Analysis: Price of hemophilia A therapy would have to drop nearly 60% to be cost-effective

SAN DIEGO — Efanesoctocog alfa prophylaxis is conventionally cost-ineffective compared with standard factor VIII for patients with severe hemophilia A without inhibitors, according to results presented at ASH Annual Meeting and Exposition.

The price of the extended half-life agent would have to decrease by nearly 60% to become cost-effective, researchers reported.

“These discussions and decisions are more for the health care system and stakeholder level, so I don’t think physicians who treat patients with hemophilia should change clinical practice,” George Goshua, MD, MSc, assistant professor of medicine (hematology) at Yale School of Medicine, told Healio. “For them, this is informative, but every patient is a special case. Physicians shouldn’t be thinking about costs in an individual environment. However, they should be thinking about health care utilization and the impact for the vast care population.”

Background

Prophylactic coagulation factor replacement reduces bleeding episodes and improves quality-adjusted life expectancy for individuals with severe hemophilia A. However, patients who receive prophylactic treatment still are at risk for bleeding events and chronic arthropathies, according to study background.

Efanesoctocog alfa (Sobi, Sanofi) — a recombinant factor VIII therapy with once-weekly dosing — received FDA approval for hemophilia A prophylaxis and management based on results of the phase 3 XTEND-1 study. Results showed once-weekly efanesoctocog alfa reduced the annualized bleeding rate by 77% compared with standard factor VIII prophylaxis for those with severe hemophilia A without inhibitors.

However, the cost-effectiveness of efanesoctocog alfa compared with standard factor VIII prophylaxis had not been established.

Methods

Goshua and colleagues built a Markov model to compare cost-effectiveness of weekly efanesoctocog alfa with three-times-weekly octocog alfa over the lifetimes of adults aged 34 years or older with severe hemophilia without inhibitors.

Phase 3 study data and FDA package insert information informed transition probabilities for annualized bleeding rates and product utilization. Researchers accounted for treated bleeding severity and bleeding event types — including intracranial hemorrhage and hemarthrosis — and assumed efanesoctocog alfa would eliminate the prevalence of chronic arthropathy with standard half-life prophylaxis.

Investigators based prices of both therapies on VA Federal Supply Schedule Service pricing.

Researchers incorporated disease-specific utilities, disutility due to frequent injection and time-variant arthropathy changes.

Key outcomes included incremental cost-effectiveness ratio — cost divided by quality-adjusted life years — at a willingness-to-pay threshold of $150,000 per quality-adjusted life year, as well as a base-case price threshold at which a cost-ineffective treatment would become cost-effective.

Goshua and colleagues also performed a distributional cost-effective analysis to derive a threshold equity weight for which equally distributed equivalents of both therapeutic approaches were equal.

Results

Base-case analysis showed efanesoctocog alfa to be conventionally cost-ineffective compared with standard factor VIII, Goshua said.

Researchers calculated lifetime costs of $17.3 million for efanesoctocog alfa vs. $9.7 million for standard factor VIII. They also reported an incremental effectiveness improvement with efanesoctocog alfa as measured by quality-adjusted life years (19.4 vs. 15.4). This equated to an incremental cost-effectiveness ratio of $1.89 million (95% CI, 1.19-3.33) per quality-adjusted life year.

Threshold analysis showed efanesoctocog alfa prophylaxis would become cost-effective if the price declined by at least 59%.

Researchers calculated a threshold inequality aversion parameter of 7.4. The accepted range in the US is 0.5 to 3, Goshua said.

Implications

Future studies should be conducted to determine disease-specific equity weights, Goshua said. This would provide transparent, equity-informed value assessments that can allow for cross comparisons.

Researchers also plan additional analyses to evaluate cost-effectiveness of other hemophilia treatments, including gene therapy, Goshua said.

“The rate of bankruptcy in this country is significant, and the highest component of that is medical bankruptcy,” Goshua told Healio. “If you look at advanced economies, we have the worst health performance but at the same time spend the most — we actually double the second-leading country in terms of [gross domestic product] spent on health care. For that reason, I feel we need to take these deep dives and evaluate how we can reappropriate resources. We have so many of them, but I don’t think we’re using them effectively.”