News Pressroom

August 7, 2003

MedImmune Amends Securities Trading Policy Pursuant to SEC Rule 10b5-1

GAITHERSBURG, Md., Aug. 7 /PRNewswire-FirstCall/ -- MedImmune, Inc. (Nasdaq: MEDI) announced today that it has amended its Confidential Information and Securities Trading Policy to provide guidelines for officers, directors and other company insiders to enter into approved, predetermined trading plans for the purchase or sale of MedImmune stock consistent with Rule 10b5-1 under the Securities Exchange Act of 1934. MedImmune believes that certain corporate officers and other insiders are currently establishing 10b5- 1 plans, and others may do so in the future.

Rule 10b5-1 trading plans, as authorized by the Securities and Exchange Commission (SEC), are primarily intended to provide insiders at public companies with a systematic method of obtaining liquidity in their securities holdings, while minimizing potential disruption to the financial markets. The SEC has described such plans as providing an affirmative defense against allegations related to insider trading liability, if, among other things, an individual or entity can demonstrate that a purchase or sale occurred pursuant to a binding contract, instruction or written plan put into place when the individual or entity was not in possession of material nonpublic information.

Under the MedImmune policy, a 10b5-1 plan may be implemented when the company is outside of a blackout period and when the individual is not in possession of material non-public information. The first trade under a MedImmune 10b5-1 plan cannot be executed until at least 30 days after such a plan has been adopted by an individual. The MedImmune policy requires that, in addition to complying with Rule 10b5-1, a trading plan for covered personnel must receive clearance from the company's legal counsel and Chief Executive Officer, or Chairman in the case of a trading plan adopted by the Chief Executive Officer, and the company must have the right to suspend or terminate the plan.

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 MedImmune, 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 with respect to MedImmune reflect the current views of MedImmune's management and are based on certain assumptions. Actual results for MedImmune 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. MedImmune is developing 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.
    -0-                             08/07/2003
    /CONTACT:  Jamie Lacey, +1-240-632-4035, Investors: Will Roberts,
+1-301-527-4358, or John Filler, +1-240-632-4086, all of MedImmune, Inc./
    /Web site:  http://www.medimmune.com/
    (MEDI)

CO:  MedImmune, Inc.; Securities and Exchange Commission; SEC
ST:  Maryland
IN:  HEA MTC BIO
SU:


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