CHICAGO, Illinois: AbbVie will acquire Apogee Therapeutics for $10.9 billion, gaining an experimental treatment for inflammatory diseases as it looks to reinforce its immunology business ahead of future patent expirations.

The deal, announced on June 22, is AbbVie's largest acquisition in more than five years and one of the biggest biotechnology transactions of the year.

AbbVie will pay US$135.11 for each Apogee share, representing a 49.49 percent premium to Apogee's closing price on June 18. The company said it would fund the acquisition through debt.

Shares of Waltham, Massachusetts-based Apogee rose 50 percent in early trading, while AbbVie shares gained 4.6 percent.

The acquisition gives AbbVie access to Apogee's lead drug candidate, zumilokibart, an experimental treatment being developed for inflammatory diseases, including atopic dermatitis and asthma.

If approved, the drug could strengthen AbbVie's position in immunology, its largest business and a central driver of growth following the decline in sales of its former blockbuster drug Humira.

AbbVie's immunology franchise generated more than $30 billion in revenue in 2025, up 14 percent from the previous year. Growth in Skyrizi and Rinvoq helped offset a 49 percent fall in Humira sales as biosimilar competition intensified.

The company is also preparing for the eventual patent expirations of Skyrizi and Rinvoq, making late-stage drug assets an important part of its strategy.

AbbVie Chief Executive Robert Michael called the acquisition an "excellent fit" with the company's strategy and said Apogee's pipeline could generate "mega-blockbuster" peak sales. AbbVie defines a mega-blockbuster as a treatment with annual sales exceeding $10 billion.

Zumilokibart could offer a more convenient alternative to Sanofi and Regeneron's blockbuster Dupixent, analysts said.

Dupixent is typically given every two weeks for atopic dermatitis. Zumilokibart is being studied as a subcutaneous injection administered every 3 or 6 months, potentially reducing treatment frequency.

"We believe the deal makes sense and that AbbVie is an ideal acquirer to maximize zumilokibart's potential," RBC Capital Markets analyst Brian Abrahams said.

J.P. Morgan analyst Chris Schott said the deal was likely to be welcomed by investors seeking more late-stage growth assets.

AbbVie has increasingly relied on acquisitions to strengthen its pipeline. Its recent transactions include the $10.1 billion purchase of ImmunoGen, which brought ovarian cancer treatment Elahere, and the acquisition of Cerevel Therapeutics, which was developing treatments for neurological and psychiatric disorders.

AbbVie said the Apogee transaction is expected to close in the third quarter and add to adjusted earnings per share in 2032.