BOSTON — A C1-esterase inhibitor (human) delivered subcutaneously for the treatment of long-term prophylaxis associated with hereditary angioedema decreased attacks by 90% compared with therapy administered intravenously, according to findings presented at the ACAAI Annual Scientific Meeting.
Additionally, the researchers determined that total attack-related drug and other medical costs were reduced by 89% over the span of 1 year in a patient treated with C1-esterase inhibitor subcutaneous (human) (Haegarda, CSL Behring) compared with intravenous treatment.
“The thing that is really important, when folks have breakthrough attacks, is that there’s an extreme amount of cost associated with the treatment of those attacks with these on-demand therapies,” Christopher Graham, MS, senior director of health economics at RTI Health Solutions in Durham, North Carolina, told Healio Internal Medicine. “And with long-term prophylaxis there’s the cost associated with giving the drug every couple days, as well as the cost associated with preventing attacks.”
Graham and colleagues developed an economic model to estimate the avoidance of breakthrough attacks and cost savings associated with long-term prophylaxis with the use of C1-esterase inhibitor subcutaneous (human) (60 IU/kg) compared with therapy administered through IV (1,000 IU) in patients with two attacks or more per month.
The researchers used a decision-tree model to estimate the annual number of hereditary angioedema (HAE) attacks and attack-related annual costs for a typical patient with HAE receiving long-term prophylaxis from a U.S. third-party payer perspective.
“We constructed an economic model to really look at the cost savings with this treatment for hereditary angioedema and compared it with a treatment that has been on the market for a few years that is an IV formulation,” Graham said. “There’s a couple of things within HAE that are really important, and we tried to keep them all estimated as best as we could within the data that is available. It’s a rare disease, so there’s a bit of estimation extrapolation, but that’s what we do with all models – they are abstractions from reality. We try and model as best as we can.”
Using data from published literature, the researchers in the economic model estimated that the patient would average 47.5 attacks per year with on-demand treatment only. Additionally, there would be a 95.1% median reduction in attacks with subcutaneous treatment versus on-demand therapy, compared with a 53.1% median reduction in IV treatment versus on-demand therapy.
When completed, the economic model estimated that patients receiving subcutaneous treatment would have 2.34 HAE attacks per year compared with 22.26 attacks in patients on IV. Additionally, attack-related and other medical costs accumulated to $21,073 per year for patients receiving subcutaneous treatment compared with $185,259 per year for patients receiving IV.
One of the contributors to such a high cost in patients receiving IV treatment is that many people are unable to administer therapy to themselves, Graham said. As a result, people tend to have to visit the ED or see an outpatient doctor which adds additional downstream costs.
“Starting a patient on subcutaneous therapy could be incredibly cost saving for patients, as HAE is a disease that has high socioeconomic burden to both the patient and also the health plan,” he said. “This shows the direct savings for the health plan.” – by Ryan McDonald
Graham C, et al. P159. Presented at: the ACAAI Annual Scientific Meeting; Oct. 26-30, 2017; Boston, MA.
Disclosures: Graham reports receiving institutional grant funding.