Apixaban trial halted, eight others continue
After writing this week about the new, direct-acting antithrombotic drugs that threaten to replace the stalwart anticoagulant, warfarin, comes news that the joint BMS/Pfizer development of apixaban has hit a snag. From Jonathan Rockoff and Kathy Shwiff in the Wall Street Journal:
Pfizer Inc. and Bristol-Myers Squibb Co. said they’ve halted one the key trials for an experimental blood-thinning drug that is one of their brightest pipeline prospects, though other pivotal studies remain on course.
The phase III study of apixaban was examining whether the pill reduces the incidence of strokes or heart attacks caused by coronary heart disease, but early results indicated it didn’t while raising the risk of bleeding. The companies said they had acted at the recommendation of an independent data-monitoring committee. All patients will be taken off the drug and the results evaluated and made public, the companies added.
Eight other trials of apixaban are ongoing in other patient populations.
Mechanistically, apixaban is most similar to rivaroxaban (Xarelto, Bayer/J&J) a direct Factor Xa inhibitor discussed this week at the American Heart Association meeting. Rivaroxaban exhibited efficacy similar to warfarin in reducing clots of atrial fibrillation patients but had caused fewer spontaneous bleeding episodes.
A careful examination of the opposite effect of apixaban in patients with coronary heart disease will be essential to understanding whether this is a function of the drug (relative to rivaroxaban) or peculiar to the patient populations studied.