Predictors of quality of life among adolescents and young adults with a bleeding disorder

Determinants of adherence and consequences of the transition from adolescence to adulthood among young people with severe haemophilia (TRANSHEMO): A multicentric French national observational cross-sectional study based on the FranceCoag registry

INTRODUCTION

It is necessary to gain insights into adherence to healthcare in people with severe haemophilia (PwSH), especially during the transition from paediatric to adult care, which is an important phase in lives of young people with childhood chronic disease. This adherence can be considered as a marker of successful transition.

OBJECTIVES

The main objective of the quantitative phase of the TRANSHEMO project was to compare the adherence to healthcare between adolescents and young adults (YAs) with severe haemophilia. The secondary objective was to identify the determinants (facilitators and barriers) of this adherence and associations between these determinants.

METHODS

A multicentre, observational, cross-sectional study was conducted in 2017-2019 on PwSH aged between 14 and 17 years (adolescents) or between 20 and 29 years (YAs), included in the FranceCoag registry and having completed the questionnaires. The adherence to healthcare (treatment regimens and clinical follow-up) was compared between adolescents and YAs using the chi-squared test. The determinants of this adherence were analysed by structural equation modelling.

RESULTS

There were 277 participants, 107 adolescents, and 170 YAs. The rate of adolescents adhering to healthcare was 82.2%, while the rate of YAs was 61.2% (p < .001). The barriers to the adherence to healthcare were being YA, having repeated at least one school grade and presenting mental health concerns.

CONCLUSION

Adolescents had better adherence to healthcare than YAs. According to the determinants enlightened in this project, targeted supportive strategies and adapted therapeutic education programs can be developed for young PwSH to facilitate their adherence to healthcare.

Von Willebrand Disease Epidemiology, Burden of Illness and Management: A Systematic Review

Introduction

Although hereditary von Willebrand disease (VWD) is the most common bleeding disorder, its epidemiology is not well understood. A systematic review (PROSPERO CRD42020197674/CRD42021244374) on the epidemiology/burden of illness of VWD was conducted to better understand patients' unmet needs.

Methods

Observational studies (published January 1, 2010 to April 14, 2021) were identified in MEDLINE and Embase databases, using free-text keywords and thesaurus terms for VWD and outcomes of interest. Pragmatic web-based searches of the gray literature, including conference abstracts, were performed, and reference lists of retained publications were manually searched for additional sources. Case reports and clinical trials (phase 1-3) were excluded. Outcomes of interest were incidence, prevalence, mortality, patient characteristics, burden of illness, and therapeutic management/treatments currently used for VWD.

Results

Of the 3095 identified sources, 168 were included in this systematic review. Reported VWD prevalence (22 sources) ranged from 108.9 to 2200 per 100,000 in population-based studies and from 0.3 to 16.5 per 100,000 in referral-based studies. Reported times between first symptom onset and diagnosis (two sources; mean 669 days; median 3 years) highlighted gaps in timely VWD diagnosis. Bleeding events reported in 72-94% of the patients with VWD (all types; 27 sources) were mostly mucocutaneous including epistaxis, menorrhagia, and oral/gum bleeding. Poorer health-related quality of life (three sources) and greater health care resource utilization (three sources) were reported for patients with VWD than in general populations.

Conclusion

Available data suggest that patients with VWD experience high disease burden in terms of bleeding, poor quality of life, and health care resource utilization.

Defining the Impact of Social Drivers on Health Outcomes for People with Inherited Bleeding Disorders

The ways in which the social drivers of health, also known as the social determinants of health (SDOH), affect health outcomes for people with inherited bleeding disorders (PwIBDs) is unclear. This systematic review of the published literature examines the impact of SDOH on health outcomes in PwIBDs. Articles that included the following parameters in PubMed informed this study: published in English between 2011–2021; available in free full text; study population diagnosed with an inherited bleeding disorder; and study measured at least one of the clinical/non-clinical outcome measures: bleeding frequency, chronic pain, mortality, quality of life (QOL), and/or cost. The main findings from the 13 included articles emphasized the unmet need for reducing the economic burden with sustainable population health strategies and treatment options for PwIBDs. Rural location was also a significant contributor to both delayed diagnosis and decreased access to care. Furthermore, the need for a multidisciplinary comprehensive care team to address physical, psychosocial, and emotional needs of PwIBDs was raised as a priority target in the desire for equitable and optimal health. This systematic literature review suggests that the SDOH are associated with inferior health outcomes and may influence the clinical progression of inherited bleeding disorders.

Altered neural control of gait and its association with pain and joint impairment in adults with haemophilic arthropathy: Clinical and methodological implications

INTRODUCTION

It is unknown whether altered neural control is associated with clinical outcomes in people with haemophilic arthropathy (PWHA). The dynamic motor control index during walking (Walk-DMC) is a summary metric of neural control.

AIMS

The primary aim of this study was to apply the Walk-DMC to assess if people diagnosed with haemophilic arthropathy have impaired neural control of gait and investigate the association of Walk-DMC with pain and joint impairment.

METHOD

The Walk-DMC was assessed using surface electromyography in 11 leg muscles. Twenty-two PWHA and 15 healthy subjects walked on a 30-m walkway at 1 m/s. In addition, pain (visual analogue scale), knee flexion contracture (degrees) and joint impairment (Haemophilia Joint Health Score, HJHS) were assessed. The clinical outcomes were correlated with the Walk-DMC. Multiple regression analysis was performed to predict the Walk-DMC using the clinical outcomes.

RESULTS

In 13 PWHA the Walk-DMC was beyond the normal range (80-120 pts). PWHA with an altered Walk-DMC showed more years with arthropathy, more pain, higher knee flexion contracture and a higher HJHS score (P < .05, effect size > .8). Significant negative moderate associations between Walk-DMC and pain, knee flexion contracture and HJHS were found (P < .05). The model that best predicted the Walk-DMC was the pain with knee flexion contracture (R²  = .44; P = .004).

CONCLUSIONS

PWHA with abnormal neural control of gait also has more years with arthropathy, more pain, and more impaired joints. Our results indicate an association between the Walk-DMC index and joint damage, specifically with pain in combination with knee flexion contracture.

The lived experience of women with a bleeding disorder: A systematic review

Background

Research studies have described the morbidity associated with inherited bleeding disorders such as hemophilia and von Willebrand disease in women, but their effect on daily living has long been underrecognized. This systematic review sought to document the lived experience of women with a bleeding disorder by assessing research findings on quality of health care, socioeconomic factors, and mental health.

Methods

A systematic search was carried out in Web of Science, the Cumulative Index to Nursing and Allied Health Literature, and PubMed on July 31, 2020. References were hand searched. Abstracts of the 2019 and 2020 congresses on bleeding disorders were hand searched. Key journals were screened for relevant studies published after the search date until the analysis was completed on December 7, 2020.

Results

Of 635 potentially eligible publications, 27 published since 1998 were selected for review. Most studies were of moderate to high quality but meta‐analysis of quantitative studies was not possible due to difference in outcomes and assessment.

Women with a bleeding disorder experience obstacles to accessing care, difficulties living with their disorder, interference with schooling and work, and poor mental health. Diagnostic delay and lack of recognition of symptoms mean treatment and support may not be available. Where comparisons with controls were made, women’s negative experiences were greater than those of men.

Conclusions

Women with bleeding disorders experience major negative impacts of their disorders on daily life and mental well‐being. Many of the challenges identified in earlier research are evident in more recent studies.

Investigating the Added Value of the EQ-5D-5L With Two Bolt-On Items in Patients With Hemophilia

Objective: This study examined the impact of adding two condition-specific bolt-on items to the EQ-5D-5L and assessed their psychometric properties in patients with hemophilia.

Methods: The data were obtained from a nationwide cross-sectional online survey of patients with hemophilia in China. Self-reported and proxy-reported data were analyzed separately. Ceiling effect, informativity, and discriminatory power of the EQ-5D-5L with two bolt-on items, dignity (DG), and bleeding (BL), were examined. Spearman's rank correlation (rho) was used to assess the associations of the EQ-5D-5L and two bolt-on items with the Hemophilia Quality of Life Questionnaire for Adults (Haem-A-QoL) and SF-12. Multiple regression analysis was performed to evaluate the explained variance of the EQ-5D-5L and bolt-on items in predicting EQ-VAS scores.

Results: A total of 895 patients and 222 caregivers completed the questionnaire. The ceiling effect decreased from 1.9 to 0.6% and 5.9 to 0.9% when using the EQ-5D-5L and the EQ-5D-5L with two bolt-on items among participants with both self- and proxy-completed questionnaires. Both DG and BL were strongly correlated with Haem-A-QoL sum score [rho: DG = 0.64 (patient) vs. 0.66(proxy); BL = 0.49 (patient) vs. 0.31 (proxy)], SF-12 mental component [rho: DG = −0.36 (patient) vs. −0.41 (proxy); BL = −0.53 (patient) vs. −0.57(proxy)], and SF-12 physical component [rho: DG = −0.61 (patient) vs. −0.61 (proxy); BL = −0.35 (patient) vs. −0.39 (proxy)]. Known-group comparisons confirmed that the two bolt-on items had satisfactory discriminatory power. Multiple regression analysis indicated that adding two bolt-on items significantly increased the ability to predict EQ-VAS scores. The adjusted R² increased by 8.2 and 8.8% for reports completed by the patients or patients' proxy respondents, respectively.

Conclusion: Adding the DG and BL bolt-on items can increase performance on the EQ-5D-5L in patients with hemophilia. A future valuation study will be carried out.

The effect of emicizumab prophylaxis on long-term, self-reported physical health in persons with haemophilia A without factor VIII inhibitors in the HAVEN 3 and HAVEN 4 studies

Introduction

Severe haemophilia A (HA) has a major impact on health‐related quality of life (HRQoL).

Aim

Assess the impact of emicizumab on HRQoL in persons with severe HA (PwHA) without factor VIII (FVIII) inhibitors in the phase 3 HAVEN 3 and 4 studies.

Methods

This pooled analysis examines the HRQoL of PwHA aged ≥ 18 years treated with emicizumab prophylaxis via Haemophilia‐Specific Quality of Life Questionnaire for Adults (Haem‐A‐QoL) and EuroQoL 5‐Dimensions 5‐levels (EQ‐5D‐5L). In particular, changes from baseline in Haem‐A‐QoL ‘Physical Health’ (PH) domain and ‘Total Score’ (TS) are evaluated.

Results

Among 176 evaluable participants, 96 (55%) had received prior episodic treatment and 80 (45%) prophylaxis; 70% had ≥ 1 target joint and 51% had experienced ≥ 9 bleeds in the previous 24 weeks. Mean Haem‐A‐QoL PH and TS improved after emicizumab initiation. Mean (standard deviation) –12.0 (21.26)‐ and –8.6 (12.57)‐point improvements were observed in PH and TS from baseline to Week 73; Week 73 scores were 27.9 (24.54) and 22.0 (14.38), respectively. Fifty‐four percent of participants reported a clinically meaningful improvement in PH scores (≥ 10 points) by Week 73. Subgroups with poorer HRQoL prior to starting emicizumab (i.e. receiving episodic treatment, ≥ 9 bleeds, target joints) had the greatest improvements in PH scores, and corresponding reductions in missed workdays; change was not detected among those previously taking prophylaxis. No change over time was detected by the EQ‐5D‐5L questionnaire.

Conclusions

Emicizumab prophylaxis in PwHA without FVIII inhibitors resulted in persistent and meaningful improvements in Haem‐A‐QoL PH and less work disruption than previous treatment.

Patient-reported Outcome Measures in Pediatric Non-Malignant Hematology: A Systematic Review

Patient-reported outcome measures (PROMs) are questionnaires completed by patients or caregivers without influence by health care professionals. As such, PROMs show subjective health experiences, enhance the clinical information available to providers, and inform clinical action. The objective of this systematic review is to identify and list which validated PROMs have been used to monitor health-related quality of life in pediatric patients with nonmalignant hematology (hemophilia, immune thrombocytopenia, sickle cell disease, and thalassemia). Databases (MEDLINE, Embase, HaPI, CINAHL, and PsycTESTS) were searched to identify publications that validated or used PROMs as an outcome measure in the 4 disease groups. Overall, 209 articles met the inclusion criteria, identifying 113 PROMs. Of the 113 identified PROMs, 95 are generic and can be used in multiple disease groups. The Pediatric Quality of Life Generic Core Scales was the most frequently used generic PROM (68 studies). The 18 remaining PROMs were disease specific. The results of this review, together with the COSMIN tool for selecting outcome measures, will allow clinicians to evaluate the PROMs that are best suited to their patient population. In addition, the focus groups are currently being conducted with patients, parents, and clinicians to determine the optimal use of PROMs in the clinical environment.

The relationship of self-compassion and hope with quality of life for individuals with bleeding disorders

INTRODUCTION

Minimal research has been conducted examining the relationship of positive psychology variables with quality of life (QOL) for individuals with bleeding disorders. While many individuals manage their bleeding disorders well, some are at higher risk of developing psychosocial complications due to the daily stressors of managing illness-related symptoms.

AIM

The purpose of this study is to better understand the relationships between two positive psychology variables, self-compassion and hope and QOL (overall, psychosocial and physical) among individuals diagnosed with bleeding disorders.

METHODS

Participants completed a survey identifying demographic information as well as rating scales of self-compassion, hope and quality of life. We conducted Pearson correlational and standard multiple regression analyses to explore the bivariate and linear relationships between the aforementioned variables in a sample of 86 patients with bleeding disorders between the ages of 15 and 65.

RESULTS

Self-compassion and hope were significantly related to QOL. Together, self-compassion and hope were predictive of overall QOL, psychosocial QOL and physical QOL. However, hope was the only individual predictor of all three QOL dimensions.

CONCLUSION

Due to the significant relationships found between self-compassion, hope and QOL in this sample, it may be beneficial to incorporate positive psychology factors into the treatment of those diagnosed with bleeding disorders, especially those at higher risk for decreased QOL.

A Systematized review of experiences of individuals in Arnett's emerging adulthood stage who live with or are at-risk for genetic conditions

Emerging adulthood, a distinct developmental period between ages 18 and 29 years, comprises five features: identity exploration, experimentation/possibilities, negativity/instability regarding one's outlook, self-focus, and feeling in-between adolescence and adulthood. A growing literature examines the impact of genetic conditions on individuals who chronologically fit the emerging adulthood period. This systematized literature review uses the emerging adulthood theory to determine whether individuals living with or at-risk for a genetic condition experience the features of this period as well as similarities and differences between these two groups. A literature search yielded 1,303 peer-reviewed papers from the 17 years since emerging adulthood theory was published. Ten papers met inclusion criteria-five for those Living With a genetic condition (e.g., cystic fibrosis) and five for those At-Risk for a genetic condition (e.g., hereditary breast and ovarian cancer). Content analysis yielded themes consistent with the five emerging adulthood features for both individuals Living With and At-Risk for genetic conditions. Negativity/instability was most prevalent, and feeling in-between was least prevalent in both groups. Results further suggest unique challenges related to one's genetic conditions/risk with respect to independence (from family, healthcare providers), career/education, relationships/social life, family planning, and life perspective experiences. Salient differences were apparent between the groups in their experiences of the emerging adulthood features. For instance, Living With individuals reported challenges concerning their ongoing physical symptoms, whereas At-Risk individuals reported challenges regarding genetic testing decisions and anticipation of physical symptoms. Thus, emerging adults Living With and At-Risk for genetic conditions appear to experience the main emerging adulthood features, but they face unique challenges related to their genetic conditions/risk. Understanding emerging adults' experiences can aid genetic counselors in addressing their specific concerns.

Congenital platelet disorders and health status-related quality of life

BACKGROUND

Patients with congenital blood platelet disorders (CPDs) demonstrate a predominantly mucocutaneous bleeding tendency. Repeated bleeds throughout life can have a significant impact on health status-related quality of life (HR-QoL), but few studies have investigated HR-QoL in patients with CPDs.

OBJECTIVES

To determine HR-QoL in patients with suspected or confirmed CPDs as compared with the general Dutch population and to assess the association between bleeding phenotype and HR-QoL.

METHODS

Data were derived from the Thrombocytopathy in the Netherlands (TiN) study, a cross-sectional study of individuals suspected for a congenital platelet defect. TiN patients with an increased ISTH Bleeding Assessment Tool (ISTH-BAT) score (>3 in men and > 5 in women) were included for analysis. HR-QoL was assessed with the Short Form (SF)-36 survey. Bleeding symptoms were evaluated with the ISTH-BAT, resulting in a bleeding score.

RESULTS

One hundred fifty-six patients were analyzed, of whom 126 (81%) were women. Sixty-two patients (40%) had a confirmed CPD. Compared to the general Dutch population, patients with a suspected or confirmed CPD reported decreased physical functioning, limitations in daily activities due to physical health problems, limitations in social activities, decreased energy levels and fatigue, pain, and lower general health status. HR-QoL was not correlated with the ISTH-BAT score and was similar in patients with a confirmed CPD and those in whom a CPD could not be diagnosed.

CONCLUSION

A bleeding tendency in patients with a suspected or confirmed CPD significantly impacts HR-QoL, independent of a confirmed explanatory diagnosis.

Economic impact model of delayed inhibitor development in patients with hemophilia a receiving emicizumab for the prevention of bleeding events

Aims: Cumulative exogenous factor VIII (FVIII) exposure is an important predictor of developing neutralizing antibodies (inhibitors) to FVIII in patients with persons with hemophilia A (PwHA). The aim of this study was to model the costs of emicizumab versus FVIII prophylaxis and total treatment costs for patients with severe HA.Materials and Methods: An Excel-based decision model was developed to calculate cumulative costs in PwHA over a 20-year time horizon from the US payer perspective. The model considered persons with severe HA beginning at age 12 months with no prior FVIII exposure and initiating prophylaxis with emicizumab or FVIII. PwHA could develop inhibitors on accumulation of 20 FVIII exposure days. PwHA with inhibitors replaced FVIII with bypassing agents until inhibitors resolved spontaneously, following immune tolerance induction (ITI), or at the end of the time horizon. The primary model outcome was the difference in emicizumab versus FVIII treatment costs in 2019 USD. Sensitivity analyses were performed to test the robustness of results.Results: Total incremental cost over 20 years was -$1,945,480 (emicizumab arm, $4,919,058; FVIII arm, $6,864,538). Prophylaxis costs (emicizumab arm, $4,096,105; FVIII arm, $6,290,919) comprised the majority of costs in both groups, followed by breakthrough bleed treatment for the FVIII arm ($342,652) and ITI costs for the emicizumab arm ($733,671). Higher costs in the FVIII group reflected earlier inhibitor development (FVIII, 4 months; emicizumab, 162 months) and switch to bypassing agents.Limitations: The model design reflects a simplified treatment pathway for patients with severe HA who initiate FVIII or emicizumab prophylaxis. In the absence of clinical data, a key conservative assumption of the model is that patients receiving emicizumab and FVIII prophylaxis have the same risk of developing inhibitors.Conclusions: This study suggests that prophylaxis with emicizumab results in cost savings compared to FVIII prophylaxis in HA.

How I manage severe von Willebrand disease

Von Willebrand disease (VWD) is the most common inherited bleeding disorder. Most patients with mild and moderate VWD can be treated effectively with desmopressin. The management of severe VWD patients, mostly affected by type 2 and type 3 disease, can be challenging. In this article we review the current diagnosis and treatment of severe VWD patients. We will also discuss the management of severe VWD patients in specific situations, such as pregnancy, delivery, patients developing alloantibodies against von Willebrand factor and VWD patients with recurrent gastrointestinal bleeding. Moreover, we review emerging treatments that may be applied in future management of patients with severe VWD.

Professional functioning of young adults with congenital coagulation disorders in the Netherlands

Introduction and Aim

Suboptimal health‐related quality of life and lowered employment rates found in a previous study in young adults (YA) with congenital coagulation disorders (CCD) in the Netherlands underline the need for more insight into professional functioning of YA with CCD and into determinants of professional functioning.

Methods

Young adults (18‐30 years) with CCD participated in a cross‐sectional study. Professional functioning was assessed with the Work Productivity and Activity Impairment questionnaire (WPAI). Potential determinants were assessed with the Course of Life Questionnaire (CoLQ), Pediatric Quality of Life Inventory Young Adult version (PedsQL_YA), Illness Cognition Questionnaire (ICQ) and Haemophilia Activities List (HAL). Logistic regression analyses were performed in the complete sample of YA with CCD, and in YA men with haemophilia separately, to examine determinants of WPAI outcomes.

Results

Ninety‐four YA (77 men; mean age 24.1 years, SD 3.5 and 17 women; mean age 24.5 years, SD 3.8) with CCD (74% haemophilia A/B) participated. 74.5% of YA were paid employed for on average 30 hours per week. Of these, more than a quarter reported work impairment. Older age and a non‐severe type of haemophilia (in the sample of YA men with haemophilia) were associated with successful (paid) employment. No variables were associated with professional functioning (expressed as Presenteeism and Overall work impairment) in patients with CCD or haemophilia.

Conclusion

Three‐quarters of YA with CCD were successful in finding paid employment. Though absenteeism was low, YA with paid employment needs attention as a considerable part experienced work impairment.

Pain Prevalence, Characteristics, and Impact Among People with Hemophilia: Findings from the First Portuguese Survey and Implications for Pain Management

Background

Hemophilia is a rare disorder characterized by spontaneous bleeding, with pain being a critical aspect. However, a systematic assessment of hemophilia-related pain in Portugal has never been conducted.

Objective

To understand the pain experience among Portuguese people with hemophilia (PWH) by describing its prevalence, characteristics, and impact and uncovering intervention needs in the realm of hemophilia-related pain care.

Methods

A cross-sectional observational survey, with age-adapted versions of questions concerning pain, emotional distress, and quality of life, was answered by 104 adults, 21 children/teenagers (10–17 years), and 19 children (1–9 years).

Results

Pain was reported by 82 (78.8%) adults, 16 (76.2%) children/teenagers, and 13 (68.4%) children, with 65 (62.5%), 13 (61.9%), and eight (42.1%) of them reporting pain lasting more than three months, respectively. The mean number of pain locations (SD) was 5.23 (3.95) for adults, 4.13 (3.48) for children/teenagers, and 3.15 (1.99) for children age 1–9 years, with lower limbs pain causing the greatest negative impact. More frequent pain-triggering factors were physical effort/movements (61, 74.4%) for adults and hemarthrosis for younger groups (children/teenagers: 14, 87.5%; children: 9, 69.2%). Bleeds yielded the highest mean pain intensity (adults: M [SD] = 5.67 [2.09]; children/teenagers: M [SD] = 5.69 [2.15]). Adults with pain revealed more anxiety (odds ratio [OR] = 1.698, P = 0.003) and depression (OR = 1.961, P = 0.025) and lower quality of life (OR = 0.928, P = 0.001).

Conclusions

The current findings highlight the high prevalence, duration, and frequency of pain at all ages, its potentially simultaneous acute and chronic nature, its likelihood to affect multiple locations concurrently, and its detrimental impact. Important insights concerning intervention needs are presented, ultimately contributing to the improvement of hemophilia-related pain management and patient care.

Psychometric properties of the Patient Reported Outcomes, Burdens and Experiences (PROBE) questionnaire

OBJECTIVE

To assess the psychometric properties of the Patient Reported Outcomes, Burdens and Experiences (PROBE) questionnaire.

METHODS

This study was a cross-sectional, multinational study. Participants were enrolled if they were more than 10 years old and people with haemophilia A or B or people without a bleeding disorder. Participants were invited through non-governmental patient organisations in 21 countries between 01/27/2016 and 02/23/2017. The following psychometric properties: missing data, floor and ceiling effects, exploratory factor analysis and internal consistency reliability were examined. A PROBE Score was derived and assessed for its convergent and known groups validity.

RESULTS

The study analysed the data on 916 participants with median age of 37.0 (IQR 27.0 to 48.0) years, 74.8% male. In the domain assessing patient-reported outcomes (PROs), more than 15% of participants presented a ceiling effect for all items but two, and a floor effect for one item. Factor analysis identified three factors explaining the majority of the variance. Cronbach's alpha coefficient indicated good internal consistency reliability (0.84). PROBE items showed moderate to strong correlations with corresponding EuroQol five dimension 5-level instrument (EQ-5D-5L) domains. The PROBE Score has a strong correlation (r=0.67) with EQ-5D-5L utility index score. The PROBE Score has a known groups validity among various groups.

CONCLUSIONS

The results of this study suggest that PROBE is a valid questionnaire for evaluating PROs in people with haemophilia as well as control population. The known-group property of PROBE will allow its use in future clinical trials, longitudinal studies, health technology assessment studies, routine clinical care or registries. Additional studies are needed to test responsiveness and sensitivity to change.

TRIAL REGISTRATION NUMBER

NCT02439710; Results.

Practical Implications of Factor IX Gene Transfer for Individuals with Hemophilia B: A Clinical Perspective

Gene therapy for severe hemophilia is on the cusp of entering clinical practice. However, there is limited clinical experience in this area given that gene transfer is a relatively recent technology. Therefore, this clinical perspective article will review the evidence supporting gene therapy in this field, examine ways to open a dialogue about gene therapy with patients in the clinic setting, and present a case of a participant in a recent clinical trial of gene therapy for hemophilia. Clinical trials in hemophilia using adeno-associated virus (AAV) vectors to transfer functional factor IX (FIX) have reported increases in FIX activity to functional levels, reduced bleed frequency, and a lessening or abrogation of the need for costly FIX replacement. The safety profile of AAV-mediated gene therapy also appears positive, with manageable, asymptomatic increases in liver enzymes being the most commonly described adverse event. Examining a clinical case in hemophilia B more closely, gene transfer decreased annualized bleeds from six (unknown or spontaneous) bleeds before treatment to three (spontaneous) bleeds after treatment alongside a 55% reduction in FIX replacement. The participant experienced an increase in traumatic bleeds after treatment, which appears to reflect increased physical activity and early prophylaxis discontinuation. After the gene transfer, the participant considered his hemophilia to be "cured," which emphasizes the need to manage patient expectations, particularly regarding activity levels and bleed risk in the immediate post-treatment period. Gene therapy for hemophilia has the potential to transform the lives of affected individuals and is likely to create a new class of hemophilia patient who has shifted from a severe to a mild phenotype. Despite having a mild phenotype, these individuals may retain a legacy of increased bleed risk and joint damage from their years with severe hemophilia and will need different clinical management compared to a more typical individual with mild hemophilia.