General Information

Rapivab (peramivir injection) is an influenza virus neuraminidase inhibitor. Neuraminidase is an enzyme that releases viral particles from the plasma membrane of infected cells.

Rapivab is specifically indicated for the treatment of acute uncomplicated influenza in patients six months and older who have been symptomatic for no more than 2 days.

Rapivab is supplied as a solution for intravenous administration. Rapivab should be administered within 2 days of onset of symptoms of influenza. The recommended dose of Rapivab in adult patients 18 years of age or older with acute uncomplicated influenza is a single 600 mg dose, administered via intravenous infusion for 15 to 30 minutes. It is administered via an intravenous infusion for a minimum of 15 minutes at a recommended dose of 12 mg/kg for pediatric patients ages six months to 12 years.

Clinical Results

The FDA approval of Rapivab was based on a randomized, multicenter, blinded trial conducted in Japan that evaluated a single intravenous administration of Rapivab 300 mg, Rapivab 600 mg, or placebo administered over 30 minutes in subjects 18 to 65 years of age with acute uncomplicated influenza. Study treatment was started within 48 hours of onset of symptoms. Subjects participating in the trial were required to self-assess their influenza symptoms as “none’, ‘mild’, ‘moderate’, or ‘severe’ twice daily. The primary endpoint, time to alleviation of symptoms, was defined as the number of hours from initiation of study drug until the start of the 24 hour period in which all seven symptoms of influenza (cough, sore throat, nasal congestion, headache, feverishness, myalgia and fatigue) were either absent or present at a level no greater than mild for at least 21.5 hours. The overall efficacy population, consisting of subjects with confirmed influenza and administered study drug, totaled 297 subjects. Overall, subjects receiving Rapivab 600 mg experienced alleviation of their combined influenza symptoms a median of 21 hours sooner than those receiving placebo. The median time to recovery to normal temperature (less than 37°C) in the 600 mg group was approximately 12 hours sooner compared to placebo.

Limitations of Use:

The efficacy of Rapivab was based on clinical trials of naturally occurring influenza in which the predominant influenza infections were influenza A virus; a limited number of subjects infected with influenza B virus were enrolled.

Influenza viruses change over time. Emergence of resistance substitutions could decrease drug effectiveness. Other factors (for example, changes in viral virulence) might also diminish clinical benefit of antiviral drugs.

The efficacy of Rapivab could not be established in patients with serious influenza requiring hospitalization.