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Illinois Attorney General
Kwame Raoul

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June 22, 2023

ChicagoAttorney General Kwame Raoul today joined the Biden administration and five attorneys general in a legal effort to block Amgen, one of the world’s largest biopharmaceutical drug companies, from purchasing Horizon Therapeutics (Horizon). In challenging the $28 billion purchase, the Federal Trade Commission (FTC) alleges that the proposed acquisition raises significant anticompetitive concerns.

“This proposed pharmaceutical merger would allow Amgen to monopolize the market for certain crucial medications and reduce affordability, access and choice of drugs for vulnerable patients in Illinois,” Raoul said. “Preserving competition within the pharmaceutical industry is essential to improving access and affordability, and I will continue to partner with other attorneys general to stop the concerning increase in consolidations that raise health care costs for patients.”

Horizon specializes in manufacturing medications for rare and often severe autoimmune diseases. Two of its main drugs are Tepezza, the only FDA-approved treatment for thyroid eye disease, and Krystexxa, the only FDA-approved treatment for chronic refractory gout. Over the next few years, competing companies are expected to introduce new medications that could be strong market competitors for Krystexxa and Tepezza. For patients, the new medications could be safer, more affordable, more durable, and better at preventing debilitating disability.

The lawsuit filed by Raoul and the FTC seeks an order to prevent finalization of the acquisition because Amgen’s proposed acquisition of Horizon likely violates the Clayton Act. If the acquisition were allowed to proceed, the newly-consolidated company would be free to muscle out competitors from the market for autoimmune disease medications. If it takes over Horizon, Amgen could leverage its market power to negotiate with insurers and pharmaceutical benefit managers for preferred or even exclusive access for Tepezza and Krystexxa on health plans – in effect, making it potentially impossible for new, more affordable medications to reach patients. 

Amgen’s history of leveraging its existing market power and bundling its drugs to exclude competitors only increases this risk, which would ultimately deter other companies from researching and introducing new drugs, and reduce affordability for vulnerable patients, 

Joining Attorney General Raoul in this lawsuit are attorneys general from California, New York, Minnesota, Washington and Wisconsin.