An economic analysis of different treatments for bleeding in patients with acquired haemophilia

Are We Capturing the Socioeconomic Burden of Rare Genetic Disease? A Scoping Review of Economic Evaluations and Cost-of-Illness Studies

BACKGROUND AND OBJECTIVES

Rare diseases have a significant impact on patients, families, the health system, and society. Measuring the socioeconomic burden is crucial to valuing interventions for rare diseases. Healthcare system costs are significant, but so are costs to other government sectors, patients, families, and society. To understand the breadth of costs captured in rare disease studies, we examined the cost categories and elements of socioeconomic burden captured in published studies.

METHODS

A scoping review was conducted using five electronic databases to identify English language economic evaluations and cost-of-illness studies of interventions for rare diseases (2011-21). We mapped costs using a previously developed evidence-informed framework of socioeconomic burden costs for rare disease.

RESULTS

Of 4890 studies identified, 48 economic evaluations and 22 cost-of-illness studies were included. While 18/22 cost-of-illness studies utilized a societal perspective, only 7/48 economic evaluations incorporated societal costs. Most reported cost categories related to medical costs, with medication and hospitalizations being the most common elements for both study designs. Costs borne by patients, families, and society were reported less among economic evaluations than cost-of-illness studies. These included: productivity (10% vs 77%), travel/accommodation (6% vs 68%), government benefits (4% vs 18%), and family impacts (0% vs 50%).

CONCLUSIONS

Contrary to cost-of-illness analyses, most of the included economic evaluations did not account for the hidden burden of rare diseases, that is, costs borne by patients, families, and societies. Including these types of costs in future studies would provide a more comprehensive picture of the burden of disease, providing empirical data to inform how we value and make decisions regarding rare disease interventions, health policy, and resource allocation.

Emicizumab for the treatment of acquired hemophilia A: Retrospective review of a single-institution experience

INTRODUCTION

Acquired haemophilia A (AHA) is a rare and potentially life-threatening bleeding disorder arising from autoantibodies that inhibit coagulation factor VIII (FVIII). Treatment entails achieving haemostasis with bypassing agents or factor replacement, and eradication of the inhibitor with immunosuppressive therapy (IST). Due to the rarity of AHA, there are few prospective data to guide management.

METHODS

We present a retrospective report of 11 AHA patients treated with emicizumab, a FVIII-mimetic bispecific antibody, administered at 3 mg/kg weekly for 4 weeks in conjunction with rituximab-based immunosuppressive therapy. The chromogenic FVIII inhibitor assay was used to assess for inhibitor eradication.

RESULTS

The median follow-up was 13.9 months. The median number of days of additional haemostatic therapy or red blood cell transfusions after initiating emicizumab was 2 (range 0-15). The median was 0 days (range 0-8) for patients who did not require vascular embolization to achieve haemostasis. Eight patients achieved a complete remission (defined as recovery of FVIII activity to > 50% with a negative inhibitor test in the absence of haemostatic and IST); two patients achieved a partial remission (FVIII activity > 50% but with detectable inhibitor); one patient experienced refractory disease. One patient experienced rebleeding and two patients experienced inhibitor recurrence. No thrombotic, thrombotic microangiopathic or infectious complications occurred.

CONCLUSION

Our observations suggest emicizumab can facilitate haemostasis for AHA patients and be combined with safer, lower-intensity immunosuppressive therapies to achieve remission.

Recombinant porcine FVIII for bleed treatment in acquired hemophilia A: findings from a single-center, 18-patient cohort

Acquired hemophilia A (AHA) is a rare bleeding disorder in which acquired autoantibodies to endogenous factor VIII (FVIII) decrease FVIII activity and lead to a bleeding phenotype. A substantial majority of individuals who develop AHA present with severe bleeding. Effective treatment requires both immunosuppressive therapy and prompt hemostatic treatment. Bleeding is commonly treated with bypassing agents (BPAs) such as recombinant activated FVII (rFVIIa) or activated prothrombin complex concentrates Disadvantages to BPAs include the inability to monitor response with standard laboratory assays, inconsistent hemostatic efficacy, and thrombosis. Recombinant porcine FVIII (rpFVIII: Obizur, Baxter, Deerfield, IL) was approved by the US Food and Drug Administration (FDA) for bleed treatment in AHA in 2014, and has the advantage of laboratory monitoring of FVIII activity levels and known hemostatic efficacy in the presence of anti-human FVIII inhibitors and after failure of BPAs. Using an algorithm-based approach, rpFVIII has been used to successfully treat 18 patients with AHA at our center with substantially lower doses than the current FDA-recommended dosing. Additionally, data from our cohort show that the preexposure anti-porcine Bethesda titer does not reliably predict the clinical response to rpFVIII treatment and is not correlated with the anti-human Bethesda titer. We also present data showing lower total rpFVIII use for initial bleed resolution when rpVIII is used upfront, as compared with use as rescue therapy. We validated our dosing algorithm, which uses much lower than FDA-recommended doses with 14 more patients than in our previously reported patient series.