PRESS RELEASE: Ambrx Announces Drug Discovery Alliance With Eli Lilly and Company

Ambrx Announces Drug Discovery Alliance With Eli Lilly and Company

Ambrx to Collaborate with Lilly to Discover Protein and Antibody Drug Candidates Targeting Multiple Therapeutic Areas Using Ambrx's Proprietary ReCODE(TM) Platform

SAN DIEGO, Dec. 17 -- Privately held Ambrx Inc. today announced that it has entered into a collaboration with Eli Lilly and Company to discover and develop novel treatments in several therapeutic areas, including metabolic diseases, central nervous system disorders and other diseases.

The collaboration will apply Ambrx's unique protein optimization technology, ReCODE(TM), with Lilly's expertise in biologics discovery, development and commercialization to pursue first-in-class or best-in-class drug candidates, including therapeutic antibodies and improved variants of native proteins.

"We are pleased to enter into this agreement with Lilly, a biologics leader with a proven ability to launch successful medicines in areas of strategic interest to Ambrx," said Stephen W. Kaldor, Ph.D., Ambrx's president and chief executive officer. "This new collaboration allows us to use our existing ReCODE(TM) technology to produce high quality protein clinical candidates while simultaneously affording us the ability to expand our reach into new areas such as therapeutic antibodies. In addition, this agreement will further solidify Ambrx's financial condition for the next several years."

"Lilly continues to be impressed with the technical breadth and depth of the Ambrx scientific staff," commented Thomas Bumol, M.D., Lilly vice president, biotech discovery research and president of Lilly's Applied Molecular Evolution subsidiary. "By leveraging Ambrx technology with our protein engineering capabilities, we hope to accelerate the development of several promising compounds in our pipeline."

Under the terms of the agreement, Ambrx will receive an initial upfront payment and ongoing research support payments. Ambrx may also receive potential research and development milestones and, if assets resulting from the collaboration are successfully commercialized, Ambrx would receive additional milestones and royalties. Other terms of the deal were not disclosed. This collaboration builds on an earlier agreement signed between the two companies in January 2007.

About Ambrx

Ambrx Inc. is a biopharmaceutical company focused on the discovery and development of first-in-class and best-in-class BioSuperior(TM), protein-based drugs. Using its technology, the company can overcome the performance limitations of high-value commercial proteins by improving their efficacy, safety and ease of use. Ambrx's core ReCODE(TM) technology enables the precise, site-specific substitution of a novel amino acid within a protein. This allows the conjugation of proteins with additional molecules that can serve to modulate their pharmacokinetic profile or biological function. Ambrx's ReCODE(TM) technology is applicable to multiple protein products across numerous therapeutic areas. Ambrx has successfully and rapidly applied its innovative technology platform to advance into the clinic with ARX201, its first proprietary molecule, and is building a broad pipeline of additional product opportunities. For additional information, call 858.875.2400 or visit http://www.ambrx.com.