(FORTUNE Magazine) – Cambridge, Mass. Founded 2001

Now that the biology century has arrived, you'd think a new drug company focused on chemistry would have all the buzz of a rotary-telephone startup. But Infinity Pharmaceuticals isn't your father's chemicals company. It has a remarkable brain trust: Advisors include Harvard's Stuart Schreiber, one of the biggest names in chemistry, and famed MIT genome decoder Eric Lander; and CEO Steven Holtzman, 50, and chief scientist Julian Adams, 49, both hail from genomics bellwether Millennium Pharmaceuticals. It has cash: VCs and, recently, Amgen have invested more than $100 million in the firm. And most important, it thinks it has a solution to a vexing drug-industry problem: While biologists are identifying an increasing number of molecules in the body worth targeting, chemists often can't find compounds that hit the bull's-eye.

Based on chemical-synthesis tricks pioneered by Schreiber, Infinity has created thousands of compounds that are similar to natural substances known to work as medicines. Such complex molecules in the past often were deemed too hard to make. Infinity's ability to churn them out should dramatically expand the list of "druggable" targets and, in time, of novel medicines. Cancer is Infinity's initial focus, and its first clinical trial may start next year. Maybe the company motto will turn out to be "more living through chemistry." --David Stipp