Merck & Co. Inc.


Pfēnex Grants Exclusive License to Merck & Co. Inc for the Production of Proteins for Undisclosed Vaccine Program

San Diego, CA (December 14, 2009) – Pfēnex Inc. announced today that it has granted Merck & Co., Inc., through an affiliate, an exclusive worldwide license to Pfēnex Expression Technology™ Pseudomonas-based recombinant protein expression technology for the production of specific proteins to be used in the development of an undisclosed vaccine candidate.

Under the terms of the agreement Pfēnex is eligible to receive approximately $52 million in upfront and milestone payments as well as additional royalty payments on any product sales derived from the agreement. This license represents the second commercial license Merck has been granted to Pfēnex Expression Technology™.

Merck and Pfēnex scientists will collaborate on developing the production strains that will be used to express clinically relevant antigens in support of the preclinical and clinical development of the vaccine candidate. The agreement also includes non- exclusive rights for the production of proteins for diagnostic applications.

“We are pleased to be partnering with Merck”, said Bertrand C. Liang, CEO of Pfēnex, “This collaboration is a clear example of the strength of the Pfēnex Expression Technology being leveraged in the discovery, development and production of novel vaccines.”

About Pfēnex

Pfēnex is a protein production company leveraging the unique and powerful Pfēnex Expression Technology™ platform based on the micro-organism, Pseudomonas fluorescens, for the production of research proteins, reagent proteins, biosimilars and innovator biopharmaceuticals. For more information please visit

Media Contact:
Patrick Lucy
Pfēnex Inc.
Vice President, Business Development 978-887-4971