WASHINGTON (MarketWatch) -- The risk of skin rashes and other serious skin reactions seen with an Oscient Pharmaceuticals Corp. (OSCI) antibiotic outweighs possible benefits of using the drug to treat sinus infections, the Food and Drug Administration said Monday.

The Waltham, Mass.-company is seeking FDA permission to expand use of its antibiotic, Factive, to treat acute bacterial sinusitis. The drug was originally approved by the FDA in 2003 to treat mild-to-moderate community acquired pneumonia and a severe form of bronchitis.

The agency has asked an outside panel of medical experts to make recommendations Tuesday about whether the drug should be approved. The FDA typically follows its panel recommendations but isn't required to do so. The FDA presented its views of Factive in documents posted to its Web site Monday.

Factive was originally developed by SmithKline Beecham, which later became GlaxoSmithKline PLC (GSK). In 2000, the FDA rejected an application for the proposed drug to treat a variety of infections including sinusitis and bronchitis because of a higher rate of rash seen among Factive users in clinical studies looking at the drug for up to 14-days use. There were also concerns about possible liver injury.

The FDA requested additional studies of Factive in order to approve the drug, which were conducted by GSK and other firms that later took over ownership of the drug.

The FDA eventually approved use of a seven-day course of Factive in treating for pneumonia and a five-day course of the drug to treat bronchitis after studies suggested the risk of skin rashes was reduced with a seven- or five-day treatment course. The agency said the benefits of treating those infections outweighed the risks of the drug, which falls into a class of antibiotics known as fluoroquinolones.

While the FDA conceded that the risk of skin rashes and more severe reactions does seem to be reduced with a shorter course of antibiotic use, the FDA said, "there is still the concern that the incidence of skin reactions is greater than comparator therapy."

Oscient said the safety profile of Factive is similar to other drugs in its class and has proven to be effective against strains of bacteria that are resistant to other antibiotics.

The company said Factive, known generically as gemifloxacin, "represents an important additional therapeutic option for treatment of ABS (sinusitis), particularly those cases where the risk of infection by resistant organisms is of concern."

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