Shire to acquire Dyax for initial $5.9 billion

LONDON — The Dublin-based drug maker Shire says it will take over U.S. biotechnology firm Dyax in a deal worth an initial $5.9 billion.

The company said Monday that Shire will pay $37.30 in cash for each Dyax share.

Shire also is pursuing Baxalta, the company spun off by Deerfield-based Baxter International in July. Shire has been an buying spree since its deal with AbbVie fell apart last year.

Dyax shareholders will receive an additional $4 a share if certain performance targets are met, which would increase the overall value of the deal by $646 million.

Based in Burlington, Massachusetts, Dyax is specialized in the development of treatments for HAE, a rare genetic disease that can be life-threatening.

The deal is expected to bolster Shire’s role in the treatment of HAE. Dyax has a number of treatment regiments being tested.