A 92.6% reduction in the list price of tafamidis—an effective but ultimately unaffordable drug designed to treat transthyretin amyloid cardiomyopathy (ATTR-CM)—would be required to make the medication accessible to the average heart patient, researchers reported in Circulation Feb. 12.
Tafamidis, which is manufactured by Pfizer, works by binding to and stabilizing transthyretin, which prevents transthyretin tetramer dissociation, first author Dhruv S. Kazi, MD, MSc, MS, and colleagues explained in the paper. The drug lowered all-cause mortality and slowed decline in quality of life and functional capacity in a major study of patients with ATTR-CM and heart failure, prompting its expedited approval via the FDA’s breakthrough pathway. It hit the U.S. market in May 2019.
In many ways, tafamidis has been a game-changer for ATTR-CM patients, who, if left untreated, typically live just 2.5 to 3.5 years after they’re diagnosed. But, at a price point of $225,000 per year, the medication isn’t a feasible option for everyone.
“It is the most expensive cardiovascular drug ever launched in the U.S., raising concerns about cost-effectiveness, affordability and access,” Kazi et al. wrote. “A timely and rigorous cost-effectiveness evaluation would help inform clinical and policy discussions regarding uptake of tafamidis and may influence drug pricing as the drug enters the market.”
The team launched an independent cost-effectiveness analysis of tafamidis, developing a Markov model of patients with wild-type or variant ATTR-CM and HF using data from the Transthyretin Amyloidosis Cardiomyopathy Clinical Trial (ATTR-ACT), published studies, FDA review documents, healthcare claims and national survey data. Tafamidis was compared with “usual care”—no disease-specific treatment—for main outcomes of lifetime incremental cost-effectiveness ratio (ICER) and annual U.S. budget impact.
Kazi and co-authors found that, compared with standard care, tafamidis was projected to add 1.29 quality-adjusted life years (QALY) at an incremental cost of $1,135,000. That would translate to an ICER of $880,000 per QALY gained.
Assuming a threshold of $100,000 per QALY gained and the current price of tafamidis, the authors reported the drug was cost-effective in 0% of 10,000 probabilistic simulations. They said the medication’s price tag would need to shrink a dramatic 92.6%—from $225,000 per year to $16,562 per year—to make tafamidis cost-effective.
Considering the fact that any savings from fewer CV hospitalizations per patient per year would be offset by patients surviving longer, Kazi and colleagues calculated U.S. healthcare spending would increase by $32.3 billion per year if all eligible patients received tafamidis therapy.
“This includes a $31.9 billion increase in annual prescription drug expenditures, which would increase the total U.S. spending for all prescription drugs by 9.3%,” the authors wrote. “As diagnosis rates increase—as a result of greater awareness about ATTR-CM, increased use of nuclear scintigraphy for accurate diagnosis and more widespread uptake of genetic tests to screen family members of individuals with variant ATTR-CM—the budget impact of tafamidis is expected to increase, as well.”
The team said that in turn, the challenge for healthcare systems and payers is likely to increase over time, too.
“If rates of diagnosis of ATTR-CM substantially increase...the impact of tafamidis therapy on total health spending would exceed our projections,” they wrote.