On December 19, the U.S. Food and Drug Administration approved Rapivab (peramivir) to treat influenza infection in adults.Influenza,
commonly known as the flu, is a contagious respiratory illness caused
by influenza viruses. Flu infections can range from mild to severe and
can sometimes lead to hospitalization and death. According to the
Centers for Disease Control and Prevention (CDC), 5-20 percent of the
American population gets the flu and more than 200,000 people are
hospitalized from seasonal flu-related complications each year.
Rapivab
is an inhibitor of influenza virus neuraminidase, an enzyme that
releases viral particles from infected cells. Neuraminidase inhibitors
are commonly used to treat flu infection. Rapivab is the first
neuraminidase inhibitor approved for intravenous (IV) administration and
is administered as a single IV dose. It is intended for patients 18
years and older who have acute uncomplicated influenza and have shown
symptoms of flu for no more than two days.
“Rapivab is the third
neuraminidase inhibitor approved by the FDA to treat flu infection, but
the first approved as an IV formulation,” said Edward Cox, M.D., M.P.H,
director of the Office of Antimicrobial Products in the FDA’s Center for
Drug Evaluation and Research. “The availability of a single-dose,
intravenous option for the treatment of acute uncomplicated flu allows
health care professionals and patients to have a choice based on an
individual patient’s needs.”
Other neuraminidase inhibitors
approved by the FDA to treat flu include oseltamivir, administered
orally, and zanamivir, which is inhaled. Older antiviral drugs for flu,
amantadine and rimantadine, are no longer recommended by CDC because
circulating influenza strains are resistant to these drugs.
Rapivab’s
efficacy was established in 297 participants with confirmed influenza
who were randomly assigned to receive Rapivab 300 milligrams (mg),
Rapivab 600 mg or placebo. Overall, participants receiving Rapivab 600
mg had their combined influenza symptoms alleviated 21 hours sooner, on
average, than those receiving placebo, which is consistent with other
drugs in the same class. Those receiving Rapivab 600 mg also recovered
to normal temperature approximately 12 hours sooner compared to placebo.
Supportive trials confirmed these findings. However, efficacy could not
be established in patients with serious influenza requiring
hospitalization.
Common side effects seen in Rapivab-treated
participants include diarrhea. Rare but serious side effects include
serious skin or hypersensitivity reactions such as Stevens-Johnson
syndrome and erythema multiforme. Patients with influenza may be at an
increased risk of hallucinations, delirium and abnormal behavior early
in their illness and should be monitored for abnormal behavior. These
events have been reported with neuraminidase inhibitor drugs, but it is
not clear that the drug caused the abnormal behavior.
Rapivab and
other antiviral drugs used to treat flu are not substitutes for early,
annual flu vaccination, as recommended by CDC’s Advisory Committee on
Immunization Practices. CDC recommends all persons ages 6 months and
older receive an annual flu vaccine.
Rapivab is manufactured by BioCryst Pharmaceuticals, based in Durham, North Carolina.
The
FDA, an agency within the U.S. Department of Health and Human Services,
protects the public health by assuring the safety, effectiveness, and
security of human and veterinary drugs, vaccines and other biological
products for human use, and medical devices. The agency also is
responsible for the safety and security of our nation’s food supply,
cosmetics, dietary supplements, products that give off electronic
radiation, and for regulating tobacco products.