FDA APPROVES RELENZA (ZANAMIVIR FOR INHALATION) FOR INFLUENZA TREATMENT

July 27, 1999

FDA has approved Relenza (zanamivir), an inhaled anti-viral drug, for adults and adolescents aged 12 years and older for the treatment of uncomplicated influenza virus. This product is approved to treat type A and B influenza; though the principal trials enrolled over 1000 patients with type A influenza, a much smaller number (approximately 120) had type B influenza. Relenza is the first approved drug for the treatment of influenza since the approval of rimantadine (Flumadine) in 1993.

Clinical studies determined that patients with influenza receiving Relenza had shorter times to improvement in influenza symptoms. Part of the evidence for efficacy was provided by studies in the Southern Hemisphere and Europe. Efficacy treatment studies enrolled more than 1500 patients with influenza-like illness, for example, fever, headache, muscle aches, cough and sore throat.

Effectiveness was demonstrated only in patients who started treatment within 2 days of symptoms. Relenza appears less effective in patients who do not have elevated temperature or severe symptoms.

Safety and effectiveness have not been established for the drug's use in preventing influenza.

This product has not been shown to be effective, and may carry risk, in patients with severe or decompensated asthma or chronic obstructive pulmonary disease. Bronchospasm was documented in some patients with mild or moderate asthma following administration of zanamivir. Any patient who develops bronchospasm should stop the drug and call their health care provider. Patients with underlying respiratory disease should be instructed to have a fast-acting inhaled bronchodilator available when they are being treated with zanamivir.

Relenza is taken twice daily for five days using a breath- activated plastic inhaler device called a Diskhaler. The device holds a Relenza Rotodisk, which is a blister package containing a powder mixture of Relenza and lactose. After a Rotadisk is loaded into the Diskhaler, a blister is pierced and the drug treatment is released into the air stream created when the patient inhales through the mouthpiece.

Before using this product, patients should be instructed by their health care provider in the proper use of the inhaler -- including a demonstration whenever possible. Patients should also read and carefully follow the Patient Instructions for Use included with the drug.

Relenza will be marketed by Glaxo Wellcome, headquartered in Research Triangle Park, N.C.