X0303 4 2011-03-11 0 0000907562 DYAX CORP DYAX 0001091925 KEMPNER THOMAS L C/O DYAX CORP. 300 TECHNOLOGY SQUARE CAMBRIDGE MA 02139 1 0 0 0 Common Stock 2011-03-11 4 P 0 20000 1.50 A 1143233 I By Trust (1) Common Stock 1308810 I By Loeb Holding Corporation (2) Common Stock 53764 I By Loeb Investors Co. IX (3) Common Stock 5021 I By Spouse Common Stock 11792 I BY Pinpoint Partners Corporation (4) Common Stock 27311 D Explanation of Responses: (1) Shares held in trust, of which Mr. Kempner is the trustee, for the benefit of Mr. Kempner's brother's children, Mr. Kempner's children, Mr. Kempner's sister-in-law, and Mr. Kempner. (2) Mr. Kempner is the Chairman, Chief Executive Officer, and also beneficial owner of a majority of the voting stock of Loeb Holding Corporation. Mr. Kempner disclaims beneficial ownership of these shares except to the extent of his pecuniary interest therein. (3) Mr. Kempner is the Managing Partner of Loeb Investors Co. IX. Mr. Kempner disclaims beneficial ownership of these shares except to the extent of his pecuniary interest therein. (4) Mr. Kempner is President of Pinpoint Partners Corporation. Mr. Kempner disclaims beneficial ownership of these shares except to the extent of his pecuniary interest therein. Thomas L. Kempner 2011-03-16