FDA approves easier-to-administer heart clot-busting drug

WASHINGTON - A new clot-busting drug approved by federal regulators can reduce the time it takes to treat heart attack victims from 90 minutes to five seconds, using a single swift injection to dissolve clots that choke off the heart's blood supply.

Tenecteplase, made by Genentech Inc., won Food and Drug Administration approval on Friday and will be made widely available as soon as possible to treat the nation's biggest killer, company officials said.

Genentech also makes TPA under the brand name Activase, currently the standard medicine for treating heart clots. Both of the drugs dissolve blockages in a similar fashion, preventing further permanent damage, said Dr. Christopher Granger of Duke University Medical Center in Durham, N.C.

A major drawback of TPA, though, is that it must be given as a continuous 90-minute infusion. Tenecteplase, to be sold under the name TNKase, can be administered through one quick, single injection.

''Early administration of these drugs is very important to saving lives,'' said Granger, who oversaw clinical research into the drug. ''Anything that simplifies approach may help in achieving the earliest treatment possible.''

Company spokeswoman Betsy Rosenberg refused to say how much the new drug would cost, saying that pricing would be announced next week. TPA costs about $2,200 per dosage.

Tenecteplase was tested on 17,000 patients in a clinical trial, resulting in a mortality rate of 6.2 percent. The mortality rate for TPA is also 6.2 percent. As with all such treatments for heart clots, the most significant side effect in the tenecteplase study was brain hemorrhaging and stroke, researchers said.

However, patients who took tenecteplase were less likely to suffer non-intracranical bleeding, and less likely to need blood transfusions, Granger said.

Another advantage of tenecteplase over TPA is that the new drug is more specific for treatment of clot in the coronary artery, he added.

The new drug ''would certainly be much easier to administer and the speed with which it can be administered can accelerate the triage of heart patients in an emergency room,'' said Dr. Hal Barron, director of cardiovascular clinical research for Genentech.

Heart attacks strike more than 1.1 million people each year in the United States, causing nearly 500,000 deaths.

On the Net:

Genentech: http://www.gene.com

FDA: http://www.fda.gov