ByLisa Seachrist

Washington Editor

With this year's flu season just beginning, consumers will now have the choice between two FDA-approved drugs.

Hoffman-La Roche's oral neuraminidase inhibitor Tamiflu received FDA's nod late Wednesday. The drug, which was developed by Foster City, Calif.-based Gilead Sciences Inc., joins London-based Glaxo Wellcome plc's inhaled neuraminidase inhibitor Relenza as the only approved drugs that fight both the A and B strains of influenza. Both drugs reduce the duration of flu symptoms.

Roche intends to have the drug available in time for this year's flu season, which is now under way. However, the company has not announced a launch date, nor has it announced the price for the drug. Roger Mills, Gilead's senior director of clinical development, told BioWorld Today Tamiflu would be priced competitively to Relenza.

"This is a momentous occasion for the treatment of viral disease," Mills said. "It really is the start of a whole new approach for treating viral illnesses with antiviral medications."

Tamiflu's clinical development took a scant 32 months. Gilead and Roche pushed ahead with the drug aggressively with full knowledge that Glaxo's Relenza was further along.

"I can't think of a therapeutic that was approved faster," Mills said. "It was a concerted effort by the two companies to move forward in order to catch up in time with Glaxo. [The quick approval] was the result of good planning, good commitment and the fact that this is a damn good compound."

Roche is responsible for the worldwide development and marketing of Tamiflu. Gilead will receive royalties on sales in the "high teens."

Tamiflu, as an oral pill formulation, is a systemic treatment for influenza. It targets one of the two major surface proteins on the influenza virus, neuraminidase. This protein is necessary for the influenza virus to replicate and spread to other cells. Tamiflu inhibits this protein's activity and stops viral replication and spread.

The drug was approved on the basis of two Phase III double-blind, placebo-controlled clinical studies - one in the U.S. and the other conducted at international sites. The two studies enrolled a total of 849 influenza-infected patients between the ages of 18 and 65. Patients who received the recommended dose of 75 mg of Tamiflu twice a day had a 1.3-day reduction in symptoms, compared with patients receiving placebo.

"We believe the systemic nature of Tamiflu may prove an advantage when it comes to marketing this drug," Mills said. Because Tamiflu is delivered orally, it may be effective in preventing viral spread in the lower respiratory tract and the ears where the inhaled Relenza cannot reach.

Both Glaxo and Roche face an education challenge with their drugs - not only must they educate doctors, but they must educate patients as well. Both drugs must be taken within a couple of days of the onset of flu symptoms, so patients must get to their doctors early.

Most of the time, companies prefer having no competitors in the market; however, because these drugs require patient education, Mills said having a competitor may actually be helpful.

"In effect, you gain from your competitor's education efforts, as well as your own," Mills said. "There will be a lot of emphasis placed in the first season on growing the market and then differentiating the two products."

Mike King, vice president and senior analyst with BancBoston Robertson Stephens Inc. in New York, agreed that the two companies will feed off each other's marketing campaigns.

"Glaxo has done a great job about getting consumers aware of Relenza," King said. "That is going to aid Roche, but they are going to have to explain the benefits of Tamiflu over Relenza. It would be like two allergy drugs hitting the market at the same time."

The fact that Tamiflu is oral may be enough of a benefit, King said. Relenza, as an inhaled product, requires some patient training and "people already know how to take pills," he noted.

Al Rauch, senior vice president and biotech analyst with Everen Securities Inc., also thinks Tamiflu's oral administration gives the drug an edge. He also noted he believes "Gilead's drug is better than Glaxo's" because Tamiflu has two supportive clinical trials, whereas Relenza has a positive and a negative result from the two Phase III trials supporting its approval.

Both King and Rauch agree a prophylaxis indication would give one drug an advantage over the other. Neither company can claim its drug prevents people from catching the flu; however, both companies are gathering the necessary data to get such an indication on their labels.

At the Interscience Conference on Antimicrobial Agents and Chemotherapy earlier this month, Glaxo presented data showing Relenza could prevent the spread of influenza from one family member to another by 79 percent. Another study showed college students taking Relenza as a prophylaxis for 28 days could significantly reduce their risk of developing the flu. (See BioWorld Today, Oct. 4, 1999, p.1.)

Coincidental with Tamiflu's approval, the New England Journal of Medicine published an article in the Oct. 28 issue showing Tamiflu can prevent the flu by 74 percent.

Gilead's stock (NASDAQ:GILD) closed at $63.75 Thursday down $1.625 a share.