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

Outcome measures in hemophilia: current and future perspectives

INTRODUCTION

Hemophilia can detrimentally affect patients' quality of life and likelihood of survival. In the evolving landscape of therapies, the therapeutic gain of each treatment must be understood to accurately position it in the therapeutic armamentarium. Accordingly, appropriate outcomes must be measured with appropriate tools.

AREAS COVERED

Our narrative review (PubMed search for 'hemophilia AND outcome' until June 2023), provides a compendium of outcome measures used in hemophilia clinical research. To define each outcome measure's relative value and applicability, several characteristics are critically discussed.

EXPERT OPINION

Bleeding assessment, first annual/annualized bleeding rate, remains central in evaluating the efficacy and safety of hemophilia treatments. As modern therapies improve clinical outcomes toward zero bleeding events, this endpoint may become less sensitive to detect differences between therapeutic approaches. Technological advancements necessitate the adaptation of outcome measures to address infrequent bleeding events, age-related comorbidities, and laboratory parameters with limited comparability after different treatments. Considerable effort has been dedicated to the development of tools that comprehensively assess coagulation, such as thrombin generation assays. Patient-reported outcome measures are gaining importance although limited by their subjectivity. A definitive set of research outcome measures remains elusive. Outcomes may need to be tailored to different therapeutic interventions.

[Treatment of haemophilia in Austria]

This guideline is intended to provide practical guidance for the diagnosis and treatment of haemophilia in Austria. Few randomized controlled interventional trials are available addressing the treatment of haemophilia, therefore recommendations are usually based on low level of evidence and represent expert consensus.This guideline is based on the WFH guideline, published in 2020, and adapted according to the national circumstances and experience.It includes recommendations and suggestions for diagnosis and follow-up visits and pharmacological therapies for treatment and prophylaxis. Further topics comprise special aspects in children and adults with severe haemophilia, outcome measurement, and management of trauma, special bleedings and interventions, including dental procedures, inhibitors, management of haemophilia carriers, and psychosocial aspects.

Expert United Kingdom consensus on the preservation of joint health in people with moderate and severe haemophilia A: A modified Delphi panel

AIM

For people with haemophilia A (PwHA), bleeding in the joints leads to joint damage and haemophilia-related arthropathy, impacting range of motion and life expectancy. Existing guidelines for managing haemophilia A support healthcare professionals (HCPs) and PwHA in their efforts to preserve joint health. However, such guidance should be reviewed, considering emerging evidence and consensus as presented in this manuscript.

METHODS

Fifteen HCPs experienced in the management of PwHA in the UK participated in a three-round Delphi panel. Consensus was defined at ≥70% of panellists agreeing or disagreeing for Likert-scale questions, and ≥70% selecting the same option for multiple- or single-choice questions. Questions not reaching consensus were revised for the next round.

RESULTS

26.8% (11/41), 44.8% (13/29) and 93.3% (14/15) of statements reached consensus in Rounds 1, 2 and 3, respectively. HCPs agreed that prophylaxis should be offered to patients with a baseline factor VIII (FVIII) level of ≤5 IU/dL and that, where there is no treatment burden, the aim of prophylaxis should be to achieve a trough FVIII level ≥15 IU/dL and maintain a longer period with FVIII levels of ≥20-30 IU/dL to provide better bleed protection. The aspirational goal for PwHA is to prevent all joint bleeds, which may be achieved by maintaining normalised (50-150 IU/dL) FVIII levels.

CONCLUSION

The panel of experts were largely aligned on approaches to preserving joint health in PwHA, and this consensus may help guide HCPs.

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

INTRODUCTION

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

Non-clotting factor therapies for preventing bleeds in people with congenital hemophilia A or B

BACKGROUND

Management of congenital hemophilia A and B is by prophylactic or on-demand replacement therapy with clotting factor concentrates. The effects of newer non-clotting factor therapies such as emicizumab, concizumab, marstacimab, and fitusiran compared with existing standards of care are yet to be systematically reviewed.

OBJECTIVES

To assess the effects (clinical, economic, patient-reported, and adverse outcomes) of non-clotting factor therapies for preventing bleeding and bleeding-related complications in people with congenital hemophilia A or B compared with prophylaxis with clotting factor therapies, bypassing agents, placebo, or no prophylaxis.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Coagulopathies Trials Register, electronic databases, conference proceedings, and reference lists of relevant articles and reviews. The date of the last search was 16 August 2023.

SELECTION CRITERIA

Randomized controlled trials (RCTs) evaluating people with congenital hemophilia A or B with and without inhibitors, who were treated with non-clotting factor therapies to prevent bleeds.

DATA COLLECTION AND ANALYSIS

Two review authors independently reviewed studies for eligibility, assessed risk of bias, and extracted data for the primary outcomes (bleeding rates, health-related quality of life (HRQoL), adverse events) and secondary outcomes (joint health, pain scores, and economic outcomes). We assessed the mean difference (MD), risk ratio (RR), 95% confidence interval (CI) of effect estimates, and evaluated the certainty of the evidence using GRADE.

MAIN RESULTS

Six RCTs (including 397 males aged 12 to 75 years) were eligible for inclusion. Prophylaxis versus on-demand therapy in people with inhibitors Four trials (189 participants) compared emicizumab, fitusiran, and concizumab with on-demand therapy in people with inhibitors. Prophylaxis using emicizumab likely reduced annualized bleeding rates (ABR) for all bleeds (MD -22.80, 95% CI -37.39 to -8.21), treated bleeds (MD -20.40, 95% CI -35.19 to -5.61), and annualized spontaneous bleeds (MD -15.50, 95% CI -24.06 to -6.94), but did not significantly reduce annualized joint and target joint bleeding rates (AjBR and AtjBR) (1 trial; 53 participants; moderate-certainty evidence). Fitusiran also likely reduced ABR for all bleeds (MD -28.80, 95% CI -40.07 to -17.53), treated bleeds (MD -16.80, 95% CI -25.80 to -7.80), joint bleeds (MD -12.50, 95% CI -19.91 to -5.09), and spontaneous bleeds (MD -14.80, 95% CI -24.90 to -4.71; 1 trial; 57 participants; moderate-certainty evidence). No evidence was available on the effect of bleed prophylaxis using fitusiran versus on-demand therapy on AtjBR. Concizumab may reduce ABR for all bleeds (MD -12.31, 95% CI -19.17 to -5.45), treated bleeds (MD -10.10, 95% CI -17.74 to -2.46), joint bleeds (MD -9.55, 95% CI -13.55 to -5.55), and spontaneous bleeds (MD -11.96, 95% CI -19.89 to -4.03; 2 trials; 78 participants; very low-certainty evidence), but not target joint bleeds (MD -1.00, 95% CI -3.26 to 1.26). Emicizumab prophylaxis resulted in an 11.31-fold increase, fitusiran in a 12.5-fold increase, and concizumab in a 1.59-fold increase in the proportion of participants with no bleeds. HRQoL measured using the Haemophilia Quality of Life Questionnaire for Adults (Haem-A-QoL) physical and total health scores was improved with emicizumab, fitusiran, and concizumab prophylaxis (low-certainty evidence). Non-serious adverse events were higher with non-clotting factor therapies versus on-demand therapy, with injection site reactions being the most frequently reported adverse events. Transient antidrug antibodies were reported for fitusiran and concizumab. Prophylaxis versus on-demand therapy in people without inhibitors Two trials (208 participants) compared emicizumab and fitusiran with on-demand therapy in people without inhibitors. One trial assessed two doses of emicizumab (1.5 mg/kg weekly and 3.0 mg/kg bi-weekly). Fitusiran 80 mg monthly, emicizumab 1.5 mg/kg/week, and emicizumab 3.0 mg/kg bi-weekly all likely resulted in a large reduction in ABR for all bleeds, all treated bleeds, and joint bleeds. AtjBR was not reduced with either of the emicizumab dosing regimens. The effect of fitusiran prophylaxis on target joint bleeds was not assessed. Spontaneous bleeds were likely reduced with fitusiran (MD -20.21, 95% CI -32.12 to -8.30) and emicizumab 3.0 mg/kg bi-weekly (MD -15.30, 95% CI -30.46 to -0.14), but not with emicizumab 1.5 mg/kg/week (MD -14.60, 95% CI -29.78 to 0.58). The percentage of participants with zero bleeds was higher following emicizumab 1.5 mg/kg/week (50% versus 0%), emicizumab 3.0 mg/kg bi-weekly (40% versus 0%), and fitusiran prophylaxis (40% versus 5%) compared with on-demand therapy. Emicizumab 1.5 mg/kg/week did not improve Haem-A-QoL physical and total health scores, EQ-5D-5L VAS, or utility index scores (low-certainty evidence) when compared with on-demand therapy at 25 weeks. Emicizumab 3.0 mg/kg bi-weekly may improve HRQoL measured by the Haem-A-QoL physical health score (MD -15.97, 95% CI -29.14 to -2.80) and EQ-5D-5L VAS (MD 9.15, 95% CI 2.05 to 16.25; 1 trial; 43 participants; low-certainty evidence). Fitusiran may result in improved HRQoL shown as a reduction in Haem-A-QoL total score (MD -7.06, 95% CI -11.50 to -2.62) and physical health score (MD -19.75, 95% CI -25.76 to -11.94; 1 trial; 103 participants; low-certainty evidence). The risk of serious adverse events in participants without inhibitors also likely did not differ following prophylaxis with either emicizumab or fitusiran versus on-demand therapy (moderate-certainty evidence). Transient antidrug antibodies were reported in 4% (3/80) participants to fitusiran, with no observed effect on antithrombin lowering. A comparison of the different dosing regimens of emicizumab identified no differences in bleeding, safety, or patient-reported outcomes. No case of treatment-related cancer or mortality was reported in any study group. None of the included studies assessed our secondary outcomes of joint health, clinical joint function, and economic outcomes. None of the included studies evaluated marstacimab.

AUTHORS' CONCLUSIONS

Evidence from RCTs shows that prophylaxis using non-clotting factor therapies compared with on-demand treatment may reduce bleeding events, increase the percentage of individuals with zero bleeds, increase the incidence of non-serious adverse events, and improve HRQoL. Comparative assessments with other prophylaxis regimens, assessment of long-term joint outcomes, and assessment of economic outcomes will improve evidence-based decision-making for the use of these therapies in bleed prevention.

Association of patient, treatment and disease characteristics with patient-reported outcomes: Results of the ECHO Registry

INTRODUCTION

Patient-reported outcomes (PROs) in people living with haemophilia A (PLWHA) are often under-reported. Investigating PROs from a single study with a diverse population of PLWHA is valuable, irrespective of FVIII product or regimen.

AIM

To report available data from the Expanding Communications on Haemophilia A Outcomes (ECHO) registry investigating the associations of patient, treatment and disease characteristics with PROs and clinical outcomes in PLWHA.

METHODS

ECHO (NCT02396862), a prospective, multinational, observational registry, enrolled participants aged ≥16 years with moderate or severe haemophilia A using any product or treatment regimen. Data collection, including a variety of PRO questionnaires, was planned at baseline and annually for ≥2 years. Associations between PRO scores and patient, treatment and disease characteristics were determined by statistical analyses.

RESULTS

ECHO was terminated early owing to logistical constraints. Baseline data were available from 269 PLWHA from Europe, the United States and Japan. Most participants received prophylactic treatment (76.2%), with those using extended-half-life products (10.0%) reporting higher treatment satisfaction. Older age and body weight >30 kg/m2 (>BMI) were associated with poorer joint health. Older age was associated with poorer physical functioning and work productivity. Health-related quality of life and pain interference also deteriorated with age and >BMI; >BMI also increased pain severity scores.

CONCLUSION

ECHO captured a variety of disease characteristics, treatment patterns, PROs and clinical outcomes obtained in real-world practice with ≤1 year's follow-up. Older age, poorer joint health and >BMI adversely affected multiple aspects of participant well-being.

Health-related quality of life following valoctocogene roxaparvovec gene therapy for severe hemophilia A in the phase 3 trial GENEr8-1

BACKGROUND

Severe hemophilia A (HA) negatively impacts health-related quality of life (HRQOL).

OBJECTIVES

We aimed to analyze HRQOL in adult men with severe HA without inhibitors after valoctocogene roxaparvovec gene transfer in the phase 3 trial GENEr8-1.

METHODS

Participant-reported outcomes were the hemophilia-specific quality of life questionnaire for adults (Haemo-QOL-A), the EQ-5D-5L instrument, the Hemophilia Activities List (HAL), and the Work Productivity and Activity Impairment Questionnaire: Hemophilia Specific (WPAI+CIQ:HS). Participants completed the questionnaires at baseline and through 104 weeks postinfusion with 6 × 1013 vg/kg of valoctocogene roxaparvovec. Scores were analyzed per participant characteristics and outcomes.

RESULTS

For 132 HIV-negative participants, mean change from baseline in Haemo-QOL-A Total Score met the anchor-based clinically important difference (CID: 5.5) by week 12; the mean (SD) increase was 7.0 (12.6) at week 104. At week 104, improvement in Consequences of Bleeding, Treatment Concern, Worry, and Role Functioning domain scores exceeded the CID (6). EQ-5D-5L Utility Index scores improved above the CID at week 52, but not at week 104. EQ-5D-5L visual analog scale and HAL scores increased from baseline to week 104. Participants reported less activity and work impairment at week 104 than baseline. Participants with problem joints had lower mean baseline Haemo-QOL-A Total and domain scores than those without them, but improved over 104 weeks, except for 11 participants with ≥3 problem joints. Participants with 0 bleeds during the baseline prophylaxis period reported Haemo-QOL-A score improvements above the CID, including in the Consequences of Bleeding domain.

CONCLUSION

Valoctocogene roxaparvovec provided clinically meaningful HRQOL improvement for men with severe HA.

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.

Hemophilia gene therapy: first, do no harm

The introduction of adeno-associated virus-mediated, liver-directed gene therapy into the hemophilia treatment landscape brings not only great promise but also considerable uncertainty to a community that has a history punctuated by the devastating effects of HIV and hepatitis C virus. These infections were introduced into people with hemophilia through the innovation of factor concentrates in the 1970s and 1980s. Concentrates, heralded as a major advance in treatment at the time, brought devastation and death to the community already challenged by the complications of bleeding into joints, vital organs, and the brain. Over the past 5 decades, considerable advances in hemophilia treatment have improved the survival, quality of life, and participation of people with hemophilia, although challenges remain and health equity with their unaffected peers has not yet been achieved. The decision to take a gene therapy product is one in which an informed, holistic, and shared decision-making approach must be employed. Bias on the part of health care professionals and people with hemophilia must be addressed and minimized. Here, we review data leading to the regulatory authorization of valoctocogene roxaparvovec, an adeno-associated virus 5 gene therapy, in Europe to treat hemophilia A and etranacogene dezaparvovec-drlb in the United States and Europe to treat hemophilia B. We also provide an overview of the decision-making process and recommend steps that should be taken by the hemophilia community to ensure the safety of and optimal outcomes for people with hemophilia who choose to receive a gene therapy product.

Gene Therapy in Hemophilia: A Transformational Patient Experience

Hemophilia is a bleeding disorder caused by a single absent/defective gene and characterized by a lack of functional clotting factors. People with hemophilia may experience joint damage, pain, and psychological impairments, all of which could contribute to reduced health-related quality of life (HRQoL). The current standard of care is clotting factor replacement, which is associated with regular infusions; therefore, alternative treatments such as gene therapy (GT) are in development. GT involves the delivery of a functional copy of the clotting factor 8/9 gene by a single infusion into the patient's cells, enabling them to produce their own clotting factor VIII/IX. The impact of treatment on patients' HRQoL can be assessed using hemophilia-specific patient-reported outcome (PRO) measures. Since these measures were designed before the advent of GT, there is a need for updated individualized PRO measures. Patient groups and regulatory authorities emphasize the need for increased patient engagement when considering clinical trial design. Here, we provide patients' perspective on undergoing GT and discuss how to capture the patient voice when measuring the therapy's transformative impact.

Building the foundation for a community-generated national research blueprint for inherited bleeding disorders: research priorities to transform the care of people with hemophilia

BACKGROUND

Decades of research have transformed hemophilia from severely limiting children's lives to a manageable disorder compatible with a full, active life, for many in high-income countries. The direction of future research will determine whether exciting developments truly advance health equity for all people with hemophilia (PWH). National Hemophilia Foundation (NHF) and American Thrombosis and Hemostasis Network conducted extensive inclusive all-stakeholder consultations to identify the priorities of people with inherited bleeding disorders and those who care for them.

RESEARCH DESIGN AND METHODS

Working group (WG) 1 of the NHF State of the Science Research Summit distilled the community-identified priorities for hemophilia A and B into concrete research questions and scored their feasibility, impact, and risk.

RESULTS

WG1 defined 63 top priority research questions concerning arthropathy/pain/bone health, inhibitors, diagnostics, gene therapy, the pediatric to adult transition of care, disparities faced by the community, and cardiovascular disease. This research has the potential to empower PWH to thrive despite lifelong comorbidities and achieve new standards of wellbeing, including psychosocial.

CONCLUSIONS

Collaborative research and care delivery will be key to capitalizing on current and horizon treatments and harnessing technical advances to improve diagnostics and testing, to advance health equity for all PWH.

Progress, and prospects in the therapeutic armamentarium of persons with congenital hemophilia. Defining the place for liver-directed gene therapy

In persons with congenital severe hemophilia A (HA) living in high-income countries, twice weekly intravenous infusions of extended half-life (EHL) factor VIII (FVIII) products, or weekly/biweekly/monthly subcutaneous injections of emicizumab are the gold standard home treatments to grant days without hurdles and limitations. Once weekly/twice monthly infusions of EHL Factor IX (FIX) products achieve the same target in severe hemophilia B (HB). Gene therapy, which is likely to be licensed for clinical use within 1-2 years, embodies a shift beyond these standards. At an individual patient level, a single functional gene transfer leads to a > 10-yr almost full correction of the hemostatic defect in HB and to a sustained (3-6-yrs) expression of FVIII sufficient to discontinue exogenous clotting factor administrations. At the doses employed, the limited liver toxicity of systemically infused recombinant adeno-associated virus (rAAV) vectors is documented by long-term (12-15 yrs) follow-ups, and pre-existing high-titer neutralizing antibodies to the AAV5 vector are no longer an exclusion criterion for effective transgene expression with this vector. A safe durable treatment that converts a challenging illness to a phenotypically curable disease, allows persons to feel virtually free from the fears and the obligations of hemophilia for years/decades. Along with patient organizations and health care professionals, communicating to government authorities and reimbursement agencies the liberating potential of this substantial innovation, and disseminating across the Centers updated information on benefits and risks of this strategy, will align expectations of different stakeholders and establish the notion of a potentially lifelong cure of hemophilia.

ACTIVLIM-Hemo: A new self-reported, unidimensional and linear measure of activity limitations in persons with haemophilia

INTRODUCTION

To assess activity limitations in people with haemophilia (PwH), the self-reported Haemophilia Activity List (HAL) is widely employed, despite several methodological limitations impacting the interpretation of categorical scores. Modern psychometric approaches avoid these limitations by using a probabilistic model, such as the Rasch model. The ACTIVLIM is a Rasch-built measurement of activity limitations previously validated in several clinical conditions like neuromuscular disorders.

AIMS

This study sought to develop the ACTIVLIM-Hemo, meaning an ACTIVLIM scale version specifically adapted to assess daily activity limitations in adult PwH.

METHODS

Daily activities were assessed as "impossible," "difficult" or "easy" by 114 PwH (median age of 44 years) with 63 of them reassessed after 12 days. The Rasch Rating Scale model was used to identify activities delineating a unidimensional and linear scale unbiased by demographic and clinical status. Concurrent validity was determined through correlation with the HAL sub-scores and sum score.

RESULTS

The ACTIVLIM-Hemo included 22 pertinent activities, with difficulties independent of demographic and clinical conditions, allowing a reliable measure of activity limitations (PSI = .92) expressed on a linear and unidimensional scale in PwH (7%-100 % range, ceiling effect of 1/114) with excellent test-retest reliability (ICC = .978). Spearman rank correlations between ACTIVLIM-Hemo and HAL sub-scores ranged between .623 and .869.

CONCLUSIONS

The ACTIVLIM-Hemo is an easy-to-administer, valid and reliable alternative to HAL in assessing activity limitations in PwH. Its invariant scale can be used across conditions and time to compare the functional status of PwH over a wide measurement range.

Untreated bleeds in people with hemophilia A in a noninterventional study and intrapatient comparison after initiating emicizumab in HAVEN 1-3

Background

Bleeding in people with hemophilia A can be life threatening, and intra‐articular bleeds can result in joint damage. Most clinical studies focus on treated bleeds, while bleeds not treated with coagulation factor(s) (untreated bleeds) are underreported.

Objectives

We assessed the incidence of untreated bleeds during a noninterventional study (NIS) wherein people with hemophilia A, with or without factor VIII (FVIII) inhibitors, were managed according to standard practice.

Patients/Methods

Using the Bleed and Medication Questionnaire, we prospectively collected data from three cohorts: Cohort A, adults/adolescents (age ≥12 years) with FVIII inhibitors; Cohort B, children (aged <12 years) with FVIII inhibitors; Cohort C, adults/adolescents without FVIII inhibitors. Untreated bleeds were analyzed for site, frequency, and etiology of bleeding and compared with those during emicizumab prophylaxis in the same individuals after transferring to a Phase III HAVEN trial.

Results

In the 221 participants enrolled in the NIS (Cohort A, n = 103; Cohort B, n = 24; Cohort C, n = 94), the incidence of untreated bleeds was approximately 40% of all bleeds in people with FVIII inhibitors and 26.2% in adolescents/adults without inhibitors. Approximately 70% of treated bleeds and approximately 54% of untreated bleeds in adults/adolescents were in joints. Untreated joint bleeds were less common (7.1%) in children. Overall, intra‐individual comparisons showed reduced treated/untreated bleeds following transition from standard to emicizumab prophylaxis.

Conclusion

A significant proportion of bleeding events are untreated in people with hemophilia A. There is a need to further understand why bleeds remain untreated and to capture such events in clinical studies.

Non‐factor therapies for bleeding disorders: A primer for the general haematologist

Management of patients with severe bleeding disorders, particularly haemophilia A and B, and to a lesser extent, von Willebrand disease, has come on leaps and bounds over the past decade. Until recently, patients relied upon the administration of factor concentrates to prevent or treat bleeding episodes. Factor administration requires intravenous access and, in up to one‐third of patients, leads to the development of neutralising antibodies, or inhibitors, which are associated with more frequent bleeding episodes and higher morbidity. Novel non‐factor therapies may offer a solution to these unmet needs. In this review, we discuss the factor mimetics, particularly emicizumab, and the rebalancing agents, which inhibit antithrombin, tissue factor pathway inhibitor and activated protein C, and novel treatments to enhance von Willebrand factor levels. We review the available trial data, unanswered questions and challenges associated with these new treatment modalities. Finally, we provide practical management algorithms to aid the general haematologist when faced with a patient receiving emicizumab who requires surgery or may develop bleeding.

Building the blueprint: Formulating a community-generated national plan for future research in inherited bleeding disorders

Introduction

Decades of inherited bleeding disorders (BD) research transformed severe haemophilia from a childhood killer to a disorder managed across a full lifespan for many in economically developed countries. Health equity, a life unimpaired by disease complications, however, remains unimaginable for most people with an inherited BD (PWIBD).

Aim

The National Hemophilia Foundation (NHF) and American Thrombosis and Hemostasis Network (ATHN) undertook the development of a community‐driven United States (US) National Blueprint for Inherited Bleeding Disorders Research to transform the experience of all PWIBD and those who care for them.

Methods

Extensive community consultations were conducted to identify the issues most important to PWIBD and those who love and care for them. Expert multidisciplinary teams distilled these key areas of need into prioritised research questions, and identified the resources and infrastructure required to pursue them. A summit was held to gather feedback and inform the detailed blueprint.

Results

Community‐prioritised research areas fell into three broad categories: issues common across inherited BDs, those specific to individual disorders, and issues of infrastructure and capacity. NHF State of the Science Research Summit discussions of the research questions derived from the community priorities by six working groups provided important input for the drafting of the research blueprint for the coming decades.

Conclusion

The inherited BD community came together to develop the US National Blueprint for Inherited Bleeding Disorders Research dedicated to transforming the lives of all PWIBD including innovating solutions for the rarest disorders and under‐represented populations.

Effects of replacement therapies with clotting factors in patients with hemophilia: A systematic review and meta-analysis

Background

Different prophylactic and episodic clotting factor treatments are used in the management of hemophilia. A summarize of the evidence is needed inform decision-making.

Objective

To compare the effects of factor replacement therapies in patients with hemophilia.

Methods

We performed a systematic search in PubMed, Central Cochrane Library, and Scopus. We included randomized controlled trials (RCTs) published up to December 2020, which compared different factor replacement therapies in patients with hemophilia. Random-effects meta-analyses were performed whenever possible. The certainty of the evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology. The study protocol was registered in PROSPERO (CRD42021225857).

Results

Nine RCTs were included in this review, of which six compared episodic with prophylactic treatment, all of them performed in patients with hemophilia A. Pooled results showed that, compared to the episodic treatment group, the annualized bleeding rate was lower in the low-dose prophylactic group (ratio of means [RM]: 0.27, 95% CI: 0.17 to 0.43), intermediate-dose prophylactic group (RM: 0.15, 95% CI: 0.07 to 0.36), and high-dose prophylactic group (RM: 0.07, 95% CI: 0.04 to 0.13). With significant difference between these subgroups (p = 0.003, I² = 82.9%). In addition, compared to the episodic treatment group, the annualized joint bleeding rate was lower in the low-dose prophylactic group (RM: 0.17, 95% CI: 0.06 to 0.43), intermediate-dose prophylactic group (RM of 0.14, 95% CI: 0.07 to 0.27), and high-dose prophylactic group (RM of 0.08, 95% CI: 0.04 to 0.16). Without significant subgroup differences. The certainty of the evidence was very low for all outcomes according to GRADE methodology. The other studies compared different types of clotting factor concentrates (CFCs), assessed pharmacokinetic prophylaxis, or compared different frequencies of medication administration.

Conclusions

Our results suggest that prophylactic treatment (at either low, intermediate, or high doses) is superior to episodic treatment for bleeding prevention. In patients with hemophilia A, the bleeding rate seems to have a dose-response effect. However, no study compared different doses of prophylactic treatment, and all results had a very low certainty of the evidence. Thus, future studies are needed to confirm these results and inform decision making.

Patients' perspective on supposedly patient-relevant process and outcome parameters: a cross-sectional survey within the 'PRO patients study'

BACKGROUND

To be able to make informed choices based on their individual preferences, patients need to be adequately informed about treatment options and their potential outcomes. This implies that studies measure the effects of care based on parameters that are relevant to patients. In a previous scoping review, we found a wide variety of supposedly patient-relevant parameters that equally addressed processes and outcomes of care. We were unable to identify a consistent understanding of patient relevance and therefore aimed to develop an empirically based concept including a generic set of patient-relevant parameters. As a first step we evaluated the process and outcome parameters identified in the scoping review from the patients' perspective.

METHODS

We conducted a cross-sectional survey among German general practice patients. Ten research practices of Witten/Herdecke University supported the study. During a two-week period in the fall of 2020, patients willing to participate self-administered a short questionnaire. It evaluated the relevance of the 32 parameters identified in the scoping review on a 5-point Likert scale and offered a free-text field for additional parameters. These free-text answers were inductively categorized by two researchers. Quantitative data were analyzed using descriptive statistics. Bivariate analyses were performed to determine whether there are any correlations between rating a parameter as highly relevant and patients' characteristics.

RESULTS

Data from 299 patients were eligible for analysis. All outcomes except 'sexuality' and 'frequency of healthcare service utilization' were rated important. 'Confidence in therapy' was rated most important, followed by 'prevention of comorbidity' and 'mobility'. Relevance ratings of five parameters were associated with patients' age and gender, but not with their chronic status. The free-text analysis revealed 15 additional parameters, 12 of which addressed processes of care, i.e., 'enough time in physician consultation'.

CONCLUSION

Patients attach great value to parameters addressing processes of care. It appears as though the way in which patients experience the care process is not less relevant than what comes of it. Relevance ratings were not associated with chronic status, but few parameters were gender- and age-related.

TRIAL REGISTRATION

Core Outcome Measures in Effectiveness Trials Initiative, registration number: 1685.

Haemophilia in France: Modelisation of the Clinical Pathway for Patients

Process-of-care studies participate in improving the efficiency of the care pathway for patient with haemophilia (CPPH) and rationalize the multidisciplinary management of patients. Our objective is to establish a current overview of the different actors involved in the management of patients with haemophilia and to provide an accurate description of the patient trajectory. This is a qualitative exploratory research based on interviews of the principal health professionals of four haemophilia services, between November 2019 and February 2020, in France. Mapping of the CPPH processes within the different institutions and/or services, as well as the rupture zones, were identified. Treatment delivery and biological analyses were carried out exclusively in healthcare institutions. The main liberal health professionals solicited were nurses, physiotherapists and general practitioner. Obstacles and barriers within the specialized service, with other hospital services and external hospital or private services, community health care providers et community environment and individual one was complex and multiples. Our research identified potential concerns that need to be addressed to improve future studies to identify influential elements. Similarly, other qualitative studies will have to be conducted on the perceptions and literacy of patients with haemophilia to develop a global interactive mapping of their trajectories.

Incorporating the patient voice and patient engagement in GOAL-Hēm: Advancing patient-centric hemophilia care

BACKGROUND

Goal Attainment Scaling for Hemophilia (GOAL-Hēm) is a novel, hemophilia-specific, validated patient engagement tool and patient-reported outcome instrument.

OBJECTIVE

We evaluated the degree to which the language of GOAL-Hēm was patient-centric and the content valuable and relevant for people with hemophilia (PWH) and/or their caregivers.

PATIENTS/METHODS

Patients and caregivers participated in one of three investigations: an online survey, one-on-one patient interviews, or a focus group. The survey and interviews assessed the clarity and relevance of the GOAL-Hēm menu items. Interviews were semistructured, audio recorded, and transcribed verbatim. Feedback from interviews was coded as "clear," "unclear," "remove," or "add." The focus group explored participants' experience of GOAL-Hēm and elicited recommendations for implementation. Quotations from focus group and interview transcripts were indexed and charted to emergent themes for analysis.

RESULTS

Participants comprised 19 adults with hemophilia and 19 caregivers of children with hemophilia (survey, n = 20; interview, n = 12; focus group, n = 6). After their feedback, 32% (15/48) of goals were retained unchanged. Further feedback resulted in the removal of 45% (286/635) of the goal descriptors, and 30% (193/635) of the retained descriptors were modified. Three new (total = 38) goals and 42 descriptors (total = 368) were added to the menu. Thematic analysis indicated that participants were enthusiastic about patient-centric language, empowered through the goal-setting process, and recognized GOAL-Hēm could measure clinically meaningful change.

CONCLUSION

By listening closely to patients and caregivers, we refined GOAL-Hēm to better capture the experiences of PWH, enhance content validity, and augment implementation strategies. Incorporating the patient voice is integral to developing patient-centered outcome measures.

Predictive Modeling Identifies Total Bleeds at 12-Weeks Postswitch to N8-GP Prophylaxis as a Predictor of Treatment Response

Background  Predicting annualized bleeding rate (ABR) during factor VIII (FVIII) prophylaxis for severe hemophilia A (SHA) is important for long-term outcomes. This study used supervised machine learning-based predictive modeling to identify predictors of long-term ABR during prophylaxis with an extended half-life FVIII.

Methods  Data were from 166 SHA patients who received N8-GP prophylaxis (50 IU/kg every 4 days) in the pathfinder 2 study. Predictive models were developed to identify variables associated with an ABR of ≤1 versus >1 during the trial's main phase (median follow-up of 469 days). Model performance was assessed using area under the receiver operator characteristic curve (AUROC). Pre-N8-GP prophylaxis models learned from data collected at baseline; post-N8-GP prophylaxis models learned from data collected up to 12-weeks postswitch to N8-GP, and predicted ABR at the end of the outcome period (final year of treatment in the main phase).

Results  The predictive model using baseline variables had moderate performance (AUROC = 0.64) for predicting observed ABR. The most performant model used data collected at 12-weeks postswitch (AUROC = 0.79) with cumulative bleed count up to 12 weeks as the most informative variable, followed by baseline von Willebrand factor and mean FVIII at 30 minutes postdose. Univariate cumulative bleed count at 12 weeks performed equally well to the 12-weeks postswitch model (AUROC = 0.75). Pharmacokinetic measures were indicative, but not essential, to predict ABR.

Conclusion  Cumulative bleed count up to 12-weeks postswitch was as informative as the 12-week post-switch predictive model for predicting long-term ABR, supporting alterations in prophylaxis based on treatment response.

Cost-Effectiveness Analysis of rFVIIIFc Versus Contemporary rFVIII Treatments for Patients with Severe Hemophilia A Without Inhibitors in the United States

BACKGROUND

A range of treatments for patients with severe hemophilia A (HA) have been developed over the last decade, allowing for reduced frequency of administration and improved outcomes (joint health and breakthrough bleeding rates). While clinically effective, the cost effectiveness of these treatments has not been established.

OBJECTIVE

This study presents a cost-effectiveness analysis of contemporary rFVIII treatments for severe HA patients without inhibitors.

METHODS

A published semi-Markov model was used to compare three different prophylaxis regimens: (1) extended half-life (EHL) recombinant Factor VIII (rFVIII) Fc-fusion protein (rFVIIIFc, Eloctate^®, Sanofi), (2) EHL PEGylated rFVIII (PEG-rFVIII, Adynovate^®, Takeda), and (3) standard half-life (SHL) rFVIII (antihemophilic factor [recombinant], Advate^®, Takeda), used as a proxy for all SHL rFVIII treatments. Acquisition costs were included based on published dosing and weight data. Benefits were incorporated through published annualized bleeding rates, rates of target joint development/resolution, and improvements in the modified hemophilia joint health score. Results were presented as total, discounted costs, and quality-adjusted life-years (QALYs).

RESULTS

rFVIIIFc was shown to provide the most QALYs (27.922) compared with both PEG-rFVIII (27.454) and SHL rFVIII (27.071), at lower costs. Discounted lifetime costs were estimated at US$18.235m (rFVIIIFc), US$20.198m (PEG-rFVIII), and US$18.285m (SHL rFVIII), and were predominantly affected by model settings related to acquisition costs, patient weight, and dosing.

CONCLUSIONS

rFVIIIFc may offer a cost-effective option for severe HA patients. Uncertainties owing to the limited evidence base is the main limitation of the study.

Clinical outcomes after joint surgery in patients on turoctocog alfa pegol (N8-GP) prophylaxis: A post hoc analysis

INTRODUCTION

Joint damage in haemophilia often requires surgical correction. However, the surgery effect on bleeding rates and other clinical joint outcomes can be unclear.

AIM

To investigate the effects of joint surgery on joint annualized bleeding rates (JABRs) and physical health outcomes in patients with haemophilia A undergoing N8-GP prophylaxis.

METHODS

Patients in the pathfinder 2 trial received N8-GP prophylaxis, enrolling in the pathfinder 3 trial for indicated surgery. Patients returned to pathfinder 2 post-surgery, continuing N8-GP prophylaxis until end-of-trial. JABRs were calculated from bleeding across all joints for pre-surgery (immediately before surgery) and post-surgery (to pathfinder 2 study end) periods. Joint-health-related outcomes were derived from patient records.

RESULTS

Data (41 joint surgeries; n = 30) were analysed statistically using datamining and descriptively. Pre-surgery mean JABR was higher in patients who later were operated than in 146 non-operated patients (p = .004). In operated patients, mean JABR decreased from 1.33 pre-surgery to .37 post-surgery (p = .011). In all but three patients, JABR improved or remained the same post-surgery. In the three patients whose JABR remained at one (all with multiple joint arthropathy), post-surgery bleeds were mostly at non-operated sites. Two of the three patients whose JABR increased post-surgery had undergone surgery for reasons unlikely to improve JABR. Mobility parameters often improved in patients whose JABR remained at zero.

CONCLUSION

Patients with haemophilia treated with N8-GP prophylaxis benefit from surgeries. However, this analysis could not differentiate the relative contributions of surgical interventions and prophylactic treatment to the improvement of JABR.

Hemophilia A Gene Therapy: Current and Next-Generation Approaches

INTRODUCTION

: Hemophilia comprises a group of X-linked hemorrhagic disorders that result from a deficiency of coagulation factors. The disorder affects mainly males and leads to chronic pain, joint deformity, reduced mobility, and increased mortality. Current therapies require frequent administration of replacement clotting factors, but the emergence of alloantibodies (inhibitors) diminishes their efficacy. New therapies are being developed to produce the deficient clotting factors and prevent the emergence of inhibitors.

AREAS COVERED

: This article provides an update on the characteristics and disease pathophysiology of hemophilia A, as well as current treatments, with a special focus on ongoing clinical trials related to gene replacement therapies.

EXPERT OPINION

: Gene replacement therapies provide safe, durable, and stable transgene expression while avoiding the challenges of clotting factor replacement therapies in patients with hemophilia. Improving the specificity of the viral construct and decreasing the therapeutic dose are critical toward minimizing cellular stress, induction of the unfolded protein response, and the resulting loss of protein production in liver cells. Next-generation gene therapies incorporating chimeric DNA sequences in the transgene can increase clotting factor synthesis and secretion, and advance the efficacy, safety, and durability of gene replacement therapy for hemophilia A as well as other blood clotting disorders.

Clinical assessment and point of care ultrasonography: How to diagnose haemophilic synovitis

BACKGROUND

The ability of clinical tools to identify early joint changes is limited. Synovitis is a fundamental finding in understanding haemophilia activity and the response to its therapies; thus, there is a need for sensitive methods to better diagnose subclinical synovitis early.

PURPOSE

Our aim was to compare the frequency with which clinical assessment and ultrasound detected synovial hypertrophy in the most frequently affected joints in patients with haemophilia (elbows, knees and ankles).

METHODS

We analysed patients with haemophilia older than 16 years who came to the haemophilia centre for routine follow-up. From the clinical assessment carried out in the consultation, the swelling, pain and history of haemarthrosis were evaluated and compared with the findings of synovial hypertrophy detected by ultrasound. This comparison was also analysed independently for elbows, knees and ankles.

RESULTS

A total of 203 joints of 66 patients with haemophilia (mean age 34 years), most of them on secondary, tertiary prophylaxis or on demand treatment, were included. In joints with swelling, pain and history of haemarthrosis, 78% of the joints showed synovial hypertrophy on ultrasound. However, in joints with no swelling, no pain and no history of haemarthrosis, 40% presented subclinical synovial hypertrophy on ultrasound. This percentage was higher in elbows than in knees and ankles.

CONCLUSION

In adults with haemophilia, physical examination and point-of-care ultrasound study provide complementary data on their joint disease. However, without ultrasound, the ability to detect subclinical synovitis is considerably reduced, especially in the elbows.

Recombinant factor IX-Fc fusion protein in severe hemophilia B: Patient-reported outcomes and health-related quality of life

INTRODUCTION

In 2017, all people with severe hemophilia B in Ireland switched to recombinant factor IX Fc fusion protein concentrate (rFIXFc) prophylaxis. Patient-reported outcomes (PROs) and health-related quality of life (HRQoL) are important to evaluate with new treatments.

AIMS

To assess HRQoL in people with severe hemophilia B and their experience after switching to rFIXFc prophylaxis.

METHODS

Participants completed a Patient Reported Outcomes Burden and Experience (PROBE) questionnaire on initiation and following two years of rFIXFc prophylaxis. The PROBE questionnaire has four domains: demographics, general health, haemophilia-specific, and European Quality of Life 5-Dimensions (EQ-5D-5L) questionnaire.

RESULTS

Twenty-three participants completed the questionnaire at both time points. The number of activities where chronic pain occurred and interfered with the activity was reduced by 25% and 33%, respectively (P < .001), following two years of rFIXFc prophylaxis. There was a 9% decrease in chronic pain during the second year of rFIXFc prophylaxis compared to baseline, but the rate remained high, at 74%. A 25% reduction in the number of affected activities of daily living (ADLs) was reported following 2 years of rFIXFc prophylaxis (P = .007). The most common health problems were arthritis, hypertension, anxiety/depression, and gingivitis. The median EQ-5D-5L score was similar following two years of rFIXFc prophylaxis, 0.76 (range, -0.01 to 0.95), compared to 0.77 (range, 0.36-1) at baseline.

CONCLUSION

This study of real-world patient experience using PROs demonstrates a reduction in chronic pain and improvement in ADLs in participants after switching to rFIXFc prophylaxis. It provides important insights into patient-identified health care needs and living with severe hemophilia B.

[Effect of FVIII doses on joint structure and function in adolescents with severe hemophilia A: mid-term results of a prospective cohort study]

OBJECTIVE

To explore the clinical phenotype and changes in joint structure and function in adolescent patients with severe hemophilia A under different doses of FVIII.

OBJECTIVE

Forty- three adolescents with severe hemophilia A aged 4-18 years were divided into on-demand group (n=7), low-dose group (FVIII dose of 10-15 U/kg, 2-3 times a week, and ≤30 U/kg a week; n=17), and intermediate-dose group (FVIII dose of 15-20 U/kg, 2-3 times a week, and 45-60 U/kg a week (n=19). The 3 groups were compared for their clinical bleeding phenotype, annual bleeding rate (ABR), annual joint bleeding rate (AJBR), annual the most severe joint bleeding rate, joint imaging scores (ultrasound HEAD-US score and IPSG MRI score), Hemophilia Joint Health Score (HJHS) and Functional Independence Score in Hemophilia (FISH) within 24 months.

OBJECTIVE

Compared with that in on-demand group, the ABR was significantly reduced in the low- and intermediate-dose groups (P=0.004 and 0.000, respectively), and was reduced by 32.87% in the intermediate-dose group as compared with the low-dose group. The AJBR (P < 0.01) and annual the most severe joint bleeding rate (P < 0.05) also differed significantly among the 3 groups. The number of bleeding episodes increased progressively with time in the on-demand group, remained stable in the low- dose group, and tended to decrease in the intermediate-dose group. The imaging scores of the most severe joints showed lesion progression in all the 3 groups. The ultrasound scores, which increased steadily in the on-demand group, showed significantly lowered increment rates in the low- and intermediate-dose groups (P=0.002 and 0.000, respectively). The MRI scores showed also delayed increment in the low- and intermediate-dose groups as compared with the on-demand group (P=0.041 and 0.000, respectively), and the increment was accelerated in the on-demand and low-dose group but remained stable in the intermediate-dose group. The increment of the HJHS scores was significantly higher in the on-demand group than in the lowand intermediate-dose groups (P=0.003 and 0.000, respectively), and the scores increased at a steady rate in the on-demand group but tended to decrease in the latter two groups. The FISH score was decreased by 0.29±3.09 in the on-demand group but was increased significantly in the low- and intermediate-dose groups compared with the on-demand group (P=0.000).

OBJECTIVE

In Chinese adolescents with severe hemophilia A, low- and intermediate-dose FVIII prophylaxis, especially at the intermediate dose, is better than on- demand treatment for protecting joint structure and function.

Understanding the evolution of coverage policies for prophylaxis treatments of hemophilia A without inhibitors: a payer Delphi panel

BACKGROUND: The landscape for hemophilia A prophylaxis is rapidly expanding from factor VIII replacement therapy to include novel treatments such as nonfactor replacement therapies that may enhance coagulation (e.g., emicizumab) or inhibit anticoagulant pathways (e.g., fitusiran and concizumab). For payers, this expansion presents challenges in balancing well-established treatments with new options that cost more and have lesser known real-world safety and efficacy. OBJECTIVE: To evaluate likely coverage practices for hemophilia A prophylaxis therapies among U.S. payers given evolving real-world data on safety and efficacy. METHODS: A 3-round modified Delphi process was conducted with representatives of U.S. commercial health plans who had considerable expertise in managing populations of patients with hemophilia. Round 1 consisted of an online questionnaire; round 2 involved an online discussion about the aggregated results from round 1; and round 3 allowed participants to revise their responses from round 1 based on insights gained during round 2. Questions elicited ratings, rankings, and estimates on access restrictions based on given safety and efficacy information for hemophilia A prophylaxis therapies. Consensus was reached if ≥ 74% of panelists (14 of 19) were within 1 SD of the median group estimate during round 3. RESULTS: 19 Payers participated in the research. Among them, 94% dealt with commercial insurance, 94% with Medicare, and 81% with Medicaid; 79% had spent ≥ 5 years in their current role. Panelists reported limited access restrictions on hemophilia A prophylaxis therapies; the most common restrictions were prior authorization (n = 16, 84%) and quantity level limits (n = 13, 67%). Tiering and step therapy were reported by 7 respondents (39%). Respondents agreed that there was an 80% median likelihood that ≥ 9 additional patients with any safety event (e.g., thrombotic event, death) per year would trigger access restrictions, with the median likelihood of restrictions increasing to 95% for another ≥ 10 patients with safety events per year. Respondents also agreed that > 5 thrombotic events requiring treatment per patient per year would have a 98% median likelihood of leading to access restrictions and that ≥ 5 years of real-world safety and efficacy data would be highly likely (95% median likelihood) to affect coverage decisions. Noncoverage was highly unlikely (ranked fifth or sixth of 6 by 14 respondents), as was no restriction-coverage parity (ranked sixth of 6 by 10 respondents). All else being equal, cost continues to affect access policies, with respondents agreeing that a 13%-30% difference in net cost may lead to preferred formulary treatment for a drug with superior efficacy and noninferior safety, inferior efficacy and noninferior safety, or noninferior efficacy and inferior safety. CONCLUSIONS: Payers prefer treatments with well-understood efficacy, safety, and cost over newer treatments with uncertain long-term effects. Relatively unrestricted access to legacy and new hemophilia A prophylaxis will likely continue unless additional real-world safety concerns or major cost differences emerge. DISCLOSURES: Financial support for this study was provided by Takeda Pharmaceutical Company, which was involved in study concept and design. Graf, Tuly, Harley, and Pednekar are employees of PRECISIONheor, a research consultancy to the health and life sciences industries that was contracted by Takeda to conduct this study and write the manuscript. Batt served as a consultant on this project through PRECISIONheor.

Outcomes for studies assessing the efficacy of hemostatic therapies in persons with congenital bleeding disorders

INTRODUCTION

Management strategies and hemostatic treatments to achieve control of bleeding are relevant across many disease areas. Identification of primary outcomes for studies assessing hemostatic intervention was the objective of a National Heart, Lung and Blood Institute (NHLBI) sponsored multidisciplinary initiative. The aim of this report is to summarize the evidence reviewed, and the outcomes identified by the subgroup tasked to assess outcomes for inherited bleeding disorders.

METHODS

The subgroup decided to focus on haemophilia, the prototypal congenital bleeding disorder and the one with the largest available body of evidence. MEDLINE, EMBASE and PsycINFO, The Cochrane Review, CINAHL, and Web of Science were searched for systematic and narrative reviews on outcomes used in haemophilia clinical trials. Three different clinical goals were identified as typical objectives of future research.

RESULTS

Out of 1322 unique citations, 24 reviews published in the period 2002-2019 were included. We identified 113 outcome measures, categorized in 6 domains: health-related quality of life (HRQoL), comorbidities and mortality, overall physical functioning and participation, bleeding and hemostasis, joint health, and costs and resource use. Three different clinical goals were identified as typical objectives of future research: Episodic 'on demand' replacement therapy, prevention of bleeding (Prophylaxis), and long-term and overall impact of bleeding. For each of these scenarios, specific outcomes were recommended.

CONCLUSIONS

Primary outcomes for clinical trials assessing the efficacy of hemostatic treatment in achieving control, prevention and limiting long-term consequences of bleeding in inherited bleeding disorders are suggested, and their strength and limitations discussed.

Outcome measures in Haemophilia: Beyond ABR (Annualized Bleeding Rate)

Options for management of haemophilia are increasing rapidly with completely novel therapeutic approaches that cannot be compared using traditional factor assays. In addition, as prophylaxis regimens have improved, bleeding rates have decreased, and consequently, it is difficult to show an impact of novel therapies on rates of spontaneous bleeding. There is currently an urgent need for a panel of outcome measures to compare therapies that are dissimilar in many essential ways. Conventional objective outcome measures including joint physical examination and joint imaging continue to hold a central importance. Factor assays are essential for evaluation of products derived from native factor genes, but are not applicable to some extended half-life factors or non-factor bypassing agents. Global assays including thrombin generation and chromogenic assays of factor X activation are under investigation for their usefulness in haemophilia assessment. Bleeding rate is a conventional subjective patient-reported outcome that, while decreasing in frequency, is indispensable as an outcome given that the primary manifestation of haemophilia is bleeding. Other patient-reported outcomes such as pain intensity and interference, health-related quality of life and activities and participation are increasingly important to distinguish superior outcomes in comparative trials. This review of outcome measures for haemophilia presents examples of existing outcome measures with an emphasis on their strengths and limitations.

Novel blood coagulation molecules: Skeletal muscle myosin and cardiac myosin

Essentials Striated muscle myosins can promote prothrombin activation by FXa or FVa inactivation by APC. Cardiac myosin and skeletal muscle myosin are pro-hemostatic in murine tail cut bleeding models. Infused cardiac myosin exacerbates myocardial injury caused by myocardial ischemia reperfusion. Skeletal muscle myosin isoforms that circulate in human plasma can be grouped into 3 phenotypes. ABSTRACT: Two striated muscle myosins, namely skeletal muscle myosin (SkM) and cardiac myosin (CM), may potentially contribute to physiologic mechanisms for regulation of thrombosis and hemostasis. Thrombin is generated from activation of prothrombin by the prothrombinase (IIase) complex comprising factor Xa, factor Va, and Ca++ ions located on surfaces where these factors are assembled. We discovered that SkM and CM, which are abundant motor proteins in skeletal and cardiac muscles, can provide a surface for thrombin generation by the prothrombinase complex without any apparent requirement for phosphatidylserine or lipids. These myosins can also provide a surface that supports the inactivation of factor Va by activated protein C/protein S, resulting in negative feedback downregulation of thrombin generation. Although the physiologic significance of these reactions remains to be established for humans, substantive insights may be gleaned from murine studies. In mice, exogenously infused SkM and CM can promote hemostasis as they are capable of reducing tail cut bleeding. In a murine myocardial ischemia-reperfusion injury model, exogenously infused CM exacerbates myocardial infarction damage. Studies of human plasmas show that SkM antigen isoforms of different MWs circulate in human plasma, and they can be used to identify three plasma SkM phenotypes. A pilot clinical study showed that one SkM isoform pattern appeared to be linked to isolated pulmonary embolism. These discoveries enable multiple preclinical and clinical studies of SkM and CM, which should provide novel mechanistic insights with potential translational relevance for the roles of CM and SkM in the pathobiology of hemostasis and thrombosis.

Core data set on safety, efficacy, and durability of hemophilia gene therapy for a global registry: Communication from the SSC of the ISTH

BACKGROUND

Gene therapy for people with hemophilia (PWH) will soon become available outside current clinical trials. The World Federation of Hemophilia (WFH), in collaboration with International Society of Thrombosis and Hemostasis Scientific and Standardization Committee (ISTH SSC), the European Haemophilia Consortium (EHC), the US National Hemophilia Foundation (NHF), the American Thrombosis and Hemostasis Network (ATHN), industry gene therapy development partners and Regulatory liaisons have developed the Gene Therapy Registry (GTR), designed to collect long-term data on all PWH who receive hemophilia gene therapy.

OBJECTIVE

The objectives of the GTR are to record the long-term safety and efficacy data post gene therapy infusion and to assess the changes in quality of life and burden of disease post-gene-therapy infusion.

METHODS

The GTR is a prospective, observational, and longitudinal registry developed under the guidance of a multi-stakeholder GTR Steering Committee (GTR SC), composed of health care professionals, patient advocates, industry representatives, and regulatory agency liaisons. All PWH who receive gene therapy by clinical trial or commercial product will be invited to enrol in the registry through their hemophilia treatment centers (HTCs). The registry aims to recruit 100% of eligible post gene therapy PWH globally. Through an iterative process, and following the guidance of the European Medicines Agency (EMA) and the US Food and Drug Administration (FDA), the GTR SC has developed a core set of data to be collected on all patients post gene therapy.

RESULTS

The core data set includes demographic information, vector infusion details, safety, efficacy, quality of life and burden of disease.

CONCLUSIONS

The GTR is a global effort to ensure that long term safety and efficacy outcomes are recorded and analysed and rare adverse events, in a small patient population, are identified. Many unknowns on the long-term safety and efficacy of gene therapy for hemophilia may also be addressed.

HJHS 2.1 and HEAD-US assessment in the hemophilic joints: How do their findings compare?

: In hemophilic patients methods are needed to better diagnose joint damage early, so that treatments can be adjusted to slow the progression of hemophilic arthropathy. The aim of this study is to investigate the relationship between the Hemophilia Joint Health Score version 2.1 (HJHS 2.1) and hemophilia early arthropathy detection with ultrasound (HEAD-US) scales, as well as each of their individual items, to better understand the value each provides on the joint condition of patients with hemophilia. The study included data from patients with hemophilia older than 16 years of age, who attended a routine check-up. HJHS 2.1 and HEAD-US assessments were performed on the elbows, knees and ankles. We studied the correlations and agreements between the two scales and analyzed the relationship between the various items of the HJHS 2.1 (inflammation, duration, atrophy, crepitation, flexion deficit, extension deficit, pain, strength, gait) and HEAD-US (synovitis, cartilage and bone). The study included 203 joints from 66 patients with hemophilia (mean age, 34 years). We found a good correlation between the two scales (r = 0.717). However, HJHS 2.1 revealed only 54% of the cases with synovitis and 75% of the cases with osteochondral damage. HEAD-US detected several relevant physical and functional aspects in less than 53% of the cases. HJHS 2.1 and HEAD-US provide complementary data on joint disease in adults with hemophilia; both assessments should therefore, be made available. HEAD-US presented the added value of detecting early joint changes (synovitis and osteochondral damage), while HJHS 2.1 showed the added value of detecting relevant physical and functional changes.

Patient-relevant outcomes: what are we talking about? A scoping review to improve conceptual clarity

Background

With respect to patient-centered care, measuring care effects based on patient-relevant outcomes is becoming increasingly important. There is some uncertainty about what outcomes are particularly relevant to patients and who determines their relevance. To determine this, we conducted a scoping review of the international literature with the aim to improve the conceptual clarity regarding (1) the terminology used for supposedly patient-relevant outcomes, (2) the variety of outcomes considered patient-relevant, and (3) justifications for the choice of these specific outcomes.

Methods

We conducted a systematic search in Embase, PubMed (including Medline), Cochrane Central, Scopus, and Google Scholar with a special focus on article titles. Search terms included patient-relevant, patient-important, patient-preferred, and outcome(s), endpoint(s), parameter(s), indicator(s). We limited the search period from January 2000 to July 2019. Full-text articles reporting outcomes that were described as patient-relevant met the inclusion criteria. Two researchers independently analyzed all eligible articles applying quantitative and structuring content analysis.

Results

We identified 155 articles, 44 of which met the inclusion criteria. A content analysis revealed 35 different terms used with regard to patient-relevant outcomes. However, authors predominantly referred to patient-important outcomes (23 articles, 52.3%) and patient-relevant outcomes (17 articles, 38.6%). A structuring content analysis of all extracted outcomes revealed a total of 281 codes, pooled in 32 inductive categories. Among these, the following categories dominated: symptoms, adverse events/complications, survival/mortality, pain. In just 16 of the articles (36.4%), authors provided justifications for the choice of the outcome being based either on patient and/or expert opinions. In another 13 articles (29.5%), no justification was provided.

Conclusion

This scoping review on patient-relevant outcomes was driven by the questions (1) what outcomes are particularly relevant to patients, and (2) who determines their relevance. We found a wide range of supposedly patient-relevant outcomes, with only one third of articles involving patients in the justification of the outcome selection. In view of this conceptual uncertainty it appears difficult to determine or even to compare a particular patient benefit of interventions. A set of generic outcomes relevant to patients would be helpful to contribute to a consistent understanding of patient relevance.

The critical need for postmarketing surveillance in gene therapy for haemophilia

INTRODUCTION

The goal of gene therapy for haemophilia is to alter the clinical phenotype to a milder form or even cure, by increasing endogenous coagulation factor levels through transfer of a functional gene encoding the respective deficient coagulation factor and subsequent transgene expression. Over the past decade, there has been tremendous progress in gene therapy, particularly in use of liver-directed adeno-associated viral vectors, such that several programmes for both haemophilia A and B are in phase 3 trials. With regulatory approval of the first gene therapy product expected as early as mid-2020, there is an urgent need for a mechanism to collect long-term data on safety and variability and durability of efficacy. There will be elements required by regulators for postmarketing surveillance and additional data needed to enhance our understanding of gene therapy outcomes and their impact on the lives of people with haemophilia.

AIM

The aim of this manuscript was to describe efforts underway by the American Thrombosis and Hemostasis Network and the World Federation of Hemophilia to collect long-term harmonized data and considerations of the European and US regulatory agencies, which will inform ongoing data collection.

METHODS

The status of data collection around gene therapy in haemophilia and important outcome measures were obtained by literature review. Each author described elements relevant to the activities of their organization.

CONCLUSION

Support of all stakeholders in gene therapy, providers, patients, industry and regulators, augers successful capture of uniform long-term safety and efficacy data to ensure optimal treatment of people with haemophilia.