Form 4: RAPT CSO Sells Shares in GSK Merger Completion

RAPT Therapeutics Chief Scientific Officer Dirk G. Brockstedt disposed of common stock and stock options following the company's acquisition by GlaxoSmithKline LLC for $58.00 per share.

Summary

• RAPT Therapeutics, Inc. completed its merger with GlaxoSmithKline LLC (Parent) through its subsidiary Redrose Acquisition Co. (Purchaser) on March 3, 2026.
• Pursuant to the merger agreement, Purchaser acquired all outstanding shares of RAPT common stock for $58.00 per share in cash.
• Chief Scientific Officer Dirk G. Brockstedt disposed of 4,648 shares of common stock, which were tendered in exchange for the offer price.
• All outstanding stock options, whether vested or unvested, were accelerated and became fully vested and exercisable immediately prior to the merger's effective time.
• Stock options with an exercise price less than the $58.00 offer price were cancelled and converted into a cash payment equal to the product of the number of shares subject to the option and the difference between the offer price and the exercise price.
• Stock options with an exercise price greater than the $58.00 offer price were cancelled for no consideration.
• Certain unvested stock options granted after March 1, 2025 (2025 Options) were converted into cash-based awards of Parent (Converted Options).
• These Converted Options will vest 50% on the closing date (March 3, 2026) and 50% nine months thereafter, with accelerated vesting upon involuntary termination.
• The number of shares and option exercise prices were adjusted to reflect a 1-for-8 reverse stock split effected by RAPT Therapeutics on June 16, 2025.
• Following the transactions, Dirk G. Brockstedt beneficially owns 0 shares of common stock and 41,667 Converted Options.

Sentiment

Score: 7

Explanation: StockSavvy.ai views this as a positive outcome for RAPT Therapeutics shareholders who tendered their shares at a premium, and for in-the-money option holders whose awards were cashed out or converted into new cash-based awards with a clear vesting schedule.

Positives

• The merger completion provides RAPT Therapeutics shareholders with a cash payout of $58.00 per share.
• All outstanding stock options, whether vested or unvested, were accelerated and became fully vested and exercisable prior to the merger's effective time.
• In-the-money stock options were converted into cash payments, providing liquidity to option holders.

Negatives

• Stock options with an exercise price greater than the $58.00 offer price were cancelled for no consideration, resulting in a loss for those option holders.
• RAPT Therapeutics, Inc. ceases to be an independent publicly traded company, becoming an indirect wholly-owned subsidiary of GlaxoSmithKline LLC.

Future Outlook

The only forward-looking aspect mentioned is the vesting schedule for the Converted Options, which will vest 50% on the closing date and 50% nine months thereafter, with accelerated vesting upon involuntary termination.

Industry Context

StockSavvy.ai notes this acquisition by GlaxoSmithKline reflects ongoing consolidation in the biopharmaceutical sector, where larger pharmaceutical companies acquire smaller, innovative firms to bolster their pipelines and intellectual property portfolios.

Stakeholder Impact

• Shareholders received a cash payment of $58.00 per share for their common stock.
• Employees holding in-the-money stock options received cash payouts or converted cash-based awards, providing liquidity and continued incentive for those with 2025 Options.
• Employees holding out-of-the-money stock options had their options cancelled for no consideration.

Next Steps

• Vesting and payment of the remaining 50% of Converted Options nine months following the closing date (March 3, 2026).

Key Dates

Keywords

RAPT Therapeutics, GSK, GlaxoSmithKline, Merger, Acquisition, Tender Offer, Stock Options, Form 4, Beneficial Ownership, Dirk Brockstedt