Lilly heart drug effective, but has risks

ORLANDO (CNNMoney.com) -- Eli Lilly revealed positive findings from a late-stage trial of its experimental heart drug prasugrel, but a side effect might prevent it from becoming the potential blockbuster that the company had hoped.

Lilly's experimental anti-clotting drug prasugrel works better than Bristol's Plavix, but its problems with bleeding are significantly worse, according to Lilly-funded study results that were unveiled on Sunday.

If approved, prasugrel would be used to prevent heart attack in patients who are receiving heart stents.

Of the 13,608 patients who enrolled in the study, 9.9 percent of those who took prasugrel died from cardiovascular causes, heart attack or stroke, and 12.1 percent of those who took Plavix died from those causes, according to Dr. Elliott Antman, professor of medicine at Harvard Medical School.

But the side effect of major bleeding showed up in 2.4 percent of prasugrel patients, compared to 1.8 percent in Plavix patients, said Dr. Antman. Nonetheless, the doctor insisted that the overall safety profile - including death, stroke and bleeding, and other factors - for prasugrel was better.

Michael Krensavage, analyst for Raymond James, said the prasugrel study's success in achieving its main goal - lowering the risk of death, heart attack or stroke - was offset by the problems with bleeding.

"I don't think the FDA will approve it without another [clinical] trial," said Krensavage.

"The company will need to prove that it needs to adequately exclude the bleeders." But Krensavage added that Lilly already tried - and failed - to exclude bleeding-prone patients from its trial.

Dr. Antman, speaking at the annual conference of the American Heart Association, said there were 24 fewer cardiovascular deaths with prasugrel, but 16 more bleeding-related deaths. Overall, there were 9 fewer deaths with prasugrel.

"I think this is definitely an approvable drug in my opinion," said Dr. Antman.

But Dr. Antman said that, based on the bleeding side effects shown in his clinical trials, he would not recommend prasugrel for stroke survivors, even though it is being studied as an anti-stroke drug.

"Maybe a future study would find the sweet spot," said Dr. Antman. "What regimen would really help in prior stroke patients?"

The anti-clotting drugs were taken in combination with aspirin, a common form of treatment in preventing heart attacks and clotting in heart disease patients receiving stents.

Barbara Ryan, analyst for Deutsche Bank North America, said that prasugrel could still be approved, but only with a "pretty ugly" warning label, that would limit the numbers of people who could actually use it.

"The efficacy was better than we expected, but the safety was worse," said Ryan. "Obviously, the negative is that it comes with a costly price in terms of bleeding."

Eli Lilly & Co. (Charts, Fortune 500) paid for the study with its Japanese partner Daiichi Sankyo Co. Ltd. The study is phase 3, the final stage before submission to the Food and Drug Administration. Despite the bad news about bleeding, Lilly said it still plans to submit prasugrel to the FDA before the end of this year.

Prasugrel prevents strokes and heart attacks by keeping platelets from clumping together. Its potential competition, the anti-clotting drug Plavix from Bristol-Myers Squibb (Charts, Fortune 500), totaled $3.4 billion in sales during the first nine months.

Bristol maintained that its drug is safe, having been studied in 100,000 patients in clinical trials and prescribed to 70 million people.

"With the wealth of safety and efficacy data on Plavix, this drug is well understood by physicians in a real-world setting," said Bristol spokesmen, in a press release. "The bleeding rate observed with prasugrel in [the study] raises important questions."

The pressure is on Lilly - and the rest of Big Pharma - to produce profitable new drugs to ward off an industry-wide sales vacuum as the patents expire on blockbuster drugs. This results in plunging sales as generic drugmakers flood the markets with low-cost versions of the brand-name drugs.

Some $20 billion worth of drugs will go off patent in 2008, according to a recent report from IMS Health.

The AHA conference features product and research announcements by several major pharmaceutical companies, including Abbott Laboratories (Charts, Fortune 500) which also unveiled significant test results Sunday for an experimental cholesterol treatment that could go on sale as soon as next year.

Abbott reported that Simcor, a combination of two drugs, effectively lowered harmful types of cholesterol, while raising beneficial types of cholesterol. The $20 billion market for cholesterol drugs is currently dominated by Pfizer Inc.'s (Charts, Fortune 500) Lipitor, the world's top-selling drug with nearly $13 billion in 2006 sales.

Simcor is a combination of Niaspan, an extended-release version of niacin (a form of vitamin B) and simvastatin, a generic version of Merck & Co Inc.'s (Charts, Fortune 500) Zocor, which lost patent protection in 2006. The experimental combo has already been submitted to the Food and Drug Administration. If the agency approves it, Simcor could enter the U.S. market in 2008.

In a late-stage, 24-week study involving 600 patients, Simcor lowered harmful types of cholesterol by 14 percent in the low-dose group, and 23 percent in the high-dose group, according to Abbott. The patients who took only simvastatin lowered harmful cholesterol by 7 percent.

Also, patients taking the low dose of Simcor experienced an 18 percent increase in a beneficial type of cholesterol known as HDL (high density lipoprotein), and high-dose patients experienced an increase of 25 percent. HDL increased by 7 percent in those who took only simvastatin, said Abbott.