Defective Device in Study Does Not Impact Xarelto’s Safety, EMA Says

The European Medicines Agency says a defect with Alere’s INRatio blood testing device used in a study does not change the agency’s conclusions on the overall safety or benefit-risk balance of Bayer’s blood thinner Xarelto.

EMA started investigating the issue when Bayer reported the defect in September 2015.

The Rocket study evaluated Xarelto versus warfarin and was the main clinical trial underpinning the use of this anti-clotting medicine in patients with non-valvular atrial fibrillation, the EMA says. This decision means that Xarelto can continue to be used as before, in line with the current prescribing information.

Because of the defect, there were concerns that the device provided lower international normalized ratio values in some patients in the warfarin group. The lower values could have led investigators to give too high a dose, increasing the risk of bleeding and giving a false impression of the comparative safety of Xarelto.

The EMA says any incorrect measurements obtained with the defective device would have had only a marginal effect on the study results. 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 agency adds.

In December, advocacy group Public Citizen sent a letter to the EMA and FDA, saying its analysis of the FDA’s Manufacturer and User Facility Device Experience database showed 9,469 malfunction reports and 1,445 injury reports from 2002 through November 2015 with INRatio devices (IDDM, Dec. 11, 2015).

In the letter, Public Citizen claimed that false readings by the device could have skewed clinical trial results in favor of Xarelto.

FDA spokeswoman Sandy Walsh tells IDDM that the agency is aware of the EMA’s findings and is continuing to review relevant data regarding the INRatio device and its use in the Rocket-AF trial. — Jonathon Shacat