Press Release: Numax Achieves Primary Endpoint In Preliminary Analysis of Data From Comparative Phase 3 Trial With Synagis

Numax Achieves Primary Endpoint In Preliminary Analysis of Data From Comparative Phase 3 Trial With Synagis - Numax Showed Non-Inferiority in Primary Endpoint with 26-Percent Relative - Reduction in RSV Hospitalizations Among High-Risk Infants - Numax Also Showed Superiority Over Synagis for a Secondary Endpoint by - Achieving a 52-Percent Relative Reduction in Incidence of Medically Attended - Outpatient Lower Respiratory Infections Caused by RSV GAITHERSBURG, Md., Nov. 6 /PRNewswire-FirstCall/ -- MedImmune, Inc. (Nasdaq: MEDI) today announced preliminary results from a Phase 3 pivotal study showing that Numax met its primary endpoint of non-inferiority by reducing the incidence of hospitalizations caused by respiratory syncytial virus (RSV) in infants at high risk for serious RSV disease by 26 percent when compared to Synagis(R) (palivizumab). The data also indicate that Numax showed superiority over Synagis in a secondary endpoint by reducing the incidence of RSV-specific medically attended outpatient lower respiratory infections (LRI) by approximately 52 percent. "We are very pleased with the outcome of this large, multi-national Phase 3 study comparing Numax to Synagis, which is the current standard of care in the U.S. for preventing RSV in high-risk infants," said Edward M. Connor, M.D., chief medical officer and executive vice president. "The preliminary results of this study are highly encouraging and indicate that Numax may have the potential to offer high-risk infants additional protection against RSV infection over and above Synagis, which has an established safety and efficacy profile. We intend to continue to evaluate the complete data set to more fully understand the trial results, and then to review the data with the U.S. Food and Drug Administration." The pivotal Phase 3 study was designed to compare the safety and efficacy of Numax with that of Synagis in infants at high risk for serious RSV disease for the reduction of serious RSV disease in the inpatient and outpatient settings. The primary endpoint was to assess the non-inferiority of Numax compared to Synagis in the incidence of hospitalizations caused by RSV. By design, non-inferiority was defined to have been demonstrated if the upper bound of the two-sided 95 percent confidence interval of the relative risk (RR) for the primary endpoint was lower than 1.265. As indicated above, Numax showed a 26-percent reduction [RR: 0.737, 95 percent CI: (0.503, 1.083)] in RSV hospitalizations compared to Synagis. The corresponding p-value for non- inferiority analysis was About RSV Each year, an estimated 125,000 infants in the United States are hospitalized with severe RSV infections, the leading cause of infant hospitalization in the U.S.(1) 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 for severe disease and hospitalization due to RSV. The virus may also cause severe illness in other high-risk groups such as the elderly, those with underlying respiratory or cardiac disease, and those with compromised immune systems (e.g., bone marrow transplant patients). About Numax Numax is an investigational humanized monoclonal antibody being evaluated for its potential to prevent serious lower respiratory tract disease caused by RSV in pediatric patients at high risk of RSV disease. Phase 1 and Phase 2 studies have been reported showing that Numax appears to have a similar safety and pharmacokinetic profile to Synagis in infants. Additionally, in early phase studies children treated with Numax had reduced RSV replication in the upper respiratory tract. About Synagis Synagis is the only monoclonal antibody approved by the U.S. Food and Drug Administration to help prevent an infectious disease. Since its licensure in 1998, Synagis has been administered to more than 800,000 infants in the U.S. and has become the standard of care for infants at high risk for RSV. Synagis is indicated for the prevention of serious lower respiratory tract disease caused by RSV in pediatric patients at high risk of RSV disease, which is prominent in the Northern Hemisphere during the winter months. Synagis is a humanized monoclonal antibody given by an intramuscular injection once a month during the RSV season. Synagis was approved in 1998 by the FDA; in 1999, by the European Medicines Evaluation Agency; and in 2002, by the Japanese Ministry of Health, Labor and Welfare. In 2003, the FDA expanded the U.S. label for Synagis for use in young children with hemodynamically significant congenital heart disease at risk of RSV disease. To date, Synagis has been approved in 62 countries, including the United States. In clinical trials, the most common adverse events occurring at least 1 percent more frequently in Synagis-treated patients were upper respiratory infection, otitis media, fever and rhinitis. Cynanosis and arrhythmia were seen in children with CHD. Very rare cases of anaphylaxis (less than 1 case per 100,000 patients) and rare hypersensitivity reactions have been reported. Synagis should not be used in patients with a history of a severe prior reaction to Synagis or its components. For full prescribing information for Synagis, see the company's website. About MedImmune, Inc. MedImmune strives to provide better medicines to patients, new medical options for physicians, rewarding careers to employees, and increased value to shareholders. Dedicated to advancing science and medicine to help people live better lives, the company is focused on the areas of pediatric infectious diseases, cancer and inflammatory diseases. With more than 2,500 employees worldwide, MedImmune is headquartered in Maryland. For more information, visit the company'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 Numax for potential future marketing. There can be no assurance that such development efforts will succeed, that Numax will receive required regulatory approval or that, even if such regulatory approval is received, that Numax would ultimately achieve commercial success. (1) Shay DK, Holman RC, Newman, RD et al. Bronchiolitis-associated hospitalizations among US children, 1980-1996. JAMA. 1999; 282:1440-1446.