NUTLEY, N.J., April 18 — Roche has filed a supplemental new drug application (sNDA) with the FDA, requesting an extension of the prophylaxis indication for Tamiflu® (oseltamivir phosphate) to include children ages one through 12. Currently, Tamiflu is indicated for the prophylaxis of influenza in adult patients and adolescents 13 years and older. Tamiflu is also indicated for the treatment of uncomplicated acute illness due to influenza type A or type B infection in patients one year and older who have been symptomatic for no more than two days. Roche is optimistic that FDA will complete their review of the sNDA before the next flu season.
The sNDA was filed based on results from a subset of pediatric patients in a clinical study where Tamiflu was used for the management of influenza in households. The study enrolled over 1000 patients in total (including adults and children). The study overall showed that post-exposure prophylaxis is effective in preventing secondary spread of influenza infection and illness in households and that the protective efficacy of Tamiflu was the same in children aged one through 12 as the whole population. Gastrointestinal events, particularly vomiting, were the most frequently reported adverse events in pediatric patients.Tamiflu is the leading prescription antiviral medication for influenza. It works by targeting one of the two major surface structures of the influenza virus, the neuraminidase protein. The neuraminidase site is virtually the same in the most common strains of influenza, types A and B. Tamiflu attacks the influenza virus and is thought to work by stopping it from spreading inside the body. Tamiflu treats flu at its source, by attacking the virus that causes the flu, rather than simply masking symptoms.
Tamiflu is generally well tolerated. In treatment studies in adults, the most frequently reported adverse events were mild-to-moderate transient nausea and vomiting. Other events reported more frequently than with placebo were bronchitis, insomnia and vertigo. In prophylaxis studies in patients aged 13 and older, adverse events were qualitatively similar to those seen in the treatment studies despite a longer duration of dosing. Events reported more frequently in subjects receiving Tamiflu compared to subjects receiving placebo in prophylaxis studies included nausea, vomiting, diarrhea, abdominal pain, dizziness, insomnia, headache, vertigo and fatigue.
In pediatric treatment studies, the most frequently reported adverse event was vomiting. Other events reported more frequently by pediatric patients treated with Tamiflu included abdominal pain, epistaxis, ear disorder and conjunctivitis. These events generally occurred once and resolved despite continued dosing. In a prophylaxis study which included pediatric patients aged one to 12 years, gastrointestinal events were most frequently reported, particularly vomiting.
Efficacy of Tamiflu in the treatment of subjects with chronic cardiac disease and/or respiratory disease has not been established.Tamiflu was approved by the U.S. Food and Drug Administration (FDA) for the treatment of uncomplicated acute illness due to influenza infection in adults in October 1999.
The FDA granted marketing approval for the prevention of naturally occurring influenza A and B in adults and adolescents 13 years and older in November 2000. The FDA granted marketing approval of the oral suspension for use in the treatment of influenza A and B in children one year and older in December 2000. Tamiflu oral suspension is used for pediatric patients one year and older or adult patients who cannot swallow a capsule. Tamiflu is the first and only liquid suspension to treat influenza A and B.
Vaccination is considered the first line of defense against influenza.