News Pressroom

April 21, 1999

MedImmune First Quarter Product Sales Nearly Triple

— SynagisTM Launch Reaches $226 million in First Season —

Gaithersburg, MD, April 21, 1999 -- MedImmune, Inc. (Nasdaq: MEDI) today reported net sales of SynagisTM (palivizumab) in first quarter 1999 of $116.2 million and total product sales of $127.0 million, nearly triple first quarter 1998. Net sales of SynagisTM for the 1998/1999 respiratory syncytial virus (RSV) season have been $225.9 million through March 31, 1999. Earnings per share more than doubled to $0.45 per share, diluted and fully taxed, on 65.5 million shares in first quarter 1999 from $0.21 per share, diluted but untaxed, on 63.2 million shares in first quarter 1998.

“The SynagisTM U.S. launch has been one of the most successful in the history of biotech,” said Wayne T. Hockmeyer, Ph.D., Chairman and Chief Executive Officer. “We are pleased with the initial response to the product and estimate that we reached 15 to 20 percent of the children who could potentially benefit from SynagisTM in this first season. We are focused now on expanding the usage of SynagisTM in the United States during next RSV season and look forward to launching SynagisTM in markets outside the United States through our partner at Abbott International during the next season as well. We also continue to work to expand the market potential for SynagisTM through ongoing clinical trials in additional patient populations.”

Dr. Hockmeyer added that, “Beyond SynagisTM we continue to make excellent progress with the development of our R&D pipeline, with five additional product candidates currently in clinical trials and two new product candidates expected to enter the clinic by the end of this year. While much of the focus is currently on our commercial success with SynagisTM, it is important to remember that our R&D base has also never been stronger.”

Total revenues in first quarter 1999 increased 117 percent to $128.7 million from $59.3 million in first quarter 1998. Revenues in first quarter 1999 included: 1) net product sales of $116.2 million for SynagisTM; 2) net product sales of $9.7 million for CytoGam® (Cytomegalovirus Immune Globulin Intravenous (Human)); 3) net product sales of $1.1 million for RespiGam® and by-products resulting from the production of CytoGam® and RespiGam®; and 4) $1.7 million for payments associated primarily with government research grants and MedImmune's collaboration with SmithKline Beecham regarding MedImmune's human papillomavirus (HPV) vaccine. Revenues in first quarter 1998 included: 1) net product sales of $32.1 million for RespiGam®; 2) net product sales of $10.8 million for CytoGam®; and 3) $16.4 million for other revenues including a $15 million up-front payment from SmithKline Beecham to enter into the HPV collaboration. Since its launch in September 1998, SynagisTM has largely replaced RespiGam® in the marketplace, as expected by the Company.

In first quarter 1999, product gross margins improved to 75 percent from 48 percent in first quarter 1998 primarily because of product mix. SynagisTM has higher product gross margins than RespiGam® and CytoGam®. In first quarter 1999, research and development expenses increased 55 percent to $8.8 million from $5.7 million primarily because of increased development activities, including additional clinical studies of SynagisTM. Selling, general and administrative expenses increased to $37.0 million in first quarter 1999 from $12.9 million in first quarter 1998 primarily because of the commission charge to the Ross Products division of Abbott Laboratories to co-promote SynagisTM, as well as the increased selling and marketing expenses associated with the launch of SynagisTM.

Earnings in first quarter 1999 grew 118 percent to $28.8 million from $13.2 million in first quarter 1998. First quarter 1999 included a charge of $18.2 million for income taxes; no tax expense was recorded in first quarter 1998. At March 31, 1999, cash and marketable securities had increased to $194.1 million compared with $134.9 million at December 31, 1998, primarily reflecting positive cash flows from operations.

SynagisTM is a humanized monoclonal antibody which was approved for marketing in June 1998 by the U.S. Food and Drug Administration (FDA) for the prevention of serious lower respiratory tract disease caused by RSV in pediatric patients at high risk of RSV disease (please see full prescribing information attached and at www.medimmune.com/products/synagispi.htm). SynagisTM is the first monoclonal antibody to be licensed for any infectious disease. SynagisTM is administered by intramuscular injection once per month during anticipated periods of RSV prevalence in the community. RSV is the most common cause of pneumonia and bronchiolitis in infants and children. In the Northern Hemisphere, the RSV season typically commences in November and lasts through April but it may begin earlier or persist later in certain communities.

CytoGam® is an intravenous immune globulin enriched in antibodies against cytomegalovirus (CMV) and is marketed by MedImmune in the United States for the prophylaxis against CMV disease associated with transplantation of kidney, lung, liver, pancreas, and heart (please see full prescribing information attached and at www.medimmune.com/products/cytopi1.htm).

RespiGam® is an intravenous immune globulin enriched in antibodies against RSV and is marketed by MedImmune in the United States for the prevention of serious lower respiratory tract infection caused by RSV in children under 24 months of age with bronchopulmonary dysplasia (BPD) or a history of premature birth (please see full prescribing information attached and at www.medimmune.com/products/resppi.htm).

MedImmune, a biotechnology company located in Gaithersburg, Maryland, develops and markets products that address medical needs in areas such as infectious disease, transplantation medicine, autoimmune disorders and cancer. MedImmune markets three products through its hospital-based sales force and has five new product candidates in clinical trials.

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 the Company's filings with the U.S. Securities and Exchange Commission. MedImmune cautions that RSV disease occurs primarily during the winter months; the Company believes its operating results will continue to reflect that seasonality for the foreseeable future.

1999 Q1 Condensed Statement of Operations (Unaudited) & Condensed Balance Sheet