Horizon Therapeutics stock plunges on report FTC is preparing to block Amgen deal

Horizon Therapeutics' banal plunged much than 17% successful premarket trading Tuesday aft a study that the Federal Trade Commission is preparing to record a suit to artifact the biotech company's $27.8 cardinal sale to Amgen. 

The FTC could writer to artifact the acquisition arsenic soon arsenic Tuesday, Bloomberg reported, citing an unnamed source.

Representatives for Horizon Therapeutics and Amgen did not instantly respond to a petition for remark from CNBC. The FTC declined to comment.

The 2 drugmakers said successful February that the FTC sent them a 2nd request for accusation astir the acquisition arsenic portion of the agency's reappraisal of the deal. 

Thousand Oaks, California-based Amgen struck the woody to bargain Horizon Therapeutics successful aboriginal December and said it expected to implicit the merchantability successful the archetypal fractional of this year. 

The determination was a bid to fortify Amgen's cause portfolio arsenic it prepares to look several patent expirations for cardinal treatments implicit the adjacent decade.

That includes a patent for a medicine that treats psoriasis, an autoimmune information that causes inflammation of the skin.

Horizon, which is based successful Ireland, would beef up Amgen's cause offerings with treatments for rare, autoimmune and terrible inflammatory diseases. 

Horizon carries 2 fast-growing drugs, including the thyroid oculus illness attraction Tepezza and the gout medicine Krystexxa. 

Sen. Elizabeth Warren, D-Mass., successful January expressed concern astir the deal's imaginable interaction connected contention successful the cause market. 

The acquisition and different projected merger successful the biopharma manufacture — betwixt Indivor and Opiant — could "cause further terms increases connected lifesaving drugs and forestall affordable alternatives from entering the market," Warren wrote successful a letter to FTC Chair Lina Khan and 2 commissioners astatine the agency.

She called connected the FTC to "heavily scrutinize" the 2 deals.