X0202 3/A 2006-05-16 2006-05-05 1 0000765258 IMCLONE SYSTEMS INC IMCL 0001361754 Denner Alexander J IMCLONE SYSTEMS INCORPORATED 180 VARICK STREET, 6TH FLOOR NEW YORK NY 10014 1 0 0 0 The Form 3 filed on May 5, 2006 is hereby amended to reflect that Alexander J. Denner separated service from Viking Global Investors LP as of May 16, 2006 and no longer serves as a portfolio manager for Viking Global Performance LLC which acts as the general partner of Viking Global Equities LP, a Delaware limited partnership ("VGE"), and investment manager to VGE III Portfolio Ltd., a Cayman Islands company (VGE III"), and that Alexander J. Denner does not have a pecuniary interest with respect to the equity securities of ImClone Systems Incorporated reported therein to be beneficially owned by VGE and VGE III. ERIK D. RAMANATHAN - BY POWER OF ATTORNEY 2006-05-18