on Thursday reported surprisingly strong first-quarter results, easily beating Wall Street's consensus profit predictions.

The Gaithersburg, Md.-based biotech company earned $114 million, or 45 cents a share, on revenue of $509.8 million for the three months ended March 31. Analysts polled by Thomson First Call had expected a profit of $94.4 million, or 36 cents a share, on revenue of $508.6 million.

For the same period last year, MedImmune earned $111 million, or 43 cents a share, on revenue of $489 million.

MedImmune's quarter was paced by its biggest-selling drug, Synagis, which posted a 12% revenue gain to $472 million. Synagis prevents a dangerous lung disease in infants and young children called respiratory syncytial virus.

MedImmune also said it is sticking by its previously announced guidance for fiscal 2005 with earnings per share in the range of 35 cents to 40 cents and revenue 10% higher than in 2004. That would put 2005's revenue at about $1.24 billion. The Thomson First Call consensus is an EPS of 36 cents and revenue of $1.25 billion. (MedImmune makes most of its sales, and all of its earnings, in the first and fourth quarters.)