Long-term aspects of hemophilia B treatment

Haemophilia B: impact on patients and economic burden of disease

Worldwide, haemophilia is the most common hereditary bleeding disorder. The incidence of haemophilia B, however, is considerably less than haemophilia A and consequently appears to have received less attention in the research literature. This article aims to summarise the available evidence documenting the patient and economic burden associated with haemophilia B and current methods of disease management. Both the immediate and long-term clinical consequences of haemophilia B can have significant implications for patients in terms of functional limitations and diminished health-related quality of life (HRQOL). Evidence demonstrates that primary prophylaxis is the optimal strategy for replacing missing clotting factor IX (FIX) and managing haemophilia B. Use of recombinant FIX (rFIX) over plasma-derived FIX (pd-FIX) is also generally preferred for safety reasons. Prophylaxis using currently available rFIX products, however, requires a demanding regimen of intravenous infusions 2–3 times a week which may have significant implications for adherence and ultimately the long-term efficacy of such regimens. Only limited assessments of the cost-effectiveness of prophylactic versus on-demand FIX treatment regimens have been conducted to date. Prophylaxis, however, is generally more costly as greater quantities of FIX are consumed. Any reduction in FIX replacement dosing frequency is expected to improve patient adherence and contribute to improved clinical outcomes, further supporting the costeffectiveness of such interventions. Although a rare disease, as economic constraints for healthcare increase, generating further information regarding the key clinical, patient and economic outcomes associated with haemophilia B will be essential for supporting improvements in care for people with haemophilia B.

Current issues in prophylactic therapy for persons with hemophilia

Factor VIII or IX replacement in a prophylactic manner is utilized for many patients with moderate to severe hemophilia A or B. Studies have shown it to be effective in reducing or preventing degenerative joint disease in many but not all patients. However, many unanswered questions still exist and optimization of this expensive treatment regimen is needed. This paper recounts the current products that are available for use and explores the literature regarding different treatment regimens. It explores age at initiation, dose, interval between infusions, joint health outcomes, barriers to compliance and age at discontinuation of prophylaxis. Individualized treatment is recommended. Collaborative efforts are needed to improve outcomes for all persons with hemophilia.

Management and prevention of recurrent hemarthrosis in patients with hemophilia

PURPOSE OF REVIEW

Degenerative arthropathy resulting from recurrent hemarthrosis remains the largest source of noninfectious morbidity for persons with hemophilia. Optimal treatment to prevent or reduce joint destruction remains controversial.

RECENT FINDINGS

The most exciting developments in the past year have contributed to our understanding of the pathophysiology behind this destructive process. Particularly interesting is the possible role of protooncogenes and angiogenic factors in the development of hypertrophic synovitis. Arthroscopic synovectomy effectively controls the hypertrophic synovium and resultant bleeding, and can be used safely even in very young patients. Prophylactic factor replacement remains the mainstay to reduce or prevent joint damage. New approaches, chiefly dose escalation strategies, have shown promise instead of standard prophylactic regimens. Additionally aggressive on-demand approaches may be feasible. These techniques allow for fewer indwelling venous access devices in small children, as rates of complications with these devices are shown to be increasingly high. Whether prophylactic therapy can be safely stopped in certain patients is an evolving area of interest. Outcome measures are being validated to assess the impact of interventions on patient quality of life.

SUMMARY

As hemophilia care evolves, current on-demand and prophylactic regimens will be optimized. Synovectomy will likely play a larger role in the control of synovitis, and validated quality-of-life scores will allow more consistent communication of outcomes. New understanding of the molecular mechanisms of joint destruction will pave the way for new therapeutic options for persons with hemophilia.

Factor IX replacement in surgery and prophylaxis

Considerations for treatment of hemophilia B patients in high-risk settings are the focus of this paper, including differences in recoveries of factor IX products and variable patient responses to replacement therapy. Data support the importance of performing individual pharmacokinetic studies in determining treatment programs for hemophilia patients-for both high-risk periods such as surgery and for prophylaxis. Other considerations in choice of plasma-derived or recombinant factor IX concentrate in high-risk and other situations include product safety, cost, and availability.