DYAX CORP.
55 Network Drive
Burlington, MA 01803
July 2, 2013
VIA EDGAR SUBMISSION
Securities and Exchange Commission
100 F Street, N.E.
Mail Stop 4720
Washington, D.C. 20549
Attention: Jim B. Rosenberg, Senior Assistant Chief Accountant
| Re: | Dyax Corp. |
| Form 10-K for the fiscal year ended December 31, 2012 |
| Filed March 4, 2013 |
| File No. 000-24537 |
Dear Mr. Rosenberg:
On behalf of Dyax Corp., we acknowledge the comments provided to Dyax from the staff of the Securities and Exchange Commission (the “Staff”) in a letter dated June 28, 2013. Pursuant to discussions with the Staff, we request an extension of 10 business days to respond to the letter and intend to provide our response via EDGAR on or before July 29, 2013.
Please contact me at (617) 250-5733 if you have any questions or require any additional information.
Very truly yours,
/s/George Migausky
George Migausky
Executive Vice President and Chief Financial Officer