Patterns of tertiary prophylaxis in Canadian adults with severe and moderately severe haemophilia B

Trends in prescribing practices for management of haemophilia: 1999-2021

INTRODUCTION

People with haemophilia rely on specialists for their care, yet the specific dosing regimens of treatments prescribed by these specialists have not been widely studied.

AIM

The objective of this study is to describe trends in clinician prescribing practices for the management of haemophilia in the United States (US).

METHODS

We administered surveys to members of the Hemostasis and Thrombosis Research Society via paper surveys at its in-person annual symposia in 1999 and 2015, and an online survey in 2021. The surveys collected information on haemophilia treatments including factor dosing, inhibitor therapy and gene therapy.

RESULTS

Clinicians treating haemophilia for more than 50% of their practice time have increased from 37.5% of respondents in 1999 to 46.3% in 2021. Clinicians prescribing factor concentrates at >40 units/kg for routine bleeding events increased from 0% in 1999 to 29.3% in 2021 in haemophilia A (HA) and from 22.5% to 87.8% in haemophilia B (HB). In 2021, the clinicians reported prescribing emicizumab to treat HA patients (>89.5% paediatric, >85.7% adult) with or without inhibitors at least some of the time. Approximately 78.0% of respondents reported that they expected to recommend gene therapy at least some of time.

CONCLUSION

These data indicate changing trends in prescribing practices among US haemophilia specialists during the past 22 years. Preference for high doses of factor (>40 units/kg) has increased during this period. Emicizumab prophylaxis has been prescribed for patients with and without HA inhibitors. Clinicians expect gene therapy to have value for some haemophilia patients.

Trends of outcomes and healthcare utilization following orthopaedic procedures in adults with haemophilia: A 3-decade retrospective review

INTRODUCTION

Haemophilic arthropathy is a serious complication of haemophilia often requiring surgical intervention. It is unclear whether advances in comprehensive care are associated with a reduction in orthopaedic interventions and peri-procedural resource utilization.

AIM

To determine temporal patterns of orthopaedic interventions in persons with haemophilia (PWH), and evaluate changes in healthcare utilization and outcomes.

METHODS

In this Canadian multicentre retrospective cohort study, adult PWH from Northern Alberta and British Columbia who underwent orthopaedic procedures (1990-2018) were included. Temporal changes in the type of procedures, length of stay (LOS), factor utilization and outcomes were examined.

RESULTS

Sixty-five patients (78% haemophilia A) underwent 102 surgeries at a median age of 46.3. Of the 46 severe PWH, 28 (61%) were on prophylaxis at time of surgery. The proportion of total knee arthroplasties (TKA) declined over time (56% 1990-1999, 51% 2000-2009, 27% 2010-2018), with a concomitant rise in ankle arthrodesis (0% 1990-1999, 18% 2000-2009, 27% 2010-2018). Over time, PWH underwent orthopaedic procedures at an older age (P = .02). There was a significant reduction in perioperative factor VIII utilization (P = .003) and median LOS (P < .0001). Major bleeds, prosthetic joint infections and thrombosis were not observed in the last decade.

CONCLUSION

In the last three decades, there was a decline in the proportion of TKA, likely reflecting the impact of widespread use of tertiary prophylaxis. However, ankle arthrodesis rates increased, suggesting that higher trough levels may be required to prevent ankle arthropathy. We observed a significant reduction in LOS and factor utilization, reflecting improvements in perioperative management.

GlycoPEGylated recombinant factor IX for hemophilia B in context

Decisions over hemophilia treatment selection and switching involve balancing many clinical and patient-related factors. The current standard of care for patients with hemophilia B is prophylaxis with plasma-derived or recombinant factor IX (rFIX) concentrates. However, several extended half-life (EHL) rFIX products have recently been developed to improve treatment convenience and clinical outcomes for these patients. Nonacog beta pegol, an rFIX product that combines the FIX protein with a 40 kDa polyethylene glycol moiety, has been evaluated in 115 previously treated patients with hemophilia B (including 25 children) in the paradigm clinical trial program. FIX activity levels and pharmacokinetics were monitored throughout these trials and showed that nonacog beta pegol offers significant pharmacological improvements over standard FIX products. Once-weekly prophylaxis with nonacog beta pegol 40 IU/kg resulted in fewer bleeds in all patients (median annualized bleeding rate of 1.0 across all ages), resolved 90% of target joints, and improved health-related quality of life. No patients developed FIX inhibitors, and there were no thromboembolic events or unexpected safety concerns. Nonacog beta pegol was also safe and effective in the perioperative setting. These findings show that nonacog beta pegol is highly effective, while also offering more convenient dosing than standard FIX products. Nonacog beta pegol represents a significant advance in the current context of treatment for hemophilia B, offering effective management across several treatment modalities and settings, and potentially easing the treatment burden for patients of all ages. Meanwhile, the development of novel treatment strategies, such as gene therapy, anti-tissue factor pathway inhibitor antibodies, and RNA interference therapy, may provide patients with additional therapeutic options, which would require reassessment of the role of EHL products in the future.

The benefits of prophylaxis in patients with hemophilia B

INTRODUCTION

The health benefits of prophylactic dosing regimens for clotting factor therapy in patients with hemophilia include reduced joint damage and improved quality of life; as such, prophylaxis is recommended in treatment guidelines. However, many patients with hemophilia B are treated on demand, and prophylaxis has been utilized less frequently than in hemophilia A. Areas covered: This review discusses the opportunities and evidence for prophylaxis in hemophilia B, in the context of treatment guidelines and with regard to factor IX (FIX) replacement therapies, including long-acting recombinant FIX (rFIX). Expert commentary: Long-acting rFIX concentrates may increase uptake of and adherence to prophylaxis regimens through attainment of higher trough levels with longer dosing intervals. In this new era of hemophilia B treatment, physicians may be able to achieve better clinical outcomes for their patients and reconsider treatment goals. Maintaining higher FIX trough levels will undoubtedly have long-term benefits for patients, such as preserving joint function. The long-acting rFIX concentrates support robust prophylaxis regimens and offer physician's flexibility in treating patients to best suit their needs, whether to enable an active lifestyle, to achieve higher trough levels for better bleed protection, or simply to decrease the burden of treatment by reducing injection frequency.

Tailoring treatment of haemophilia B: accounting for the distribution and clearance of standard and extended half-life FIX concentrates

The prophylactic administration of factor IX (FIX) is considered the most effective treatment for haemophilia B. The inter-individual variability and complexity of the pharmacokinetics (PK) of FIX, and the rarity of the disease have hampered identification of an optimal treatment regimens. The recent introduction of extended half-life recombinant FIX molecules (EHL-rFIX), has prompted a thorough reassessment of the clinical efficacy, PK and pharmacodynamics of plasma-derived and recombinant FIX. First, using longer sampling times and multi-compartmental PK models has led to more precise (and favourable) PK for FIX than was appreciated in the past. Second, investigating the distribution of FIX in the body beyond the vascular space (which is implied by its complex kinetics) has opened a new research field on the role for extravascular FIX. Third, measuring plasma levels of EHL-rFIX has shown that different aPTT reagents have different accuracy in measuring different FIX molecules. How will this new knowledge reflect on clinical practice? Clinical decision making in haemophilia B requires some caution and expertise. First, comparisons between different FIX molecules must be assessed taking into consideration the comparability of the populations studied and the PK models used. Second, individual PK estimates must rely on multi-compartmental models, and would benefit from adopting a population PK approach. Optimal sampling times need to be adapted to the prolonged half-life of the new EHL FIX products. Finally, costs considerations may apply, which is beyond the scope of this manuscript but might be deeply connected with the PK considerations discussed in this communication.

Utilization Patterns of Coagulation Factor Consumption for Patients with Hemophilia

Hemophilia is a serious rare disease that requires continuous management and treatment for which the medicine is costly at the annual average of 100 million KRW for an individual. The aim of this study was to investigate trends in the utilization of coagulation factor (CF) used for hemophilia treatment using the National Health Insurance database from 2010 to 2013 in Korea and compare the utilization of CF with other countries. The consumption of CF per capita (IU) in Korea was not more than other countries with similar income to Korea. However, CF usage per patient IU was higher because the prevalence rate of hemophilia in Korea was lower than in other countries while the number of serious patients was much more. Therefore, it is difficult to say that the consumption of hemophilia medicine in Korea is higher than that in other countries. The consumption and cost of hemophilia medicine in Korea is likely to increase due to the increased utilization of expensive bypassing agents and the widespread use of prophylaxis for severe hemophilia. Even during the research period, it increased slightly and other countries show a similar trend. Thus, hemophilia patient management should accompany active monitoring on the health and cost outcomes of pharmaceutical treatment in the future. This study is expected to contribute to further insight into drug policies for other countries that face similar challenges with high price pharmaceuticals.

Joining the patient on the path to customized prophylaxis: one hemophilia team explores the tools of engagement

BACKGROUND

The relationship between hemophilia team interventions and achievement of optimal clinical outcomes remains to be elucidated. The British Columbia Hemophilia Adult Team has previously reported results of a comprehensive approach to individualize prophylaxis that has resulted in substantially reduced bleeding rates. In order to facilitate knowledge exchange and potential replication, it was important to gain a thorough understanding of the team's approach.

METHODS

A focus group of the British Columbia Hemophilia Adult Team was conducted to identify specific roles and processes that might be contributing to the prophylaxis regimen outcomes in this clinic. The focus group consisted of two workshops; one to describe the individual and collective roles of the clinic team in providing clinical care and guiding patients toward individualized prophylaxis; and the other to describe the patient journey from initial contact through reaching a successful engagement with the clinic.

RESULTS

Analysis of the results revealed team roles and processes that underpinned a shared decision-making relationship with the patient with a particular focus on supporting the patient's autonomy. Within this relationship, team focus shifts away from "adherence" toward the process whereby patients design and implement prophylaxis regimens resulting in reduction or elimination of bleeding episodes.

LIMITATIONS

Using the current methodology, it is not possible to demonstrate a causal link between specific team processes and improved bleeding rates in patients.

CONCLUSION

Through the active support of patient autonomy in all aspects of decisions related to hemophilia management, the British Columbia Hemophilia Adult Team approach de-emphasizes "adherence" as the primary goal, and focuses on a prophylaxis plan that is customized by the patient and aligned with his priorities. Adoption of this comprehensive team approach facilitates shared goals between the patient and the team that may optimize treatment adherence, but more importantly, reduce bleeding rates.

Men, Masculinities, and Hemophilia

Hemophilia is a congenital bleeding disorder that predominantly affects men. Home intravenous replacement of missing clotting factor is the most effective treatment; however, the uptake of preventative treatment (also known as prophylaxis) varies among men with hemophilia. The purpose of the current qualitative study was to describe the connections between masculinities and men's (n = 11) experiences of hemophilia across varying age groups. The inductively derived findings revealed bleed-related joint pain as the primary prompt for men to treat or seek medical help. Many men reported experiencing a high number of bleed-related injuries in adolescence, particularly in high school, oftentimes as a result of engaging in idealized masculine physical activities. Though the limitations imposed by hemophilia were contested by most men early on in their lives, as men grow older more conservative approaches were employed both in terms of treatment and activity to reduce the potential for residual bleed-related disabilities. Overall, the results indicate that men with hemophilia may benefit from peer and professional education about recognition, prevention, and optimal treatment of bleeds. Furthermore, masculine ideals act as important context in which men navigate hemophilia management practices and may facilitate contesting or conceding behaviors. Masculine ideals of strength and control may be garnered to facilitate optimal hemophilia management practices.