GAITHERSBURG, Md., Oct 1, 2003 /PRNewswire-FirstCall via COMTEX/ -- MedImmune, Inc. (Nasdaq: MEDI) today announced that it has submitted an investigational new drug (IND) application to the U.S. Food & Drug Administration to evaluate Numax as a potential new product to help prevent serious respiratory syncytial virus (RSV) disease. Under this IND, a protocol has been prepared to assess the safety and tolerability of Numax in healthy adult volunteers, as well as to gather pharmacokinetics and immunogenicity data. Preclinical studies have shown Numax may be 20 to 100 times more potent against the RSV virus than MedImmune's Synagis(R) (palivizumab), the first monoclonal antibody ever approved for any infectious disease.

"The filing of the Numax IND is the first step in our clinical development plan aimed at eventually bringing the next generation anti-RSV antibody to market," said Dr. Edward M. Connor, MedImmune's senior vice president, clinical development. "In 1998, we began marketing Synagis, our flagship product that has been used over the last five years to protect approximately 500,000 young children worldwide from the risk of serious RSV disease. Numax offers us the opportunity to build on this success with an even more potent antibody that may offer increased benefit to these high-risk infants."

Dr. Connor added: "MedImmune has made a substantial commitment to the prevention of serious pediatric infectious diseases. We have brought three products to market that prevent serious respiratory diseases in Synagis, RespiGam(R) (respiratory syncytial virus immune globulin intravenous (human)) and FluMist(TM) (Influenza Virus Vaccine Live, Intranasal). In addition, we are developing a number of product candidates that have the potential to prevent other serious childhood infectious diseases, including cytomegalovirus, parainfluenza virus type 3, human metapneumovirus and Streptococcus pneumomiae, as well as developing new approaches to preventing RSV and influenza."

The regulatory submission for Numax was based on preclinical studies demonstrating that the antibody has enhanced potency compared to Synagis measured by RSV neutralization in tissue culture and RSV titer reduction in the lungs and upper respiratory tract in animal models. The Phase 1 and pharmacokinetic trial is designed to evaluate Numax administered to healthy adults in a dose escalation safety study before testing in the targeted pediatric populations at risk for RSV disease.

RSV is the most common respiratory infection in infancy or childhood, resulting in over 125,000 hospitalizations in the U.S. annually in children less than one year of age. 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 marketed for the prevention of serious lower respiratory tract disease caused by respiratory syncytial virus in pediatric patients at high risk of RSV disease, which is prominent in the Northern Hemisphere from October through May. FluMist is marketed for active immunization for the prevention of disease caused by influenza A and B viruses in healthy children and adolescents, 5-17 years of age, and healthy adults, 18-49 years of age. For full prescribing information of all of MedImmune's products, see the company's website at www.medimmune.com.

About MedImmune, Inc.

MedImmune is a leading biotechnology company focused on researching, developing and commercializing products to prevent or treat infectious disease, autoimmune disease and cancer. MedImmune actively markets four products, Synagis(R) (palivizumab), FluMist(TM) (Influenza Virus Vaccine Live, Intranasal), Ethyol(R) (amifostine) and CytoGam(R) (cytomegalovirus immune globulin intravenous (human)), and has additional products in clinical testing. MedImmune employs approximately 1,700 people, is headquartered in Gaithersburg, Maryland, and has additional operations in Frederick, Maryland, as well as Pennsylvania, California, the United Kingdom and the Netherlands. For more information on the company and its products, visit MedImmune's website at www.medimmune.com.

This announcement may contain, in addition to historical information, certain forward-looking statements that involve risks and uncertainties. Such statements reflect management's current views and are based on certain assumptions. Actual results could differ materially from those currently anticipated as a result of a number of factors, including risks and uncertainties discussed in MedImmune's filings with the U.S. Securities and Exchange Commission. The company is developing several products for potential future marketing. There can be no assurance that such development efforts will succeed, that such products will receive required regulatory clearance or that, even if such regulatory clearance were received, such products would ultimately achieve commercial success.

SOURCE MedImmune, Inc.

Media: Jamie Lacey, +1-240-632-4035, or Investors: Will
Roberts, +1-301-527-4358, or John Filler, +1-240-632-4086, all of MedImmune,
Inc.

http://www.medimmune.com