X0306 4 2020-09-30 1 0001478121 Pfenex Inc. PFNX 0001357550 Weiss Asset Management LP 222 BERKELEY STREET, 16TH FLOOR BOSTON MA 02116 0 0 1 0 0001357643 WEISS ANDREW M 222 BERKELEY STREET, 16TH FLOOR BOSTON MA 02116 0 0 1 0 0001504664 WAM GP LLC 222 BERKELEY STREET, 16TH FLOOR BOSTON MA 02116 0 0 1 0 Common Stock 2020-09-30 4 U 0 801424 12 D 3418631 I See Footnote 2 In addition, for each share tendered we are expecting to receive one Contingent Value Right (CVR) which, by its terms, will entitle the holder to either $0 or $2 payable by December 31, 2021. Shares reported herein represent shares beneficially owned by two private investment funds for which Weiss Asset Management LP serves as an investment manager. WAM GP LLC is the general partner of Weiss Asset Management LP and Andrew Weiss is the Managing Member of WAM GP LLC. All of Weiss Asset Management LP, WAM GP LLC, and Andrew Weiss disclaim beneficial ownership of the shares reported herein except to the extent of their pecuniary interest therein. Georgiy Nikitin, Chief Compliance Officer, Weiss Asset Management LP and WAM GP LLC 2020-10-02 Georgiy Nikitin, duly authorized under a power of attorney by Andrew M. Weiss 2020-10-02