Dronedarone (Multaq) permanent atrial fibrillation study (“PALLAS”) stopped early due to increased major cardiovascular events in active treatment group

Henry I. Bussey, Pharm.D., FCCP, FAHA
July, 2011

The heart.org just released a write-up on a press release from Sanofi-Aventis which announced the decision to terminate the phase IIIb “PALLAS” study (see http://www.theheart.org/article/1251405.do?utm_campaign
=newsletter&utm_medium=email&utm_source=20110707_breaking).

Dr. Stuart Connolly, a co-primary investigator, was not able to provide details about specific event rates that led to the termination of PALLAS, but he pointed out that the patients in the PALLAS study were very different from the patients in the ATHENA study (which previously reported benefits with dronedarone therapy). Specifically, patients in the ATHENA study had intermittent atrial fibrillation and relatively mild additional risk factors. By contrast, the patients in PALLAS had permanent atrial fibrillation and more severe risk factors (including previous stroke or myocardial infarction, reduced ejection fraction, and others). Previously, concerns had arisen about the safety of dronedarone in certain patients, particularly those with heart failure. Dr. Connolly did not feel that dronedarone needed to be stopped in “ATHENA – like” patients who have been taking this medication for its approved indication of intermittent atrial fibrillation.