A new,
pre-specified analysis of the landmark Phase III head-to-head TRITON-TIMI
38 study showed patients who took prasugrel for acute coronary syndromes
(ACS) managed with an artery-opening procedure known as percutaneous
coronary intervention (PCI) and had survived their first cardiovascular
event and then suffered a subsequent event, were 35 percent less likely to
have a recurrent event (composite endpoint of heart attack, stroke or
cardiovascular death) than those who took clopidogrel (10.8% vs. 15.4%;
P=0.016). These data appear as a special advance access online publication
from the European Heart Journal.
The recurrence of subsequent events assessment was part of the larger
TRITON-TIMI 38 trial, the primary measure of which showed that prasugrel
taken with aspirin reduced the relative risk of the combined endpoint of
cardiovascular death, non-fatal heart attacks or non-fatal stroke by 19
percent more than clopidogrel (Plavix(R)/Iscover(R)) taken with aspirin.
These benefits were accompanied by an increased risk of serious bleeding
with prasugrel overall, some of which may be life threatening. Overall, for
every 1,000 people treated, there were six more TIMI major bleeding events,
but 23 fewer heart attacks in patients taking prasugrel compared with
patients taking clopidogrel.(1) The risk of cardiovascular death overall in
the study was not statistically different between treatment groups
[prasugrel (2.0%) compared with clopidogrel (2.2%)].
Additional data from this further analysis of recurrent events showed:
-- The reduction in recurrent events among prasugrel patients persisted
over the duration of the trial (15 months).
-- Among patients taking prasugrel, there were 58 recurrent events
compared with 115 recurrent events in the clopidogrel group.
-- The risk of cardiovascular death after a heart attack while on
therapy was significantly reduced with prasugrel (3.7%) compared with
clopidogrel (7.1%).
-- Diabetics treated with prasugrel showed a risk reduction of 60
percent in subsequent events (P=0.003).
-- Even after adjusting for variables such as age, gender, tobacco use
and other health conditions, those taking prasugrel still showed a
statistically significant reduction of 34 percent in recurrent events
(P=0.024).
-- While recurrent bleeding events occurred infrequently among patients
with at least one TIMI non-CABG major or minor bleeding (17 in the
prasugrel group and 13 in the clopidogrel group), the analysis noted the
high percentage of discontinuation following an initial major bleeding
event, which were similar among those patients taking prasugrel (42%) and
those taking clopidogrel (43%).
"Not only do multiple heart events increase healthcare costs due to
additional hospitalizations, tests and physician visits, but they also
result in higher morbidity for many patients," said Elliott Antman, M.D.,
director of the Samuel A. Levine Cardiac Unit at Brigham and Women's
Hospital (BWH) in Boston and principal investigator with the BWH-based TIMI
Study Group for the TRITON-TIMI 38 clinical trial.
Methodology
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 to compare the effects of
prasugrel to clopidogrel on 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 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 low dose of aspirin.
To measure the risk of recurrent events, a Poisson regression analysis
was performed to compare the number of occurrences of cardiovascular events
over a period in patients who had suffered at least one primary endpoint.
About Acute Coronary Syndromes
Acute coronary syndromes (ACS), which is comprised of heart attacks and
unstable angina (chest pain), affects more than 1.4 million people in the
United States annually.(2) Coronary heart disease, which can result in ACS,
is the single most common cause of death in the European Union, accounting
for more than 741,000 deaths in the EU each year.(3) Coronary artery
disease occurs when the arteries become narrowed or clogged by cholesterol
and fat deposits and cannot supply enough blood to the heart. In some
cases, a blood clot may partially or totally block the blood supply to the
heart resulting in ACS.(4) Many ACS patients are managed with PCI, which
usually includes a stent placement.
About prasugrel
Daiichi Sankyo Company, Limited (TSE: 4568), and Eli Lilly and Company
(NYSE: LLY) are co-developing prasugrel, an investigational oral
antiplatelet agent invented by Daiichi Sankyo and its Japanese research
partner Ube Industries, Ltd., as a potential treatment, initially for
patients with acute coronary syndromes who are managed with PCI. Prasugrel
works by inhibiting platelet activation and subsequent aggregation by
blocking the P2Y12 adenosine diphosphate (ADP) receptor on the platelet
surface. Antiplatelet agents prevent platelets from clumping or sticking
together, which can result in clogged arteries and may lead to heart attack
or stroke.
About Daiichi Sankyo Company, Limited
Daiichi Sankyo Company, Limited, established in 2005 after the merger
of two leading century-old Japanese pharmaceutical companies, is a global
pharmaceutical innovator, continuously generating innovative drugs that
enrich the quality of life for patients around the world. The company uses
its cumulative knowledge and expertise in the fields of cardiovascular
disease, cancer, metabolic disorders, and infection as a foundation for
developing an abundant product lineup and R&D pipeline.
About Eli Lilly and Company
Lilly, a leading innovation-driven corporation, is developing a growing
portfolio of first-in-class and best-in-class pharmaceutical products by
applying the latest research from its own worldwide laboratories and from
collaborations with eminent scientific organizations. Headquartered in
Indianapolis, Ind., Lilly provides answers - through medicines and
information - for some of the world's most urgent medical needs.
This press release contains certain forward-looking statements about
the potential of the investigational compound prasugrel (CS-747, LY640315)
and reflects Daiichi Sankyo's and Lilly's current beliefs. However, as with
any pharmaceutical compound under development, there are substantial risks
and uncertainties in the process of development and regulatory review.
There is no guarantee that the compound will receive regulatory approval,
that the regulatory approval will be for the indication(s) anticipated by
the companies, or that later studies and patient experience will be
consistent with study findings to date. There is also no guarantee that the
compound will prove to be commercially successful. For further discussion
of these and other risks and uncertainties, see Lilly's filing with the
United States Securities and Exchange Commission and Daiichi Sankyo's
filings with the Tokyo Stock Exchange. Daiichi Sankyo and Lilly undertake
no duty to update forward-looking statements.
Plavix(R)/Iscover(R) are registered trademarks of Sanofi-Synthelabo
Inc.
References
(1) Wiviott, S, Braunwald, E, et al. Prasugrel versus Clopidogrel in
Patients with Acute Coronary Syndromes. New England Journal of Medicine.
November 2007; 357: 2001-15.
(2) American Heart Association. Heart Disease and Stroke Statistics -
2008 Update. Dallas, TX. American Heart Association. (Pg. 14)
(3) British Heart Foundation Health Promotion Research Group. European
Cardiovascular Disease Statistics 2008,
ehnheart/content/ItemPublication.asp?docid=7069&level0=1500&level1=2157, Accessed April 24 2008.
(4) WebMD Medical Reference in Collaboration with the Cleveland Clinic.
Heart Disease: Coronary Artery Disease. June 2004.
Eli Lilly and Company
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