Amgen buys Horizon Therapeutics for US$27.8bn

US BIOTECH company Amgen has completed its US$27.8bn acquisition of Horizon Therapeutics after a legal challenge by the US antitrust watchdog was dropped. 

The company had been expected to close the deal in the first half of 2023, having agreed to acquire Horizon in late 2022.  

But the buyout was put on hold when in May, the US Federal Trade Commission (FTC) sought to block the transaction. 

Horizon develops medicines to treat rare autoimmune and severe inflammatory diseases. Two of its biggest products are Tepezza, a prescription medicine used to treat Thyroid Eye Disease (TED), a condition where the immune system attacks the muscle and fat tissue behind eyes, and Krystexxa. The latter is used to treat uncontrollable gout, a form of inflammatory arthritis. 

Amgen has its own anti-inflammatory rheumatoid arthritis drug, Enbrel, which, in 2021, generated US$4.35bn in sales. However, its patent protection is due to end in 2029, meaning other pharmaceutical companies will be able to manufacture and sell their own cheaper generic versions of the drug.  

The FTC argued Amgen might use its large portfolio of blockbuster drugs to stifle competition in the pharmaceutical industry, or to pressure insurance companies and pharmacy benefit managers into favouring Tepezza and Krystexxa. 

However, it reached a deal with the drug giant in early September to allow the company’s acquisition to move forward.  

Under the agreement, Amgen is prohibited from bundling an Amgen product with Tepezza and Krystexxa. Amgen is also barred from using any product rebate or contract term to exclude or disadvantage any product that would compete with Tepezza or Krystexxa.  

The agreement also ends the anticompetitive claims by six states – California, Illinois, Minnesota, New York, Washington, and Wisconsin – which joined the FTC in its challenge of the buyout. 

Henry Liu, director of the FTC’s Bureau of Competition, said: “Consolidation in the pharmaceutical industry has given companies the power and incentive to engage in exclusionary rebating practices, which can lead to sky-rocketing prices on essential medications…[the] proposed resolution sends a clear signal that the FTC and its state partners will scrutinise pharmaceutical mergers that enable such practices, and defend patients and competition in this vital marketplace.” 

A string of other limiting conditions have also been imposed on Amgen as part of the agreement. These will be in place for 15 years after the consent order is finalised, including a requirement that Amgen submit annual compliance reports to the FTC and states. 

Speaking of the buyout, which was described as the largest healthcare merger of the year, Robert A Bradway, Amgen's chairman and CEO, said: "We have strong momentum in our core business and the addition of Horizon will further position Amgen as a leader across a broader range of diseases."