X0306 4 2012-10-26 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 2012-10-26 4 S 0 9788 0.72 D 8905726 I By Limited Partnership 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). 5,117,117 shares of Common Stock are held by SSFQP, 1,638,677 shares of Common Stock are held by Cayman 1,219,360 shares of Common Stock are held by PE and 930,572 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 2012-06-29 David Greenhouse 2012-06-29