http://www.washingtonpost.com/wp-dyn/articles/A7331-2003Jun17.html

Spray Vaccine For Flu Wins FDA Clearance

By Michael Barbaro
Washington Post Staff Writer
Wednesday, June 18, 2003; Page A01

The Food and Drug Administration yesterday approved the first flu vaccine designed to be sprayed into the nose rather than injected into the arm, clearing the way for the product to reach doctors' offices and pharmacies in time for this year's flu season.

Federal regulators said the vaccine, called FluMist, could be used by healthy people between the ages of 5 and 49, a population of about 160 million that typically avoids the flu shot.

Doctors hope the inhaled vaccine will sharply increase the number of healthy people who seek flu immunization, potentially preventing some of the 114,000 hospitalizations and 36,000 deaths a year from the disease. FluMist is also expected to free up the supply of the injected vaccine, which often runs short, for those who need it most: the very young and the very old.

FluMist's manufacturer, MedImmune Inc. of Gaithersburg, said the vaccine will be available to consumers well before the start of the flu season, which runs from November to March.

The FDA recommends that children 5 to 8 years old receive two doses at least six weeks apart in their first year of vaccination with FluMist, and that those age 9 to 49 should get one dose. FluMist is expected to cost $46 per dose, more than three times as much as a flu shot.

"With FluMist we have the ability to block the whole cycle of transmission," said MedImmune chief executive David M. Mott, who estimated that the drug could eventually achieve sales of $1 billion a year.

MedImmune will only produce up to 6 million doses this year because of manufacturing constraints, and many Wall Street analysts predict that the company will be able to sell all of them. With MedImmune revenue expected to reach as much as $140 million in FluMist's first year, the vaccine's introduction could be one of the biotechnology industry's biggest product launches.

"It is a very significant vaccine," said Martin G. Myers, an associate director at the Sealy Center for Vaccine Development in Galveston, Tex. "Nasal administration is a much easier way to get vaccine."

But doctors warn that the initial impact of the vaccine will be limited because FluMist is not approved for use in children under 5 and adults over 49, two populations with the highest risk of developing flu-related health complications. People with asthma or respiratory diseases also should not use the spray, the FDA said.

Use has been limited because, unlike the injectable flu vaccine, which contains a dead virus, FluMist has a live but diluted virus that could pose a health risk to people with weakened immune systems.

The nasal spray fights the same range of influenza as the injected vaccine, with both containing three virus strains that the government will target for the upcoming flu season.

Rates of influenza infection are highest among children ages 5 to 14, who frequently transmit the illness in school, but the most severe illnesses and fatalities occur among people with chronic medical conditions, children under 2 and adults over 65, the FDA says.

"The patient group that is most appropriate for influenza vaccination is a group that is excluded from FluMist under the FDA approval," said David Hines, president of Avalon Research Group Inc. in Boca Raton, Fla., a firm that has often been skeptical about MedImmune and FluMist in its stock reports to fund managers.

The CDC estimates that only 13 percent of healthy people under 50, or about 17 million Americans, got flu shots last year.

MedImmune said it will soon seek clearance to sell FluMist to people under 5 and over 49, a task that industry analysts say will require at least two years of further testing.

Investors have been expecting the approval for more than a month, and yesterday MedImmune's stock fell $1.02, or nearly 3 percent, to $38.71.

MedImmune predicts FluMist will become the company's second blockbuster drug, after Synagis, a treatment to prevent respiratory infection in premature babies, which is approaching $1 billion a year in sales.

But Joel Sendek, a biotechnology analyst at Lazard Freres & Co., expressed doubt that MedImmune and its partner, Wyeth Pharmaceuticals, can turn FluMist into a widely used consumer product. "The flu is life-threatening in old people, but it is not typically life threatening in the 5-to-49-year-old age bracket," he said.

Mott said the healthy adults for which FluMist is approved is "the largest population that MedImmune will be able to target."

"It is the first vaccine intended for that population," he said.

To encourage flu immunizations among healthy children and adults, Wyeth plans a three-year, $100 million campaign on the advantages of nasal flu vaccine and the negative effects of flu infection, such as missing work, school and time with family.

MedImmune said its expects most vaccinations in the first year to be given by pediatricians, primary-care physicians and pharmacists. A health care professional must administer the vaccine.

FluMist, which is sprayed from a syringe into both nostrils as a fine mist, is designed to provide stronger immunity against the flu than an injectable vaccine. The live flu virus in the spray vaccine can only grow in cooler temperatures in the nasal passages, where it can block the virus at its point of entry into the body, but it cannot survive in the warmer lungs, where it might trigger illness.

Many companies have abandoned older vaccines that sell for pennies a dose and begun researching more expensive alternatives. But many insurers and consumers have resisted paying sharply higher prices for vaccines, and it is an open question whether potential users will view FluMist's big advantage -- no needles -- as being worth a 200 percent price increase.

© 2003 The Washington Post Company