Based: San Diego, CA
Founded: 2003
www.ambrx.com 

Bottom line: Going strong.

What we said: Ambrx is a young biotech with a long record of research behind it. For 17 years, Dr. Peter Schultz studied the inner working of proteins at The Scripps Research Institute. His challenge was overcoming the considerable obstacles that block a protein from becoming a therapeutic. What he came up with was a way to insert an amino acid into a cell, redesigning it in such a way as to give it a therapeutic quality. Out of that research came Ambrx, an 18-month-old hard charger that has taken a novel amino acid and wrapped it around a protein, "like a Velcro strip," so it could conjugate with a small molecule, toxin, polymer, etc. to carry on its medicinal work. Dr. Schultz allied himself with Richard DiMarchi (now CEO), a former vice president at Eli Lilly and the inventor of fast-acting insulin, and Troy Wilson (the chief business officer) in the creation of Ambrx.

What happened: You'll find the Fierce 15 logo on Ambrx's home page, today, along with a lineup of new partnership deals. Last April the developer raised an additional $10 million in venture capital-on top of the $96 million it had raised since getting started in 2003. Ambrx has also inked four major drug development partnerships and has the luxury of sitting on more than $50 million in cash. The developer has 80 workers and 11 development programs underway.