New Drug No Substitute for Standard Blood-Clot Therapy

Idraparinux effective, but research found higher rates of bleeding with long-term use.

By Serena Gordon
HealthDay Reporter
Wednesday, September 12, 2007; 12:00 AM

Copyright © 2007 ScoutNews, LLC. All rights reserved.

WEDNESDAY, Sept. 12 (HealthDay News) -- Three studies on the new anti-clotting medication idraparinux found the drug was effective at treating deep vein thrombosis (DVT) and for the long-term prevention of blood clots. But it was not as effective as the usual treatment for potentially life-threatening pulmonary embolisms.

And, with long-term use, idraparinux appears to have a higher rate of serious bleeding complications than standard therapy.

"This wish to find new anti-coagulants (anti-clotting medications) is urgent," said lead researcher Dr. Harry Buller, chairman of the department of vascular medicine at the Academic Medical Center in Amsterdam, the Netherlands. "Our conclusion in the DVT study was that it was a good alternative. For pulmonary embolism, idraparinux was not as good as standard therapy."

And, Buller said, in the study that compared idraparinux to standard therapy for preventing the formation of new blood clots, the new drug was effective, but "there is a bleeding risk that is too high."

"Clearly, this drug in its present form won't come to the market," said Buller, who added that the drug's manufacturer, Sanofi-Aventis, is working on the medication and adding a biomarker to the drug so it could be quickly removed from the system if a complication such as excessive bleeding occured.

Sanofi-Aventis provided support for all three studies.

Buller said that in western societies, about two to four people per every 1,000 develop either a deep vein thrombosis or pulmonary embolism each year. That means that hundreds of thousands of people in the United States experience these problems each year, he said.

The current treatment regimen includes intravenously delivered or injections of the blood-thinner heparin, followed by six to 12 months of warfarin, an oral anti-coagulant. The currently available treatments are effective but necessitate careful monitoring and require patients to modify their diets and watch what medications they take to prevent complications.

"We wanted to find a medication that was a little safer, more patient-friendly and that could improve the quality of life," Buller said.