Bayer's Xarelto 'Safe' Despite ROCKET Device Defect
This article was originally published in Scrip
A defective INR device used to monitor blood clotting in the main study supporting the 2011 approval of Bayer AG's new oral anticoagulant Xarelto (rivaroxaban) in stroke prevention in atrial fibrillation had no effect on the safety and benefit/risk balance of the product, the EMA has concluded. Xarelto can continue to be used as before, in line with the current prescribing information, it said.
The conclusions provide reassurance for the top-selling product ahead of Bayer's full year results presentation on Feb. 25. Xarelto posted sales of €571m in 3Q 2015, missing expectations but still up by 30% on 3Q 2014.
The ROCKET AF study, conducted by Bayer and its partner Janssen Pharmaceuticals Inc., compared Xarelto with warfarin for preventing stroke and systemic embolisms in patients who have non-valvular atrial fibrillation, and tested the drug's blood clotting ability using a device from Alere Inc. that measured the International Normalized Ratio, or INR. Alere issued a notice detailing the mechanical defect in December 2014, but it took some months before Bayer become aware of the problem and for it to be confirmed that the devices used in the ROCKET AF trial were affected. The EMA began an investigation into the issue when it was informed of it by Bayer in September 2015.
The concern was that the faulty INR device could have provided lower INR values in some patients in the warfarin group. The lower values could in turn have led investigators to give too high a dose in the warfarin group, increasing their risk of bleeding and so giving a false impression of the comparative safety of Xarelto.
However, the EMA says that after further analyses of the ROCKET data taking into account the defect in the INR device, the CHMP concluded that any incorrect measurements obtained with the defective device would have had only a marginal effect on the study results, and the safety of Xarelto remains unchanged. In addition, data from other large studies confirmed the comparative safety of the medicine and showed similar rates of bleeding in their warfarin groups, the EMA noted. The CHMP's assessment report with all the details of the analyses will be published shortly on the EMA website.
In December, Bayer announced findings from a secondary analysis of the study that were consistent with the first in a bid to reassure patients and investors of the product's safety and efficacy profile. Stroke prevention in AF is a key indication for the newer oral anticoagulants that also include Bristol-Myers Squibb/Pfizer's Eliquis (apixaban).