A rock star of biotechs plans IPO

Sirtris Pharmaceuticals Inc. , a young Cambridge biotechnology company trying to parlay life-extension research into drugs for diabetes and other metabolic problems, said yesterday it hopes to raise up to $60 million in an initial public offering.

Founded in 2004, Sirtris quickly ascended to near-celebrity status in the biotech world based on the extraordinary promise of its research, which emerged from a Harvard Medical School scientist who found that a substance extracted from red wine could extend the lifespan of yeast. Since then, the red-wine extract, called resveratrol , has also been shown to prevent obese mice from developing health problems.

Sirtris, which has just 39 employees, is currently testing its own modified version of resveratrol in people with Type 2 diabetes.

In going public so early in its history, Sirtris is bucking a recent biotechnology trend in which companies have steered away from initial public offerings. Once seen as a ticket to high returns and a quick cash-out for financial backers, IPOs have become less lucrative in the past few years. Many promising young companies now elect either to remain private or to take themselves public through an alternate route, such as a so-called reverse merger with a publicly traded shell company.

Some recent biotech IPOs have been shelved, and others have disappointed. BioVex Inc. of Woburn attempted a $45 million public offering last summer, but withdrew it in October. Synta Pharmaceuticals Corp. of Lexington had hoped for a $90 million IPO, but raised only $50 million when it went public in February.

Sirtris hopes to duplicate the success of two other companies cofounded by Sirtris chief executive Christoph Westphal , Momenta Pharmaceuticals Inc. and Alnylam Pharmaceuticals Inc . Both went public in 2004, and they are now trading considerably above their IPO prices.

Even as Sirtris announced its IPO, a biotech company across town charted a different course: Microbia Inc. said it was raising $50 million in private financing to pay for clinical trials of its drugs to treat constipation and high cholesterol. Although eight years old -- a point at which venture backers often look for a public offering to start cashing out their investments -- Microbia has remained private, raising $125 million in venture and private-equity money in the past year alone.

Chief executive Peter Hecht said Microbia has considered public offerings, but found it was easier to raise money privately.

"Clearly there are some advantages to being public, in terms of liquidity for your employees and investors," he said. But in the end, Hecht said, it was easier to raise funds without the distractions of a public "road show" for potential buyers. The private financing, he said, "came and found us, so it was very quick and easy."

Stephen Heuser can be reached at sheuser@globe.com.