AstraZeneca P.L.C. said its MedImmune division has filed its formal regulatory reply to a complete-response letter from the U.S. Food and Drug Administration about motavizumab, Bloomberg News reported.

The drug would be used in children at risk of disease because of a respiratory ailment.

A complete-response letter is the FDA's indication that a medication is not ready for approval.

AstraZeneca, which is based outside London, has U.S. headquarters near Wilmington. Its MedImmune division has operations in Philadelphia and Bensalem.    - Inquirer Staff