Pfenex Inc. and Boehringer Ingelheim Corporation Announce Non-Exclusive Strategic Agreement for the use of Pfenex Expression Technology(TM)

San Diego, California, and Ingelheim, Germany, 15 February 2011 – Pfenex Inc., an industry leader in protein expression through the Pfenex Expression Technology™ platform and Boehringer Ingelheim International GmbH, a leading pharmaceutical company and global leader in biopharmaceutical contract development and manufacture, announced today that they have entered into a strategic agreement. It provides Boehringer Ingelheim with non-exclusive access to the Pfenex Expression Technology. Under the terms of the multi-year agreement, Pfenex Inc. will engineer production strains and processes for Boehringer Ingelheim’s proprietary molecules, and molecules from Boehringer Ingelheim’s contract manufacturing customers. This collaboration provides Boehringer Ingelheim and their customers with access to an industry-leading expression platform to enable preclinical and clinical development to progress much more quickly and efficiently.

“We are very pleased to have established this agreement with Boehringer Ingelheim,” said Dr Bertrand Liang, CEO of Pfenex Inc. “This partnership combines a cutting edge expression technology with the leading innovative pharmaceutical company and contract services provider, facilitating the speed and reliability with which important new drugs can be brought to patients.”

“This collaboration extends our contract manufacturing service portfolio by an additional high expression system and is a further step in our strategy to offer customers leading technologies”, stated Simon Sturge, Corporate SVP of the Biopharmaceuticals Division at Boehringer Ingelheim. “The Pfenex Expression Technology™ delivers excellent expression rates, and we are looking forward to realizing customer projects with this technology.”

About Pfenex Inc. Pfenex Inc. is a protein production company leveraging the unique and powerful Pfenex Expression Technology™ platform based on the microorganism, Pseudomonas fluorescens, for the production of research proteins, reagent proteins, biosimilars and innovator biopharmaceuticals. For more information please visit www.pfenex.com

About Boehringer Ingelheim The Boehringer Ingelheim group is one of the world’s 20 leading pharmaceutical companies. Headquartered in Ingelheim, Germany, it operates globally with 142 affiliates in 50 countries and more than 41,500 employees. Since it was founded in 1885, the family-owned company has been committed for 125 years to researching, developing, manufacturing and marketing novel products of high therapeutic value for human and veterinary medicine.

In 2009, Boehringer Ingelheim posted net sales of 12.7 billion euro while spending 21% of net sales in its largest business segment Prescription Medicines on research and development.

For more information please visit www.boehringer-ingelheim.com.

Today, Boehringer Ingelheim is one of the world’s leading companies for contract development and manufacture of biopharmaceuticals. All types of services from mammalian cell line or microbial strain development to final drug production can be delivered within a one-stop-shop concept. Boehringer Ingelheim delivers services for pre-clinical development up to global market supply with a strong commitment to its customers at its manufacturing facilities for mammalian cell culture and microbial fermentation. Boehringer Ingelheim has brought 18 molecules to market and has many years of experience in multiple molecule classes such as monoclonal antibodies, recombinant proteins, interferons, enzymes, fusion molecules and plasmid DNA. Furthermore, high-titer platform technologies for new antibody mimetic formats such as scaffold proteins and antibody fragments are available for the manufacture of customer products. For more information contact: bio-cmo@boehringer-ingelheim.com or www.biopharma-cmo.com

Media Contact: Pfenex Inc. Patrick Lucy Pfenex Inc. Vice President, Business Development 978-887-4971 pkl@pfenex.com Boehringer Ingelheim Corporate Communications Media + PR Heidrun Thoma 55216 Ingelheim/Germany Phone: + 49 - 6132 – 77 3966 E-mail:press@boehringer-ingelheim.com Twitter: www.twitter.com/boehringer