After Hours and Pre-Market Movers

[JoeHall]

DYAX news AH

Dyax Announces Underwriter’s Exercise of Over-allotment Option

CAMBRIDGE, Mass.--(BUSINESS WIRE)--Dyax Corp. (NASDAQ: DYAX) announced today that Jefferies & Company, Inc. exercised in full its over-allotment option to purchase an additional 2,550,000 shares of the Company’s common stock at a public offering price of $3.25 per share. The over-allotment option was granted to the underwriters by Dyax in connection with its recent offering of common stock. The exercise of the option brings the aggregate net proceeds from the offering to approximately $59.6 million. The sale of the additional shares closed on April 5, 2010.

Jefferies & Company, Inc. acted as the sole book-running manager of the offering with Needham & Company, LLC acting as the co-lead manager.

Dyax intends to use the net proceeds from this offering to fund commercialization and distribution activities for KALBITOR® (ecallantide), its lead product for the treatment of acute attacks for hereditary angioedema, to fund other research and preclinical development activities, and for general corporate purposes.

A registration statement relating to the shares of Dyax common stock being offered has been filed with, and declared effective by, the Securities and Exchange Commission (the “SEC”). A final prospectus supplement related to the offering has been filed with the SEC and is available on the SEC’s website at http://www.sec.gov. Copies of the final prospectus supplement and related prospectus may be obtained from Jefferies & Company, Inc., Attention: Syndicate Prospectus Department, 520 Madison Avenue, New York, NY, 10022 or at [phone]. This press release shall not constitute an offer to sell or the solicitation of an offer to buy, nor shall there be any sale of, these securities in any state or other jurisdiction in which such offer, solicitation or sale would be unlawful prior to the registration or qualification under the securities laws of any such state or jurisdiction.

About Dyax

Dyax is a fully integrated biopharmaceutical company focused on discovering, developing and commercializing novel biotherapeutics for unmet medical needs, with an emphasis on inflammatory and oncology indications. Dyax utilizes its proprietary drug discovery technology to identify antibody, small protein and peptide compounds for clinical development. Dyax’s first product, KALBITOR® (ecallantide), is available in the United States for the treatment of acute attacks of hereditary angioedema in patients 16 years of age and older.

Dyax’s lead product candidate is DX-88, a recombinant, small protein that is being evaluated for its therapeutic potential in other angioedema indications (ACE inhibitor-induced and acquired angioedemas). DX-88 is also being evaluated through Dyax’s partner, Fovea Pharmaceuticals (sanofi aventis), in a Phase 1 trial for retinal vein occlusion-induced macular edema.

DX-88 and other compounds in Dyax’s pipeline were identified using its patented phage display technology, which rapidly selects compounds that bind with high affinity and specificity to therapeutic targets. Dyax leverages this technology broadly with over 70 revenue generating licenses and collaborations for therapeutic discovery, as well as in non-core areas such as affinity separations, diagnostic imaging, and research reagents. Dyax is headquartered in Cambridge, Massachusetts. For online information about Dyax Corp., please visit www.dyax.com.

Dyax and the Dyax logo are registered trademarks of Dyax Corp.

Contacts

Dyax Corp.
George Migausky, 617-250-5733
Executive Vice President
and Chief Financial Officer
[e-mail]
or
Nicole Jones, 617-250-5744
Director, Investor Relations and
Corporate Communications
[e-mail]