Trius Therapeutics launched a low-wattage IPO that raised $50 million to support development of torezolid phosphate, its late-stage oral antibiotic treatment for skin infections. If approved, the drug would compete with Pfizer's Zyvox tablets, which generated about $575 million in U.S. sales for Pfizer during 2009, as well as Cubist Pharmaceuticals' injectable Cubicin, which pulled in $524 million in U.S. sales that year.

After Tuesday's Nasdaq market close, the San Diego company said it had managed to raise net proceeds after expenses of $45.6 million.

At $5 per share, the amount raised fell far short of the $12 to $14 per share the company had aimed for when it initially priced the offering. But lack of investor appetite for risk, which has dampened enthusiasm for IPOs in general, made that a stretch.

Trius faced the additional hurdle of not having marketed products and operating in the red. In June, though, it announced that it reached an agreement with the U.S. Food and Drug Administration on what late-stage trial data would serve to support a claim of torezolid's efficacy, a step toward finalizing a new drug application for the antibiotic.

Shares of Trius, which is trading under the symbol “TRSX,” closed at $5.47 per share Wednesday.

Horizon Pharma is next on deck in the biotech IPO line-up. The Northbrook, Illinois biopharmaceutical hopes to raise $86.3 million to support regulatory and marketing activities for its drugs for arthritis, pain and inflammatory diseases.