After short FTC fight, Amgen wraps up $27.8B Horizon buyout

Amgen has completed its $27.8 billion acquisition of Horizon Therapeutics after fending off a legal challenge by the U.S. antitrust watchdog.

The California-based drugmaker made the announcement Friday following a signoff from the High Court of Ireland the prior day.

The company originally expected to close the deal—unveiled late 2022—in the first half of 2023. But the U.S. Federal Trade Commission (FTC) in May sued to block the transaction, arguing Amgen might bundle its existing blockbuster meds with Horizon’s rare disease products in reimbursement talks to disadvantage potential competitors.

The two sides resolved the litigation last month after Amgen explained that it couldn’t bundle those drugs under the current U.S. healthcare system and promised not to do so.

Horizon comes with several commercial products that bolster Amgen’s autoimmune portfolio. Tepezza for thyroid eye disease, Krystexxa for gout and CD19-targeted Uplizna each have blockbuster peak sales estimates to live up to.

Still, some investors have already questioned whether Amgen has paid too much.

After a disappointing first quarter, Horizon posted encouraging results for the second quarter. Tepezza sales of $446 million were 9% above analysts’ expectations, while Krystexxa and Uplizna beat consensus by 26% and 32%, respectively.

That kind of revenue momentum is attractive to Amgen, whose top-selling drug Enbrel is under pressure thanks to biosimilars to its anti-TNF rival, AbbVie’s Humira. Oral psoriasis drug Otezla, another blockbuster product in Amgen’s autoimmune business, has also shown signs of slowing down amid competition from Bristol Myers Squibb’s Sotyktu and newer biologics.

The Horizon products will become part of a newly formed rare disease business, which is separate from the inflammation department. All Horizon employees are transitioning to Amgen as the Horizon name dissolves. 

Horizon marks the latest deal in an M&A spree for Amgen as the California drugmaker struggled to find growth internally. Before the Horizon announcement last year, Amgen bought ChemoCentryx for $3.7 billion. The deal gave Amgen Tavneos, which is approved to treat a rare autoimmune disease called anti-neutrophil cytoplasmic antibody-associated vasculitis.

Otezla also came to Amgen’s possession through a $13.4 billion acquisition in 2019. After that, Amgen bought Five Prime Therapeutics, Rodeo Therapeutics and Teneobio in quick succession in 2021.

Now that Amgen has moved past the FTC, watchers of biopharma M&A have shifted their attention to Pfizer’s $43 billion bid for Seagen. In what’s known as a “second request,” the FTC in July asked for more information about the deal. Elsewhere, the European Commission has set Oct. 19 as the decision date for its antitrust review.