Item 8.01. Other Events.

On June 21, 2012, Dyax Corp. ("Dyax") and Sigma-Tau Rare Diseases S.A., as successor-in-interest to Defiante Farmaceutica S.A. ("Sigma-Tau"), entered into a Fifth Amendment (the "Fifth Amendment") to the Joint Development and License Agreement dated effective as of June 18, 2010, as amended by the First Amendment to Joint Development and License Agreement dated December 21, 2010, the Second Amendment to Joint Development and License Agreement dated May 21, 2011, the Third Amendment to Joint Development and License Agreement dated December 26, 2011 and the Fourth Amendment to Joint Development and License Agreement dated May 29, 2012.

The Fifth Amendment eliminates Sigma-Tau's rights to develop and commercialize KALBITOR (ecallantide) in the remaining countries of Latin America (Brazil and Argentina having been previously eliminated pursuant to a prior amendment), and also removes Sigma-Tau's payment obligations to Dyax in relation to these countries.

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