By Randall Osborne

West Coast Editor

Just as autumn's nippy temperatures have begun to hint at winter and the onset of flu season in much of North America, Glaxo Wellcome plc submitted an application for Relenza (zanamivir), its neuraminidase inhibitor, to prevent influenza strains A and B.

Approved last year as a flu therapy, inhaled Relenza had been licensed to London-based Glaxo by Biota Holdings Ltd., of Melbourne, Australia. It's also been approved in Australia and the European Union. (See BioWorld Today, July 28, 1999, p. 1.)

Al Rauch, senior vice president and biotech analyst with First Union Securities Inc. in Chicago, said the prevention indication is more promising in children than in senior citizens, although both groups are considered at particular risk for flu.

"[Relenza] probably is going to be used by parents who take their child to the doctor when there's someone in the house with the flu," Rauch said, adding that the treatment use is "going to generate the most interest" in the short run. Later, the drug as used for prevention could become more profitable, he said.

Meanwhile, Hoffmann-La Roche Inc. said new data show its competing treatment drug, Tamiflu (oseltamivir phosphate), an oral neuraminidase inhibitor, works better when taken early in the onset of symptoms.

Tamiflu, co-developed with Gilead Sciences Inc., of Foster City, Calif., also was approved by the FDA last year. It reduced the total duration of illness by more than three days when taken within the first 12 hours of symptoms' appearance, as opposed to waiting 48 hours. (See BioWorld Today, October 29, 1999, p. 1.)

The data came from a study that enrolled 958 laboratory-confirmed influenza patients. Of these, 140 entered within the first six hours of symptom onset, 240 entered within the first 12 hours, 573 (or 60 percent) within 24 hours, and all had entered within 48 hours. Nutley, N.J.-based Roche disclosed the data at the annual Interscience Conference on Antimicrobial Agents and Chemotherapy in Toronto.

Mike King, senior analyst with Robertson Stephens Inc., said the study data is "frankly, old news. The data has been out there for quite some time."

Rauch noted the drugs were approved just last year, and prescription numbers are not precise, but Tamiflu "is taking more and more share of the market. It was launched later, and Relenza had the lion's share, but Relenza ran into some problems with the FDA. [Glaxo] is going to have to put warnings on the label for people with pulmonary conditions."

He conceded some patients "are a little concerned about [gastrointestinal] distress with Tamiflu," but it's minimal. Glaxo might have gone with oral delivery, Rauch added, but "from what I heard, their compound is like a rock. That's why they went with an inhaled drug."

Another company developing a late-stage flu therapy is BioCryst Pharmaceuticals Inc., of Birmingham, Ala., which has taken its neuraminidase inhibitor, RWJ-270201, into Phase III trials, partnered for marketing with R.W. Johnson Pharmaceutical Research Institute, a Johnson & Johnson company. (See BioWorld Today, Feb. 9, 2000, p. 1.)

"There's not much information on it yet," Rauch said, noting the BioCryst compound is an oral drug. "Conditions favor that. It's going to come down to people being more comfortable with an oral treatment."

Glaxo's stock (NYSE:GLX) closed Monday at $54.375, up 50 cents. Gilead's shares (NASDAQ:GILD) ended the day at $93.25, down $10.187.