MedImmune Inc announced that the US FDA has approved a new liquid formulation of Synagis (palivizumab). In 1998, the original formulation of Synagis was approved by the FDA to prevent serious lower respiratory tract disease caused by respiratory syncytial virus (RSV) in paediatric patients at high risk of RSV disease. Synagis is the first monoclonal antibody approved for prevention of an infectious disease, and the first such drug to be safely used in children, a MedImmune release said.

The new liquid Synagis offers healthcare providers, parents and high-risk infants improved convenience. The original formulation is a freeze-dried preparation that is reconstituted with sterile water, a process that takes approximately 20 minutes, from which the final product must be used within the next six hours.

The new liquid formulation of Synagis is already supplied as a sterile solution ready for injection, thus eliminating the additional preparatory steps and reducing the time a high-risk infant will spend in a physician's waiting room among other sick children.

In October 2004, MedImmune plans to end production of the current formulation for the US and to begin manufacturing liquid Synagis, which should be available for use in the US for the 2005 - 2006 RSV season.

RSV is the most common respiratory infection in infancy or childhood. Approximately one half of all infants are infected with RSV during the first year of life, and nearly all children have been infected at least once by the time they reach their second birthday. Children born prematurely as well as those with chronic lung disease or congenital heart disease are at highest risk of severe disease and hospitalization due to RSV.

Synagis is a humanized monoclonal antibody given through a simple intramuscular injection once a month during the RSV season. Synagis was initially licensed by the FDA in 1998, and in 2003, its label was expanded to include safety and efficacy data supporting its use in young children with hemodynamically significant congenital heart disease to prevent hospitalization caused by RSV, the release added.