Founded only eight months ago, Sirtris Pharmaceuticals Inc. already has completed its second financing round, raising $27 million to push development efforts based on Class III histone deacetylases (HDACs).

To date, the Waltham, Mass.-based company has raised $45 million, including $5 million in seed money in August and $13 million from a Series A financing round in December. Sirtris CEO and co-founder Christoph Westphal said the rapid fund-raising efforts were due to the promising potential of Class III HDACS, known as sirtuins, as drug targets in several therapeutic areas.

When contacted by BioWorld Today, the company referred to its press release.

The recent financing was led by Portola Valley, Calif.-based Three Arch Partners, a new investor to the company, along with co-lead investors Cargill Ventures, of San Mateo, Calif., and Novartis Bioventures Fund, a subfund of Basel, Switzerland-based Novartis' Venture Fund. Previous investors - Waltham, Mass.-based Polaris Venture Partners; Munich, Germany-based Techno Venture Management; Princeton, N.J.-based Cardinal Partners; Palo Alto, Calif.-based Skyline Ventures; and London-based The Wellcome Trust - also participated.

Since its inception, Sirtris has focused on sirtuins. Indeed, even its name is a reference to the seven human sirtuins that could be targets for treating metabolic, inflammatory, cancer or neurodegenerative disorders. While the investigation into drugs that inhibit HDACs has increased over the past several years, most of the development work has revolved around Class I and II HDACS, such as FK228 (depsipeptide), an HDAC inhibitor developed by Cambridge, Mass.-based Gloucester Pharmaceuticals Inc., which began a pivotal trial earlier this month in cutaneous T-cell lymphoma.

But Sirtris has directed its efforts solely on the Class III enzymes, using patents and other intellectual property licensed from Harvard University, where Sirtris co-founder David Sinclair did much of his sirtuin work as an assistant professor of pathology. The company has built on those developments to begin creating therapeutics that modulate sirtuin activity and downstream targets.

In addition to Westphal, who is former co-founder and CEO of Alnylam Pharmaceuticals Inc., and Sinclair, Sirtris also was co-founded by Rich Aldrich, Richard Pops and Paul Schimmel. Pops is CEO of Alkermes Inc. and chairman of the Biotechnology Industry Organization.