X0303 4 2011-05-12 0000907562 DYAX CORP DYAX 0001021045 BLAIR HENRY E C/O DYAX CORP. 300 TECHNOLOGY SQUARE CAMBRIDGE MA 02139 1 0 0 0 Stock Option (right to buy) 2.09 2011-05-12 4 A 0 50000 0 A 2021-05-12 Common Stock 50000 50000 D Such option will become exercisable in twelve (12) substantially equal installments at the end of each monthly anniversary of the date of grant (with any fractional shares to be cumulated and to become exercisable at the end of the earliest succeeding monthly period in which a whole share equivalent is accumulated) for a period of eleven (11) months, with the 12th monthly installment to become exercisable as of the commencement of business on the date of the next Annual Meeting of Stockholders. Nathaniel S. Gardiner, as attorney-in-fact 2011-05-13