GSK’s $2.2 Billion Acquisition of RAPT Therapeutics Faces Legal Scrutiny

RAPT Therapeutics US75382E1091

The proposed acquisition of biopharmaceutical firm RAPT Therapeutics by industry giant GSK is now entering a phase of detailed legal examination. Although the $2.2 billion deal promises shareholders a substantial premium, several law firms have initiated investigations into the circumstances surrounding the agreement. This scrutiny centers on whether the offered price truly represents fair value for the company's promising clinical assets.

British pharmaceutical leader GSK announced its intention to acquire RAPT Therapeutics on January 20. The all-cash offer of $58.00 per share aims to grant GSK full access to RAPT's portfolio of oral therapies designed for inflammatory and immunological diseases. The crown jewel of this portfolio is the drug candidate ozureprubart.

• Acquisition Price: $58.00 per share in cash
• Total Enterprise Value: Approximately $2.2 billion
• Acquiring Entity: GSK plc
• Key Asset: Ozureprubart (currently in Phase 2b trials for food allergies)
• Institutional Ownership: Around 99%
• Expected Closing: First quarter of 2026

Ozureprubart is undergoing Phase 2b clinical trials for the prevention of allergic reactions to common foods such as peanuts, milk, and eggs. GSK anticipates a competitive advantage from this asset, as its mechanism of action could potentially allow for less frequent dosing compared to existing treatments. This feature is seen as a significant factor in improving patient adherence to therapy.

Shareholder Fairness Under Review

Despite the agreement between the companies' leadership, legal challenges have emerged. Firms including Kahn Swick & Foti launched formal inquiries last Thursday. These investigations are assessing whether RAPT Therapeutics' board of directors fulfilled its fiduciary duties to shareholders during the sale process.

A core question is if the $58-per-share bid adequately reflects the long-term potential value of RAPT's clinical pipeline or if the negotiation process was flawed. While such legal reviews are a common feature of large-scale mergers and acquisitions in the United States, they represent a formal procedural hurdle that must be cleared for the tender offer to proceed.

Market Reaction and Procedural Timeline

The market responded positively to January's announcement, with RAPT's share price surging to a new 12-month high. The deal appears to have strong backing from sophisticated investors, as current ownership data reveals that hedge funds and institutional investors collectively hold nearly 99% of the company's outstanding shares.

Completion of the transaction, targeted for Q1 2026, remains contingent on two key conditions. A majority of RAPT's shareholders must tender their shares, and the necessary regulatory approvals must be secured. A critical administrative milestone will be the expiration of the mandatory waiting period stipulated by the Hart-Scott-Rodino Antitrust Improvements Act.