Biotech star Zafgen nabs $21M round to back dramatic weight-loss drug

Just a few weeks after moving its unique new obesity drug into a midstage study, Cambridge, MA-based Zafgen grabbed a $21 million D round to fuel its clinical development plans. Alta Partners has jumped into the venture syndicate with the financing, joining prolific biotech investor Third Rock and its high-profile colleagues at Atlas Venture, which are gambling that beloranib, which inhibits the MetAP2 enzyme, can set a whole new standard for weight-loss treatments.

Zafgen, a 2009 Fierce 15 company, has set out to see if a Phase IIa study with 150 obese patients can continue to register the kind of dramatic weight loss seen in early studies. Data from that trial should be in hand next summer. In a brief, 4-week trial, patients lost a kilo a week, and now the virtual Zafgen team--with a staff of 5--wants to see if that track record can be sustained over 12 weeks.

Recent approvals of modestly effective weight loss drugs have helped dispel a cloud of uncertainty that had lingered over the field for more than a year, creating a notably improved regulatory and clinical environment for its drug work. For a time Zafgen had been looking at a possible sale, but CEO Tom Hughes told FierceBiotech last month that the biotech will keep all its options open. With one of the most intriguing development programs in the industry, new advances in the clinic would attract even more positive attention for a drug that holds the promise of significantly altering the standard of care in obesity--provided it can continue to skirt the heavy risks faced by all drugs in clinical development. 

"We are thrilled to have attracted more world-class investors to our syndicate as we move forward with phase 2a clinical testing for beloranib," said Hughes in a statement. "Alta Partners has a strong portfolio and consistent track record of recognizing and investing in high-growth firms. We appreciate their confidence in the promise of beloranib to help address the unmet needs of severely obese patients." 

- here's the press release

Special Report: Zafgen - 2009 Fierce 15