By Jim Shrine
Special to BioWorld Today
Glaxo Wellcome plc submitted a new drug application to the FDA seeking approval of Relenza (zanamivir), an inhaled influenza drug.
The product was developed with Biota Holdings Ltd., of Melbourne, Australia. Last month, marketing applications for Relenza were filed in Europe and Canada, and in Australia the marketing application was filed in March.
Relenza is designed to inhibit the neuraminidase enzyme on the surface of the virus. That enzyme promotes the spreading of the virus to other cells in the respiratory tract. The drug, which is inhaled using a breath-activated device, has been tested in more than 6,000 patients.
The NDA was based on three Phase III trials that showed Relenza reduced the severity and duration of symptoms one to 2.5 days faster than placebo. And, if taken within 36 hours of the onset of symptoms among high-risk patients, the symptoms were relieved 1.5 to 2.5 days sooner.
The flu typically lasts seven to 10 days, said Glaxo Wellcome spokeswoman Julie Dean. "When you're looking at a day to two-and-a-half days, that's significant, especially when you look at the severity early on within the course of the disease. It's much worse the first few days."
Glaxo Targeting 1999-2000 U.S. Launch
Dean told BioWorld Today that Glaxo hopes to have Relenza available for the 1999-2000 flu seasons in the U.S. and Europe and this year's flu season in Australia.
She said an advantage of Relenza is that it proved effective against both influenza A and B, while other available treatments (rimantadine and amantadine) are effective against only type A. Salomon Smith Barney analysts said 65 percent of the 120 million people infected each year in the U.S., Europe and Japan have type A influenza.
Biota presented data in September showing that Relenza reduced the severity of fever, myalgia, weakness, cough and loss of appetite.
High-risk patients experienced a 71 percent reduction in influenza complications when compared to placebo and a 65 percent reduction in associated antibiotic use.
Salomon Smith Barney, in a research report Wednesday, said even with fast-track approval, it is unlikely Relenza would be launched in time to catch the end of the 1998-99 flu season. It projects a launch in the third quarter next year.
Salomon Smith Barney projected revenues of 35 million pounds(U.S.$51 million) next year from Relenza,230 million pounds(U.S.$382 million) in 2002 and peak sales of 400 million pounds (U.S.$664 million).
Relenza would be the first orally inhaled drug for influenza. The method helps deliver drug directly to the surface of the respiratory tract, where infection occurs.
The collaboration between London-based Glaxo and Biota began in 1989. Glaxo took over development in 1992.
When the Australian filing was made in March, Biota said it would receive royalties of 10 percent in Australia, New Zealand, Indonesia and South Africa.
Royalties in the rest of the world would be 7 percent. Biota officials were not available for comment Wednesday.
BioChem's Flu Vaccine Succeeds In Phase I Trial
In another influenza development, BioChem Pharma Inc., of Laval, Quebec, said Wednesday that results of a Phase I trial of its nasal inactivated influenza vaccine candidate produced significant increases in systemic IgG and in mucosal IgA, as well as proving safe.
Claude Vezeau, president of BioChem Vaccines, told BioWorld Today that development plans are being refined as a collaboration with SmithKline Beecham Biologicals, of Rixensart, Belgium, is being finalized. That deal will give SmithKline Beecham responsibility for development, manufacturing and commercialization, with BioChem Pharma retaining rights in Canada and a joint venture being established in the U.S.
"We will accelerate development and get to market as quickly as possible," Vezeau said.
The vaccine is formulated in a mucosal carrier developed by Biovector Therapeutics SA, of Toulouse, France. *