8-K: RAPT Therapeutics Acquired by GSK Subsidiary for $58/Share

RAPT Therapeutics, Inc. has completed its merger with GlaxoSmithKline LLC's subsidiary, Redrose Acquisition Co., becoming a wholly-owned entity.

Summary

• RAPT Therapeutics, Inc. completed its merger with Redrose Acquisition Co., a wholly-owned subsidiary of GlaxoSmithKline LLC, on March 3, 2026.
• The tender offer, which expired on March 2, 2026, resulted in approximately 30,137,567 shares, or 93.36% of outstanding shares, being validly tendered and not withdrawn.
• Purchaser accepted all tendered shares for payment at the offer price of $58.00 per share in cash.
• The merger was effected pursuant to Section 251(h) of the Delaware General Corporation Law, without a vote of RAPT Therapeutics' stockholders.
• RAPT Therapeutics, Inc. is now a direct wholly-owned subsidiary of GlaxoSmithKline LLC and will continue under the same name.
• All outstanding shares not tendered in the offer (excluding certain exceptions) were converted into the right to receive the $58.00 per share merger consideration.
• Outstanding stock options (excluding 2025 Options) and restricted stock units (excluding 2025 RSUs) were automatically accelerated, vested, and converted into cash payments based on the merger consideration.
• 2025 Options and 2025 RSUs were converted into cash amounts subject to their original vesting terms, with 50% vesting on the closing date and 50% vesting on the earlier of nine months post-closing or an involuntary termination.
• Outstanding warrants were automatically converted into cash based on the excess of the merger consideration over their exercise price.

Sentiment

Score: 6

Explanation: StockSavvy.ai views this as a neutral to slightly positive event. While it marks the end of RAPT Therapeutics as an independent public entity, the completion of the merger at the agreed-upon price provides a definitive positive outcome for shareholders who tendered their shares.

Positives

• Shareholders who tendered their shares received a cash payment of $58.00 per share, representing a premium.
• The acquisition provides a clear exit strategy and liquidity for RAPT Therapeutics' public shareholders.
• Employees with equity awards (options, RSUs) received cash consideration, with specific vesting terms for recent grants ensuring retention incentives.

Negatives

• RAPT Therapeutics' common stock has been delisted from The Nasdaq Stock Market LLC, removing its public trading status.
• The company intends to terminate its registration under the Exchange Act, suspending its public reporting obligations.
• Existing shareholders no longer have an equity stake in the company or the potential for future capital appreciation as a standalone public entity.

Future Outlook

RAPT Therapeutics, Inc. is now a wholly-owned subsidiary of GlaxoSmithKline LLC and will no longer operate as an independent publicly traded company. Its future operations and strategic direction will be determined by its new parent company.

Industry Context

StockSavvy.ai notes that this acquisition reflects a continuing trend of consolidation within the biotechnology and pharmaceutical sectors, where larger pharmaceutical companies acquire innovative smaller biotechs to bolster their pipelines and intellectual property. GSK's acquisition of RAPT Therapeutics, a clinical-stage immunology company, aligns with strategies to expand therapeutic areas and leverage promising drug candidates.

Comparison to Industry Standards

• The acquisition price of $58.00 per share represents a significant premium over RAPT Therapeutics' pre-announcement trading price, which is common in strategic acquisitions within the biotech sector, often reflecting the value of pipeline assets and intellectual property.
• The high percentage of shares tendered (93.36%) indicates strong shareholder acceptance of the offer, consistent with successful tender offers where the offer price is deemed attractive.
• The use of a Section 251(h) merger, which bypasses a shareholder vote after a successful tender offer, is a standard and efficient mechanism for completing such transactions in Delaware-incorporated companies, similar to other recent biotech acquisitions like Pfizer's acquisition of Seagen or AbbVie's acquisition of ImmunoGen.

Management Changes

Corporate Governance

Stakeholder Impact

• Shareholders: Received $58.00 per share in cash for their tendered shares, providing immediate liquidity and a return on investment.
• Employees: Those with outstanding equity awards (options, RSUs) received cash consideration, with specific vesting schedules for recent grants to ensure continuity and retention.
• Customers/Suppliers: No direct impact mentioned, but the change in ownership may lead to integration with GSK's broader operations.
• Creditors: No specific impact mentioned, but the company's financial backing is now part of GSK's larger corporate structure.

Next Steps

• The Company will file a Form 25 Notification of Removal from Listing and/or Registration with the SEC to delist and deregister its shares under Section 12(b) of the Exchange Act.
• The Company intends to file a Form 15 with the SEC to terminate registration of its shares under Section 12(g) and suspend its reporting obligations under Sections 13 and 15(d) of the Exchange Act.

Key Dates

Keywords

RAPT Therapeutics, GlaxoSmithKline, GSK, Merger, Acquisition, Tender Offer, Delisting, Biotechnology, Pharmaceuticals, Corporate Governance