Show me the evidence: Effectiveness of low‐dose prophylaxis

The World Federation of Hemophilia World Bleeding Disorders Registry: insights from the first 10,000 patients

Background

The prevalence of hemophilia varies globally, with close to 100% of patients diagnosed in high-income countries and as low as 12% diagnosed in lower-income countries. These inequalities in the care of people with hemophilia exist across various care indicators.

Objectives

This analysis aims to describe the clinical care outcomes of patients in the World Bleeding Disorders Registry (WBDR).

Methods

In 2018, the World Federation of Hemophilia developed a global registry, the WBDR, to permit hemophilia treatment centers to collect clinical data, monitor patient care longitudinally, and identify gaps in management and treatment.

Results

As of July 18, 2022, 10,276 people with hemophilia were enrolled from 87 hemophilia treatment centers in 40 countries. Nearly half (49%, n = 5084) of patients had severe hemophilia; 99% were male, 85% had hemophilia A, and 67% were from low-middle-income countries. Globally, the age of diagnosis for people with severe hemophilia has improved considerably over the last 50 years, from 82 months (∼7 years) for those born before 1980 to 11 months for those born after 2010, and most prominently, among people with severe hemophilia in low- and low-middle-income countries, the age of diagnosis improved from 418 months (∼35 years) for those born before 1970 to 12 months for those born after 2010. Overall, the age of diagnosis of people with hemophilia in low- and low-middle-income countries is delayed by 3 decades compared to patients in upper-middle-income countries and by 4 decades compared to patients in high-income countries.

Conclusion

Data reveal large treatment and care disparities between socioeconomic groups, showing improvements when prophylaxis is initiated to prevent bleeding. Overall, care provided in low-income countries lags behind high-income countries by up to 40 years. Limitations in the interpretation of data include risk of survival and selection bias.

Management of Severe Hemophilia A: Low-Dose Prophylaxis vs. On-Demand Treatment

INTRODUCTION

Prophylactic clotting factor infusion regimens to prevent bleeding and joint deformity has become the standard of care in severe hemophilia A patients.

AIM

To assess low-dose factor prophylaxis in our population as an alternative approach to managing severe hemophilia A.

METHODS

A prospective cohort study that included 68 hemophilia A patients divided into two groups, i.e., Prophylaxis and on-demand. The two groups were compared for annualized bleeding rate (ABR), hospitalization, units of factor VIII (FVIII) infused, or plasma products transfused, i.e., fresh frozen plasma (FFP) and cryoprecipitate (CP), and development of FVIII inhibitors.

RESULTS

Of the 68 patients recruited in this study, 25 (36.7%) were in the prophylaxis group, and 43(63.3%) were in the on-demand group. The on-demand group presented a higher median-IQR ABR [8(20-3) vs. 5(10-1.5), p-value 0.024], several hospitalizations (39.7% vs. 0, p-value 0.001), and inhibitor development (9.3% vs. 0, p-value 0.289) compared to the prophylaxis group. The prophylaxis approach demonstrated a significant negative correlation of ABR with FVIII prophylaxis (r=-0484, p=value=0.014). Moreover, no hospitalizations or inhibitor development was observed in the prophylaxis group. The estimated annual consumption of FVIII was 328 IU/kg/year in the on-demand group and 1662.6 IU/kg/year in the prophylaxis group. However, a highly significant difference in plasma product utilization was observed between the two groups, i.e., p-value <0.001 and 0.038 for FFP and CP, respectively.

CONCLUSION

Low-dose factor prophylaxis resulted in improved outcomes compared to on-demand treatment in terms of ABR, joint bleeding, hospitalization, and the development of inhibitors. This treatment approach should be adopted as an economically feasible alternative to high-dose Prophylaxis in resource-constrained countries.

Achieving access to haemophilia care in low-income and lower-middle-income countries: expanded Humanitarian Aid Program of the World Federation of Hemophilia after 5 years

Highly effective treatment of haemophilia A and B is primarily available to 15% of the world's population, in high-income countries. In low-income countries (LICs) and lower-middle-income countries (LMICs), morbidity and mortality are high because of greatly reduced access to diagnosis, care, and treatment. We report the challenges and impact after the first 5 years (mid-2015-2020) of the expanded World Federation of Hemophilia (WFH) Humanitarian Aid Program (HAP). WFH HAP donated coagulation products were used to treat more than 250 000 acute bleeding episodes, manage approximately 4000 surgeries, and establish bleeding preventive prophylaxis in about 2000 patients in 73 countries. Health-care providers worldwide learned optimal management of patients with complex needs through virtual and in-person training. In response to the programme, some governments increased investment in haemophilia care, including independent purchases of small amounts of treatment products. With unparalleled scope and complexity, and substantial benefits to people with haemophilia and society in general, the WFH HAP is an exemplar of partnership between for-profit and not-for-profit organisations advancing health-care equity in LICs and LMICs, which could be replicated by other organisations supporting people with different monogenic diseases.

Hemophilia gene therapy-New country initiatives

Gene therapy is an opportunity for haemophilia patients to receive a one-time treatment and have lasting factor levels for years or decades instead of dependence on repeated administration within short intervals and on sustained supply of drug. Great strides have been made in the development of gene therapy for haemophilia in the last decade. Adeno-associated virus (AAV) vector-mediated gene transfer in haemophilia A and B has entered the phase III trial stage. Gene transfer by lentiviral vector or gene editing technologies using factor VIII (FVIII) or IX (FIX) genes are now entering clinical evaluation. It is expected that the first FVIII and FIX gene therapy products will soon be approved and distributed in major markets. Global access to gene therapy is a critical goal. This review presents new and ongoing efforts towards this goal in countries other than North America and Europe. In Japan, researchers, regulators and funders have established a promising gene therapy development platform for multiple diseases including haemophilia. Decades of scientific and clinical research in haemophilia gene therapy in China have led to a recently registered clinical trial of AAV-mediated gene therapy for haemophilia B. Other countries are in earlier phases of building gene therapy programmes or participate in international trials. A phase 2 feasibility trial of AAV-mediated FIX gene therapy in low- and middle-income countries aims to demonstrate that gene therapy could become available in resource-constrained socio-economic settings. The different strategies for establishing gene therapy provide opportunities for closing the global gap in haemophilia care.