AstraZeneca announced that MedImmune, its biologics unit, has filed its formal regulatory reply to a Complete Response Letter (CRL) from the US Food and Drug Administration (FDA). MedImmune received the CRL asking for additional information regarding motavizumab on 25 November 2008, and the company has been in ongoing discussions with US FDA reviewers since then to complete and file its CRL reply.

The CRL is in connection with the Biologics License Application (BLA) for motavizumab for the prevention of serious respiratory syncytial virus (RSV) disease in high-risk infants, which was submitted on 30 January 2008. Motavizumab is an investigational monoclonal antibody (MAb) with enhanced activity against RSV compared to Synagis (palivizumab).

MedImmune was not required to conduct additional clinical trials in responding to the CRL. MedImmune will continue discussions with the US FDA reviewers as needed throughout the remainder of the registration process.

MedImmune, the worldwide biologics business for AstraZeneca PLC, has approximately 3,300 employees worldwide and is headquartered in Gaithersburg, Maryland.