Further evidence that the post-Facebook initial public offering (IPO) jitters seem to have dissipated, and that the environment for biotech IPOs continues to improve comes with Thursday's debut of venture-backed Durata Therapeutics Inc., of Morristown, N.J. The company priced its initial public offering of 7.5 million shares of common stock at a price of $9 per share.

Although well below its original target price range of $11 to $13, an increased number of shares on offer meant that Durata generated proceeds from the offering – $67.5 million – that were just 9 percent below what the company, which is developing new therapeutics to treat infectious diseases, had hoped to raise. Durata's shares began trading on Nasdaq under the ticker symbol "DRTX," and they opened strongly but by the end of the day had eased back to close at $9.04, up 4 cents.

The Durata IPO follows closely on the heels of the IPO of oncology-focused company Tesaro Inc., of Waltham, Mass., which priced within its expected range. That has fueled speculation that more biotech IPOs will follow in the second half of the year. According to BioWorld Snapshots, there are nine biotechs poised on the IPO runway. (See BioWorld Today, June 29, 2012.)

In its SEC S-1 filing in March 2012, Durata said it plans to use the proceeds from its IPO to complete clinical development of its lead drug candidate, dalbavancin, currently in a second pivotal Phase III trial for the treatment of patients with acute bacterial skin and skin structure infections (abSSSI), and to fund commercialization activities in the U.S. and Europe. (See BioWorld Today, March 26, 2012.)

Dalbavancin, a lipoglycopeptide in the same class as vancomycin, is being developed for the treatment of Gram-positive infections, including methicillin-resistant Staphylococcus aureus. In September 2011 the company initiated enrollment in a second global, pivotal, Phase III study (DISCOVER-2) of dalbavancin. Durata's two trials (DISCOVER-1 and DISCOVER-2) are being conducted under separate special protocol assessments agreed upon with the FDA. Each of those studies is expected to enroll 556 patients.

Durata's DISCOVER-2 study is a randomized, double-blind, double-dummy study designed to compare the efficacy and safety of dalbavancin to vancomycin, with patients randomized to vancomycin allowed to switch to oral Zyvox (linezolid, Pfizer Inc.) after three days of intravenous vancomycin therapy.

The company said it expects to complete those trials and to have initial top-line data available early in 2013 and, if successful, will submit a new drug application to the FDA in the first half of next year.

In its S-1 document, Durata said dalbavancin's advantages over competitors included its safety and tolerability profile, broad coverage for Gram-positive bacteria, limited drug-drug interactions and simpler administration.

The company is operating in an extremely competitive arena that currently is dominated by generic vancomycin, which, according to company estimates, generated sales of approximately $189 million in the U.S. in 2011 and represented a majority of courses prescribed.

After years of shying away from the space, regulatory stability is encouraging investment in the area, which also received a boost from the recently signed FDA Safety and Innovation Act (FDASIA). The Act has provisions to accelerate reviews of novel drugs for infectious diseases. (See BioWorld Insight, June 11, 2012.)

One of Durata's competitors, Cempra Inc., of Chapel Hill, N.C., also completed an IPO this year raising $50.4 million in February. (See BioWorld Today, Feb. 6, 2012.)

That company is developing Taksta (fusidic acid) for the treatment of serious Gram-positive infections, including skin infections. In addition, Rib-X Pharmaceuticals Inc. is another serious competitor, and is sitting on the IPO runway. The company said it had recently completed a Phase IIb trial for the treatment of abSSSIs.

In other financings news:

• Anthera Pharmaceuticals Inc., of Hayward, Calif., said it intends to offer and sell shares of its common stock in an underwritten public offering. The number of shares and share price have not yet been disclosed. News of the offering came days after the firm reported positive results from the final dataset from its Phase IIb PEARL-SC study showing that the highest dose of blisibimod hit statistical significance against placebo in lupus patients, sending shares of Anthera up 87 percent. The company's stock (NASDAQ:ANTH) fell 12.8 percent, to close Thursday at $1.16. Piper Jaffray & Co. and Leerink Swann LLC are acting as joint book-running managers for the offering.