Aclidinium bromide maintains its effectiveness in moderate to severe COPD for up to 52 weeks, according to an extension study.

The analysis was performed to satisfy the US Food and Drug Administration, “but physicians also want to know if it will still be working a year from when it’s first prescribed,” said Stephen Rennard, MD, from the University of Nebraska Medical Center in Omaha.

The drug, a long-acting muscarinic receptor antagonist that helps relax the muscles around the large airways of the lungs, received FDA approval for COPD in 2012.