Amgen agrees €25bn deal to buy Horizon Therapeutics

Irish-headquartered firm planning major expansion in Waterford

Horizon shares have surged 24% since November 29, when it disclosed Amgen, Sanofi and a Johnson & Johnson unit were in preliminary talks about a possible acquisition

Amgen has agreed to buy Irish pharmaceutical firm Horizon Therapeutics at a valuation of about $26bn (€24.7bn) in what would be its biggest-ever acquisition, according to a person familiar with the matter.

The US biotechnology giant offered around $116.5 for each Horizon share, said the person, who asked not to be identified as the information is private. The offer price is at a around 20% premium to Horizon’s closing price of $97.29 on Friday.