Effect of low-dose factor VIII prophylaxis therapy on bone mineral density and 25(OH) vitamin D level in children with severe haemophilia A

Simoctocog alfa (Nuwiq®) in children: early steps in life's journey for people with severe hemophilia A

People with severe hemophilia A usually experience their first bleed early in life. In children with severe hemophilia A, primary prophylaxis is recommended to prevent recurrent and potentially life-threatening bleeds that significantly impact day-to-day life. Factor VIII (FVIII) prophylaxis is well-established in children and has been shown to reduce the development of hemophilic arthropathy. However, a major challenge of FVIII therapy is the development of neutralizing anti-FVIII antibodies (FVIII inhibitors). Simoctocog alfa (Nuwiq®) is a human cell line-derived recombinant FVIII (rFVIII) whose immunogenicity, efficacy, and safety have been studied in 167 children with severe hemophilia A across two prospective clinical trials and their long-term extensions. In 105 previously untreated children, the inhibitor rate of 16.2% for high-titer inhibitors (26.7% for all inhibitors) was lower than published rates for hamster cell line-derived rFVIII products. There was no inhibitor development in previously untreated children with non-null F8 mutations and in previously treated children. In a case series of 10 inhibitor patients, 8 (80%) underwent successful immune tolerance induction with simoctocog alfa with a median time to undetectable inhibitor of 3.5 months. In an analysis of 96 children who enrolled in the extension studies and received long-term simoctocog alfa prophylaxis for up to 5 years, median spontaneous, joint, and total annualized bleeding rates were 0.3, 0.4, and 1.8, respectively. No thromboembolisms were reported in any of the 167 children, and there were no treatment-related deaths. Optimal care of children should consider several factors, including minimization of inhibitor development risk, maintaining tolerance to FVIII, highly effective bleed prevention and treatment, safety, and impact on long-term outcomes such as bone and joint health. In this context we review the pediatric clinical data and ongoing studies with simoctocog alfa.

Targeting higher factor VIII levels for prophylaxis in haemophilia A: a narrative review

INTRODUCTION

The standard of care in severe haemophilia A is prophylaxis, which has historically aimed for a factor VIII (FVIII) trough level of ≥1%. However, despite prophylactic treatment, people with haemophilia remain at risk of bleeds that have physical and quality of life implications, and that impact everyday life.

AIM

The aim of this review was to evaluate evidence supporting the relationship between targeting higher FVIII activity levels with prophylaxis and improved outcomes in people with haemophilia A.

METHODS

We conducted a narrative review that defined the unmet needs and treatment goals in people with haemophilia A, evaluated evidence to support targeting higher FVIII activity levels, and highlighted therapies that may support higher and sustained FVIII activity levels and improved outcomes for people with haemophilia A.

RESULTS

Despite recent advances in treatment, unmet needs remain, and people with haemophilia continue to experience joint and functional impairment, acute and chronic pain, and poor mental health. All these negatively impact their health-related quality of life. Evidence suggests that FVIII activity levels of up to 50% may be needed to achieve a near-zero joint bleed rate. However, achieving high FVIII activity levels with current standard and extended half-life (EHL) FVIII replacement therapies is associated with a high treatment burden. Innovative treatment options may provide high sustained FVIII activity levels and improved patient outcomes.

CONCLUSION

Evidence suggests that FVIII activity levels in people with haemophilia A should be sustained at higher levels to improve joint and patient outcomes and enable progression towards health equity.

Long-term immunogenicity, efficacy and tolerability of simoctocog alfa in patients with severe haemophilia A who had completed the NuProtect study in previously untreated patients

BACKGROUND

The NuProtect study reported data on the immunogenicity, efficacy and tolerability of simoctocog alfa (Nuwiq^® ) in 108 previously untreated patients with severe haemophilia A planned to be treated for ≥100 exposure days or up to 5 years. The NuProtect-Extension study collected long-term prophylaxis data in children with severe haemophilia A.

METHODS

Patients who completed the NuProtect study according to the protocol were eligible for the NuProtect-Extension study, a prospective, multinational, non-controlled, Phase 3b study.

RESULTS

Of 48 patients who entered the extension study, 47 (median age 2.8 years) received prophylaxis with simoctocog alfa for a median of 24 months, with 82%-88% on a twice-weekly or less regimen. No patient developed FVIII inhibitors during the extension study. The median (IQR) annualized bleeding rate (ABR) during prophylaxis was 0 (0-0.5) for spontaneous bleeding episodes (BEs) and 1.00 (0-1.95) for all BEs. ABRs estimated using a negative binomial model were .28 (95% CI: .15, .53) for spontaneous and 1.62 (95% CI: 1.09, 2.42) for all BEs. During the median follow-up of 24 months, 34 (72%) patients had zero spontaneous BEs and 46 (98%) had zero spontaneous joint BEs. Efficacy in treating BEs was excellent or good for 78.2% of rated BEs, and efficacy of surgical prophylaxis was excellent for two rated surgeries. No treatment-related adverse events were reported.

CONCLUSION

No FVIII inhibitors developed during long-term prophylaxis in the NuProtect-Extension study. Prophylaxis with simoctocog alfa was efficacious and well-tolerated, and is therefore an attractive long-term option for children with severe haemophilia A.

Haemophilia and Fragility Fractures: From Pathogenesis to Multidisciplinary Approach

Haemophilia A (HA) and haemophilia B (HB) are X-linked inherited bleeding disorders caused by the absence or deficiency of coagulation factors VIII (FVIII) and IX (FIX), respectively. Recent advances in the development of effective treatments for haemophilia have led to a significant increase in life expectancy. As a result, the incidence of some comorbidities, including fragility fractures, has increased in people with haemophilia (PWH). The aim of our research was to perform a review of the literature investigating the pathogenesis and multidisciplinary management of fractures in PWH. The PubMed, Scopus and Cochrane Library databases were searched to identify original research articles, meta-analyses, and scientific reviews on fragility fractures in PWH. The mechanism underlying bone loss in PWH is multifactorial and includes recurrent joint bleeding, reduced physical activity with consequent reduction in mechanical load, nutritional deficiencies (particularly vitamin D), and FVIII and FIX deficiency. Pharmacological treatment of fractures in PWH includes antiresorptive, anabolic and dual action drugs. When conservative management is not possible, surgery is the preferred option, particularly in severe arthropathy, and rehabilitation is a key component in restoring function and maintaining mobility. Appropriate multidisciplinary fracture management and an adapted and tailored rehabilitation pathway are essential to improve the quality of life of PWH and prevent long-term complications. Further clinical trials are needed to improve the management of fractures in PWH.

Osteoporosis management and falls prevention in patients with haemophilia: Review of haemophilia guidelines

INTRODUCTION

Patients with haemophilia (PWH) have a high prevalence of osteoporosis, falls and fractures at all ages. The role of haemophilia itself may contribute to low bone mineral density (BMD) due to coagulation factor deficiency. Guidelines for the management of osteoporosis, fracture and fall risk may help to reduce fracture and fall risk, and delay osteoporosis onset.

AIM

We aim to review current haemophilia guidelines regarding osteoporosis prevention, screening, diagnosis and management, and fall prevention.

METHOD

A database search (Ovid MEDLINE) revealed two haemophilia guidelines (World and British) published within the last ten years. Local Australian haemophilia guidelines were identified through a manual search.

RESULTS

All haemophilia guidelines were found to contain inadequate recommendations for osteoporosis management and fall prevention due to a lack of evidence in the literature.

CONCLUSION

Further studies are required to assess the trajectory of bone health in PWH, the mechanism of bone loss in PWH, and the effectiveness of weight-bearing exercises, interventions for fall prevention, screening programmes, and use of anti-osteoporosis medications in PWH across the lifecourse.

Low Bone Mineral Density in Hemophiliacs

Objective

To review the current knowledge on bone health in patients with hemophilia A and the underlying pathogenetic mechanisms.

Data Sources

Original research articles, meta-analyses, and scientific reviews.

Data Synthesis

Already in childhood, patients with hemophilia A are prone to low bone mineral density, leading to osteopenia and/or osteoporosis. Initially associated with the life style of hemophilia, today we are faced with accumulating evidence that coagulation factor VIII is involved directly or indirectly in bone physiology.

Conclusion

Understanding the role of factor VIII and the mechanisms of decreased bone mineral density in hemophilia A is critically important, especially as non-factor replacement therapies are available, and treatment decisions potentially impact bone health.

A Delphi Consensus Approach for Difficult-to-Treat Patients with Severe Hemophilia A without Inhibitors

Introduction

Over the past decade, there has been an increase in novel therapeutic options to treat hemophilia A. It is still unclear how these novel treatments are used in the management of patients with hemophilia A, particularly those with challenging clinical scenarios who are typically excluded in clinical trials.

Purpose

This study aimed to understand the areas of consensus and disagreement among hematologists regarding the preferences toward therapeutic approaches for difficult-to-treat patients with severe hemophilia A without inhibitors.

Patients and Methods

During February-June 2020, a three-round modified Delphi study was conducted to generate consensus among 13 US experts in the field of hemophilia. Experts were asked about their preferences toward therapeutic options for patients with challenging clinical situations, including age-related morbidities (eg, myocardial infarction, joint arthropathy), increasing demand for high-impact physical activities, early onset osteoporosis, and newborns with hemophilia A. Consensus was defined as ≥75% agreement between the panelists.

Results

Consensus was reached on many, but not all cases, leaving uncertainty about appropriateness of therapeutic approaches for some patients where clinical evidence is not available or driven by physicians' or patients' preferences toward therapeutic options. A majority of panelists preferred FVIII replacement therapy rather than emicizumab prophylaxis for the challenging cases presented due to established evidence on safety, efficacy, and level of bleed protection for FVIII treatment.

Conclusion

Recommendations emerging from this study may help guide practicing hematologists in the management of challenging hemophilia A cases. Future studies are needed to address treatment options in the clinical cases where no consensus was reached.

Design of an international investigator-initiated study on MOdern Treatment of Inhibitor-positiVe pATiEnts with haemophilia A (MOTIVATE)

Background:

Inhibitor development is the most serious treatment-related complication of replacement coagulation factor VIII (FVIII) therapy for patients with haemophilia A. Immune tolerance induction (ITI), which involves intensive and prolonged treatment with plasma-derived or recombinant FVIII, is the only clinically proven strategy for eradication of inhibitors. The bispecific antibody emicizumab is approved for use in patients with and without inhibitors to prevent bleeding but does not eliminate inhibitors. MOTIVATE (www.motivate-study.com) aims to capture different approaches to the treatment and management of patients with haemophilia A and inhibitors, document current ITI approaches from real-world clinical experience, and evaluate the efficacy and safety of ITI, emicizumab prophylaxis and ITI with emicizumab prophylaxis.

Methods:

The investigator-initiated MOTIVATE study [ClinicalTrials.gov identifier: NCT04023019; EudraCT 2019-003427-38] will investigate in real-life clinical practice the management of patients with haemophilia A of any severity who have developed inhibitors to FVIII. All treatment is at the investigator’s discretion. The following treatment approaches will be evaluated: Group 1 – ITI with Nuwiq^®, octanate^® or wilate^® and aPCC/rFVIIa if needed to treat bleeding episodes (BEs) or during surgery or for prophylaxis; Group 2 – ITI with Nuwiq^®, octanate^® or wilate^® and emicizumab prophylaxis and aPCC/rFVIIa if needed to treat BEs or during surgery; Group 3 – routine prophylaxis with emicizumab, aPCC or rFVIIa without ITI and aPCC/rFVIIa if needed to treat BEs or during surgery. Patients will not be randomised to a treatment group and may change groups during the study.

Conclusions:

It is planned to enrol 120 patients who will be followed for up to 5 years. Optional sub-studies will explore factors that may influence ITI results as well as the impact of different treatment approaches on important aspects of patient health, including joint and bone health and the risk of thrombotic events.

The Bone Microarchitecture Deficit in Patients with Hemophilia Is Influenced by Arthropathy, Hepatitis C Infection, and Physical Activity

Low bone mineral density (BMD) is common in patients with hemophilia (PWHs). The aim of the present study was to describe BMD and microarchitecture in PWHs in Northern Germany and to determine factors contributing to possible skeletal alterations. Demographic characteristics, BMD and microarchitecture, bone metabolism markers, and orthopaedic joint score (OJS) were assessed during routine check-ups. Areal BMD was assessed by dual-energy X-ray absorptiometry (DXA) at the hip and lumbar spine. Volumetric BMD and microarchitecture were quantified by high-resolution peripheral quantitative computed tomography at the distal radius and tibia. Eighty male PWHs (median age, 33 years; range, 18-77) were retrospectively analyzed, of whom 67 (84.0%) and 13 (16.0%) had hemophilia A and B, respectively. Fifty-four (68.0%), six (7.0%), and 20 (25.0%) patients had severe, moderate, or mild hemophilia, and 35 (44.0%) were hepatitis C virus (HCV) positive. DXA analysis revealed low BMD (Z-score ≤ - 2.0) in 27.5% of PWHs, and higher bone turnover values were associated with lower BMD. Bone microarchitecture was dominated by cortical deficits at the radius and trabecular deficits at the tibia. Cortical deficits at the radius were influenced by lower body mass index, low-grade inflammation, and treatment regimen (higher cortical thickness on primary prophylaxis). Trabecular alterations at the tibia were mainly associated with OJS and HCV status. A positive effect of self-reported sportive activity on BMD could be shown. In conclusion, our findings demonstrate that the site-specific microarchitectural deficit observed in PWHs is primarily negatively influenced by poor joint status, inflammation, HCV infection, and high bone turnover.

FVIII at the crossroad of coagulation, bone and immune biology: Emerging evidence of biological activities beyond hemostasis

Hemophilia A is an X-linked hereditary disorder that results from deficient coagulation factor VIII (FVIII) activity, leading to spontaneous bleeding episodes, particularly in joints and muscles. FVIII deficiency has been associated with altered bone remodeling, dysregulated macrophage polarization, and inflammatory processes that are associated with the neoformation of abnormal blood vessels. Treatment based on FVIII replacement can lead to the development of inhibitors that render FVIII concentrate infusion ineffective. In this context, hemophilia has entered a new therapeutic era with the development of new drugs, such as emicizumab, that seek to restore the hemostatic balance by bypassing pathologically acquired antibodies. We discuss the potential extrahemostatic functions of FVIII that may be crucial for defining future therapies in hemophilia.

Factor VIII replacement prophylaxis in patients with hemophilia A transitioning to adults: a systematic literature review

BACKGROUND

Despite the advantages of prophylactic treatment for hemophilia, patients tend to discontinue or not adhere to it because of several challenges such as long-term use, high cost, young patients transitioning to adolescents, and switch to self-infusion or self-care. The goal of this systematic literature review is to emphasize adherence to and efficiency of prophylactic treatment in adults.

METHODS

A literature review was conducted in PubMed, Embase, and Cochrane databases until April 2021 according to PRISMA guidelines, and the protocol was registered with PROSPERO (CRD42020220085). Studies evaluating the efficacy of prophylaxis in enhancing the quality of life were included.

RESULTS

A total of 31 articles involving 2379 patients with hemophilia were included in this systematic review. Of these, 26 studies were observational, questionnaire-based studies, and 5 were randomized controlled trials. The majority of studies reported lower annualized bleeding rates in patients receiving prophylaxis compared with those receiving on-demand treatment or those who discontinued prophylaxis. Standard-dose prophylaxis was reported to be effective in most of the studies. In developing countries like China, data suggest that low doses were administered because of limited available resources. However, standard dose or individualized prophylaxis should be provided to prevent joint damage in the long term. Compared with adults, greater adherence to treatment was observed in patients aged < 16 years.

CONCLUSION

This systematic review emphasizes the importance of adherence to prophylaxis among young adults transitioning from childhood. In countries like China, low-dose prophylaxis can help in preventing joint bleeds in the short term, but in the long term, standard-dose therapy has shown high adherence among young adults and better joint health, in turn improving the quality of life.

Asymptomatic Joint Bleeding and Joint Health in Hemophilia: A Review of Variables, Methods, and Biomarkers

Joint health is a key contributor to quality of life in patients with hemophilia. However, variables that impact long-term joint outcomes have not been comprehensively defined. A systematic literature search identified publications relating to joint health in patients with hemophilia. Studies clearly show that early, sustained prophylaxis with factor replacements improves long-term joint outcomes. However, a subset of patients appear to develop arthropathy despite maintaining excellent bleeding outcomes, which suggests possible recurrent asymptomatic bleeding into the joints in these patients. Furthermore, limited data are available on how long-acting factor VIII and factor IX replacement therapies could impact long-term joint outcomes. Many variables were identified as potential indicators that a patient may develop hemophilic arthropathy, including genetic mutations, endogenous factor VIII and IX levels, bone health, and physical activity levels. Tools for the diagnosis and monitoring of hemophilic arthropathy are critical to detect early joint damage, so that management can be adjusted accordingly. Imaging techniques, particularly magnetic resonance imaging, can detect synovial changes, a strong predictor for the future development of hemophilic arthropathy. In addition, several biomarkers associated with cartilage and bone formation, vascularization, and angiogenesis could potentially identify the onset and progression of early joint damage. Since the development of hemophilic arthropathy is complex, a comprehensive therapeutic approach is necessary for the effective prevention of arthropathy in patients with hemophilia.

PHILEOS (haemoPHILia and ostEoporOSis) Study: protocol of a multicentre prospective case-control study

INTRODUCTION

Two meta-analyses showed lower bone mineral density (BMD) in patients with haemophilia (haemophilia type and severity were often not specified) compared with healthy controls. This finding could be related to reduced mobility and sedentary lifestyle, and/or hepatitis C or HIV infection. The aim of this study is to determine osteoporosis prevalence in patients with haemophilia classified in function of the disease type (A or B) and severity, and to evaluate the potential role of regular prophylactic factor replacement (early vs delayed initiation) in preserving or restoring BMD.

METHODS AND ANALYSIS

The haemoPHILia and ostEoporOSis Study is a prospective, controlled, multicentre study that will include patients in France (13 haemophilia treatment centres), Belgium (1 centre) and Romania (1 centre). In total, 240 patients with haemophilia and 240 matched healthy controls will be recruited (1:1). The primary objective is to determine osteoporosis prevalence in patients with severe haemophilia A and B (HA and HB) without prophylaxis, compared with healthy controls. Secondary outcomes include: prevalence of osteoporosis and osteopenia in patients with mild, moderate and severe HA or HB with prophylaxis (grouped in function of their age at prophylaxis initiation), compared with healthy subjects; BMD in patients with HA and HB of comparable severity; correlation between BMD and basal factor VIII/IX levels and thrombin potential; and quantification of plasmatic markers of bone remodelling (formation and resorption) in patients with haemophilia.

ETHICS AND DISSEMINATION

The protocol was approved by the French Ethics Committee and by the French National Agency for Medicines and Health Products Safety (number: 2019-A03358-49). The results of this study will be actively disseminated through scientific publications and conference presentations.

TRIAL REGISTRATION NUMBER

NCT04384341.

Low bone mass and hypovitaminosis D in haemophilia: A single-centre study in patients with severe and moderate haemophilia A and B

INTRODUCTION

Haemophilia (H) is frequently associated with a multifactorial reduction in bone mineral density (BDM), but little is known about possible differences between HA and HB according to their severity.

AIM

To evaluate the association between low bone mineral density (BMD), 25-hydroxyvitamin D [25(OH)D] concentrations and bone turnover markers in patients with HA and HB younger or older than 50 years.

METHODS

In 78 patients <50 years and 33 patients >50 years with severe (S) or moderate (M) HA and HB, BMD was measured by dual-energy X-ray absorptiometry at femoral neck (FN) and lumbar spine and then correlated to annual bleeding rate (ABR), World Federation of Haemophilia orthopaedic joint scale (WFH score), 25(OH)D concentrations, parathyroid hormone (PTH), amino-terminal telopeptide of type 1 collagen (NTx), urinary pyridinolines, osteocalcin and bone-specific alkaline phosphatase.

RESULTS

Overall, a high prevalence of hypovitaminosis D was diagnosed. In patients <50 years, low FN-BMD was significantly more frequent in HA than in HB, while PTH, pyridinolines, ABR and WFH score were associated with H type and severity. In patients >50 years, similarly low FN-BMD was observed in HA and HB, while ABR and WFH score were associated with H type and severity, being milder in HB.

CONCLUSIONS

Low bone mass is a frequent comorbidity in haemophilic patients of all ages, apart from those with MHB. Clinical and laboratory assessments confirm a higher bone impairment and faster bone resorption in HA compared with HB. Looking at H type and severity, MHB seems to have a normal bone metabolism and a less severe disease.