Preclinical biopharma Verastem raised $55 million in an initial public offering, the second life sciences IPO this year. But unlike many of the other drug developers that have gone public in the last couple of years, it garnered enough interest from investors to increase the size of its offering and price within its target range.

Analysts covering IPOs had a hard time understanding the logic behind Verastem’s successful offering and several recommended against investing in it. Verastem said in an S-1 filing dated January 13 that existing stockholders including Advanced Technology Ventures, Bessemer Venture Partners, CHP III, Longwood Fund, and MPM Bioventures, indicated an interest in purchasing an aggregate of up to approximately $16.3 million in shares of its common stock in the initial public offering price. Still this is a common ploy in recent times.

The Massachusetts-based startup managed to attract investors despite the fact that the company is barely a year and a half old and has no drugs in clinical development. Under the current risk-averse market environment, most private drug developers aiming for a public offering need to have at least one compound ready for late-stage testing. The performance of the eight therapeutics companies that went public in 2011, down an average 14.8 percent, was lackluster compared to the performance of the broader group of public biotechs.

What Verastem does have, however, is an experienced management team, headed by its CEO Christoph Westphal. Westphal is known for having sold Sirtris Pharmaceuticals, his previous venture, to GlaxoSmithKline for $720 million in 2008 on the promise of its preclinical pipeline of anti-aging drugs based on resveratrol—a promise that has grown increasingly unlikely to be fulfilled.

Verastem is focused on developing drugs that target cancer stem cells, also known as tumor-initiating cells, which it believes play a crucial role in tumors’ ability to resist treatment and spread. Verastem uses proprietary technology licensed from MIT and Harvard to screen for small molecules that target these cells. It also plans to in-license small molecules of interest from other companies, which will then be developed into clinical candidates along with companion diagnostics. In its registration statement, Verastem says it expects to file an IND for one of four preclinical compounds in its pipeline by the end of 2012 and another in 2013.

The Massachusetts-based company sold 5.5 million shares at $10, the midpoint of the target range, one million more shares than originally intended, to begin trading on the Nasdaq Global Market under the symbol VSTM. Verastem’s investors include Longwood Founders Fund, a firm started by Westphal, holding a 15.4 percent stake. Other stakeholders include CHP, with a 13.5 percent stake, Bessemer Venture Partners, which holds 12.9 percent, Eastern Capital with 7.8 percent, and Advanced Technology Ventures with a 5 percent stake.

Three other drug developers have recently started gauging investor interest. Merrimack Pharmaceuticals is planning to go public during the week beginning January 30 by selling 16.7 shares at $8 to $10 per share, according to its most recent filing. ChemoCentryx is seeking to raise $60 million by offering 4 million shares at $14 to $16 per share. TVAX Biomedical plans to raise $20 million by offering 2 million shares at $9 to $11 per share.

Verastem was trading at $10.90 a share toward the close of its first trading day, up 9 percent.