MARLEY SEAMAN AP Health Writer NEW YORK (AP) — BioCryst Pharmaceuticals Inc. said Friday that a version of its flu drug candidate peramivir failed in a clinical trial, sending its shares sharply lower in afternoon trading. BioCryst tested an intramuscular form of the drug against a placebo as a treatment for seasonal influenza. The difference in recovery time for patients was not statistically significant. Shares of the Birmingham, Ala., company fell 25 cents, or 7.9 percent, to $2.93 in afternoon trading. The midstage trial included 405 patients. Those who had peramivir injected into their muscles recovered in an average of 91.1 hours, or a bit less than four days. Patients who received a placebo treatment recovered in 106.1 hours. The company is also developing a form of peramivir that is delivered intravenously, but Leerink Swann analyst Joseph Schwartz said both versions of the drug have been dealt serious setbacks. "Peramivir has failed several clinical studies," he said. "The intramuscular form looks to be challenged by delivery, and the intravenous form is difficult because there's never been a drug developed for uncomplicated hospital or inpatient influenza," meaning it will be harder to determine the goals of clinical future studies. The intravenous version of peramivir is intended to be delivered at hospitals or by doctors. The intramuscular form is intended for outpatient use, similar to drugs like Tamiflu and Relenza. BioCryst is seeking approval for the intravenous version of the drug through a pre-emergency use authorization, which would allow the company to ship the drug to the government for one year as a preventive measure to stop a large flu outbreak. BioCryst said Friday that it is preparing to deliver part of its inventory of the drug, about 1,000 doses, to the Centers for Disease Control and Prevention. The company also reported its first-quarter financial results. BioCryst narrowed its loss to lost $9.3 million, or 24 cents per share, from $13.1 million, or 34 cents per share, a year ago. Revenue fell to $4.4 million from $10.8 million, but the company cut its expenses nearly in half by reducing research and development costs. The two analysts reporting to Thomson Reuters were expecting a loss of 28 cents per share and $10.8 million in revenue, on average.