Remember initial public offerings?

As cold as it's been around here over the last week, it's been positively arctic-like for the IPO market. Renaissance Capital said there were only 63 IPOs in the United States in 2009, after a dismal 43 in 2008 - well below the more than 200 a year from 2004 through 2007.

The last Philadelphia-area company to go public was CardioNet Inc., of Conshohocken. Actually, it completed its IPO in March 2008 while it was based in San Diego before moving its headquarters east.

With Wednesday's registration filing with the Securities and Exchange Commission by Tengion Inc., the region could have its first homegrown IPO in close to two years. While it's easy to get excited by IPOs, there's nothing like a close read of a 155-page preliminary prospectus to expose the warts of any company.

Based in East Norriton, Tengion is in the field of regenerative medicine. Since 2004, it has been working to develop new organs based on a patient's own cells. Last fall, Tengion and its more than 100 employees had been heading toward a Phase III, late-stage, clinical trial of its first product.

However, according to the registration statement, the company postponed the start of Phase III testing earlier this year and cut loose 34 employees.

Tengion's chief financial officer, chief medical officer and general counsel all left during the summer months. As of Sept. 30, the privately held company employed 68 people, according to the Form S-1 filing.

Where the company once seemed to be intending to commercialize its "Neo-Bladder Augment" product first, now the lead candidate is a "Neo-Urinary Conduit," an implant that would be used in bladder cancer patients. Tengion's offering statement indicates that the new product could be produced more quickly, efficiently and less expensively than the Neo-Bladder.

Over the years, Tengion has raised about $144 million in venture capital privately from a variety of firms, including Quaker BioVentures of Philadelphia and Safeguard Scientifics Inc. of Wayne. Research and development and clinical testing are very costly, so Tengion has accumulated a deficit of $171 million during its brief history.

The registration statement, which lists the underwriter as Piper Jaffray & Co., doesn't disclose how much Tengion hopes to raise through its first public offering.