FDA completes review of FluMist

May 28 2007

MedImmune, Inc. has announced that the U.S. Food and Drug Administration (FDA) has stated the agency has completed its review of all submissions made related to the supplemental biologics license application (sBLA) to extend the age indication of FluMist (Influenza Virus Vaccine Live, Intranasal).

The agency also acknowledged the agreed-upon labeling for the vaccine and post- marketing commitments made by the company, but reserved final action on this supplement until compliance issues identified in the March 21-29, 2007 annual inspection of MedImmune's U.K. bulk manufacturing plant are satisfactorily resolved.

The correspondence from the FDA came in the form of a Complete Response Letter related to the supplement to extend the age range and a separate Warning Letter related to the compliance issues at the U.K. plant. The Warning Letter is expected to be posted to the FDA website on Tuesday, May 29, 2007. MedImmune had anticipated a response from the FDA today to its supplement in accordance with the Prescription Drug User Fee Act.

"We are pleased with the progress made with the FDA relating to our supplement to extend the age range for FluMist. We take the agency's observations with respect to compliance at our bulk manufacturing plant very seriously and are working to promptly and thoroughly respond to its concerns," said Linda J. Peters, senior vice president, regulatory affairs. "We are working with the FDA to ensure timely approval of pending supplements and release of vaccine as planned for the 2007-2008 influenza season."

The FDA's action does not affect the tender offer or the subsequent merger pursuant to which AstraZeneca PLC proposes to acquire MedImmune.

FluMist is currently indicated for active immunization for the prevention of disease caused by influenza A and B viruses in healthy children and adolescents, 5 to 17 years of age, and healthy adults, 18 to 49 years of age. There are risks associated with all vaccines, including FluMist. As with any vaccine, FluMist does not protect 100 percent of individuals vaccinated and may not protect against viral strains not contained in the vaccine.

Under no circumstances should FluMist be administered as an injection (i.e. parenterally). FluMist is contraindicated in persons with hypersensitivity to any component of the vaccine, including eggs; in children and adolescents receiving aspirin therapy or aspirin-containing therapy; in individuals with a history of Guillain-Barre syndrome; and in individuals with known or suspected immune deficiency. The safety and efficacy of FluMist have not been established in pregnant women or for patients with chronic underlying medical conditions, including asthma or reactive airways disease; the vaccine should not be administered to these patients.

In randomized, placebo-controlled clinical trials of FluMist in its refrigerated and frozen formulations, the most common solicited adverse events in the indicated population (n=11,604) included runny nose/nasal congestion, sore throat, cough, irritability, headache, chills, vomiting, muscle aches, decreased appetite, abdominal pain, and decreased activity/feeling of tiredness/weakness.

On January 5, 2007, the FDA approved MedImmune's sBLA for a refrigerated version of FluMist, which is expected to be manufactured for the 2007-2008 influenza season. Prior versions required frozen storage. Due to the seasonal nature of influenza vaccine, full prescribing information for the refrigerated version does not yet contain complete details on vaccine strains to be included for next season's vaccine. However, preliminary prescribing information can be found at http://www.fda.gov/cber/label/inflmed010507LB.pdf.