By Randall Osborne

West Coast Editor

It's a number more than big enough to see through the FluMist: $400 million, raised by Aviron Inc. through the sale of 4 million shares at $50 per share, plus $200 million worth of convertible notes.

The pricing ups Mountain View, Calif.-based Aviron's original target offering of 3 million shares to 4 million, and increases the offering of 5.25 percent convertible notes from $150 million in aggregate principal to $200 million. The conversion price for the notes is $62.50.

Aviron's stock (NASDAQ:AVIR) closed down 6 cents Friday at $50, having recorded a 52-week high of $70.609, and a 52-week low of $19.50.

Underwriters got an option to buy up to 600,000 more shares - 200,000 from selling stockholders, and 400,000 from the company - and $30 million worth of notes as overallotments. Managing the offering are J.P. Morgan, of San Francisco, and Morgan Stanley Dean Witter and SG Cowen Securities Corp., both of New York.

Aviron began pivotal trials in 1996 for FluMist, its intranasal influenza vaccine, and had its approval submission rejected two years later by the FDA, which wanted more manufacturing data. (See BioWorld Today, Sept. 2, 1998.)

After more delays, the company tried another biologics license application last fall, and the FDA accepted it for filing in December. If approved, Aviron would market FluMist with Wyeth Lederle Vaccines, a business unit of the pharmaceutical division of American Home Products Corp., of Madison, N.J.

"They certainly made it farther than they did last time," said David Molowa, managing director and senior biotechnology analyst at J.P. Morgan H&Q, in New York. "If this product makes it to the finish line, it's going to be one of the big new product stories of the year."

He said FluMist could be, "at a minimum, a $500 million product," adding that other factors are helping to drive the firm's success.

"You have to look at what has transpired over the last 18 months," Molowa told BioWorld Today. "They've had a total upgrade and broadening of the management team, from the CEO on down," including a new chief scientific officer and three new board members.

"Also, [Aviron] only controlled one part of the manufacturing process, and they have acquired those two pieces," Molowa said. "The company now has total control over the process."

Aviron's total control includes manufacturing at Medeva Pharma Ltd., of Liverpool, UK, and operations at Packaging Coordinators Inc., of Philadelphia, where the commercial formulation of FluMist will be blended, filled, packaged, labeled and stored, Molowa said.

In Phase II testing is Liquid FluMist, required for international markets where frozen storage is mostly unavailable. Aviron also is developing a parainfluenza virus type III vaccine to prevent the most common cause of croup. With partner GlaxoSmithKline plc, of London, Aviron has begun Phase II trials with an Epstein-Barr virus subunit vaccine.