Evidence of a disability paradox in patient-reported outcomes in haemophilia

Clinical and Humanistic Burden of Non-inhibitor Haemophilia A in Five European Countries: Insights from the CHESS II Study

INTRODUCTION

Haemophilia A (HA) is a congenital bleeding disorder caused by a deficiency/absence of factor VIII (FVIII) and characterised by frequent, acute and prolonged spontaneous or traumatic bleeding events, often leading to haemophilic arthropathy and progressive joint deterioration. HA severity is characterized by endogenous FVIII activity: mild (> 5-40%), moderate (1-5%), or severe (< 1%). HA poses a substantial clinical and socioeconomic burden on people with HA (PWHA), their caregivers, and society. This analysis evaluates clinical and patient-centric outcomes of a cohort of individuals with non-inhibitor HA sampled from France, Germany, Italy, Spain, and the UK in the 'Cost of Haemophilia in Europe: A Socioeconomic Survey II' (CHESS II) study.

METHODS

CHESS II was a cross-sectional burden-of-illness study collecting clinical and socioeconomic data on adult (≥ 18 years) individuals with haemophilia A or B of any severity with or without inhibitors from eight European countries. Descriptive analyses were conducted examining physician-reported demographics, clinical and health resource utilisation information. PWHA-reported health-related quality of life (HRQoL) using the EQ-5D-5L and Work Productivity and Activity Impairment (WPAI) were also examined. Outcomes were stratified by HA severity and reported at country level.

RESULTS

Demographics and clinical characteristics of the cohort (N = 880) were generally consistent across countries. Individuals with severe HA experienced more frequent bleeding events and joint disease despite broad use of factor replacement therapy long-term prophylaxis. A minority of those with mild or moderate HA also experienced such challenges. HRQoL and workforce participation diminished, and chronic pain increased, with increasing HA severity.

CONCLUSION

This analysis provides up-to-date insights on the impact of HA across five European countries. Increasing HA severity was generally associated with worse clinical outcomes, HRQoL and workforce participation. These findings suggest a place for continued evidence-based tailored treatment and clinical management approaches in addressing the residual burden of HA.

Exploring the relationship between condition severity and health-related quality of life in people with haemophilia A across Europe: a multivariable analysis of data from the CHESS II study

BACKGROUND

Haemophilia A (HA; Factor VIII deficiency) is a congenital X-linked bleeding disorder characterized by trauma-related or spontaneous bleeding events, most notably arising within the intraarticular space and resulting in chronic inflammation and degeneration of affected joints. Endogenous clotting factor activity relative to normal levels determines the severity of HA symptoms, as mild (> 5-40%), moderate (1-5%), or severe (< 1%). Within the current environment of rapid evolution in HA management, we seek to understand the interplay of condition severity and health-related quality of life (HRQoL) to characterise and differentiate unmet needs among people with HA (PwHA).

METHODS

A generalised linear regression model (GLM) was developed to explore the relationship between HA severity and EQ-5D-5 L index score from adult HA patients sampled in the "Cost of Haemophilia across Europe - a Socioeconomic Survey II" (CHESS II) cross-sectional, retrospective burden of illness study among adults with hereditary haemophilia A or B from eight European countries. HA patients of any severity with no active inhibitors during the 12 months prior to data capture and a completeEQ-5D-5 L response were included. A base GLM model was specified with covariates for demographic and clinical characteristics (age, body mass index, country, employment, HA severity, annual bleeding rate, problem joints, and chronic pain).

RESULTS

Of 381 evaluable patients, 221 (58.0%) had severe HA, 96 (25.2%) had moderate HA, and 64 (16.8%) had mild HA. Among the covariates included in the GLM model and after controlling for haemophilia-related outcomes, a significant association was observed between mild HA and higher EQ-5D-5 L index score (average marginal effects, 0.084; p = 0.016) relative to severe HA. Patient country of residence and magnitude of HA-related chronic pain were also associated with significant differences in index scores, with the latter showing a negative relationship with HRQoL outcomes.

CONCLUSIONS

Condition severity and chronic pain are significant predictors of HRQoL in PwHA. Durable bleeding protection and effective management of chronic pain have the potential to address unmet treatment needs in this population.

Appropriateness of the EQ-5D-5L in capturing health-related quality of life in individuals with transfusion-dependent β-thalassemia: a mixed methods study

BACKGROUND

Individuals with transfusion-dependent β-thalassemia (TDT) experience symptoms and functional impacts that reduce their health-related quality of life. However, EQ-5D-derived health utility index scores in TDT often indicate good HRQoL, suggesting the EQ-5D may not adequately capture the impact of TDT. This study explored the disease and treatment burden of TDT and examined the appropriateness of the EQ-5D-5L descriptive system (DS) in measuring HRQoL in TDT.

METHODS

Adults with TDT in the United Kingdom, United States, and France completed a background questionnaire and EQ-5D-5L DS, followed by 60-minute semi-structured interviews on symptoms and HRQoL impacts of TDT (concept elicitation) and appropriateness of EQ-5D-5L DS (cognitive debrief). Transcribed interviews were analyzed using thematic and content analyses. The relationship between TDT symptoms and impacts were summarized in a conceptual model. EQ-5D-5L DS was mapped to concepts identified in the qualitative data to assess its capture of HRQoL concepts. Participants' EQ-5D-5L DS scores were compared to their qualitative descriptions for each dimension to assess their concordance.

RESULTS

Thirty participants in the United States (n = 14 [46.7%]), United Kingdom. (n = 12 [40.0%]), and France (n = 4 [13.3%]) completed the study (73.3% female; mean age = 28.4 years [standard deviation (SD) = 5.1]; mean annual red blood cell transfusion [RBCT] frequency = 18.4 [SD = 7.6]). Participants reported TDT symptoms and impacts on HRQoL, all fluctuating across the RBCT cycle. EQ-5D-5L DS did not fully capture 11 of 16 (68.8%) HRQoL concepts reported. Most participants (n = 20/27 [74.1%]) reported that EQ-5D-5L DS did not capture important aspects of living with TDT, and 42.9% (n = 12/28) reported negative/neutral overall impressions of EQ-5D-5L DS. The highest degree of discordance between participants' qualitative data and EQ-5D-5L DS dimension scores was observed with mobility (42.3%) and self-care (34.6%), where the qualitative descriptions relating to these dimensions were worse than their quantitative scores.

CONCLUSION

Current findings suggest that EQ-5D-5L DS lacks content validity and the derived health utility index score may not fully represent the burden of disease in TDT.

Three-year outcomes of valoctocogene roxaparvovec gene therapy for hemophilia A

BACKGROUND

Valoctocogene roxaparvovec transfers a human factor (F)VIII coding sequence into hepatocytes of people with severe hemophilia A to provide bleeding protection.

OBJECTIVES

To present 3-year efficacy and safety in the multicenter, open-label, single-arm, phase 3 GENEr8-1 trial.

METHODS

GENEr8-1 enrolled 134 adult males with severe hemophilia A who were receiving FVIII prophylaxis. Efficacy endpoints included annualized bleeding rate, annualized FVIII utilization, FVIII activity (chromogenic substrate assay; imputed as 1 IU/dL at baseline and 0 IU/dL after discontinuation), and the Haemophilia-Specific Quality of Life Questionnaire for Adults. Safety was assessed by adverse events (AEs).

RESULTS

At week 156, 131 of 134 participants remained in the study; overall, 17 of 134 resumed prophylaxis. Mean annualized bleeding rate for treated bleeds decreased from 4.8 (SD, 6.5) bleeds/y at baseline to 0.8 (SD, 2.3; P < .0001) bleeds/y after prophylaxis (prophylaxis cessation to last follow-up) and 0.97 (SD, 3.48) bleeds/y during year 3. Annualized FVIII utilization decreased 96.8% from baseline after prophylaxis and 94.2% during year 3. At week 156, mean and median FVIII activity were 18.4 (SD, 30.8) and 8.3 IU/dL, respectively. FVIII activity decrease was lower between years 2 and 3 than between years 1 and 2. At the end of year 3, clinically meaningful improvements in the Haemophilia-Specific Quality of Life Questionnaire for Adults Total Score were observed (mean change from baseline, 6.6; 95% CI, 4.24-8.87; P < .0001). Mild alanine aminotransferase elevations remained the most common AE during year 3 (23.7% of participants). A serious AE of B-cell acute lymphoblastic leukemia was considered unrelated to treatment.

CONCLUSION

Hemostatic efficacy was maintained, and safety remained unchanged from previous years.

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.

A 360-degree perspective on adeno-associated virus (AAV)-based gene therapy for haemophilia: Insights from the physician, the nurse and the patient

BACKGROUND

Adeno-associated virus (AAV)-based gene therapy for haemophilia has advanced substantially in the last 13 years; recently, three products have received approvals from regulatory authorities. Although the impact on quality of life seems promising, some limitations remain, such as the presence of pre-existing anti-AAV neutralising antibodies and the occurrence of hepatotoxicity. This review follows the CSL Behring-sponsored symposium at the 27th Congress of the European Hematology Association (EHA) 2022 that examined the haemophilia gene therapy process from a 360-degree multidisciplinary perspective. Here, the faculty (haematologist, nurse and haemophilia patient) summarised their own viewpoints from the symposium, with the aim of highlighting the key considerations required to engage with gene therapy effectively, for both patients and providers, as well as the importance of multidisciplinary collaboration, including with industry.

RESULTS

When considering these new therapies, patients face a complex decision-making process, which includes whether gene therapy is right for them at their current stage of life. The authors agreed that collaboration and tailored education across the multidisciplinary team (including patients and their carers/families), starting early in the process and continuing throughout the long-term follow-up period, is key for the success of gene therapy. Additionally, patient expectations, which may surround eligibility, follow-up requirements and treatment outcomes, should be continually explored. During these ongoing discussions, transparent communication of the unknown factors, such as anticipated clotting factor levels, long-term factor expression and safety, and psychological changes, is critical. To ensure efficiency and comprehensiveness, clearly‑defined protocols should outline the whole process, which should include the recording and management of long-term effects.

CONCLUSION

In order to engage effectively, both patients and providers should be familiar with these key considerations prior to their involvement with the haemophilia gene therapy process. The future after the approval of haemophilia gene therapies remains to be seen and real-world evidence is eagerly awaited.

Emicizumab is well tolerated and effective in people with congenital hemophilia A regardless of age, severity of disease, or inhibitor status: a scoping review

Background

With the treatment landscape continually evolving, it is vital that the hemophilia community have an overview of all published data for approved therapies, such as emicizumab, to support shared decision making.

Objectives

To bring together the clinical and real-world data for emicizumab use in people with congenital hemophilia A, regardless of age, disease severity, or factor VIII inhibitor status. Key focus areas were safety, efficacy, and quality of life (QoL).

Methods

This scoping review used citation databases (PubMed, Embase, and the Cochrane Library) and manual searches of abstract books. Publications reporting original data for emicizumab in people with hemophilia A, published in English after December 2014, and reporting select endpoints were included. This narrative synthesis focused on zero bleeds, treated annualized bleeding rate (ABR), adverse events, and QoL measures.

Results

Overall, 97 publications were included (cut-off: August 9, 2022). Treated ABR remained low (calculated mean and median treated ABRs ranged between 0.7-1.3 and 0.0-1.4, respectively), and the median percentage of people with zero treated bleeds was 66.7%. The proportion of people experiencing treatment-related adverse events ranged from 0.0% to 60.0%; most were injection-site reactions. Across 37 publications reporting on safety and enrolling >2300 individuals, 11 thrombotic events and 4 thrombotic microangiopathies were reported. Data from well-established tools show QoL benefits with emicizumab.

Conclusion

This scoping review consolidates the global published experience for emicizumab in people with hemophilia A and supports the fact that emicizumab has an acceptable safety profile, is effective and efficacious in bleed prevention, and is associated with improvements in QoL.

Effect of etranacogene dezaparvovec on quality of life for severe and moderately severe haemophilia B participants: Results from the phase III HOPE-B trial 2 years after gene therapy

INTRODUCTION

For people with haemophilia B (PwHB), bleeding may occur despite prophylaxis, negatively affecting health-related quality of life (HRQoL). The pivotal phase 3 HOPE-B trial investigating the adeno-associated virus gene transfer product, etranacogene dezaparvovec (EDZ), demonstrated sustained factor IX (FIX) activity and bleed protection in PwHB with baseline FIX levels ≤2%.

AIM

Assess how EDZ affects HRQoL in HOPE-B trial participants.

METHODS

HRQoL was evaluated using generic and disease-specific patient reported outcomes (PROs) including the EQ-5D-5L and the Hem-A-QoL questionnaires. Mean domain and total scores were compared 6 months pre- and the first 2 years post-EDZ administration using repeated measures linear mixed models. The percentage of participants with minimal clinically important improvements in HRQoL was also evaluated.

RESULTS

Two years post-EDZ, there were nominally significant increases in the least squares (LS) mean score for the EQ-5D-5L Index Value (.04; p = .0129), reflecting better HRQoL. Nominally significant decreases in the LS mean scores, reflecting better HRQoL, were also found for the Hem-A-QoL total score (-6.0; p < .0001) and the Treatment (-13.94; p < .0001), Feelings (-9.01; p < .0001), Future (-6.45; p = .0004) and Work/School (-5.21; p = .0098) domains. The percentage of participants with ≥15-point improvement ranged from 45.83% (95% CI: 31.37%, 60.83%) for Treatment to 13.89% (95% CI: 4.67%, 29.50%) for Family Planning. Results were similar for Year 1.

CONCLUSION

In conclusion, gene therapy with EDZ improved HRQoL in the first and second years in several Hem-A-QoL domains, including Treatment, Feelings, Work/School and Future domains, whereas improvement in other aspects of HRQoL were not demonstrated.

Patient-reported quality of life and working status outcomes in ambulatory patients with idiopathic inflammatory myopathy

OBJECTIVE

To investigate the health-related quality of life (HR-QoL), work productivity and activity impairment and associated factors among patients with idiopathic inflammatory myopathy (IIM).

METHODS

This was an observational, cross-sectional study. The 189 ambulatory patients with IIM were recruited from May 2019 to May 2022. HR-QoL was measured by the European Quality of Life 5-Dimension (EQ-5D) questionnaire. The Work Productivity and Activity Impairment (WPAI) questionnaire was used to evaluate work productivity and activity impairment. The IIM-related parameters were assessed by the 8-item Manual Muscle Test (MMT-8), Myositis Disease Activity Assessment visual analogue scale (MYOACT), Myositis Damage Index (MDI), Disease Activity Score (DAS) and Physician/Patient Global Assessment (PhGA/PtGA). Quantile regression and ordinal logistic regression were performed to identify the factors, considering EQ-5D or WPAI scores as dependent variables, respectively.

RESULTS

Of the 189 IIM patients enrolled, 60% had DM, 13% had PM and 27% had clinical amyopathic DM. The median EQ-5D score was 1.00 (95% CI 0.73, 1.00), 28% were employed and 45% of overall work was impaired due to health problems. EQ-5D values were positively associated with MMT-8 and negatively with MYOACT, DAS, MDI-global and PhGA/PtGA. For the WPAI, activity impairment was associated with a lower MMT-8 score, older onset age and higher PhGA only in 25th-75th percentile. Increased PtGA was associated with increased activity and overall working productivity impairment in most quantiles (P<0.05).

CONCLUSION

Multiple disease characteristics were associated with reduced HR-QoL or working productivity impairment in patients with IIM, especially for PtGA.

Current status of treatment and disease burden of a cohort of hemophilia B in China

Objective

Hemophilia B is a rare X-chromosome linked hereditary bleeding disorder. Patients require lifelong treatment and it is costly, but there is a lack of research in China on the treatment and burden for this group. Our aim was to review the actual treatment pattern of hemophilia B patients in China, and describe the financial burden and other disease burden from the patient's perspective.

Methods

Using data collected by the Beijing Hemophilia Home Care Center, descriptive statistics were made on the sociodemographic characteristics and treatment of patients. The annual drug costs were calculated according to the actual factor dosage and price.

Results

During the study period, 29.9% of the patients only received on-demand treatment, while the rest of the patients received varying numbers of prophylaxis treatment. The total cost of clotting factors for 341 patients in one year was 16.0 million CNY ($2.5 million), with 46990.8 CNY ($7283.7) per patient. The drug cost of prophylaxis was significantly higher than that of on-demand treatment. The amount of prothrombin complex concentrates used by patients was the largest, more than 5 times of recombinant coagulation factor IX. Based on the average annual wage and average working time of Chinese employees in 2021, the average annual wage loss of HB patients reached 31544.2 CNY ($4889.4). The results of the questionnaire showed that 77.1% and 65.3% of patients had chronic pain and acute pain of different frequencies.

Conclusion

The level of prophylaxis for Chinese patients is low; safer and more effective recombinant drugs are not widely available. Patients also face a high burden of drug costs, as well as indirect costs that cannot be underestimated. Therefore, continued efforts are needed to improve the quality of life of patients by reducing their financial burden and promote standardized treatment.

Preferences for potential benefits and risks for gene therapy in the treatment of sickle cell disease

Objective of this study is to quantify benefit-risk tradeoffs pertaining to potential gene therapies among adults and parents/caregivers of children with sickle cell disease (SCD). A discrete-choice experiment survey was developed in which respondents selected their preferred treatment alternatives in a series of experimentally controlled pairs of hypothetical gene therapies and a "no gene therapy" option. Gene therapy alternatives were defined based on the chance of eliminating SCD symptoms, expected increases in life expectancy they could offer, treatment-related risk of death, and potential increases in lifetime cancer risk. Respondents made selections based on their current disease severity and in the context of expectations of worsened disease. Three clinical sites and 1 patient organization recruited 174 adult patients and 109 parents of children with SCD to complete the survey. Adult and parent respondents were generally willing to choose gene therapies, but the adults required higher expected levels of efficacy (ie, higher chance of eliminating symptoms) than parents to choose gene therapies that conferred mortality risks of ≥10%. When adults and parents of children with less severe symptoms were asked to consider scenarios of higher levels of disease severity, the increased risk tolerance, and the lowest acceptable level of efficacy for gene therapies with mortality risks dropped by >50%. Baseline SCD symptoms are a major driver of gene therapy acceptability. Adults and parents of patients with milder symptoms may prefer other treatment options; however, an expectation of symptoms deterioration triggers strong reassessment of the acceptable benefit-risk balance of this novel technology.

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.

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.

Discrete Choice Experiments in Health State Valuation: A Systematic Review of Progress and New Trends

BACKGROUND

Discrete choice experiments (DCEs) are increasingly used in health state valuation studies.

OBJECTIVE

This systematic review updates the progress and new findings of DCE studies in the health state valuation, covering the period since the review of June 2018 to November 2022. The review reports the methods that are currently being used in DCE studies to value health and study design characteristics, and, for the first time, reviews DCE health state valuation studies published in the Chinese language.

METHODS

English language databases PubMed and Cochrane, and Chinese language databases Wanfang and CNKI were searched using the self-developed search terms. Health state valuation or methodology study papers were included if the study used DCE data to generate a value set for a preference-based measure. Key information extracted included DCE study design strategies applied, methods for anchoring the latent coefficient on to a 0-1 QALY scale and data analysis methods.

RESULTS

Sixty-five studies were included; one Chinese language publication and 64 English language publications. The number of health state valuation studies using DCE has rapidly increased in recent years and these have been conducted in more countries than prior to 2018. Wide usage of DCE with duration attributes, D-efficient design and models accounting for heterogeneity has continued in recent years. Although more methodological consensus has been found than in studies conducted prior to 2018, this consensus may be driven by valuation studies for common measures with an international protocol (the 'model' valuation research). Valuing long measures with well-being attributes attracted attention and more realistic design strategies (e.g., inconstant time preference, efficient design and implausible states design) were identified. However, more qualitative and quantitative methodology study is still necessary to evaluate the effect of those new methods.

CONCLUSIONS

The use of DCEs in health state valuation continues to grow dramatically and the methodology progress makes the method more reliable and pragmatic. However, study design is driven by international protocols and method selection is not always justified. There is no gold standard for DCE design, presentation format or anchoring method. More qualitative and quantitative methodology study is recommended to evaluate the effect of new methods before researchers make methodology decisions.

Quality of life in children and adolescents with hemophilia A: A systematic review and meta-analysis

Background

Various instruments have been used to assess health-related quality of life (HRQoL) in children and adolescents with hemophilia A.

Objective

We systematically reviewed the literature to summarize HRQoL measurement instruments and outcomes in this population.

Methods

MEDLINE, Embase, Cochrane CENTRAL, and LILACS databases were searched. Studies published from 2010 to 2021, reporting HRQoL assessed by generic or hemophilia-specific instruments in individuals aged 0 to 18 years were included. Two independent reviewers performed screening, selection, and data abstraction. Data were meta-analyzed using the generic inverse variance method with the random-effects model for single-arm studies reporting instrument-specific mean total HRQoL scores. Prespecified subgroup meta-analyses were performed. Heterogeneity among studies was assessed using the I 2 statistic.

Results

Six instruments were identified in 29 studies meeting the following inclusion criteria: 4 generic instruments (PedsQL [5 studies], EQ-5D-3L [3 studies], KIDSCREEN-52 [1 study], and KINDL [1 study]) and 2 hemophilia-specific instruments (Haemo-QoL [17 studies] and CHO-KLAT [3 studies]). The overall risk of bias was moderate to low. There was a substantial variability in the primary outcome (mean total HRQoL score) among studies using the same instrument (Haemo-QoL), with scores ranging from 24.10 to 89.58 on a scale from 0 to 100 (higher scores indicating higher HRQoL). Meta-regression with 14 studies using the Haemo-QoL questionnaire demonstrated that 79.34% (R 2 ) of the observed 94.67% total heterogeneity (I 2 ) was explained by the proportion of patients receiving effective prophylactic treatment.

Conclusion

HRQoL assessment in young people with hemophilia A is heterogeneous and context specific. The proportion of patients on effective prophylactic treatment is positively correlated with HRQoL. The review protocol was registered prospectively with PROSPERO (CRD42021235453).

Psychometric Validation of the Haemo-QOL-A in Participants with Hemophilia A Treated with Gene Therapy

Purpose

The hemophilia-specific health-related quality of life (HRQOL) questionnaire (Haemo-QOL-A) is validated for detecting QOL changes following standard therapy for hemophilia A, but has not been rigorously evaluated after gene therapy. This post hoc analysis evaluated the psychometric properties of Haemo-QOL-A in adult people with severe hemophilia A (PWSHA) receiving valoctocogene roxaparvovec (AAV5-hFVIII-SQ) in 2 clinical trials (phase 1/2, NCT02576795; phase 3, NCT03370913).

Patients and Methods

Adult PWSHA (factor VIII levels ≤1 IU/dL) received 1 AAV5-hFVIII-SQ infusion (6×10¹³ vg/kg). Participants were assessed using the Haemo-QOL-A and the EuroQOL (EQ)-5D-5L and visual analog scale (VAS) questionnaires pre- and post-infusion. Psychometric analyses included convergent and discriminant validity, internal consistency, and reliability. Clinically important difference (CID) was estimated using 3-point change in EQ-5D-5L VAS as anchor.

Results

Haemo-QOL-A data were analyzed from 7 (phase 1/2, 3-year follow-up) and 16 participants (phase 3, 26-week analysis). Change in Haemo-QOL-A Total Scores correlated with EQ-5D-5L VAS score change at 26 weeks (Pearson’s correlation 0.77). At 26 weeks, increased Haemo-QOL-A Physical Functioning was associated with decreased EQ-5D-5L Pain and Discomfort and decreased Anxiety and Depression (Spearman’s Rank correlations −0.73 and −0.62, respectively, P <0.01). Internal consistency analysis showed good reliability for all domains (Cronbach’s alpha >0.7) except Treatment Concern (Cronbach’s alpha = 0.31). Anchor-based CID estimates were met for Haemo-QOL-A Total Score (≥5.5) and domain scores (≥6) for Consequences of Bleeding, Physical Functioning, Role Functioning, and Worry.

Conclusion

Our preliminary results suggest that the Haemo‐QOL‐A is a valid, reliable instrument for HRQOL assessment in PWSHA undergoing gene therapy. Future research should be undertaken to confirm these findings in a larger number of participants.

Assessing the value of orphan drugs using conventional cost-effectiveness analysis: Is it fit for purpose?

Conventional cost-effectiveness analysis—i.e., assessing pharmaceuticals through a cost per quality-adjusted life year (QALY) framework—originated from a societal commitment to maximize population health given limited resources. This "extra-welfarist" approach has produced pricing and reimbursement systems that are not well- aligned with the unique considerations of orphan drugs. This framework has been slow to evolve along with our increased understanding of the impact of rare diseases, which in turn has complicated the assessment of orphan drugs meant to treat rare diseases. Herein, we (i) discuss the limitations of conventional cost-effectiveness analysis as applied to assessing access to, as well as the pricing and reimbursement of, orphan drugs, (ii) critically appraise alternative and supplemental approaches, and (iii) offer insights on plausible steps forward.

Association of factor expression levels with health-related quality of life and direct medical costs for people with haemophilia B

AIMS

Gene therapy trials aim to provide a functional cure for patients with haemophilia B (HB), and treatment impact is analyzed by factor IX expression levels (FELs). We investigated the relationship of FELs with health-related quality of life (HRQoL) and costs.

MATERIALS AND METHODS

This was a retrospective cross-sectional analysis of the European (CHESS I-II) and US (CHESS-US) CHESS population studies. Physicians recruited consecutive patients and extracted information from the medical records; patients completed questionnaires between 2014 and 2015 (CHESS-I), 2018-2019 (CHESS-II) and 2019 (CHESS US). Patients with inhibitors were excluded. HRQoL was assessed using the EQ-5D-5L. Twelve-month haemophilia-related direct medical costs included office visits and hospitalizations based on country-level unit costs. A Tobit model was used to analyze FELs and HRQoL and generalized linear models for direct medical costs.

RESULTS

A total of 191 men with HB completed the EQ-5D questionnaire; the mean age was 36.8 years, with a mean FEL of 10.1 IU/dL (median, 4.0). Mean EQ-5D was 0.77 (SD, 0.23). The Tobit model adjusting for age, body mass index and blood-borne viruses showed every 1% increase in FEL was associated with +0.006 points in the mean EQ-5D score (p = .003). Mean haemophilia-related direct medical costs excluding factor replacement therapy were €2,028/year (median, €919) in CHESS I-II (EU, n = 226), and $7,171/year (median, $586) in CHESS US (n = 181). Adjusted EU and US models showed every 1% increase in FEL was associated with a decrease in haemophilia-related direct medical costs of €108/year and $529/year, respectively.

LIMITATIONS

Direct medical costs were based on physician extraction of encounters from medical records, potentially underestimating costs of care. The voluntary nature of participation may have introduced selection biases.

CONCLUSIONS

We observed a significant association of increases in FEL with increased HRQoL and decreased costs in Europe and the United States among men with HB and no inhibitors.

Real-World Rates of Bleeding, Factor VIII Use, and Quality of Life in Individuals with Severe Haemophilia A Receiving Prophylaxis in a Prospective, Noninterventional Study

Regular prophylaxis with exogenous factor VIII (FVIII) is recommended for individuals with severe haemophilia A (HA), but standardised data are scarce. Here, we report real-world data from a global cohort. Participants were men ≥18 years old with severe HA (FVIII ≤ 1 IU/dL) receiving regular prophylaxis with FVIII. Participants provided 6 months of retrospective data and were prospectively followed for up to 12 months. Annualised bleeding rate (ABR) and FVIII utilisation and infusion rates were calculated. Differences between geographic regions were explored. Of 294 enrolled participants, 225 (76.5%) completed ≥6 months of prospective follow-up. Pre-baseline and on-study, the median (range) ABR values for treated bleeds were 2.00 (0–86.0) and 1.85 (0–37.8), respectively; the median (range) annualised FVIII utilisation rates were 3629.0 (1008.5–13541.7) and 3708.0 (1311.0–14633.4) IU/kg/year, respectively; and the median (range) annualised FVIII infusion rates were 120.0 (52.0–364.0) and 122.4 (38.0–363.8) infusions/year, respectively. The median (range) Haemo-QoL-A Total Score was 76.3 (9.4–100.0) (n = 289), ranging from 85.1 in Australia to 67.7 in South America. Physical Functioning was the most impacted Haemo-QoL-A domain in 4/6 geographic regions. Despite differences among sites, participants reported bleeding requiring treatment and impaired physical functioning. These real-world data illustrate shortcomings associated with FVIII prophylaxis for this global cohort of individuals with severe HA.

Generic PROMIS item banks in adults with hemophilia for patient-reported outcome assessment: Feasibility, measurement properties, and relevance

BACKGROUND

Legacy hemophilia-specific questionnaires are considered too long, show floor-/ceiling effects, and/or include irrelevant questions. Patient Reported Outcomes Measurement Information System (PROMIS) item banks, including Computer Adaptive Tests (CATs) and short forms, were designed for more efficient outcome assessment.

OBJECTIVES

Evaluate the feasibility, measurement properties, and relevance of seven PROMIS CATs and two short forms in patients with hemophilia.

PATIENTS/METHODS

In this cross-sectional study, Dutch adults with hemophilia completed nine PROMIS item banks electronically. Feasibility was assessed by number of items and floor/ceiling effects. Reliability was determined as the proportion of reliable scores (standard error ≤3.2). Construct validity was assessed by comparison with legacy instruments and expected differences between subgroups. Relevance of item banks was determined by proportions of limited scores.

RESULTS

Overall, 142 of 373 invited patients (mean age, 47 [range, 18-79], 49% severe hemophilia, 46% receiving prophylaxis) responded. Per CAT item bank, mean number of items answered varied from 5 (range, 3-12) to 9 (range, 5-12), with floor effects in pain interference (26% lowest scores) and depression (18% lowest scores). Construct validity and reliability were good for physical function, pain interference, satisfaction with social roles and activities, and fatigue. The CAT physical function showed the most limited scores (38%). The self-efficacy short forms showed ceiling effects (22%-28%) and no relation with the legacy instruments.

CONCLUSIONS

The PROMIS CATs physical function, pain interference, satisfaction with social roles and activities, and fatigue are feasible, reliable, and valid alternatives to legacy instruments for patients with hemophilia, with few items and low floor-/ceiling effects.

Hemophilia Gene Therapy Value Assessment: Methodological Challenges and Recommendations

Gene therapy for hemophilia is designed to produce health gains for patients over many years. Rewarding that value creation on the basis of a one-time treatment implies a large upfront cost. This cost can only be justified by long-term health benefits and being cost-effective compared with conventional treatments. Yet, uncertainties about the long-term benefits make it challenging to assess clinical and economic value of gene therapies at launch. We identify and discuss key methodological challenges in assessing the value of gene therapy for hemophilia, including the immaturity of evidence on the durability of benefits, lack of definition and valuation of cure for chronic diseases, absence of randomized controlled trials, limitations of traditional quality of life measures in hemophilia, approach for qualifying cost-savings compared with current treatments, and choice of perspective. The Institute for Clinical and Economic Review has developed a framework for assessing single or short-term therapies (ICER-SST) and has applied it in hemophilia. After reviewing this framework and its application, we recommend the following when assessing the value of hemophilia gene therapies: (1) leveraging expert clinical opinion to justify assumptions on the durability of benefits; (2) using external synthetic controls and lead-in, self-controlled trials to assess comparative effectiveness; (3) addressing limitations of traditional quality of life measures through the use of modified utility collection approaches; (4) adjusting cost offsets from gene therapies with caution; (5) considering outcome-based contracting to address uncertainties about prices and long-term outcomes; and (6) presenting societal and healthcare system perspectives in parallel.

The impact of extended half-life factor concentrates on patient reported health outcome measures in persons with hemophilia A and hemophilia B

BACKGROUND

Recombinant factors VIII and IX Fc (rFVIIIFc/rFIXFc) were the only available extended half-life (EHL) products in Canada during 2016 to 2018.

OBJECTIVES

To evaluate if patient-reported outcome measures (PROMs) improved in Canadian persons with hemophilia who switched from standard half-life (SHL) to EHL products (rFVIIIFc/rFIXFc).

PATIENTS/METHODS

This prospective cohort study enrolled persons with moderate or severe hemophilia aged ≥6 years who switched to rFVIIIFc/rFIXFc (2016-2018) and those who remained on SHL. Health-related quality of life (HRQoL) was assessed using the Haemophilia-specific Quality of Life (Haem-A-QoL) and 36-item Short-Form Survey (SF-36) at baseline, 3-months, 12 months, and 24 months. Other PROMs included the Work Productivity and Impairment Questionnaire, chronic pain scale, partner/parent ratings of mood, International Physical Activity Questionnaire, and Treatment Satisfaction Questionnaire for Medication. We identified meaningful changes using minimally important difference for SF-36 and responder definition for Haem-A-QoL.

RESULTS

We enrolled 25 switchers (16 rFVIIIFc, 9 rFIXFc) and 33 nonswitchers. Those switched to rFVIIIFc/rFIXFc had improved overall HRQoL, and improved subscale physical activity, mental health, and social functioning at 3 months. The rFIXFc switchers had improved chronic pain and ability to engage in normal activities while the rFVIIIFc switchers had improved treatment satisfaction. There was no change in work impairment after the switch. Observed improvement disappeared by 24 months in most domains.

CONCLUSION

Switching from SHL to rFVIIIFc/rFIXFc resulted in short-term meaningful improvement in overall HRQoL and other PROMs in a small proportion. Longitudinal changes on PROMs are affected by ceiling effects and response shift, warranting further studies in instrument optimization in the era of EHL and nonfactor products.

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.

Persistence of haemostatic response following gene therapy with valoctocogene roxaparvovec in severe haemophilia A

Introduction

Valoctocogene roxaparvovec is an investigational AAV5‐based factor VIII (FVIII) gene therapy that has demonstrated sustained clinical benefit in people with severe haemophilia A.

Aim

To report safety, tolerability, efficacy, and quality of life (QOL) among participants who received valoctocogene roxaparvovec in a phase 1/2 clinical study (NCT02576795).

Methods

Men ≥18 years of age with severe haemophilia A (FVIII ≤1 IU/dl) without history of FVIII inhibitors or anti‐AAV5 antibodies received a single infusion of valoctocogene roxaparvovec and were followed for 5 years (6 × 10¹³ vg/kg dose, n = 7) and 4 years (4 × 10¹³ vg/kg dose, n = 6).

Results

Over the past 2 years, few adverse events and no FVIII inhibitors were reported. Per chromogenic substrate (CSA) assay at years 5 and 4, four of seven and three of six participants in the 6 × 10¹³ and 4 × 10¹³ vg/kg cohorts, respectively, maintained median FVIII levels >5 IU/dl, corresponding to mild haemophilia. By regression analysis, rate of change in FVIII activity was ‐0.14 (95% confidence interval [CI]: ‐.32 to .03) IU/dl/wk in the 6 × 10¹³ vg/kg cohort in year 5 and ‐.06 (95% CI: ‐.14 to .01) IU/dl/wk in the 4 × 10¹³ vg/kg cohort in year 4. No participants resumed FVIII prophylaxis, and eight of 13 participants reported zero bleeds in the past 2 years. Improved QOL from baseline persisted in the 6 × 10¹³ vg/kg cohort; all six Haemo‐QOL‐A domain scores increased. For the 4 × 10¹³ vg/kg cohort, high baseline Haemo‐QOL‐A scores persisted.

Conclusion

These results demonstrate transgene expression and haemostatic response for up to 5 years in individuals with haemophilia A.