<="" strong="">Bayer has responded to claims in the German press that its novel oral anticoagulant Xarelto may have been approved on the back of trials using a defective testing device.
The assertion – made in German newspaper Handelsblatt – is that both the EMA in Europe and the US FDA are investigating suggestions that the device to measure blood clotting in patients that was used in the ROCKET AF trial, which underpinned Xarelto’s approval for non-valvular atrial fibrillation (AF), may have been faulty.
Last week, the British Medical Journal also reported that the results of the trial are under scrutiny from regulators, specifically concerns that they may have exaggerated Xarelto’s benefits. Bayer sells the drug in Europe while Johnson & Johnson’s Janssen unit sells it in the US.
In a statement, Bayer said it had conducted analyses that confirm the results of ROCKET AF, which have also been corroborated by a second investigation by the Duke Clinical Research Institute (DCRI), which ran the study.
In ROCKET AF, Xarelto (rivaroxaban) was found to be non-inferior to warfarin in reducing the risk of stroke or systemic embolism, without significantly increasing the risk of bleeding, in patients with non-valvular AF. In addition, the drug significantly reduced intracranial bleeding compared with warfarin.
The trial used a device called INRatio, manufactured by Alere, to determine whether doses of warfarin should be adjusted to keep the drug in the right therapeutic range. In December 2014 however some INRatio devices were recalled after nearly 19,000 reports of malfunctions, with the results achieved differing significantly from laboratory tests.
The implication is that patients on warfarin may have been more prone to bleeds than usual, making Xarelto appear superior by comparison. The drug is Bayer’s biggest-selling pharmaceutical product, bringing in €1.60bn ($1.76bn) in the first nine months of this year.
Bayer stressed that Xarelto “is an important anticoagulant used to treat and reduce the risk of life-threatening blood clots”.
“Beyond ROCKET AF, Bayer evaluated the performance of Xarelto in more than 91,000 patients across its approved indications in real-world research following the medicine’s approval, and study after study continues to confirm that Xarelto is performing as expected with a positive benefit-risk profile.”