Abbott Laboratories announced that it has received approval from the European Commission to market Synagis (palivizumab) for use in infants less than two years of age born with hemodynamically significant congenital heart disease (CHD) to prevent serious lower respiratory tract infection (LRTI) hospitalization caused by respiratory syncytial virus (RSV). RSV is the most common cause of LRTI (e.g., bronchiolitis and pneumonia) in infants and children worldwide, with infections predominantly occurring from autumn through the spring seasons.

Synagis was initially approved for marketing by the European Commission in 1999 and the U.S. Food and Drug Administration in 1998 to prevent LRTI caused by RSV in premature infants and infants with chronic lung disease (CLD) at high risk for severe RSV illness.

Abbott and its U.S. partner for Synagis, MedImmune Inc. (Gaithersburg, Maryland, USA), received approval for expanded use in children with CHD in the United States in September 2003. Abbott filed for E.U. approval for the new CHD indication in March 2003, and received a positive opinion from the EMEA in July.

"Infants and children with CHD are at a high risk for RSV and have higher morbidity rates than those without heart disease," said Timothy Feltes, M.D., chief, pediatric cardiology, Columbus Children's Hospital, Columbus, Ohio, USA, and one of the principal investigators of the pivotal study submitted to the EMEA for the new Synagis indication. "With E.U. approval, European physicians will be able to offer better care and treatment for these vulnerable children."

Congenital heart defects are structural problems of the heart that are present at birth and can vary in type and degree of severity. Current estimates are that four to eight out of every 1,000 infants in Europe are born with some type of CHD each year. Decreased cardiac or pulmonary reserve predisposes children with serious CHD to a higher risk of severe RSV infection. The mortality rate for children with CHD who are hospitalized with RSV is three times greater than children without CHD. Children with CHD and RSV have demonstrated an increased need for costly intensive care and mechanical ventilation when compared to children without CHD.

European approval of this new indication in CHD was based on positive findings from a four-year, double-blind, placebo-controlled multinational study assessing 1,287 children less than 2 years of age with serious CHD. In the study, children were randomized to receive monthly intramuscular injections (15 mg/kg) of either Synagis (n=639) or placebo (n=648) for a period of five months during a single RSV season. The clinical trial was conducted over four consecutive RSV seasons, which in the Northern Hemisphere lasts from October through April. The study was conducted at 76 centers in France, Germany, North America, Poland, Sweden, and the United Kingdom and was completed in 2002.

RSV-related hospitalizations were nearly 50 per cent less in the Synagis treatment arm (p=0.003) compared to the placebo group, with 34 and 63 patients, respectively, requiring hospitalization. Data showed there were significantly fewer RSV-related hospital days (p=0.003) and fewer days of increased oxygen usage (p=0.014) in the treated group than in the placebo group. Adverse events reported in the two treatment groups were similar, with injection site reaction and fever reported as the most common.

"The European approval of Synagis, and the data that support it, provide new hope to parents and their vulnerable infants and children," said Herrera. "The data indicate shorter hospitalizations for at-risk infants. Shorter hospital stays could result in lower treatment costs," said Guillermo Herrera, senior vice president, International Operations, Abbott Laboratories.

For children with CHD and premature infants who are 35 weeks gestational age or younger, previous clinical studies have demonstrated that Synagisis safe, effective, and well-tolerated for the prevention of RSV. Abbott has exclusive rights to Synagisin markets outside of the United States. In the United States, MedImmune Inc. and Abbott have an exclusive agreement to co-promote Synagis.