Researchers reveal new weapon in flu fight

SAN FRANCISCO — Researchers on Sunday delivered a double dose of good news in the fight against flu: successful tests of what could become the first new flu medicine in a decade, and the strongest evidence yet that such drugs save lives, not only shorten illness.

A single intravenous dose of the experimental drug, peramivir (purr-AM-uh-veer), cleared up flu symptoms as well as five days of Tamiflu pills did, a large study in Asia found. An IV treatment is badly needed because many sick people can't swallow pills and because illness hinders the body's ability to absorb oral medicines.

Several other studies, meanwhile, confirmed the value of treatment with Tamiflu. In one study of hundreds of people stricken with bird flu, half of those given Tamiflu survived, while nearly 90 percent of those not given flu medicines died. Other research showed Tamiflu improved survival from seasonal flu, too.

"There has been an accumulation of evidence over time that the antiviral drugs can save lives," and the new studies confirm that hope, said Nancy Cox, flu chief at the Centers for Disease Control and Prevention (CDC).

Results were reported at an American Society for Microbiology conference in California, the first big meeting of infectious-disease specialists since the H1N1 swine flu emerged in April. Treatment options are receiving huge attention because it will take a month or more for people to get the swine-flu vaccine and have time to develop immunity. Meanwhile, reports are streaming in that swine flu is causing havoc in children and young adults.

The virus currently accounts for most flu cases in the United States. More than 1 million Americans have been infected and nearly 600 have died from it, the CDC estimates.

Treatment with Tamiflu or a similar drug, Relenza, is recommended for anyone hospitalized with flulike symptoms or at high risk of complications. The drugs should be started within two days of first symptoms, and they shorten illness by about a day. With the drugs in limited supply, and worries about resistance developing to them, new medicines are desperately needed.

Peramivir was tested in nearly 1,100 people with seasonal flu last winter in Asia. They were given either Tamiflu pills for five days or a single infusion of 300 or 600 milligrams of peramivir.

Symptoms cleared in about 78 hours and 81 hours with lower and higher doses of peramivir, respectively, and in 82 hours with Tamiflu. Adverse drug reactions were less common with peramivir, said study leader Dr. Shigeru Kohno of Nagasaki University in Japan.

The fact peramivir is not a pill like Tamiflu or an inhaled drug like Relenza makes it less convenient yet "very promising" and valuable, Cox said.

"You can get it into the blood, into the lungs, where infection is occurring," she said.

Others were cautious.

"I'm very enthusiastic about peramivir for hospitalized patients," but it was compared in a season when many flu cases were at least somewhat resistant to Tamiflu, said Dr. Frederick Hayden, a virus expert at the University of Virginia and a World Health Organization flu consultant.