment duration: 4.8/3.6 years). HRQoL outcomes improved for all ages; most pronounced changes were in the sports and leisure and physical health domains. After switch to rFVIIIFc prophylaxis, total modified Hemophilia Joint Health Score and joints with pain decreased in 64.6% and 29.2% of patients with HA. Insufficient data from patients with HB limited joint health evaluation of rFIXFc.

Conclusions

Findings add to existing evidence and demonstrate the clinical and HRQoL benefits of switching patients from on-demand treatment to rFVIIIFc/rFIXFc prophylaxis.

Quality of life, self-reported outcomes and impact of education among people with moderate and severe hemophilia A: An integrated perspective from a Latin American country

Collecting and interpreting self-reported outcomes among people with hemophilia A supports the understanding of the burden of the disease and its treatment to improve holistic care. However, in Colombia, this information is limited. Therefore, this study aimed to describe the knowledge, perception and burden of hemophilia A from the patients' perspective. A cross-sectional study was conducted in the context of a hemophilia educational bootcamp held from November 29th to December 1st, 2019, in Medellin, Colombia. The bootcamp was organized by a hemophilia patient association responsible for contacting and inviting patients with hemophilia A (PwHA). Information on patients' health beliefs, treatment experiences, and health-related quality of life (HRQoL) was obtained through focus groups, individual interviews and the Patient Reported Outcomes, Burdens and Experiences (PROBE) questionnaire. A total of 25 moderate or severe PwHA were enrolled in this study and completed the PROBE questionnaire. Acute pain was the most frequently reported symptom, with 88% of the patients reporting the use of pain medication. Difficulty with activities of daily living was reported by 48%. Furthermore, 52% reported having more than 2 spontaneous bleeding events in the last year. Treatment was administered at home for 72% of patients, with regular prophylaxis as the most common treatment regimen. In terms of overall HRQoL, the median EQ-5D VAS score was 80 (IQR: 50-100). PwHA in Colombia still suffer from disease complications related to bleeding events, pain and disability that affect their HRQoL, which highlights the need to develop patient-centered initiatives to improve the wellness of this population.

Etranacogene dezaparvovec-drlb gene therapy for patients with hemophilia B (congenital factor IX deficiency)

INTRODUCTION

Congenital hemophilia B (HB) is an X-linked bleeding disorder resulting in Factor IX (FIX) deficiency and bleeding of variable severity. There is no cure for HB. Typical management consists of prophylactic intravenous (IV) recombinant or plasma-derived FIX infusions. Etranacogene dezaparvovec-drlb (Hemgenix, AMT-061) is an adeno-associated virus serotype 5 (AAV5) vector containing a codon-optimized Padua variant of the human F9 gene with a liver-specific promoter. Etranacogene dezaparvovec-drlb received FDA approval on 22 November 2022 for the treatment of HB in adult patients who use FIX prophylaxis therapy, have current or historical life-threatening hemorrhage, or have experienced repeated, serious spontaneous bleeding episodes.

AREAS COVERED

This drug profile discusses the safety and efficacy of etranacogene dezaparvovec-drlb in patients with HB.

EXPERT OPINION

Etranacogene dezaparvovec-drlb therapy results in stable and sustained expression of near-normal to normal FIX levels in patients with HB regardless of neutralizing antibodies to AAV5 up to a titer of 678. Its use has led to significant reduction in bleeding and FIX prophylaxis. Etranacogene dezaparvovec-drlb was well tolerated; however, 17% of patients required corticosteroid therapy for alanine aminotransferase (ALT) elevation. Etranacogene dezaparvovec-drlb therapy marks the beginning of an exciting era in HB treatment and opens questions regarding treatment longevity and long-term safety.

Efanesoctocog alfa for the prevention and treatment of bleeding in patients with hemophilia A

INTRODUCTION

Hemophilia A is an inherited bleeding disorder due to a deficiency of coagulation factor VIII (FVIII). Prevention and treatment of bleeding is traditionally through intravenous infusion of a FVIII concentrate. Modifications of recombinant FVIII (rFVIII) with an aim to prolong the half-life have been modest, thought because FVIII is dependent on plasma von Willebrand factor (VWF) for its half-life. Efanesoctocog alfa (ALTUVIIIO), approved by the Federal Drug Administration (FDA) in February 2023, was made independent of endogenous VWF by linking of the FVIII-binding D'D3 domain of VWF to B-domain deleted single chain FVIII.

AREAS COVERED

This review will outline the development of efanesoctocog alfa and the pharmacokinetic and safety data from clinical trials, as well as efficacy data from the phase 3 trials. These data formed the basis for the FDA approval.

EXPERT OPINION

Efanesoctocog alfa is a new type of FVIII replacement with an extended half-life allowing once weekly dosing to achieve hemostasis and FVIII trough levels of 13-15 IU/dL. This provides a highly effective option for treatment and prevention of bleeding in hemophilia A, where FVIII levels are easily measured. It also provides an option for treatment of bleeding and coverage for surgery with few infusions.

Bleeding events in people with congenital haemophilia A without factor VIII inhibitors receiving prophylactic factor VIII treatment: A systematic literature review

BACKGROUND

Evidence on bleeding rates in people with congenital haemophilia A (PwcHA) without inhibitors on factor VIII (FVIII) replacement products is inconsistent.

AIM

This systematic literature review assessed bleeding outcomes in PwcHA using FVIII-containing products as prophylactic treatment.

METHODS

A search was conducted using the bibliographic databases Medline, Embase and Cochrane Central Register of Controlled Trials on the Ovid platform. The search involved a bibliographic review of clinical trial studies, routine clinical care studies and registries and a search of ClinicalTrials.gov, EU Clinical Trials Register and conference abstracts.

RESULTS

The search yielded 5548 citations. A total of 58 publications were included for analysis. In 48 interventional studies, the pooled estimated mean (95% confidence interval [CI]) annualized bleeding rate (ABR), annualized joint bleeding rate (AJBR) and proportion of participants with zero bleeding events were 3.4 (3.0-3.7), 2.0 (1.6-2.5), and 38.5% (33.1-43.9), respectively. In 10 observational studies, the pooled estimated mean (95% CI) ABR, AJBR and proportion of participants with zero bleeding events were 4.8 (4.0-5.5), 2.6 (2.1-3.2), and 21.8% (19.9-47.5), respectively. A large variation in mean effect size for ABR, AJBR and zero bleeding event data across cohorts and cohort types was observed. Funnel plots indicated potential reporting bias for publications incorporating ABR and AJBR data across both interventional and observational studies.

CONCLUSION

This meta-analysis shows that PwcHA without inhibitors still have bleeds despite FVIII prophylaxis. Improved standardization on capturing and reporting bleeding outcomes is needed so that effective comparisons between treatments can be made.

[Gene therapy of Hemophilia: Recommendations from the German, Austrian, and Swiss Society for Thrombosis and Haemostasis Research (GTH)]

Gene therapy has recently become a realistic treatment perspective for patients with hemophilia. Reviewing the literature and our personal experience from clinical trials, we discuss key aspects of hemophilia A and B gene therapy with vectors derived from adeno-associated virus, including predictable results, risks, adverse events, and patient-reported outcomes. Patient selection, informed consent, administration, and monitoring of gene therapy as well as data collection are explained. We also discuss the need for interdisciplinary cooperation with hepatology and other specialties. We emphasize structural and organizational requirements for treatment centers according to the hub-and-spoke model and recommend the use of electronic diaries to ensure safe and timely collection and exchange of data. Electronic diaries will play a key role as a primary source of data for pharmacovigilance, postmarketing clinical studies, national and international registries, as well as health technology and benefit assessment. Reimbursement aspects and the future of gene therapy in adolescents and children are also considered. In a rapidly evolving scientific environment, these recommendations aim to support treatment providers and payers to prepare for the implementation of gene therapy following marketing authorization.

Bispecific antibodies mimicking factor VIII in hemophilia A: converting innovation to an essential medicine

Preventive subcutaneous treatment of severe hemophilia A with bispecific antibodies that mimic the action of coagulation factor VIII (FVIII) is emerging as an effective alternative to replacement therapy with intravenous administration of FVIII concentrates, either derived from plasma or produced by biotechnology. Access to this innovative therapeutic approach for a growing number of patients worldwide increasingly appears to be a priority public health strategy. Inclusion of FVIII mimetic bispecific antibodies on the World Health Organization essential medicines list would contribute to health equity in lower-income countries.

The hidden joint in children with haemophilia on prophylaxis

Prophylaxis is the gold standard treatment for children with haemophilia (CWH). MRI studies revealed joint damage, even with this treatment; this suggests the presence of subclinical bleeding. In the case of children with haemophilia, it is relevant to detect early signs of joint damage, as this allows the medical team to provide the appropriate treatment and follow-up, in order to avoid arthropathy development and its consequences. The aim of this study is to detect the hidden joint in children with haemophilia on prophylaxis (CWHP) and analyse, by age group, which joint is the most affected. We define the hidden joint in CWH on prophylaxis as the joint that presents joint damage secondary to repetitive bleeding episodes and is detected in the joint evaluation, despite being asymptomatic or with mild symptoms. It is most commonly caused by repetitive subclinical bleeding.

METHODS

This was an observational, analytical, cross-sectional study of 106 CWH on prophylaxis treated in our centre. Patients were divided according to age and type of treatment. Joint damage was defined as a HEAD-US score ≥ 1.

RESULTS

Patients' median age was 12 years. All had severe haemophilia. The median age of onset of prophylaxis was 2.7. Forty-seven (44.3 %) patients received primary prophylaxis (PP) and 59 (55.7 %), secondary prophylaxis. Six hundred and thirty-six joints were analysed. Type of prophylaxis and joint involvement showed statistically significant differences (p < 0.001). However, patients on PP had a greater number of damaged joints at older ages. Twenty-two % (140) of the joints scored ≥1 on HEAD-US. Cartilage was most frequently involved, followed by synovitis, and bone damage. We observed a greater frequency and degree of arthropathy in subjects aged 11 and above. Sixty (12.7 %) joints showed a HEAD-US score ≥ 1, with no history of bleeding. The ankle was the most affected joint, representing the hidden joint according to our definition.

CONCLUSION

Prophylaxis is the best treatment for CWH. However, symptomatic or subclinical joint bleeding may occur. The routine evaluation of joint health is relevant, particularly, of the ankle. In our study, early signs of arthropathy according to age and type of prophylaxis were detected by HEAD-US.

Clinical Delivery of Circular RNA: Lessons Learned from RNA Drug Development

Circular RNAs (circRNA) represent a distinct class of covalently closed-loop RNA molecules, which play diverse roles in regulating biological processes and disease states. The enhanced stability of synthetic circRNAs compared to their linear counterparts has recently garnered considerable research interest, paving the way for new therapeutic applications. While clinical circRNA technology is still in its early stages, significant advancements in mRNA technology offer valuable insights into its potential future applications. Two primary obstacles that must be addressed are the development of efficient production methods and the optimization of delivery systems. To expedite progress in this area, this review aims to provide an overview of the current state of knowledge on circRNA structure and function, outline recent techniques for synthesizing circRNAs, highlight key delivery strategies and applications, and discuss the current challenges and future prospects in the field of circRNA-based therapeutics.

Screening for subclinical synovial proliferation in haemophilia: A systematic review and meta-analysis comparing physical examination and ultrasound

INTRODUCTION

Ultrasound is increasingly used as addition to physical examination for detection of subclinical joint changes in haemophilia. However, the added value of ultrasound to physical examination for detecting synovial proliferation is not fully established.

AIM

To determine the diagnostic accuracy of swelling at physical examination for ultrasound-detected synovial proliferation in haemophilia.

METHODS

PubMed and EMBASE were searched up to 2 August 2022. Studies reporting original data on occurrence of swelling at physical examination and synovial proliferation on ultrasound of index joints in persons with haemophilia were included. Risk of bias and applicability were assessed using the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool. Diagnostic accuracy parameters of swelling at physical examination for ultrasound-detected synovial proliferation were determined. Summary sensitivity and specificity were calculated using a bivariate random-effects model.

RESULTS

Fifteen studies reporting on swelling at physical examination and synovial proliferation on ultrasound in 2890 joints of 627 patients were included. Prevalence of subclinical synovial proliferation ranged between 0% and 55%. Sensitivity of swelling was low [summary estimate .34; 95% confidence interval (CI) .24-.46], while specificity was high (summary estimate .97; CI .92-.99). Predictive values varied widely due to inter-study differences in prevalence of synovial proliferation.

CONCLUSION

Joint swelling has low sensitivity for presence of ultrasound-detected synovial proliferation in haemophilia, suggesting underestimation of synovial proliferation by physical examination alone. Consequently, ultrasound screening may generate important information on synovial changes which would otherwise remain undetected.

Synovitis and joint health in patients with haemophilia: Statements from a European e-Delphi consensus study

INTRODUCTION

Synovitis, a common feature in haemophilia, is triggered by the presence of blood in joints, and represents the first step towards the development of chronic arthropathy. Synovitis may be detected early by means of ultrasound or magnetic resonance imaging scan; clinical joint scores are less sensitive in this setting. Regular long-term prophylaxis with clotting factor concentrates, as primary prophylaxis and tailored to individual needs, has high efficacy in preventing synovitis. In general, higher factor levels lower bleeding risk, but no direct correlation between factor levels and synovitis incidence has been demonstrated.

AIM

This study aimed to develop an expert consensus relating to the definition, pathophysiology, diagnosis, prevention, follow-up and treatment of synovitis, recognising its relevance for joint health and taking into account existing knowledge gaps.

METHODS

A Delphi consensus study was designed and performed. An expert group prepared 22 statements based on existing literature; a wider expert panel subsequently voted on these.

RESULTS

Retention of panellists was high. Four statements required amending and consensus on all statements was achieved after three rounds of voting.

CONCLUSION

This e-Delphi consensus study addressed the importance of synovitis in joint health of people with haemophilia and highlighted knowledge gaps in this field. Studies on the natural course of synovitis are lacking and the biological mechanisms underlying this process are not yet fully elucidated. While basic and clinical research proceeds in this field, expert consensus can help guide clinicians in their routine clinical practice, and Delphi methodology is often used to produce best-practice guidelines.

Physical activity in Norwegian teenagers and young adults with haemophilia A compared to general population peers

INTRODUCTION

Limited evidence exists on objectively measured habitual physical activity (PA) of young people with haemophilia (PWH).

AIMS

To compare different outcomes of objective PA between young PWH A and controls using a commercial activity tracker.

METHODS

We enrolled males aged 13-30 years with moderate and severe haemophilia A, without inhibitors on regular prophylaxis. PA was measured with the activity tracker Fitbit Charge 3 for 12 weeks. Control group data was obtained from ≈60,000 Fitbit users, matched on age, sex and measurement period. PA variables [steps, intensities, volume, activity types, exercise frequencies and proportion meeting the World Health Organization's moderate-to-vigorous PA (MVPA) recommendations] were compared between groups descriptively and using Welch's two-sample t-test and two-sample test of proportions.

RESULTS

Forty PWH A were enrolled (mean age 19.5 years, 50% teenagers, 50% adults, three (7.5%) with moderate and 37 (92.5%) with severe haemophilia). Mean daily steps and minutes MVPA were similar between PWH and controls. PWH spent more time in light PA (mean 227 vs. 192 min/day, P = .033) and exercised more frequently (mean 5.6 vs. 3.9 exercise sessions/week, P < .001). Among teenagers, 40% PWH and 8% controls reached MVPA recommendations, compared to 95% and 100% among adults. The most common type of PA was walking.

CONCLUSION

This cohort of young PWH A on prophylactic treatment had PA levels comparable to controls. Still, a considerable proportion of teenagers did not meet the recommended weekly volume of MVPA, and we encourage clinicians to have a particular focus on promoting PA for this group.

Adherence to prophylaxis and bleeding outcome: A multicenter Nigerian study

In Nigeria, low-dose prophylaxis is the standard of care as it reduces bleeding, development of target joints, arthropathy, and improvement of quality of life. Non-adherence or poor adherence can prevent the achievement of these outcomes. The levels and determinants of (non-)adherence among persons with haaemophilia (PWH) in Sub-Saharan Africa have not been evidenced. We aimed to evaluate self-reported adherence among PWH, provide evidence of determinants/predictors of adherence, and establish the associations between nonadherence and presence of target joints and annualized bleed rate. A cross-sectional survey of 42 participants on low-dose prophylaxis recruited during outpatient appointments in 5 haemophilia treatment centers in Nigeria. We used the validated Haemophilia Regimen Treatment Adherence Scale- Prophylaxis (VERITAS -Pro), 24 questions on six subscales (time, dose, plan, remember, skip, and communicate) questionnaire. The options of VERITAS -Pro were represented in a 5 Likert scale and the possible subscale ranged from 4 points (most adherent) to 20 points (least adherent) and the possible total score ranged from 24 (most adherent) to 120 (least adherent) the cutoff for overall adherence put at > 61 to indicate nonadherence. Information on the presence of target joints, the number of target joints, and annualized bleeding rates were collected from medical files. The mean age of the participants was 9.79 (6.29) years, with 96.6% having hemophilia A and 79.3% having target joints. Overall adherence to the prophylaxis regimen was 81.0%. The mean total VERITAS-Pro for the adherent group and the non-adherent group was 37.35 ±9.08 and 63.0± 6.37, respectively. The mean subscale scores for the adherent group ranged from 0.67 (communication) to 8.68 (planning), while the mean subscale scores range from 1.0 communication to 13.88 (planning) for the nonadherent group. The mean difference of all except the dosing subscale was statistically significant with p<0.05. Only the skipping subscale showed a statistically significant positive correlation with ABR in the non-adherent group p = 0.02. The findings indicate that adherence was very good, and most were in communication with their treatment centers. The skipping subscale was significantly associated with ABR for the nonadherent group. Interventions aimed at improving adherence are the key to better treatment outcomes. A multicenter study was needed to assess the reason for poor adherence.

Efficacy of emicizumab is maintained throughout dosing intervals for bleed prophylaxis

Background

Across the HAVEN clinical trial program, the efficacy of emicizumab has been demonstrated in children, adolescents, and adults with hemophilia A, with or without factor VIII inhibitors. After the 4-week loading dose period, emicizumab concentrations are expected to remain at levels that provide bleed protection throughout the entire dosing interval, regardless of the chosen maintenance dosing regimen, ie, weekly, every 2 weeks, or every 4 weeks.

Objectives

The objective of this study was to examine the timing of treated bleeds within the dosing intervals for emicizumab administered during the HAVEN 1 to 4 studies.

Methods

In this post hoc analysis, we pooled data from all the participants of the HAVEN 1 to 4 studies and analyzed the timing of treated bleeds in relation to the emicizumab dose.

Results

A total of 392 participants were included in this analysis, with a median (range) age of 28.0 years (1.1-77.0 years). Target joints were identified in 237 of 392 (60.5%) participants before the study entry. Overall, 211 of 392 (53.8%) participants experienced 907 treated bleeding events. The total mean (SD) annualized bleeding rate across the 4 studies was 1.6 (5.9). There was no evidence that bleeding events clustered on any 1 particular day in any dosing schedule from HAVEN 1 to 4 (P > .05 for all 3 treatment regimens).

Conclusion

Data from the HAVEN 1 to 4 trials show consistent bleed prevention within the dosing interval, regardless of the dosing regimen chosen. These findings provide further evidence of the sustained efficacy of emicizumab across all approved dosing regimens to reduce bleeding in people with hemophilia A.

Clinical experience of switching patients with severe hemophilia to rVIII-SingleChain or rIX-FP

OBJECTIVE

Prophylaxis treatment is the current standard of care for patients with severe hemophilia. Factor concentrates with improved pharmacokinetics have offered more options for individualizing treatment. The treatment focus may be on increased protection, aiming for higher trough factor levels or longer dosing intervals to reduce the burden of hemophilia. Both aspects can have long-term effects on joint health. Products, such as rVIII‑SingleChain and rIX-FP have been developed to reduce the treatment burden for patients with hemophilia and optimize prophylactic efficacy. The objective of this report is to provide a summary of the clinical experience of different Hemophilia Treatment Centers in managing the switch to rVIII-SingleChain or rIX-FP in patients with hemophilia.

METHODS

This report summarizes a selection of patient cases presented at the 3rd Alliance for Coagulation Academy Meeting in October 2020. The cases from the participating centers provide examples of the clinical experience in managing patients' switch to rVIII-SingleChain and rIX‑FP, including which types of patients are suitable for switching, and practical steps in managing a switch.

RESULTS

It is important to take into consideration the physical and social fulfillment of the patient when deciding to switch to rVIII-SingleChain or rIX-FP. The physician plays an important role in the motivation of patients as they understand not only the patient's needs but the potential benefits of the new treatment.

CONCLUSION

The selected patient cases reported here demonstrate that patients may wish to switch factor products for a variety of reasons; therefore, it is critical to understand why patients switch and what they expect from switching.

IDEAL study: A real-world assessment of pattern of use and clinical outcomes with recombinant coagulation factor IX albumin fusion protein (rIX-FP) in patients with haemophilia B in Italy

INTRODUCTION

Factor IX replacement therapy is used for treatment and prophylaxis of bleeding in haemophilia B. rIX-FP is an extended half-life albumin-fusion protein, which, in clinical studies, has demonstrated prolonged dosing intervals up to 21 days for routine prophylaxis, providing therapeutic benefit.

AIMS

To describe dosing frequency and consumption (primary endpoint), efficacy and safety of rIX-FP treatment during routine clinical practice in Italy.

METHODS

Patients with moderate/severe haemophilia B on prophylaxis with rIX-FP for ≥6 months, were enrolled in this observational study from October 2017 to February 2019 and followed-up for 2 years. Descriptive analysis included prospective and retrospective data (12 months prior to switching to rIX-FP).

RESULTS

Data were collected from 59 male patients (median age 30.1 years) enrolled by 23 Italian centres. Of them, 50 were on prophylaxis during the entire observation period and completed the study. The infusion frequency changed from 2-3 times/week in 86.0% of patients with previous treatment, to less than once a week in 84.0% of patients treated with rIX-FP at the 2nd-year follow-up. The annual number of infusions decreased by about 70%, whereas the mean FIX activity trough level increased from 3.8% to 14.4% (mean > 10% in all the infusion regimens). Median Annualised Bleeding Rate of .0 was achieved across all prophylaxis regimens. Subjects with zero bleedings increased from 66.0% to 78.0% with rIX-FP.

CONCLUSION

Treatment with rIX-FP reduced infusion frequency, while providing higher FIX trough levels with substantial benefit in terms of annualised bleeding rate and a good safety profile.

Long-term impact of primary prophylaxis on joint status in patients with severe hemophilia A

Background

Primary prophylaxis with factor VIII concentrates is the therapeutic gold standard for severe hemophilia A. Although this approach will change substantially with the use of nonsubstitutive therapies, the long-term effects of primary prophylaxis remain unclear. We present information on joint health with tailored primary prophylaxis in a consecutive series at a single center.

Methods

We retrospectively analyzed 60 patients who did not develop early inhibitors. The annual bleeding rate and annual joint bleeding rate, prophylaxis characteristics, physical activity, adherence, and development of inhibitors were compared between those with and without joint involvement at the end of follow-up. Joint involvement was defined as a Hemophilia Joint Health Score or Hemophilia Early Arthropathy Detection with an ultrasound score ≥1.

Results

Among 60 patients with median follow-up of 113 ± 6 months after starting prophylaxis, 76.7% had no joint involvement at the end of the follow-up. Those without joint involvement started prophylaxis at a younger median age (1 [IQR 1-1] year vs 3 [IQR 2-4.3] years). They also had lower annual joint bleeding rate (0.0 [IQR 0-0.2] vs 0.2 [IQR 0.1-0.5]), were more often physically active (70% vs 50%), and had lower trough factor VIII levels. Adherence to treatment was not significantly different between groups.

Conclusion

Initiation of primary prophylaxis at a younger age was the main factor associated with long-term preservation of joint status in patients with severe hemophilia A.

Real-World Use of Albutrepenonacog Alfa, A Recombinant Coagulation Factor IX Albumin Fusion Protein, for Personalized Prophylaxis in Japanese Individuals With Hemophilia B: A Case Series

Currently, the mainstay of disease management for hemophilia B, a hemorrhagic disease caused by a congenital deficiency or molecular abnormalities of blood coagulation factor IX (FIX), is prophylaxis using FIX concentrate. On-demand injections of FIX concentrate may also be required, even during prophylaxis, when a patient with hemophilia B is bleeding. Albutrepenonacog alfa (rFIX-FP) is a human albumin fusion gene recombinant FIX, which is administered once every seven, 14, or 21 days, depending on patient preferences and symptoms. Studies have demonstrated its efficacy and safety in a range of patients; however, to date, reports of real-world experiences of the use of rFIX-FP in Japan are limited. We present a case series of three Japanese individuals with moderately severe (FIX activity 1 to <2%) or severe (FIX activity <1%) hemophilia B who benefited from prophylaxis using rFIX-FP in our clinical practice setting. We highlighted the good effectiveness of rFIX-FP in a patient with moderately severe hemophilia B who required prophylaxis due to joint bleeding, which was causing deterioration of his left ankle joint, as well as in a patient with severe hemophilia B and atherothrombotic cerebral infarction, whose trough level had to be ≥5% for concomitant use of an antiplatelet drug, and in a patient with severe hemophilia B who was working in nursing care, which involved heavy labor and night shifts, and who had previously been treated with on-demand FIX concentrate. In all three cases, rFIX-FP improved disease symptoms, and the patients were able to maintain steady states of therapy due to the treatment characteristics of rFIX-FP, which stabilizes FIX at high trough levels.

Considerations for shared decision management in previously untreated patients with hemophilia A or B

Recent advances in therapeutics are now providing a wide range of options for adults and children living with hemophilia. Although therapeutic choices are also increasing for the youngest individuals with severe disease, challenges remain about early management decisions, as supporting data are currently limited. Parents and healthcare professionals are tasked with helping children achieve an inclusive quality of life and maintain good joint health into adulthood. Primary prophylaxis is the gold standard to optimize outcomes and is recommended to start before 2 years of age. A range of topics need to be discussed with parents to aid their understanding of the decisions they can make and how these will affect the management of their child/children. For those with a family history of hemophilia, prenatal considerations include the possibility of genetic counseling, prenatal investigations, and planning for delivery, together with monitoring of the mother and neonate, as well as diagnosis of the newborn and treatment of any birth-associated bleeding. Subsequent considerations, which are also applicable to families where infant bleeding has resulted in a new diagnosis of sporadic hemophilia, involve explaining bleed recognition and treatment options, practical aspects of initiating/continuing prophylaxis, dealing with bleeds, and ongoing aspects of treatment, including possible inhibitor development. Over time, optimizing treatment efficacy, in which individualizing therapy around activities can play a role, and long-term considerations, including retaining joint health and tolerance maintenance, become increasingly important. The evolving treatment landscape is creating a need for continually updated guidance. Multidisciplinary teams and peers from patient organizations can help provide relevant information. Easily accessible, multidisciplinary comprehensive care remains a foundation to care. Equipping parents early with the knowledge to facilitate truly informed decision-making will help achieve the best possible longer-term health equity and quality of life for the child and family living with hemophilia.

Plain language summary

Points to be taken into account to help families make decisions to best care for children born with hemophilia Medical advances are providing a range of treatment options for adults and children with hemophilia. There is, however, relatively limited information about managing newborns with the condition. Doctors and nurses can help parents to understand the choices for infants born with hemophilia. We describe the various points doctors and nurses should ideally discuss with families to enable informed decision-making. We focus on infants who require early treatment to prevent spontaneous or traumatic bleeding (prophylaxis), which is recommended to start before 2 years of age. Families with a history of hemophilia may benefit from discussions before pregnancy, including how an affected child would be treated to protect against bleeds. When mothers are pregnant, doctors can explain investigations that can provide information about their unborn child, plan for the birth, and monitor mother and baby to minimize bleed risks at delivery. Testing will confirm whether the baby is affected by hemophilia. Not all infants with hemophilia will be born to families with a history of the condition. Identification of hemophilia for the first time in a family (which is 'sporadic hemophilia') occurs in previously undiagnosed infants who have bleeds requiring medical advice and possibly hospital treatment. Before any mothers and babies with hemophilia are discharged from hospital, doctors and nurses will explain to parents how to recognize bleeding and available treatment options can be discussed. Over time, ongoing discussions will help parents to make informed treatment decisions:• When and how to start, then continue, prophylaxis.• How to deal with bleeds (reinforcing previous discussions about bleed recognition and treatment) and other ongoing aspects of treatment. ○ For instance, children may develop neutralizing antibodies (inhibitors) to treatment they are receiving, requiring a change to the planned approach.• Ensuring treatment remains effective as their child grows, considering the varied needs and activities of their child.

Gene Therapy for Hemophilia-Opportunities and Risks

BACKGROUND

AAV (adeno-associated virus)-based gene therapy is a new treatment for hemophilia and has recently received approval for the treatment of severe hemophilia A. It does not suffer from the limitations of the current standard treatment (regular prophylactic intravenous injections of the missing clotting factor; subcutaneous injection of a bispecific antibody in hemophilia A) and can, it is hoped, raise the concentration of the missing clotting factor over the long term. AAV-based gene therapy can only be performed once, however, because of the generation of antibodies to AAV.

METHODS

This review is based on publications retrieved by a selective search in the MEDLINE/PubMed database employing the relevant key words, supplemented by expert opinions and the recommendations of the relevant medical societies.

RESULTS

Data from non-randomized phase 1 to phase 3 trials reveal an adequate expression of factors VIII and IX in patients with mostly severe hemophilia A or B. Even though they were no longer receiving prophylactic treatment, most patients experienced a considerable reduction, by 53% to 96%, in the number of bleedings compared to previous therapy. Persistently elevated factor levels have been described for up to six years in hemophilia A and up to eight years in hemophilia B. The most common side effect of gene therapy is an inflammatory response with elevated alanine aminotransferase levels (17% to 89%, depending on the study), which may be associated with a reduced clotting factor level and requires treatment with transient immunosuppression.

CONCLUSION

Gene therapy for hemophilia holds out the prospect of freedom from hemorrhage without the need for regular treatment with drugs. The various steps that need to be carried out in gene therapy should be coordinated in a graded and partly overlapping integrated care model (a so-called hub-and-spoke model). Electronic platforms should be used for data acquisition and transmission.

The role of point-of-Care Musculoskeletal Ultrasound for Routine Joint evaluation and management in the Hemophilia Clinic - A Real World Experience

BACKGROUND

The use of musculoskeletal ultrasound (MSKUS) for point-of-care (POC) evaluation of hemophilic arthropathy is growing rapidly. However, the extent to which MSKUS influences clinical treatment decisions is unknown.

METHODS

We conducted a three-year, prospective, multi-center study at three hemophilia treatment centers in the United States to evaluate the utilization of POC-MSKUS for routine clinical decision-making in adult persons with hemophilic arthropathy. Bilateral elbows, knees and ankles were assessed clinically [Hemophilia Joint Health Score (HJHS)] and with POC-MSKUS by the Joint _TissueActivity and Damage Exam (JADE) protocol at baseline and approximately annually for two additional times. Treatment decisions, including physical therapy (PT) and "medical" (joint injections/aspirations, referrals to orthopedics, changes/adjustments of hemostatic plans, and use of oral anti-inflammatory medications) were recorded in relation to POC-MSKUS.

RESULTS

Forty-four persons [median age 37 years (IQR 29, 51)], mostly with severe Hemophilia A on clotting factor prophylaxis, completed 129 visits, yielding 792 joint exams by POC-MSKUS and HJHS [median at baseline 27 (IQR 18, 42)] over a median follow up of 584 days (range: 363 to 1072). Among 157 management decisions, 70% were related to PT plans (n = 110) and 30% were "medical". Point-of-care MSKUS influenced 47/110 (43%) PT plans, mostly informing treatment of specific arthropathic joints (45/47 plans) in patients with high HJHS. Physical therapy plans influenced by POC-MSKUS directed more manual therapy/therapeutic exercises, while plans based on physical exam were focused more on global exercises and wellness. Treatment decisions were mostly based on the identification of specific musculoskeletal abnormalities visualized by POC-MSKUS. Of note 20/47 (43%) POC-MSKUS plans included de-escalation strategies, thereby reducing exercise intensity, mostly for joint instability and subclinical hemarthroses. Point-of-care MSKUS also informed 68% (32/47) of "medical" decisions, surprisingly mostly for injections/aspirations and referrals to orthopedics, and not for adjustments of hemostatic treatment. Although not formally studied, ultrasound images were used frequently for patient education.

CONCLUSION

Routine joint evaluations with POC-MSKUS resulted in few changes regarding medical management decisions but had a profound effect on the formulation of PT plans. Based on these findings, new studies are essential to determine the benefit of MSKUS-informed management plans on joint health outcomes.

The value of radiosynoviorthesis for treatment of chronic synovitis in hemophilic joint disease

Chronic synovitis is contributing to the development of arthropathy in hemophilia A and B. In most patients with severe and moderate hemophilia, during lifetime, joint damage progresses despite early prophylaxis and intense treatment with coagulation factor concentrates. Recurrent hemorrhages into the joints and subclinical bleeding lead to chronic inflammation of the synovium, neoangiogenesis and remodeling, sustaining a vicious circle of bleeding-remodeling-bleeding and progression of osteochondral damage. Imaging techniques including ultrasound and MRI are able to early visualize synovitis and osteochondral changes. Early detection and sustained therapy of synovitis are important preconditions to prevent further deterioration of joint status. Chronic synovitis requires intensified substitution of coagulation factors and concomitant analgetic, antiphlogistic and physical therapy. The value of early radiosynoviorthesis (RSO) as effective method to control ongoing synovitis is discussed here. RSO is recommended as first choice therapy in case of persistant chronic synovitis, recorded in both national and international guidelines.

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.

Promoting physical activity for people with haemophilia in the age of new treatments

Haemophilia treatment has seen great advances in recent years with an accompanied reduced risk of physical activity (PA) related bleeds. Based on its known health benefits, people with haemophilia (PWH) are currently encouraged to regularly engage in PA. However, this may not always translate to increased levels of PA. In this narrative review we aim to provide a brief overview of what is currently understood regarding PA levels and influences for the three broad age groups of children and adolescents, adults and older adults. We also provide recommendations for members of the haemophilia team on important aspects related to promotion of PA in their clinical practice. We highlight that PA behaviour is multifactorial and that many PWH still have limited access to adequate care. Whilst some still face unique challenges to being more physically active, overall, the barriers and facilitators to activity are very similar to that of the general population.

Approach to Knee Arthropathy through 180-Degree Immersive VR Movement Visualization in Adult Patients with Severe Hemophilia: A Pilot Study

(1) Background: Hemarthrosis is a typical clinical manifestation in patients with hemophilia. Its recurrence causes hemophilic arthropathy, characterized by chronic joint pain. Watching movement recorded from a first-person perspective and immersively can be effective in the management of chronic pain. The objective of this study was to evaluate the effectiveness of an immersive virtual reality intervention in improving the pain intensity, joint condition, muscle strength and range of motion in patients with hemophilic knee arthropathy. (2) Methods: Thirteen patients with hemophilic knee arthropathy were recruited. The patients wore virtual reality glasses and watched a flexion-extension movement of the knee on an immersive 180° video, recorded from a first-person perspective over a 28-day period. The primary variable was the pain intensity (visual analog scale). The secondary variables were the joint status (Hemophilia Joint Health Score), quadriceps and hamstring strength (dynamometry), and range of motion (goniometry). (3) Results: After the intervention period, statistically significant differences were observed in the intensity of the joint pain (Standard error [SE] = 19.31; 95% interval confidence [95%CI] = -1.05; -0.26), joint condition (SE = 18.68; 95%CI = -1.16; -0.52) and quadriceps strength (SE = 35.00; 95%CI = 2.53; 17.47). We found that 38.46% and 23.07% of the patients exhibited an improvement in their quadriceps muscle strength and joint condition above the minimum detectable change for both variables (8.21% and 1.79%, respectively). (4) Conclusions: One hundred and eighty degree immersive VR motion visualization can improve the intensity of joint pain in patients with hemophilic knee arthropathy. An intervention using immersive virtual reality can be an effective complementary approach to improve the joint condition and quadriceps strength in these patients.

Comparison of Real-World Dose and Consumption for Two Extended Half-Life Recombinant Factor VIII Products for the Treatment of Hemophilia A in the United States

Background

US patients with hemophilia A can receive prophylaxis with extended half-life recombinant factor VIII (rFVIII) products, including efmoroctocog alfa (fragment crystallizable fusion protein) and rurioctocog alfa pegol (antihemophilic factor [recombinant], PEGylated).

Objective

To evaluate dosing patterns and weekly consumption of extended half-life rFVIII products in the United States.

Methods

We performed a retrospective analysis using the US Specialty Pharmacy Database (2015–2018). Included patients had a diagnosis of hemophilia A, ≥2 consecutive monthly claims for efmoroctocog alfa or rurioctocog alfa pegol for prophylaxis, and weight data. Outcome measures included weekly dosing frequency and dispensed weekly dose.

Results

The analysis included 774 patients (efmoroctocog alfa, 506; rurioctocog alfa pegol, 268). Mean (SD) age was 24.2 (15.8) and 26.3 (14.9) years for patients receiving efmoroctocog alfa and rurioctocog alfa pegol, respectively; mean (SD) weight was 68.4 (36.8) and 79.8 (37.7) kg, respectively. The most frequent efmoroctocog alfa regimen was twice weekly (45.7%), followed by every 4 days (20.6%), every 3 days (9.1%), and 3 times per week (7.5%). The most frequent rurioctocog alfa pegol regimen was twice weekly (72.4%), followed by 3 times per week (8.7%), every 4 days (7.6%), and every 3 days (5.5%). The proportion of efmoroctocog alfa twice-weekly dispensing records increased from 31.5% to 50.9%, and every 4 days dispensing records decreased from 31.3% to 14.5% (2015–2018). The proportion of rurioctocog alfa pegol dispensing records remained broadly stable (2016–2018). Overall, mean (SD; median) weekly prophylactic dose was 105.4 (77.9; 92.6) IU/kg with efmoroctocog alfa, and 96.8 (41.9; 90.9) IU/kg with rurioctocog alfa pegol.

Conclusion

In this database study, the most frequently observed dosing frequency was twice weekly for patients receiving efmoroctocog alfa or rurioctocog alfa pegol. The observed mean weekly consumption was slightly higher, and variation was greater, in patients receiving efmoroctocog alfa versus rurioctocog alfa pegol.

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.

Advances in Hemophilia A Management

Hemophilia A is an inherited insufficiency of Factor VIII (FVIII), one of the critical clotting factors. The gold standard for the management of moderate-to-severe hemophilia A is prophylaxis using regular replacement therapy with clotting factor concentrates. Compared with conventional treatment, extended half-life products reduce the burden of frequent factor replacement injections. Of note, up to 30% of patients with hemophilia A receiving prophylactic factor infusions develop "inhibitors," neutralizing anti-FVIII autoantibodies. Therapeutic options for patients with hemophilia A and inhibitors include the immune tolerance induction (ie, eradication of inhibitors) and the management of acute bleeds with bypassing agents and/or emicizumab. Emicizumab is a biphasic monoclonal antibody mimicking activated FVIII, approved for patients with hemophilia A with/without inhibitors. Gene therapy is an emerging therapy for hemophilia A, essentially curing patients with hemophilia A or transforming them to a milder phenotype by establishing continuous endogenous expression of FVIII after one-time treatment.

Thromboelastography and thrombin generation assessments for pediatric severe hemophilia A patients are highly variable and not predictive of clinical phenotypes

Background

Severe hemophilia A (SHA) patients vary in severity of bleeding, arthropathy, and requirements for replacement factor VIII (FVIII). Baseline hemostatic activity assays using calibrated automated thrombography (CAT) and thromboelastography (TEG) may offer insights into the physiological basis of clinical heterogeneity.

Objectives

Use CAT and TEG to measure baseline hemostatic activity in a cohort of 30 pediatric SHA patients with available clinical data. Determine effect of contact activation inhibition with corn trypsin inhibitor (CTI). Assess heterogeneity among patients for baseline hemostatic activity and examine correlations between assay results and clinical parameters including FVIII dosing regimen, von Willebrand factor level, and Pettersson arthropathy score.

Methods

SHA blood after FVIII washout was subjected to TEG, and platelet-rich (PRP) and platelet-poor plasma was used for CAT assays. Varying concentrations of tissue factor (TF) were used. Statistical analysis examined relationships between assay results, and clinical parameters.

Results

CTI treatment was required to obtain TEG and CAT results representative of baseline hemostatic activity. Weak activity was observed in assays with low TF concentrations (0.5-2 pM), and most but not all samples approached normal activity levels at high TF concentrations (10-20 pM). A significant positive correlation was observed between results of TEG and CAT-PRP assays. Correlations were not detected between hemostatic assay results and clinical parameters.

Conclusions

In vitro hemostatic assay results of samples containing platelets showed concordance. Assay results were not predictive of FVIII requirements or correlated with other clinical parameters. SHA patient heterogeneity is influenced by factors other than baseline hemostatic activity.

Prevalence of pain in adult patients with moderate to severe haemophilia: a systematic review

OBJECTIVES

Patients with haemophilia (PwH) often suffer from joint pain due to repetitive haemarthroses and resulting arthropathy. Literature focuses so far on pain causes, diagnosis or treatment. A summary of prevalence rates, providing facts on the absolute occurrence of pain, is not sufficiently described so far. This review aimed to explore and systematically review different pain conditions, focussing on prevalence rates of pain in adult PwH.

METHODS

A review of English articles using PubMed and Web of Science was conducted in February 2020. The search strategy included patients with haemophilia A or B suffering from pain. The articles were selected based on defined PICOS-selection criteria.

RESULTS

Out of 606 identified articles, 13 studies matched the given eligibility criteria and indicated pain prevalence rates. The weighted mean (WM) for the prevalence rate (varying timeframes) for chronic pain was 40% whereas for point prevalence the rate was WM=75%. Regarding pain intensity, findings of the EQ-5D-3L revealed moderate pain to be more present (61.0%) compared to extreme (11.6%). The main problem was the inconsistency of the definition of both acute and chronic pain as well as for prevalence types.

CONCLUSIONS

Pain is a major problem in patients with haemophilia. Pain therapy should be carried out taking into account the difference between bleeding-related or arthropathy-related causes of pain. In addition, the intensity and duration of pain should be recorded consistently to better monitor therapy and allow comparison with existing data.

Efanesoctocog alfa elicits functional clot formation that is indistinguishable to that of recombinant factor VIII

BACKGROUND

Factor VIII (FVIII) binding to endogenous von Willebrand factor (VWF) has constrained half-life extension of recombinant FVIII (rFVIII) products for hemophilia A. Efanesoctocog alfa (rFVIIIFc-VWF-XTEN; BIVV001) is a novel fusion protein designed to decouple FVIII from VWF in circulation and maximize half-life prolongation by XTEN® polypeptides and Fc fusion. FVIII, VWF, and platelets interact to achieve normal hemostasis. Thus, bioengineered FVIII replacement products, such as efanesoctocog alfa, require comprehensive assessment of their hemostatic potential.

OBJECTIVES

We compared functional clot formation and injury-induced platelet accumulation between efanesoctocog alfa and rFVIII.

PATIENTS/METHODS

The hemostatic potential of efanesoctocog alfa and rFVIII were assessed by measuring their dose-dependent effects on in vitro fibrin generation in hemophilic plasma and in vivo injury-induced platelet accumulation using intravital microscopy and repeat saphenous vein laser-induced injuries in hemophilia A mice.

RESULTS

Equal concentrations of efanesoctocog alfa or rFVIII (up to 1 IU/ml) added to plasma from patients with hemophilia A elicited similar kinetics for dose-dependent fibrin polymerization between factor products. In the presence of tissue plasminogen activator (tPA), clots formed had similar stability between products. Single intravenous doses (50, 100, or 150 IU/kg) of efanesoctocog alfa or rFVIII shortly before repeat saphenous vein laser-induced injuries increased platelet accumulation over time in a dose-dependent manner in hemophilia A mice. Platelet deposition kinetics were similar between products.

CONCLUSIONS

Equivalent doses of efanesoctocog alfa and rFVIII had similar efficacy in promoting fibrin clot formation and injury-induced platelet accumulation. The hemostatic potential of efanesoctocog alfa was indistinguishable from that of rFVIII.

Analysis of pooled real-world data from Germany, Italy, and the United States of rVIII-SingleChain compared with standard- and long-acting FVIII products for prophylaxis of hemophilia A

OBJECTIVE

To evaluate real-world annualized bleeding rates (ABRs), dosing frequency, and factor consumption of four recombinant FVIII (rFVIII) products using pooled data from centers in the US, Germany, and Italy.

METHODS

De-identified patient medical chart data were collected from 48 hemophilia treatment centers in the US, Germany, and Italy. Patients included in this analysis had hemophilia A and were treated with rVIII-SingleChain, rFVIIIFc, octocog alfa, or BAY 81-8973 for ≥12 weeks. Where possible, patient selection considered age and disease severity in order to balance patient groups across products. Summary statistics were presented descriptively by product for dosing frequency, consumption, ABR/annualized spontaneous bleeding rate (AsBR), and corresponding percentage of patients with zero bleeds. Logistic regression was performed for patients with zero bleeds or zero spontaneous bleeds (vs. patients with any such bleeds). Generalized linear model regression was performed for ABR, AsBR, and consumption. All regression models included the product variable for comparison as well as additional independent variables for adjustment (age, weight, severity, and country for the consumption model, with the addition of consumption for the bleeding outcomes models).

RESULTS

Overall, 616 patients were included (rVIII-SingleChain, n = 129; rFVIIIFc, n = 159; octocog alfa, n = 181; BAY 81-8973, n = 147). Dosing frequency was ≤2 times a week for 65.9%, 75.5%, 25.4%, and 40.1% of patients treated with rVIII-SingleChain, rFVIIIFc, octocog alfa, and BAY 81-8973, respectively. ABRs were not significantly different among products, with mean (median) values of 1.1 (0.0), 1.0 (0.0), 1.4 (1.0), and 1.9 (1.0) for rVIII-SingleChain, rFVIIIFc, octocog alfa, and BAY 81-8973, respectively. The percentage of patients with zero bleeds was comparable between rVIII-SingleChain and rFVIIIFc (59.7% vs. 62.3%; p =.916) and significantly higher for rVIII-SingleChain compared with octocog alfa (p <.001) and BAY 81-8973 (p =.003). Comparison of mean weekly consumption showed: rVIII-SingleChain (83.0 IU/kg/week) vs. rFVIIIFc (96.9; p =.055) and significantly lower for rVIII-SingleChain vs. octocog alfa (108.6; p <.001) and BAY 81-8973 (104.3; p =.001). The median values for weekly consumption were 85.7, 90.1, 100.1, and 98.5 IU/kg/week for rVIII-SingleChain, rFVIIIFc, octocog alfa, and BAY 91-8973, respectively. Similar trends were observed for all outcomes when analyzing the subgroups of patients aged ≥12 years and patients with severe disease (all age and ≥12 years).

CONCLUSIONS

rVIII-SingleChain prophylaxis may provide improved bleed protection, less frequent dosing, and lower consumption compared with standard-acting FVIII products, and comparable protection and consumption to the other long-acting FVIII product, in patients with hemophilia A.

Treatment Individualization Using Pharmacokinetic Studies and Joint Ultrasound Imaging in Pediatric Patients With Hemophilia

Hemophilia is characterized by bleeding diathesis, primarily affecting the joints. Prophylactic use of missing factor aims at limiting the number of bleeds and, in the long term, the risk of permanent joint damage. However, standard prophylactic regimens are usually applied empirically, not adjusting for variations in bleeding phenotype or drug metabolism. Aim of the present study was to evaluate the need for individualizing prophylaxis, with guidance of pharmacokinetic (PK) studies and joint ultrasound in a setting of everyday clinical practice. To evaluate adequacy of applied regimens, joint status was assessed using the Hemophilia Joint Health Score as well as ultrasound imaging, while PK studies were performed using the Web-Accessible Population Pharmacokinetic Service-Hemophilia. Imaging results were consistent with early joint damage in a large proportion of pediatric patients, whereas PK measures were indicative of inadequate prophylaxis in many cases-despite the limited number of bleeds reported by patients. The study revealed the need for prophylaxis adjustment in the majority of patients. Real world data confirm that traditional prophylaxis is often unable to achieve therapeutic goals, while an individualized approach, guided by the use of novel modalities, may be of great benefit to young hemophilia patients.

Associated comorbidities, healthcare utilization & mortality in hospitalized patients with haemophilia in the United States: Contemporary nationally representative estimates

INTRODUCTION

Current in-hospital burden and healthcare utilization patterns for persons with haemophilia (PWH) A and B, including both children (ages < 18 years) and adults (ages ≥ 18 years), in the United States (US) are lacking.

AIM

To evaluate healthcare utilization, the prevalence of comorbidities, and mortality in hospitalized paediatric and adult PWH using a contemporary nationally representative cohort.

METHODS

Hospitalizations of PWH either as the primary reason for admission (principal diagnosis) or one of all listed diagnoses were identified using ICD-10 codes from the 2017 Nationwide Inpatient Sample (NIS), the largest publicly available all-payer inpatient discharge database in the US. Sampling weights were applied to generate nationally representative estimates.

RESULTS

The contemporary cohort included 10,555 hospitalizations (paediatrics, 18.3%; adults, 81.7%) among PWH as one-of-all listed diagnoses (n = 1465 as principal diagnosis). Median age (interquartile range) was 46 (24-66) years overall; adults, 54 (35-70) years and paediatric, 4 (1-11). The most common comorbidities in adults were hypertension (33.4%), hyperlipidaemia (23.6%), and diabetes (21.1%). In children, hemarthrosis (11.4%), contusions (9.6%), and central line infections (9.3%) were the most common. The overall mortality rate was 2.3%. Median hospital charges per haemophilia admission were $52,616 ($24,303-$135,814) compared to $26,841 ($12,969-$54,568) for all-cause admissions in NIS.

CONCLUSION

Bleeding and catheter-related infections are the significant reasons for paediatric haemophilia admissions. Adult haemophilia admissions tend to be associated with age-related comorbidities. Costs for haemophilia-related hospitalizations are higher than the national average for all-cause hospitalizations.

Patient-derived assessment tool using musculoskeletal ultrasound for validation of haemarthrosis

INTRODUCTION

Haemophilia patients experience painful joint episodes which may or may not be associated with haemarthrosis. We sought to validate a questionnaire developed by the Canadian Haemophilia Society using point-of-care musculoskeletal ultrasound (POC MSKUS) to confirm haemarthrosis.

METHODS

The questionnaire comprised of 20 questions (10 each associated with haemarthrosis and arthritis pain) and was administered to adult haemophilia patients reporting to the Haemophilia Treatment Centre (University of California San Diego). We confirmed the presence (or absence) of haemarthrosis using POC MSKUS [Joint Activity and Damage Exam (JADE)]. We fitted univariate and multivariate generalized estimating equations to identify symptoms associated with haemarthrosis.

RESULTS

We evaluated 79 painful episodes in 32 patients [median age = 38 years (range 21-74)]. POC MSKUS detected haemarthrosis in 36 (46%) episodes. The strongest predictor for haemarthrosis pain was 'like a balloon swelling with water' (odds ratio [OR] 2.88 [CI .68;12.10]); 'no feeling of sponginess with movement' (OR .24[CI .07;.76]) was the strongest for arthritic pain. We identified four questions with the strongest OR for differentiating haemarthrosis pain from arthritic pain to develop an algorithm for haemarthrosis prediction. Answering these questions in "yes/no" fashion yielded estimates of the probability of haemarthrosis CONCLUSION: Objective diagnosis of haemarthrosis by MSKUS facilitated the development of a symptom-based prediction tool for diagnosis of haemarthrosis. The tool requires further validation and will be particularly helpful in situations where MSKUS is not readily available.

Prolonged α-thrombin-related activation and delayed active protein C-associated degradation confer mild phenotype in a patient with severe hemophilia A with F8 p.H118R

In hemophilia A, bleeding mostly correlates with factor VIII activity (FVIII:C), although some patients show discrepancy in bleeding severity and FVIII:C. We report a novel procoagulant mechanism associated with F8 p.H118R (c.353A > G) in a young Japanese man with few bleeding episodes despite low levels of FVIII:C (< 1 IU/dL). Plasma FVIII:C was < 1 IU/dL measured by one-stage clotting assay (OSA) and chromogenic substrate assay (CSA), whereas FVIII antigen (FVIII:Ag) was 9.7%. The global coagulation assay showed higher max speed in clot waveform analysis (CWA), shorter clotting time in rotation thromboelastometry (ROTEM) (1605 vs. > 5000 s), shorter lag time (4.87 vs. 12.47 min) and larger ETP (207.9 vs. 53.3 nM*min) in thrombin generation assay, compared with FVIII-deficient control. Expressed recombinant H118R mutant in culture media showed low FVIII:C (1-5 IU/dL) by OSA, with non-hemophilia level of FVIII:Ag. Western blot analysis using recombinant H118R showed longer persistence of heavy-chain of H118R after incubation with α-thrombin, compared with wild-type. Incubation of H118R with activated protein C (APC) also showed longer persistence of A1-A2 domain. In conclusion, H118R showed prolonged activation by α-thrombin and delayed APC-related FVIII degradation. These properties may confer the procoagulant activity and few bleeding episodes despite low FVIII:C.

LongHest project: A prospective, observational study of extended half-life treatment in the musculoskeletal health of patients with severe haemophilia A

Background

Prophylactic treatment is the gold standard in the treatment of patients with haemophilia. Prophylaxis with extended half‐life (EHL) treatment has shown long‐term safety and efficacy in patients with haemophilia.

Aim

To evaluate the efficacy of prophylaxis with EHL treatment in the frequency of haemarthrosis and musculoskeletal health in adult patients with severe haemophilia A.

Methods

Prospective cohort study. Forty‐six patients with severe haemophilia A were recruited. The frequency of haemarthrosis (self‐reports), joint condition (Haemophilia Joint Health Score), pain intensity (visual analogue scale), range of motion (goniometry), and strength (dynamometry) and muscle activation (surface electromyography) were evaluated. Three assessments were carried out: at baseline (T0), at 6 months (T1) and at 12 months following treatment (T2).

Results

There were significant changes in the within‐subject effect in the frequency of haemarthrosis in elbow (F(1.05;96.20) = 3.95; P < .001) and knee (F(1.73;157.99) = 9.96; P < .001). Significant within‐subject effect in elbow pain intensity (F(2;182) = 63.51; P < .001) was found. The mean values of the frequency haemarthrosis in elbow (from .66±1.01 to .04±.20) and knees (from .55±.68 to .33±.53) decrease after the period study. The intensity of elbow pain and (from 3.08±1.69 to 2.67±1.73), decrease after the 12‐month follow‐up period.

Conclusions

Prophylaxis with extended half‐life treatment reduces the frequency of haemarthrosis in elbow and knee in adult patients with haemophilia. EHL treatment reduces the intensity of elbow pain in patients with haemophilic arthropathy.

Pharmacokinetic profile of children with haemophilia A receiving low-dose FVIII prophylaxis in Indonesia: A single centre experience

BACKGROUND

Pharmacokinetic (PK) studies of low-dose prophylaxis (LDP) of coagulation factor VIII (FVIII) in children with severe haemophilia A (SHA) are scarce.

OBJECTIVE

This study aims to investigate the PK profile of children with SHA receiving LDP of FVIII.

METHODS

Paediatric patients receiving FVIII infusions (10 IU/kg twice weekly) were included. PK profiles were estimated using the Web Accessible Population Pharmacokinetic Service for Haemophilia (WAPPS-Haemo). The primary outcomes were the terminal half-life (t_1/2 ), concentration-time profile, and time to reach an FVIII level of < 1%. The secondary outcome was the suggested dosing interval of FVIII prophylaxis based on the individual PK profile.

RESULTS

Twenty-five patients were recruited; their mean age was 12.3 ± 3.0 years. The t_1/2 differed among patients receiving LDP of FVIII twice weekly, with a median of t_1/2 was 14.8 h (IQR 12.6-16). The median time to reach an FVIII level of < 1% was 73.8 h (IQR 58.8-80.3). Most patients could maintain a trough level of FVIII > 1% longer than 48 h. At 72-96 h, patients needed a second dose of FVIII infusion because the FVIII level was < 1%. The suggested dosing interval of FVIII prophylaxis ranged from daily to every 96 h, depending on the individual PK profile.

CONCLUSION

Our study identified inter-individual differences in the PK parameters using LDP of FVIII twice weekly. The inter-individual results in different dosing intervals advise the timing of LDP. Estimating individual PK parameters enables the identification of the optimal prophylaxis frequency to prevent bleedings.

Bleeding in patients with hemophilia who have inhibitors: Modeling US medical system utilization and cost avoidance between recombinant factor VIIa products with different clinical dosing requirements

BACKGROUND: A mainstay of treatment in patients with hemophilia with inhibitors (PWIs) is the use of a recombinant factor VIIa (rFVIIa) bypassing agent. A new rFVIIa product may allow reduced rFVIIa utilization for on-demand treatment of bleeding episodes (BEs). OBJECTIVE: A decision analytic health economic model was developed to compare the utilization and consequent need for bleed-related clinical encounters of 2 rFVIIa products, with the International Nomenclature Name of eptacog alfa (EA) and eptacog beta (EB). METHODS: This study uses recent, peer-reviewed, and published data from clinical trials with similar endpoints for 1 million insured male lives in the United States. rFVIIa product utilization was modeled in hemophilia (A and B) PWI for on-demand treatment of BEs with rFVIIa treatment. Estimated annual BE rates were modeled to include prophylaxis and on-demand management. The clinical encounter avoidance estimates are based on refractory bleeding through 24 hours. RESULTS: In a cohort of 1 million insured, 5-6 patients with hemophilia A or B with inhibitors annually receive on-demand treatment for a total of 59 mild/moderate BEs. The model suggests that EB requires less unit utilization per BE (13,125 μg and 17,850 μg for the 75μg/kg and 225μg/kg dose regimens, respectively) than EA 90 μg/kg dosing (20,178μg), with wholesale acquisition costs expanding the difference. Further, both EB initial dose regimens would permit decreased total nonmedication health plan spending for the acute treatment of BEs by reducing the need for clinical encounters arising from BEs that fail to respond within 24 hours. CONCLUSIONS: With reduced infusion requirements, the model consistently shows that EB could generate lower insured-cohort drug utilization, as well as reduce costly clinical encounters by keeping mild and moderate BEs amenable to home bypassing agent management. DISCLOSURES: The article was funded by HEMA Biologic, LLC. The authors approved all content and results in this article without being subject to sponsor censorship. Mr Jensen, Mr Cyr, and Ms Hathway are employees of PRECISIONheor, which provides consulting services to the pharmaceutical industry, including HEMA Biologics, LLC. Dr Batt is an advisor to PRECISIONheor. Dr Alexander is a former employee of HEMA Biologics, LLC, and provides consulting services to the pharmaceutical industry.