Horizon Therapeutics’ (NASDAQ:HZNP) stock price plunged soon after Tuesday’s open after a report that the Federal Trade Commission is preparing to file a lawsuit to block the biotech company’s $27.8 billion sale to Amgen.
The FTC could sue to block the acquisition as soon as Tuesday, Bloomberg reported, citing an unnamed source.
An Amgen spokesperson told media outlets the company isn’t aware of any decision made by the FTC. The FTC declined to comment.
The two drugmakers said in February that the FTC sent them a second request for information about the acquisition as part of the agency’s review of the deal.
Thousand Oaks, California-based Amgen struck the deal to buy Horizon Therapeutics in early December and said it expected to complete the sale in the first half of this year.
The move was a bid to strengthen Amgen’s drug portfolio as it prepares to face several patent expirations for key treatments over the next decade.
That includes a patent for a medicine that treats psoriasis, an autoimmune condition that causes inflammation of the skin.
Horizon, which is based in Ireland, would beef up Amgen’s drug offerings with treatments for rare, autoimmune and severe inflammatory diseases.
HZNP shares tumbled $20.74, or 18.5%, at Tuesday’s open to $91.51.
