X0202 4 2005-07-27 1 0000885259 TRANSKARYOTIC THERAPIES INC TKTX 0001236371 PERRY GREGORY D C/O TRANSKARYOTIC THERAPIES, INC. 700 MAIN STREET CAMBRIDGE MA 02139 0 1 0 0 Sr. VP - Finance & CFO Stock Option (right to buy) 23.79 2005-07-27 4 D 0 15000 13.21 D 2015-03-24 Common Stock 15000 0 D Stock Option (right to buy) 21.74 2005-07-27 4 D 0 32500 15.26 D 2014-11-11 Common Stock 32500 0 D Stock Option (right to buy) 10.62 2005-07-27 4 D 0 8959 26.38 D 2014-03-24 Common Stock 8959 0 D Stock Option (right to buy) 7.05 2005-07-27 4 D 0 3816 29.95 D 2013-05-27 Common Stock 3816 0 D Stock Option (right to buy) 7.05 2005-07-27 4 D 0 14184 29.95 D 2013-05-27 Common Stock 14184 0 D Stock Option (right to buy) 7.05 2005-07-27 4 D 0 1080 29.95 D 2013-05-27 Common Stock 1080 0 D Stock Option (right to buy) 7.05 2005-07-27 4 D 0 70920 29.95 D 2013-05-27 Common Stock 70920 0 D This option, which was granted on March 24, 2005 and provided for vesting in three equal annual installments beginning on March 24, 2006, was cancelled pursuant to a merger agreement among the Issuer, Shire Pharmaceuticals Group plc and Sparta Acquisition Corporation, dated April 21, 2005, in exchange for a cash payment of $198,150, representing the excess of $37.00 over the per share exercise price of the option multiplied by the number of shares subject to the option, whether vested or unvested. This option, which was granted on November 11, 2004 and provided for vesting in three approximately equal annual installments beginning on November 11, 2005, was cancelled in the merger in exchange for a cash payment of $495,950, representing the excess of $37.00 over the per share exercise price of the option multiplied by the number of shares subject to the option, whether vested or unvested. This option, which was granted on March 24, 2004 and provided for vesting in three approximately equal annual installments beginning on March 24, 2005, was cancelled in the merger in exchange for a cash payment of $236,338.42, representing the excess of $37.00 over the per share exercise price of the option multiplied by the number of shares subject to the option, whether vested or unvested. This option, which was granted on May 27, 2003 and provided for immediate vesting, was cancelled in the merger in exchange for a cash payment of $114,289.20, representing the excess of $37.00 over the per share exercise price of the option multiplied by the number of shares subject to the option, whether vested or unvested. This option, which was granted on May 27, 2003 and provided for immediate vesting, was cancelled in the merger in exchange for a cash payment of $424,810.80, representing the excess of $37.00 over the per share exercise price of the option multiplied by the number of shares subject to the option, whether vested or unvested. This option, which was granted on May 27, 2003 and provided for vesting in five equal annual installments beginning on March 24, 2006, was cancelled in the merger in exchange for a cash payment of $32,346, representing the excess of $37.00 over the per share exercise price of the option multiplied by the number of shares subject to the option, whether vested or unvested. This option, which was granted on May 27, 2003 and provided for vesting in five equal annual installments beginning on March 24, 2006, was cancelled in the merger in exchange for a cash payment of $2,124,054, representing the excess of $37.00 over the per share exercise price of the option multiplied by the number of shares subject to the option, whether vested or unvested. /s/ Gregory D. Perry 2005-07-27