MUNICH (Reuters) - Eli Lilly's new heart drug Effient failed to beat the older product Plavix in a head-to-head clinical study, dashing hopes for its expanded use in treating less critically sick heart patients.
The finding, released at a medical meeting on Sunday, is good news for rival AstraZeneca, whose competitor product Brilinta did show an edge over Plavix in a comparable group of patients in an analysis published last year.
The battle among the different blood-thinning drugs, which are all designed to prevent dangerous clots in heart patients, has moved up a gear this year with the expiry of patents on Sanofi and Bristol-Myers Squibb's Plavix.
That has opened the door to cut-price generic versions of Plavix, or clopidogrel, on both sides of the Atlantic, upping the ante on the newer rivals to prove they really offer a distinctive edge.
Lilly and its partner Daiichi Sankyo had hoped to prove that Effient was a better option for patients with acute coronary syndrome (ACS) who do not get a stent to open blocked arteries or bypass surgery.
ACS covers a range of serious conditions, including heart attacks and unstable angina, caused by a sudden reduction of blood flow to part of the heart.
In fact, the large study funded by the two companies and involving more than 9,000 patients found there was no difference between Effient and Plavix in preventing heart attacks, strokes and deaths. Both drugs were tested alongside aspirin.
There was also no difference in serious bleeding complications, which is always a risk with blood-thinners.
There was a lower risk of adverse events in patients on Effient after 12 months of treatment, but this trend was not conclusive and lead investigator Dr Magnus Ohman of Duke University Medical Center said further exploration of the finding was needed.
Most trials evaluating anti-clotting drugs for ACS have focused on patients undergoing invasive procedures, usually getting a stent - a tiny wire mesh tube that is left in the coronary artery to prevent it from closing up again.
But some 40 percent of patients who are not in urgent need of such invasive intervention are managed solely with drug therapy, and it had been thought that they should do better on a newer and more potent medicine like Effient.
Daiichi research head Glenn Gormley said the trial result was "not the outcome we anticipated" and medical experts at the European Society of Cardiology annual congress, where the findings were reported, agreed the result was unexpected.
"The outcome is a bit surprising because we think usually that more aggressive therapy in the face of acute coronary syndrome would lead to less adverse outcome - but the data is what the data is," said Dr William Zoghbi, president of the American College of Cardiology.
Effient was launched three years ago and the drug has taken off more slowly than many analysts expected, with worldwide sales last year of $302.5 million. Analysts, on average, expect sales to reach $1.1 billion by 2016, according to Thomson Reuters Pharma.
The results of the Effient study were published simultaneously online by the New England Journal of Medicine.
(Editing by Hugh Lawson)