Idraparinux is being developed as an alternative to standard treatment heparin, and can be taken less often than current medication.
The researchers' primary measure of success was whether a symptomatic venous clot would reoccur three months after treatment. Patients were randomized to either receive idraparinux or the standard daily treatment regimen of heparin. In the study, idraparinux was not as effective as the standard treatment in the pulmonary embolism group. The incidence of blood clot reoccurrence after three months was 1.6% in the control group and 3.4% in those taking idraparinux.
However the DVT group experienced some success as idraparinux was found to be just as effective as heparin, with a nearly identical incidence of reoccurrence of 2.9% in the patients taking idraparinux and 3% in the control group.
“Although the results for idraparinux in the pulmonary embolism group were surprising and disappointing, for patients with deep vein thrombosis our findings should have a remarkable impact,” said Harry Buller, chairman of the Department of Vascular Medicine at the Academic Medical Center, Amsterdam.
“The fact that once-a-week injections of idraparinux are just as effective and safe as traditional treatment frees patients with DVT from the daily injections and continuous monitoring that would otherwise be required.”
This is the second time idraparinux has failed in a study. The drug failed to meet the main goals of phase III trials last year.