Amgen to buy Horizon for nearly $28 billion

Amgen has agreed to buy Horizon Therapeutics, a Dublin-based biotech specializing in medicines for rare, autoimmune, and severe inflammatory diseases, for about $27.8 billion in cash. The deal has the highest price tag of any pharmaceutical industry merger this year. Prior to the agreement, Horizon had also been in talks with Sanofi and Johnson & Johnson.

“The acquisition builds on Amgen’s success in rare diseases, and provides a strong platform for us to expand in this space in the future,” Amgen CEO Robert A. Bradway said on a Dec. 12 conference call with stock analysts.

Amgen, which markets blockbuster medicines like Otezla for plaque psoriasis and Aimovig for migraines, will receive Horizon’s Tepezza and Uplizna, both monoclonal antibodies, and Krystexxa, an enzyme. Those three drugs, all for rare diseases, garnered $2 billion in sales in the first 9 months of 2022, Bradway said.

Horizon also has several candidates in the clinic for various indications. David Reese, executive vice president of R&D at Amgen, highlighted several programs from Horizon’s pipeline in the conference call, including two monoclonal antibodies, a fusion protein, and a receptor antagonist. Three of those are in Phase 2 trials, while one is in Phase 1. “Amgen has the scale, expertise, and resources to advance the company’s pipeline molecules with speed and to support global registration and commercialization,” Reese said.

Stock analysts at SVB Securities, in a note to clients on the deal, say the purchase will bring Amgen new products that help it offset the impact of drug patent expirations that loom mid-decade. Among the molecules in Horizon’s pipeline, SVB highlights the fusion protein dazodalibep. It treats the immune system disease Sjögren’s syndrome and could have a $4 billion market, the note says.

The acquisition follows several other big pharma buys of smaller companies focused on rare disease, including Novo Nordisk’s purchase of Forma Therapeutics, announced in September, for $1.1 billion; Merck & Co.’s acquisition of Acceleron Pharma, announced in late 2021, for $11.5 billion, and AstraZeneca’s 2021 purchase of Alexion Pharmaceuticals for $39 billion.

Amgen also announced in August that it would acquire ChemoCentryx, a firm specializing in drugs for autoimmune diseases, inflammatory disorders, and cancer, for roughly $3.7 billion.