GSK to acquire US-based biopharma company RAPT Therapeutics via a $2.2 billion deal — Details here

According to the official announcement, UK-based GSK Plc announced on Tuesday, January 20, 2026 that the firm has signed a definitive agreement to potentially acquire US-based biopharmaceutical company RAPT Therapeutics through a deal valued at $2.2 billion in equity value.

The filing showed that the British biopharma company’s acquisition moves come at a time when RAPT Therapeutics is focused on developing new treatments for patients living with inflammatory and immunological diseases.

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“GSK Plc today announced that it has entered into a definitive agreement to acquire RAPT Therapeutics, a California-based, clinical-stage biopharmaceutical company dedicated to developing new treatments for patients living with inflammatory and immunological diseases,” according to the press release.

The acquisition is expected to be completed by the end of the first quarter of calendar year 2026, according to the company.

Acquisition details

According to deal details, GSK plans to pay shareholders $58 over the closing price, for an estimated total equity value of $2.2 billion. The company also announced that the upfront investment in the acquisition agreement will be $1.9 billion.

Following the acquisition of GSK, the company will acquire global rights to RAPT Therapeutics’ ozureprubart program, excluding rights in Mainland China, Macau, Taiwan and Hong Kong.

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“GSK will also be responsible for achievement-based milestone and royalty payments for ozureprubart owed to RAPT’s partner Shanghai Jeyou Pharmaceutical Co., Ltd,” the company said.

GSK’s subsidiary will submit a tender offer to purchase all outstanding shares of RAPT common stock for $58 per share in cash within 10 business days of signing.

Evercore is the financial advisor to the offering, while A&O Shearman is serving as legal counsel to GSK. JP Morgan Securities LLC and Cooley LLP are financial advisor and legal advisor, respectively, to RAPT Therapeutics.

“The addition of Ozureprubart brings a promising new, potentially best-in-class treatment to GSK’s product range. Food allergies cause serious health effects in patients with existing treatments requiring injections every 2 weeks. Ozureprubart offers the opportunity to provide ongoing protection to patients with dosing every 12 weeks and is consistent with our approach to acquiring assets against validated targets and where there are clear unmet medical needs,” said GSK Chief Scientific Officer Tony Wood.

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stock movement

GSK shares on the London Stock Exchange traded at 1,798.50p (British Pence) in Tuesday’s stock exchange session, down 0.96% from 1,816.00p at the previous market close, according to MarketWatch data.

GSK shares have given UK investors a return of over 28% on their investment over the last five years and over 32% over the last one-year period.

However, on Wall Street, shares of RAPT Therapeutics rose over 63% to $57.41 in the pre-market trading session on Nasdaq following the acquisition update, compared to $35.10 at the previous market close.

While the shares of the US-based biopharma company increased by 265% in the last one-year period, they lost over 79% in the last five years.

Read all stories written by Anubhav Mukherjee

Disclaimer: This story is for educational purposes only. Because market conditions and conditions can change rapidly, we recommend that investors consult certified professionals before making any investment decisions.