Measuring the impact of changing from standard half-life (SHL) to extended half-life (EHL) FVIII prophylaxis on health-related quality of life (HRQoL) in boys with moderate/severe haemophilia A: Lessons learned with the CHO-KLAT tool

Real-World Amount of Clotting Factor Products and Non-Factor Products Dispensed and Annual Medical Expenditures for Japanese Patients with Haemophilia A

BACKGROUND

Treatment for haemophilia A has expanded from plasma-derived factor VIII (pdFVIII) and standard half-life (SHL) recombinant FVIII (rFVIII) to extended half-life (EHL) rFVIII and non-factor products that mimic FVIII activity.

OBJECTIVE

To determine amounts of clotting factor concentrates (CFCs) and emicizumab dispensed and associated healthcare expenditures in Japanese patients with haemophilia A.

METHODS

This retrospective, non-interventional, observational study analysed data from 2016 to 2020 from a large-scale, hospital-based administrative database. Patients had haemophilia A without inhibitors and ≥ 2 prescriptions of the same CFC or emicizumab.

RESULTS

In total, 974 patients with haemophilia A (median age, 30.0 years; median follow-up, 3.7 years) were included. Outpatient use of EHL rFVIII and emicizumab increased, although pdFVIII/SHL rFVIII were still used over the study. Median annual total healthcare expenditures/patient increased from ¥9,200,230 in 2016 to ¥19,748,221 in 2020. Overall, the median annual drug expenditure/patient increased from ¥8,723,120 in 2016 to ¥18,051,689 in 2020. Drug expenditure was highest with emicizumab, with an increase in median annual expenditure/patient from 2018 (n = 4, ¥26,030,206) to 2020 (n = 107, ¥45,430,408). Overall, 233 patients (23.9%) switched from an SHL to an EHL product. Although amounts of FVIII prescribed increased in the 3 months after switching, overall, there was no noticeable difference before and after switching. Median total healthcare and FVIII product expenditures increased following switching.

CONCLUSIONS

Prescribing of EHL products increased over the study and healthcare expenditures increased for patients who switched from SHL to EHL rFVIII products.

Moderate- to vigorous-intensity physical activities for hemophilia A patients during low-dose pharmacokinetic-guided extended half-life factor VIII prophylaxis

BACKGROUND

Low-dose pharmacokinetic (PK)-guided extended half-life (EHL) factor VIII (FVIII) prophylaxis can reduce the bleeding risk in hemophilia A (HA) patients. An increase in physical activities for promoting musculoskeletal health may enhance the benefits of prophylactic therapy.

OBJECTIVES

To determine the clinical impact of moderate- to vigorous-intensity physical activities in HA patients during low-dose PK-guided EHL FVIII prophylaxis.

PATIENTS/METHODS

This prospective study enrolled patients with moderate/severe HA (baseline FVIII levels ≤ 5 IU/dL) who had received low-dose PK-guided EHL FVIII prophylaxis for ≥ 6 months. An individualized exercise protocol was introduced to each participant, targeting a 65% increase in the maximum predicted heart rate for ≥ 150 min/week, while continuing low-dose PK-guided EHL FVIII prophylaxis for 6 months. Before and after implementing the intervention, annualized bleeding rates (ABR), annualized joint bleeding rates (AJBR), Hemophilia Joint Health Scores (HJHS), skeletal muscle mass, hemophilia-specific quality-of-life (QoL) scores and annualized FVIII consumption were compared.

RESULTS

Of 13 participants (mean age ± standard deviation [SD]: 20.1 ± 6.8 years), ABR, AJBR, and HJHS were significantly reduced (mean differences [MD] ± SD: -5.7 ± 2.6 bleeds/year, -4.2 ± 2.6 joint bleeds/year, and -4.3 ± 3.2 marks, respectively; P < 0.05) after applying the 6-month exercise protocol. Skeletal muscle mass and QoL scores had also improved (P = 0.001), while FVIII usage had decreased (MD ± SD: -129.1 ± 208.7 IU/kg/year; P < 0.05).

CONCLUSIONS

The combination of moderate- to vigorous-intensity physical activities with low-dose PK-guided EHL FVIII prophylaxis improves bleeding prevention, musculoskeletal status and QoL in patients with moderate/severe HA. By minimizing FVIII consumption, this strategy helps optimize hemophilia care in countries with budget constraints.

CLINICALTRIALS

gov NCT05728528.

rFVIII-Fc in severe haemophilia A: The incentive switch in case of high risk of joint bleedings

BACKGROUND

Efmoroctocog alfa, the first recombinant factor VIII fusion protein with extended half-life (rFVIII-Fc), has been hypothesized to lower FVIII consumption in patients with severe Haemophilia A (pwSHA), without reducing clinical efficacy. What about real life?

METHOD

MOTHIF-II was a noninterventional, multicentre, before/after study, via the collection of retrospective data from July 2015 to June 2016 (called T1), and from July 2017 to June 2018 (called T2), in 7 French haemophilia treatment centres. We examined the prescriptions and dispensations of factor VIII and the Annual Bleeding Rate (ABR), in pwSHA without current inhibitors on prophylaxis, before and after the introduction of rFVIII-Fc. The data gathered from the BERHLINGO research database and from the French Healthcare claims database with a determinist pairing process based on the national unique identification number.

RESULTS

A total of 156 pwSHA were included in the prescription cohort and 83 in the ABR cohort. For switched patients, the mean amounts of prescribed FVIII were significantly higher during T1 compared to T2 (4333 (2052) vs. 3921 (2029) IU/kg/year/patient, p: 0.028); a significant decrease in their ABR was also observed between T1 and T2 (6.3 (6.0) vs. 4.4 (5.4), p: 0.047). These patients had a more severe bleeding profile centred on haemarthrosis.

CONCLUSION

The results are related to those of the pivotal clinical trials for the reduction in FVIII consumption following the switch to rFVIII-Fc, with a significant improvement in the haemorrhagic phenotype for pwSHA.

Efmoroctocog Alfa: A Review in Haemophilia A

Efmoroctocog alfa (Elocta®, Eloctate®, Eloctate™), an extended half-life (EHL) recombinant factor VIII (rFVIII)-Fc fusion protein, is approved for the treatment and prophylaxis of bleeding in patients with haemophilia A. The efficacy of efmoroctocog alfa in the prevention and treatment of bleeding in previously treated patients (PTPs) and previously untreated patients (PUPs) with severe haemophilia A has been demonstrated in phase III studies; this includes its use in the perioperative setting (in PTPs). Furthermore, the effectiveness of efmoroctocog alfa in clinical practice has been confirmed in numerous real-world studies; compared with conventional, standard half-life (SHL) FVIII products, prophylaxis with this EHL FVIII product achieved similar or reduced bleeding rates with fewer injections. Efmoroctocog alfa was generally well tolerated; inhibitors occurred in approximately one-third of PUPs in a phase III study. Efmoroctocog alfa is an established and effective EHL FVIII replacement therapy for the management of haemophilia A. Compared with SHL FVIII products, EHL FVIII products such as efmoroctocog alfa have the potential to optimise prophylactic outcomes by decreasing the burden of treatment or increasing the level of bleed protection.

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 VIII Fc Fusion Protein (rFVIIIFc) in Real Life: One-Year Clinical and Economic Outcomes

Background

Recombinant factor VIII Fc fusion protein (rFVIIIFc) is the first extended half-life (EHL) recombinant clotting factor with marketing authorization; it has been available in France since October 2016. However, data and literature about rFVIIIFc in clinical practice are scarce.

Objective

We propose a 1-year clinical and economic outcome evaluation in patients with hemophilia A taking into consideration treatment adherence.

Patients and methods

We reviewed the diaries of all patients treated with rFVIIIFc at Marseille Hemophilia Center for 1 year. All the data were related to the patients’ infusion (i.e., annual number of infusions, weekly dose/kg, and annual consumption) and bleeding reports. The clotting factor costs were considered, whereas additional costs (e.g., infusion devices and nurse intervention) were neglected.

Results

A total of 34 patients were evaluated. Their median age was 18 years (IQR = 18). Treatment adherence was observed in 62% for FVIII and 66% for rFVIIIFc. The analysis revealed a negligible decrease in the annual clotting factor consumption following the switch (− 2%, p = 0.7339). These data were combined with a significant reduction in the annual number of infusion (− 22.5%, median = 138.5, IQR = 65.8 for FVIII; median = 105, IQR = 24 for rFVIIIFc, p < 0.0001) and bleeding (− 50%, median = 5, IQR = 7.5 for FVIII; median = 1, IQR = 4 for rFVIIIFc, p < 0.0001). With regard to the cost, a decreasing trend was observed (− 8%, p = 0.1300).

Conclusion

The analysis in a real-life setting revealed that the input of switches toward rFVIIIFc in different treatment (age of patients and regimen) patterns seems to corroborate previous studies. The results suggest that switches have a beneficial effect in terms of efficacy, clotting factor consumption, and cost.

Haemophilia

Haemophilia A and B are rare congenital, recessive X-linked disorders caused by lack or deficiency of clotting factor VIII (FVIII) or IX (FIX), respectively. The severity of the disease depends on the reduction of levels of FVIII or FIX, which are determined by the type of the causative mutation in the genes encoding the factors (F8 and F9, respectively). The hallmark clinical characteristic, especially in untreated severe forms, is bleeding (spontaneous or after trauma) into major joints such as ankles, knees and elbows, which can result in the development of arthropathy. Intracranial bleeds and bleeds into internal organs may be life-threatening. The median life expectancy was ~30 years until the 1960s, but improved understanding of the disorder and development of efficacious therapy based on prophylactic replacement of the missing factor has caused a paradigm shift, and today individuals with haemophilia can look forward to a virtually normal life expectancy and quality of life. Nevertheless, the potential development of inhibitory antibodies to infused factor is still a major hurdle to overcome in a substantial proportion of patients. Finally, gene therapy for both types of haemophilia has progressed remarkably and could soon become a reality.

Factor product utilization and health outcomes in patients with haemophilia A and B on extended half-life concentrates: A Canadian observational study of real-world outcomes

INTRODUCTION

Recombinant factors VIII and IX Fc (rFVIIIFc/rFIXFc) became available in Canada in 2016 and were the only extended half-life (EHL) factor concentrates available in Canada until 2018.

OBJECTIVES

We aim to describe the change in product utilization in Canadians who switched to rFVIIIFc/rFIXFc.

METHODS

This prospective and retrospective cohort study enrolled males aged ≥6 years with moderate or severe haemophilia who switched to rFVIIIFc/rFIXFc and those who remained on standard half-life (SHL) between 2016 and 2018. Factor utilization and annualized bleeding rates (ABR) were collected at baseline, 1-year and 2-years. Due to low prospective enrolment (n = 25 switchers), prospective and retrospective data were pooled.

RESULTS

125 switchers (93 rFVIIIFc, 32 rFIXFc) and 33 non-switchers were included. The median age was 17 (rFVIIIFc) and 38 years (rFIXFc). Prior to switch, over 80% were on prophylaxis. There was a statistically significant reduction in the prescribed weekly prophylactic dose after the switch to rFVIIIFc/rFIXFc for all age groups, with a corresponding reduction (15-16%) in actual annualized FIX utilization in switchers (combined adults and children) to rFIXFc, and a smaller non-significant reduction in actual annualized FVIIII utilization (7%) in children who switched to rFVIIIFc. A significant reduction in the median ABR was only observed in children who switched to rFVIIIFc, but not in adults who switched to rFVIIIFc or rFIXFc.

CONCLUSION

Switching from SHL to EHL products led to a small reduction in factor utilization, while preserving a low ABR in children and adults with haemophilia. Further patient-reported outcomes data will further elucidate the role of EHL in the haemophilia landscape.

Converting factor and nonfactor usage into a single metric to facilitate benchmarking the resources consumed for haemophilia care across jurisdictions and over time

INTRODUCTION

The World Federation of Hemophilia started measuring factor utilization at the country level as IU/capita (International Units of factor concentrates used per country population) in 2001 for its Annual Global Survey. IU/capita have been used to benchmark a country's usage over time and for advocacy. The introduction of a common metric usage spanning across standard half-life (SHL), and extended half-life (EHL) clotting factor concentrates (CFCs) and emicizumab would be a valuable simplification for national healthcare policymaking and industrial production planning.

AIM

Develop and examine a method of converting IU of SHL or EHL, and milligrams of emicizumab into a single metric.

METHODS

We developed conversion factors from manufacturer's recommended dose for prophylaxis with SHL, EHL, and emicizumab as reported on the licensing information for the United States and Europe. We validate the accuracy of these conversion factors against real-world usage data.

RESULTS

The prescribing information in the United States and Europe is marginally different. The SHL/EHL conversion factors are higher when calculated based on the prescribing information than on real-world studies, which are considered more representative of clinical practice. The best estimate of the SHL/EHL conversion factors for FVIII and FIX were 1.04 and 1.87. The conversion factor for emicizumab to SHL is 70 IU/mg.

CONCLUSION

We have generated robust estimates of conversion factors for currently used treatment options for prophylaxis in haemophilia. Usage of a single, harmonized metric will facilitate benchmarking across different countries or longitudinally irrespective of the case-mix of treatment options.

Updating the Canadian Hemophilia Outcomes-Kids' Life Assessment Tool (CHO-KLAT) in the era of extended half-life clotting factor concentrates

INTRODUCTION

The purpose of this study was to review and update the content of the Canadian Hemophilia Outcomes-Kids' Life Assessment Tool version 2.0 (CHO-KLAT), in the context of extended half-life (EHL) factor concentrates (FCs) and to establish the validity and reliability of the updated CHO-KLAT.

METHODS

Focus groups were conducted with boys with hemophilia, their parents, and health care providers across Canada to review the CHO-KLAT v2.0 and determine if any modifications were required. The validity of the revised CHO-KLAT (version 3.0) was then determined in a sample of boys with hemophilia and their parents by calculating its correlation with the Pediatric Quality of Life Core Module (PedsQL-Core). Test-retest reliability was assessed using an intraclass correlation coefficient (ICC).

RESULTS

Thirteen focus groups at 5 pediatric hemophilia treatment centers (HTCs) (n = 71) resulted in 19 changes to the CHO-KLAT v2.0, generating a revised 40-item CHO-KLAT, the CHO-KLAT v3.0. Thirty-five boys with hemophilia (median age, 14; range, 7-17 years) and 47 parents participated in the validation of the CHO-KLAT v3.0. There was a moderate correlation between the CHO-KLAT v3.0 child self-report and PedsQL-Core (r = 0.56, P = .01), and a strong correlation between the CHO-KLAT v3.0 parent-proxy and PedsQL-Core (r = .79, P = .0007). The test-retest reliability ICC was 0.90 for the child self-report CHO-KLAT v3.0 and 0.68 for the parent-proxy CHO-KLAT v3.0.

CONCLUSION

The CHO-KLAT v3.0 is a reliable and valid child-centric tool that effectively measures health-related quality of life in boys with hemophilia who are receiving standard half-life or EHL FCs.