GlaxoSmithKline plc Sponsored ADR (GSK.US) acquired RAPT Therapeutics (RAPT.US) for a valuation of $2.2 billion, causing a significant increase in pre-market trading.

British pharmaceutical giant GlaxoSmithKline plc Sponsored ADR (GSK.US) has agreed to acquire RAPT Therapeutics (RAPT.US), a US-based biotechnology company focused on developing therapies for patients with inflammatory and immune system diseases. The deal is valued at $2.2 billion. Before the US stock market opened on Tuesday, RAPT Therapeutics (RAPT) saw its stock price rise by nearly 64% to $57.40. Under the terms of the agreement, GlaxoSmithKline plc Sponsored ADR will pay RAPT Therapeutics shareholders $58.00 per share at the close of the transaction, with an estimated total equity value of $2.2 billion. After deducting the cash acquisition, GSK's expected initial investment is $1.9 billion. GlaxoSmithKline plc Sponsored ADR's subsidiary is obligated to initiate a tender offer within 10 working days after the agreement is signed, to acquire all of RAPT's outstanding common shares for $58.00 cash per share. The transaction is expected to be completed in the first quarter of 2026. GlaxoSmithKline plc Sponsored ADR will account for this transaction as a business combination. The acquisition includes ozureprubart, a long-acting monoclonal antibody against IgE, currently in phase IIb clinical development for preventative protection against food allergens. GlaxoSmithKline plc Sponsored ADR will have global rights to the ozureprubart project (excluding mainland China, Taiwan, Macau, and Hong Kong). Additionally, GlaxoSmithKline plc Sponsored ADR will be responsible for paying milestone payments and licensing fees to RAPT's partner, Shanghai Jeyou Pharmaceutical Co., based on the successful development of ozureprubart. Chief Scientific Officer of GlaxoSmithKline plc Sponsored ADR, Tony Wood, said: "The addition of ozureprubart brings a highly promising and 'best-in-class' new therapy to GSK's R&D pipeline. Food allergies have a serious impact on patient health, with current treatments requiring injections every 2 weeks. Ozureprubart has the potential to provide lasting protection to patients with dosing every 12 weeks, aligning with our strategy of acquiring assets targeting validated targets with clear unmet medical needs."