X0306 4 2014-08-05 1 0001093649 IDENIX PHARMACEUTICALS INC IDIX 0001513422 Beckman Daniella C/O IDENIX PHARMACEUTICALS 320 BENT STREET CAMBRIDGE MA 02141 0 1 0 0 SVP, CFO and Treasurer Stock Option (Right to Buy) 5.32 2014-08-05 4 D 0 15000 0.00 D 2018-03-02 Common Stock 15000 0 D Stock Option (Right to Buy) 5.46 2014-08-05 4 D 0 6000 0.00 D 2019-02-12 Common Stock 6000 0 D Stock Option (Right to Buy) 2.96 2014-08-05 4 D 0 7500 0.00 D 2020-02-09 Common Stock 7500 0 D Stock Option (Right to Buy) 3.17 2014-08-05 4 D 0 30000 0.00 D 2021-02-20 Common Stock 30000 0 D Stock Option (Right to Buy) 4.57 2014-08-05 4 D 0 50000 0.00 D 2021-06-01 Common Stock 50000 0 D Stock Option (Right to Buy) 12.08 2014-08-05 4 D 0 100000 0.00 D 2022-02-28 Common Stock 100000 0 D Stock Option (Right to Buy) 4.65 2014-08-05 4 D 0 100000 0.00 D 2023-02-19 Common Stock 100000 0 D Stock Option (Right to Buy) 7.01 2014-08-05 4 D 0 100000 0.00 D 2024-02-09 Common Stock 100000 0 D These options, which vested in 48 equal monthly installments beginning on March 31, 2008, were cancelled pursuant to the Agreement and Plan of Merger between the Issuer and Merck & Co. Inc. (the "Merger Agreement") in exchange for a cash payment of $19.18 per share, representing the difference between the exercise price of the options and $24.50 per share. These options, which vested in 48 equal monthly installments beginning on February 28, 2009, were cancelled pursuant to the Merger Agreement in exchange for a cash payment of $19.04 per share, representing the difference between the exercise price of the options and $24.50 per share. These options, which vested in 48 equal monthly installments beginning on February 28, 2010, were cancelled pursuant to the Merger Agreement in exchange for a cash payment of $21.54 per share, representing the difference between the exercise price of the options and $24.50 per share. These options, which vested in 48 equal monthly installments beginning on February 28, 2011, were cancelled pursuant to the Merger Agreement in exchange for a cash payment of $21.33 per share, representing the difference between the exercise price of the options and $24.50 per share. These options, which vested in 48 equal monthly installments beginning on June 30, 2011, were cancelled pursuant to the Merger Agreement in exchange for a cash payment of $19.93 per share, representing the difference between the exercise price of the options and $24.50 per share. These options, which vested in 48 equal monthly installments beginning on February 29, 2012, were cancelled pursuant to the Merger Agreement in exchange for a cash payment of $12.42 per share, representing the difference between the exercise price of the options and $24.50 per share. These options, which vested in 48 equal monthly installments beginning on February 28, 2013, were cancelled pursuant to the Merger Agreement in exchange for a cash payment of $19.85 per share, representing the difference between the exercise price of the options and $24.50 per share. These options, which vested in 48 equal monthly installments beginning on February 28, 2014, were cancelled pursuant to the Merger Agreement in exchange for a cash payment of $17.49 per share, representing the difference between the exercise price of the options and $24.50 per share. /s/Maria Stahl, Attorney-in-Fact for Daniella Beckman 2014-08-05