Deal includes an already-approved drug for angioedema and an experimental antibody treatment

Irish-headquartered Shire has agreed to buy US biotech Dyax for around $5.9 billion (£3.8 billion) in cash. The deal gives Shire access to Dyax’s portfolio of approved and developmental drugs for treating hereditary angioedema – a blood disorder that causes episodic attacks of swelling in various body locations, as well as programmes in other rare diseases.

Kalbitor (ecallantide) is a peptide drug that is approved in the US, but Dyax withdrew its application for approval in the EU in 2011. The drug functions by inhibiting plasma kallikrein. Dyax’s pipeline includes DX-2930, an antibody currently in clinical trials. If DX2930 gets approved, Shire will pay an additional $646 million to Dyax shareholders under the terms of the deal.

Dyax’s products complement Shire’s existing hereditary angioedema drugs, Firazyr (icatibant) and Cinryze (C1 esterase inhibitor [human]). Shire is still pursuing an ongoing takeover bid for Baxalta – the recently spun-off pharmaceutical arm of Baxter.