June 15, 2013 (Vol. 33, No. 12)

The Pfenex Expression Technology™ platform is a very powerful protein expression technology based on the microorganism Pseudomonas fluorescens. The Pfenex platform technology can deliver a robust production strain with unprecedented speed and a success rate that transcends legacy production hosts.

Traditional recombinant protein expression hosts such as E. coli, insect cells, or yeast tend to have high failure rates regarding their ability to produce high titers of soluble, full-length active target protein. In addition, the time required to identify the optimal expression strain in these systems, due to a linear and iterative approach to strain engineering, is protracted, resulting in significant opportunity cost for the drug developer.

Pfenex Expression Technology drama­tically reduces strain development time and hence product development time via robotically enabled high-throughput, parallel-expression strain screening. The resultant selected production strain delivers a lower overall cost of goods associated with rapid fermentation cycle times, higher cell densities, and low cost media. The combination of speed, success rate, and reduced cost of goods has established Pfenex Expression Technology as the premier technology for recombinant protein production.

The Pfenex Expression Technology platform offers a robust solution to the real and opportunity costs incurred through the maintenance of several recombinant expression platforms. Even with smaller scale programs, the utmost importance is placed on speed, while not sacrificing quality and quantity of protein delivered.

Performance data derived from traditional expression hosts suggest development program delays in the range of 5 to 12 months on programs that have utilized such a serial approach.

The real costs of such delays, including materials, FTEs, and facility costs are in the millions of dollars, and the delays of a product reaching the commercialization stage could certainly add millions of dollars more to that total.

As a result, utilizing the proven parallel-processing methods of the Pfenex Expression Technology platform in discovery and throughout development provides tangible benefits in expediting programs by efficient protein production, allowing programs to avoid attrition due to inability to produce product, and delivering a reduced long-term cost of goods that provides a sustainable competitive advantage against other competing products.

Figure 1. Discarding the traditional, linear and iterative approach, Pfenex Strain Engineering adopts a parallel, high-throughput method for microbial development. Thousands of unique host strains and plasmid combinations are seamlessly integrated to enable rapid strain engineering for optimal protein production.


MedImmune’s pipeline includes novel molecules that do not require glycosylation but are difficult to express. To enable the production of these novel molecules, MedImmune searched for a partner with strong capabilities in microbial expression and experience with difficult to express proteins, to compliment their internal expertise. MedImmune desired a partner who could quickly deliver scalable processes for novel and difficult to express proteins in order to support and sustain their early-stage research teams.

After an extensive search MedImmune identified Pfenex, due to Pfenex’s novel expression host platform, high-throughput screening capabilities, a fully integrated process development and bioanalytical capability and an unprecedented success rate of delivering bioprocesses capable of producing high titers of active soluble protein.

A case study presented by Ron Schoner, Fellow, MedImmune (Figures 1 and 2), shows his company’s experience with Pfenex Strain Engineering for the expression of a novel molecule, and the desirable timelines achieved through the application of Pfenex Expression Technology.

Outlined is the novel protein expression project from this partnership where an expression strain and fermentation conditions enabled production of 10 g/L of soluble active product for this nonantibody, multiple intra-chain disulfide-protein in less than eight weeks.

Figure 2. Fermentation condition screening enables the accelerated production of high-quality proteins. Eight 1-L fermentations were performed on a single expression strain (each under a different set of operating conditions); highest yield was approximately 10 g/L.


Chuck Squires, Ph.D.
Vice President
Discovery and Partnerships
[email protected]

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