San Francisco, CA Dec. 8, 2010 – Sutro Biopharma, a biopharmaceutical company developing both novel and biosuperior protein therapeutics with improved pharmaceutical properties, today announced that it has appointed Trevor Hallam, Ph.D., as chief scientific officer (CSO). Dr. Hallam will lead Sutro’s ongoing efforts in the application of the company’s proprietary protein biochemical synthesis platform for the research and development of novel and biosuperior therapeutics, including those that cannot be made using conventional technologies. Sutro is pursuing these protein therapeutics through its own programs as well as through collaborative relationships.

“Our unique programs, technology and capabilities have enabled us to attract exceptional and experienced professionals who will contribute to Sutro’s growth and continued success,” said William Newell, chief executive officer of Sutro Biopharma. “Dr. Hallam’s appointment as CSO reflects our commitment to establishing our own biosuperior portfolio. Additionally, Dr. Hallam’s experience and leadership in innovative collaborations will be important to the relationships we will be forming in the coming years.”

Dr. Hallam brings more than 25 years of experience in drug discovery and development to Sutro. Most recently, he was executive vice president of research & development and executive officer at Palatin Technologies where he was responsible for discovery and clinical development and led the development of several INDs for drug candidates in a variety of therapeutic areas.

Before this, Dr. Hallam held several senior management positions at AstraZeneca, most recently vice president, biologics (respiratory and inflammatory diseases), vice president, U.S. medical affairs, and vice president, preclinical research and development, respiratory and inflammation, Sweden. He began his pharmaceutical career at Smith Kline & French Research, U.K., followed by senior management positions at Glaxo Group Research, U.K., Roche Research Centre, U.K., and Rhone Poulenc Rorer, U.S. Dr. Hallam conducted his post-doctoral training in the laboratory of Timothy J. Rink, M.D., Sc.D., at the Physiological Laboratory, University of Cambridge after receiving his Ph.D. in biochemistry from King’s College, University of London.

About Sutro Biopharma, Inc.

Sutro Biopharma is a biopharmaceutical company that develops and designs novel protein therapeutics and biosuperiors that have site-directed modifications, including modifications incorporating non-natural amino acids. Sutro’s biochemical protein synthesis technology opens up opportunities to create protein therapeutics that cannot be produced using conventional methods. Sutro’s technology enables the rapid and systematic exploration of many protein drug variants to identify drug candidates. Once identified, production of these protein drug candidates can be efficiently scaled to commercial levels. In addition to developing its own drug pipeline, Sutro Biopharma is collaborating with select pharmaceutical and biotechnology companies in the development of novel protein therapeutics that cannot be designed, produced or studied with current technologies.