INTRODUCTION

The model is designed to assess the budgetary impact of HAE therapies on your population. The model compares the costs and expected clinical outcomes of an environment without TAKHZYRO against an environment with TAKHZYRO (with projected changes in market share for products), allowing for a user-defined pattern of anticipated market uptake and evaluation of associated costs of TAKHZYRO over the time horizon.

Although TAKHZYRO is approved for adult and pediatric patients 2 years of age and older, this model focuses on budget impact in patients aged ≥12 years old.

HAE is a long-term, debilitating, and life-threatening condition caused by mutations in the C1-INH gene, resulting in deficiency or dysfunction of C1-INH protein. HAE manifests clinically as unpredictable, intermittent attacks of SC or submucosal edema of the face, larynx, gastrointestinal tract, limbs, and/or genitalia.1,2 HAE is characterized by recurrent attacks of debilitating pain, along with intense, disfiguring swelling, making it difficult to perform everyday tasks.2 HAE attacks can result in costly burdens on payers and patients.3 HAE is a rare, genetic disease that may be passed down within families, with an estimated global prevalence of 1 in 50,000 individuals. There are ~6700 people with HAE in the United States.^1,5

The approach to HAE management rests on four principles: (1) availability of effective, on-demand therapy; (2) early treatment to prevent attack progression; (3) treatment of attack irrespective of site of swelling; (4) incorporation of long-term prophylaxis based on individualized decision-making. Novel, long-term prophylaxis options offer improved efficacy, ease of use, and safety, with the potential to normalize the lives of patients with HAE, and are increasingly being incorporated into the treatment paradigm. First-line, long-term prophylaxis options include IV pdC1-INH replacement, SC pdC1INH replacement, and a monoclonal inhibitor of plasma kallikrein. Second-line therapies include anabolic androgens and antifibrinolytics. The US HAEA medical advisory board recommends first-line medication when long-term prophylaxis is indicated. Second-line prophylactic medication should be reserved for when first-line medication is not available or when patients only accept oral therapy, with acknowledgment of potential side effects.

TAKHZYRO is a human monoclonal antibody that specifically binds and inhibits plasma kallikrein approved by FDA in 2018. It is indicated for prophylaxis to prevent HAE attacks in patients ≥2 years of age. Uncontrolled plasma kallikrein activity leads to excessive generation of bradykinin, a vasodilator thought to be responsible for the localized swelling, inflammation, and pain associated with HAE.^6,15

The recommended starting dosage in adult and pediatric patients 12 years of age and older is 300 mg administered subcutaneously Q2W. A dosing interval of 300 mg Q4W is also effective and may be considered if the patient is well controlled (eg, attack free) for more than 6 months. An overview of the Phase III trials is provided below.⁶