X0202 4 2005-07-27 1 0000885259 TRANSKARYOTIC THERAPIES INC TKTX 0001215120 YETTER WAYNE P C/O TRANSKARYOTIC THERAPIES, INC. 700 MAIN STREET CAMBRIDGE MA 02139 1 0 0 0 Stock Option (right to buy) 14.61 2005-07-27 4 D 0 10000 22.39 D 2014-06-22 Common Stock 10000 0 D Stock Option (right to buy) 11.08 2005-07-27 4 D 0 10000 25.92 D 2013-07-01 Common Stock 10000 0 D Stock Option (right to buy) 36.00 2005-07-27 4 D 0 6750 1.00 D 2012-06-06 Common Stock 6750 0 D Stock Option (right to buy) 30.30 2005-07-27 4 D 0 6750 6.70 D 2011-06-14 Common Stock 6750 0 D Stock Option (right to buy) 32.688 2005-07-27 4 D 0 6750 4.312 D 2010-06-16 Common Stock 6750 0 D This option, which was granted on June 22, 2004 and provided for vesting in three approximately equal annual installments beginning on June 22, 2005, 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 $223,900, 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 July 1, 2003 and provided for vesting in three approximately equal annual installments beginning on July 1, 2004, was cancelled in the merger in exchange for a cash payment of $259,200, 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 June 6, 2002 and provided for vesting in three equal annual installments beginning on June 6, 2003, was cancelled in the merger in exchange for a cash payment of $6,750, 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 June 14, 2001 and provided for vesting in three equal annual installments beginning on June 14, 2002, was cancelled in the merger in exchange for a cash payment of $45,225, 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 June 16, 2000 and provided for vesting in three equal annual installments beginning on June 16, 2001, was cancelled in the merger in exchange for a cash payment of $29,106, 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/ Wayne P. Yetter 2005-07-27