Results from a health economic substudy of the TRITON-TIMI 38 clinical trial showed that among patients with acute coronary syndromes (ACS) managed with percutaneous coronary intervention (PCI), including stenting, treatment with prasugrel compared with clopidogrel was more cost effective, and in most cases cost saving. These results were published in Circulation on January 5, 2010.

In the pre-specified analysis of 6,705 patients, treatment with prasugrel compared with clopidogrel reduced total hospitalization costs over approximately 15 months, not including the cost of study drugs, by $530 per patient. This cost offset estimate includes bleeding-related costs that a sensitivity analysis showed were not a major driver of the overall cost difference between the two treatments.

The analysis also found that, including cost of the active study drugs as well as costs associated with the initial and subsequent hospitalizations, treatment with prasugrel compared with clopidogrel decreased cumulative medical costs by $221 per patient over the 14.7-month study. Study drug costs used in the analysis were the net wholesale price as of August 2009, which was $5.45 per day for prasugrel and $4.62 per day for clopidogrel.

"Results of the cost-effectiveness analysis showed that treatment with prasugrel was highly cost effective and an economically dominant option compared with clopidogrel," said David J. Cohen, M.D., M.Sc., director of cardiovascular research, Saint Luke's Mid America Heart Institute and professor of medicine, University of Missouri-Kansas City. "These favorable results were found in an analysis that considered only the first 30 days of treatment, as well an analysis that considered the time period starting from 31 days through the rest of the follow-up period. These analyses are important because the results provide the healthcare community, including formulary decision makers, with new data regarding the cost-effectiveness of prasugrel for patients with ACS undergoing PCI."

"Dominant" is a health economics term used when a new treatment yields greater clinical effectiveness at lower costs. In TRITON-TIMI 38, prasugrel plus aspirin (ASA) was shown to significantly reduce the rate of a combined endpoint of cardiovascular death, nonfatal heart attack, or nonfatal stroke compared to clopidogrel plus ASA. In addition, patients treated with prasugrel also had significantly fewer stent thromboses compared to those treated with clopidogrel. These benefits were accompanied by a significantly higher risk of bleeding, which in some cases were life-threatening or even fatal in patients treated with prasugrel compared with clopidogrel.

The analysis also compared prasugrel to generic clopidogrel at a hypothetical cost of $1 per day. When compared to clopidogrel at this lower cost, treatment with prasugrel in the subpopulation as a whole was economically dominant (e.g., cost saving) during the first 30 days of treatment. After day 31, although not cost-saving, it continued to be a cost-effective therapy relative to many other accepted medical interventions.

"The hypothetical comparison with generic clopidogrel is important because the patent exclusivity for clopidogrel will expire in 2011 or 2012. Results from this comparison to generic clopidogrel will be useful information for the medical community, especially payers, in the future," said Dr. Cohen, "and suggest that the overall benefit of prasugrel was still favorable relative to its higher cost in this setting."

TRITON-TIMI 38 was a Phase III, randomized, double-blind, head-to-head clinical trial comparing the effects of prasugrel versus clopidogrel in patients with ACS who were managed with PCI, a procedure to open blockages in heart arteries, including the use of coronary stenting. The study enrolled 13,608 patients at 707 trial sites in 30 countries.

The primary endpoint of the study was the combined incidence of cardiovascular death, non-fatal heart attack or non-fatal stroke during a median period of at least 12 months following PCI. Patients were randomly assigned to one of two treatment groups and given a loading dose of either prasugrel 60 mg or the FDA-approved loading dose of clopidogrel 300 mg, followed by a daily maintenance dose of either prasugrel 10 mg or clopidogrel 75 mg. All patients also received a daily dose of aspirin (75 mg to 325 mg).

The economic analysis was completed using data from 6,705 study patients enrolled in eight pre-specified countries, including the United States, Australia, Canada, France, Germany, Italy, Spain and United Kingdom. The primary economic measure was total in-trial costs including hospitalization and medication costs. The approach to estimating costs was to multiply counts of resource use (hospitalizations, physician costs, procedures, medications) by price weights derived from comparable populations of US patients. All costs other than study drug costs were assessed in 2005 US dollars.