X0303 4 2011-02-02 0 0001055726 INOVIO PHARMACEUTICALS, INC. INO 0001044321 MARXE AUSTIN W & GREENHOUSE DAVID M C/O SPECIAL SITUATIONS FUNDS 527 MADISON AVENUE, SUITE 2600 NEW YORK NY 10022 0 0 1 0 Common Stock 2011-02-02 4 S 0 400000 1.3411 D 20730400 I By Limited Partnership Common Stock 2011-02-02 4 S 0 105000 1.362 D 20625400 I By Limited Partnership This is a weighted average price This is a joint filing by Austin W. Marxe (Marxe) and David M. Greenhouse (Greenhouse). They share voting and investment control over all securities owned by Special Situations Fund III QP, L.P. (SSFQP), Special Situations Cayman Fund, L.P. (Cayman), Special Situations Private Equity Fund, L.P. (PE) and Special Situations Life Sciences Fund, L.P. (LS). 11,882,953 shares of Common Stock are held by SSFQP, 3,819,483 shares of Common Stock are held by Cayman 2,801,018 shares of Common Stock are held by PE and 2,121,946 shares of Common Stock are held by LS. The interest of Marxe and Greenhouse in the shares of Common Stock owned by SSFQP, Cayman, PE and LS is limited to the extent of his pecuniary interest. Austin Marxe 2011-02-04 David Greenhouse 2011-02-04