EXPLANATORY NOTE
This Amendment No. 2 (this “Amendment”) amends and supplements the Solicitation/Recommendation Statement on Schedule 14D-9 previously filed with the U.S. Securities and Exchange Commission (the “SEC”) on February 2, 2026 (together with the exhibits thereto and as amended or supplemented from time to time, the
“Schedule 14D-9”) by RAPT Therapeutics, Inc., a Delaware corporation (the “Company”). The Schedule 14D-9 relates to the tender offer by Redrose
Acquisition Co., a Delaware corporation (“Purchaser”), a direct wholly-owned subsidiary of GlaxoSmithKline LLC, a limited liability company organized under the laws of Delaware (“Parent”), which is an indirect wholly-owned
subsidiary of GSK plc, a public limited company organized under the laws of England and Wales (“Ultimate Parent”), to purchase all of the issued and outstanding shares (the “Shares”) of the Company Common Stock in exchange
for $58.00 per Share, net to the stockholder in cash, without interest (the “Offer Price”) and less any applicable tax withholding, upon the terms and subject to the conditions set forth in the Offer to Purchase, dated as of
February 2, 2026 (the “Offer to Purchase”), and in the related Letter of Transmittal (which, together with the Offer to Purchase, as each may be amended or supplemented from time to time, collectively constitute the
“Offer”). The Offer is described in a Tender Offer Statement (the “Schedule TO”) filed jointly by Ultimate Parent, Parent and Purchaser with the SEC on February 2, 2026.
Capitalized terms used but not otherwise defined in this Amendment have the meanings ascribed to them in the Schedule 14D-9. The information in the Schedule 14D-9 is incorporated into this Amendment by reference to all applicable items in the Schedule
14D-9, except that such information is hereby amended and supplemented to the extent specifically provided herein.
Item 8. Additional Information.
Item 8 “Additional Information” of the Schedule 14D-9 is hereby amended and supplemented by
adding a new section titled “Final Results of the Offer and Completion of the Merger” immediately before the section entitled “Item 8. Additional Information — Cautionary Note Regarding Forward-Looking
Statements” on page 47 as follows:
“Final Results of the Offer and Completion of the Merger
The Offer and related withdrawal rights expired, as scheduled, at one minute past 11:59 P.M., Eastern Time, on March 2, 2026 (such date
and time, the “Expiration Time”), and was not extended. Purchaser was advised by Citibank N.A., which is the depository and paying agent for the Offer, that, as of the Expiration Time, a total of 30,137,567 Shares had been validly
tendered and not validly withdrawn pursuant to the Offer, representing approximately 93.36% of the issued and outstanding Shares as of the Expiration Time. Accordingly, the Minimum Condition has been satisfied.
All conditions to the Offer having been satisfied, Purchaser accepted for payment, and will cause the Depository to pay, as promptly as
practicable, for all Shares validly tendered and not validly withdrawn pursuant to the Offer.
The Company expects that on March 3,
2026, Parent will complete its acquisition of the Company through the Merger of Purchaser with and into the Company, without a vote of the Company’s stockholders and in accordance with Section 251(h) of the DGCL and the terms of, the
Merger Agreement, with the Company continuing as the surviving corporation and becoming a direct wholly owned subsidiary of Parent.
Following the consummation of the Merger, the Shares will be delisted and will cease to trade on the Global Select Stock Market. Parent and
Purchaser intend to take steps to cause the termination of the registration of the Shares under the Exchange Act and suspend all of the Company’s reporting obligations under the Exchange Act as promptly as practicable.”
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