X0306 4 2015-12-01 0 0001478121 Pfenex Inc. PFNX 0001612846 Talbot Henry W. Jr. CO PFENEX INC, 10790 ROSELLE STREET SAN DIEGO CA 92121 0 1 0 0 VP of Operations Common Stock 2015-12-01 4 S 0 2000 15.084 D 118678 D Represents the weighted average share price of an aggregate total of 2,000 shares sold in the price range of $15.00 to $15.56 by the reporting person. The reporting person undertakes to provide upon request by the Commission staff, the issuer of security holder of the issuer, full information regarding the number of shares sold at separate price. Includes 688 shares acquired under the PFNX employee stock purchase plan on February 17, 2015 and 700 shares acquired under the PFNX employee stock purchase plan on August 17, 2015. /s/ Patricia Lady, as Attorney-in-Fact 2015-12-02