UPDATE 2-New flu drug reduces symptoms - study

(Adds share price in 5th paragraph)

By Maggie Fox, Health and Science Editor

WASHINGTON, Oct 28 (Reuters) - A new, injected influenza drug appears to reduce symptoms as well as rival drugs Tamiflu and Relenza, researchers reported on Tuesday.

They said BioCryst Inc's (BCRX.O) peramivir cut by a third the number of days that people were sick with flu in a phase II trial, meant to show safety and efficacy.

The company should be able to move to phase III trials, the last phase before seeking U.S. Food and Drug Administration approval, Dr. Shigeru Kohno of the Nagasaki University Graduate School of Medicine, told a new conference.

A 2007 trial failed to show the new drug worked well but using an intravenous injection apparently delivered the drug more effectively, said Dr. Bill Sheridan, chief medical officer of BioCryst.

The Alabama-based company's share price was down 7 percent, at $1.54 a share, in mid-afternoon trading.

Two different doses of peramivir cut the time that people were sick with flu by 32 percent, Kohno, who studied the drug on behalf of Japan's Shionogi & Co (4507.T), told a meeting of the American Society of Microbiology and the Infectious Diseases Society of America.

"We believe that peramivir will be a fine future option for influenza treatment as well as needed medication for highly pathogenic influenza virus and future influenza pandemics," Kohno told a news conference.

Kohno's team studied 300 patients age 20 to 64, giving them either a placebo or one of two doses of peramivir.

They asked the patients to describe their flu symptoms, including cough, sore throat, aches, headache and fatigue.

This is the same method used in testing Roche (ROG.VX) and Gilead Sciences Inc's (GILD.O) Tamiflu and GlaxoSmithKline (GSK.L) and Biota Holdings Ltd's (BTA.AX) Relenza.

LESS MISERY

Peramivir cut short time of flu misery by a little more than a day on average, Sheridan said in a telephone interview.

"Everyone is interested in having alternatives to current drugs," Sheridan said. "We have an inhaled one in Relenza and we have an oral one in Tamiflu." Injected drugs can be given to people too sick to take pills.

Peramivir can be either injected or given intravenously.