RAPT Therapeutics (RAPT) CEO disposes equity in $58-per-share sale

Rhea-AI Filing Summary

Wong Brian Russell reported disposition transactions in this Form 4 filing.

RAPT Therapeutics President and CEO Brian Russell Wong reported multiple equity disposals tied to the company’s sale to GlaxoSmithKline. On March 3, 2026, his common shares were tendered for $58.00 per share in cash under a completed tender offer and merger.

Employee stock options were adjusted for a prior 1-for-8 reverse stock split and, at the merger’s effective time, became fully vested. Options with exercise prices below $58.00 were cancelled and converted into rights to receive cash based on the spread between the offer price and each option’s exercise price.

Certain unvested options granted after March 1, 2025 were instead converted into cash-based awards of the acquirer, with payments scheduled 50% at closing and 50% nine months later, subject to continued service and accelerated payout upon qualifying involuntary termination.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

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X

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Wong Brian Russell

(Last) (First) (Middle)

C/O RAPT THERAPEUTICS, INC.

561 ECCLES AVENUE

(Street)

SOUTH SAN FRANCISCO CA 94080

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
RAPT Therapeutics, Inc. [ RAPT ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	PRESIDENT AND CEO

3. Date of Earliest Transaction (Month/Day/Year)
03/03/2026

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	03/03/2026		U(1)(2)		64,102(3)	D	(4)	0	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Employee Stock Option (right to buy)(5)	$49.44	03/03/2026		D(1)(2)			25,000	(6)	(6)	Common Stock	25,000	(6)	0	D
Employee Stock Option (right to buy)(5)	$50.4	03/03/2026		D(1)(2)			8,334	(6)	(6)	Common Stock	8,334	(6)	0	D
Employee Stock Option (right to buy)(5)	$12.56	03/03/2026		D(1)(2)			10,417	(6)	(6)	Common Stock	10,417	(6)	0	D
Employee Stock Option (right to buy)(5)	$12.56	03/03/2026		D(1)(2)			7,500	(6)	(6)	Common Stock	7,500	(6)	0	D
Employee Stock Option (right to buy)(5)	$12.56	03/03/2026		D(1)(2)			18,750	(6)	(6)	Common Stock	18,750	(6)	0	D
Employee Stock Option (right to buy)(5)	$12.56	03/03/2026		D(1)(2)			37,500	(6)	(6)	Common Stock	37,500	(6)	0	D
Employee Stock Option (right to buy)(5)	$12.56	03/03/2026		D(1)(2)			31,250	(6)	(6)	Common Stock	31,250	(6)	0	D
Employee Stock Option (right to buy)(5)	$12.56	03/03/2026		D(1)(2)			34,375	(6)	(6)	Common Stock	34,375	(6)	0	D
Employee Stock Option (right to buy)(5)	$9.12	03/03/2026		D(1)(2)			218,250	(6)	(6)	Common Stock	218,250	(6)	0	D
Employee Stock Option (right to buy)	$7.43	03/03/2026		D(1)(2)			371,875	(7)(8)	(7)(8)	Common Stock	371,875	(7)(8)	265,625	D

Explanation of Responses:

1. The Issuer entered into an Agreement and Plan of Merger, dated January 19, 2026 (the "Merger Agreement") with GlaxoSmithKline LLC, a Delaware limited liability company ("Parent"), Redrose Acquisition Co., a Delaware corporation and a wholly owned subsidiary of Parent ("Purchaser") and solely for purposes of providing a guaranty pursuant to Section 8.11 of the Merger Agreement, GSK plc, a public limited company organized under the laws of England and Wales. Pursuant to the Merger Agreement, Purchaser completed a tender offer to acquire all of the issued and outstanding shares of common stock of the Issuer, for $58.00 per share (the "Offer Price"), in cash, without interest and subject to any applicable withholding of taxes. On March 3, 2026, Purchaser merged with and into the Issuer, with the Issuer surviving as an indirect wholly owned subsidiary of Parent (the effective time of such merger, the "Effective Time").

2. This Form 4 reports securities transacted pursuant to the Merger Agreement.

3. The number of shares was adjusted to reflect the 1-for-8 reverse stock split effected by the Issuer on June 16, 2025.

4. Pursuant to the terms of the Merger Agreement, at the Effective Time, each share of common stock held by the Reporting Person was tendered in exchange for the Offer Price.

5. The number of shares underlying this option and the exercise price were adjusted to reflect the 1-for-8 reverse stock split effected by the Issuer on June 16, 2025.

6. Pursuant to the terms of the Merger Agreement, each stock option that was outstanding as of immediately prior to the Effective Time, whether vested or unvested, was accelerated and became fully vested and exercisable as of immediately prior to the Effective Time. At the Effective Time, each stock option that was outstanding and unexercised as of immediately before the Effective Time and which had a per share exercise price that was less than Offer Price was cancelled and converted solely into the right to receive cash in an amount equal to the product of (i) the total number of shares subject to such stock option immediately prior to the Effective Time, multiplied by (ii) the excess of (x) the Offer Price, over (y) the exercise price payable per share under such stock option.

7. Pursuant to the terms of the Merger Agreement, each stock option that is unvested as of immediately prior to the Effective Time and was granted after March 1, 2025 (a "2025 Option") was cancelled and converted into a cash-based award of Parent (a "Converted Option"), which shall entitle the holder thereof to receive an amount in cash equal to the Option Consideration (the "Converted Option Consideration").

8. Each Converted Option (and the right to receive the Converted Option Consideration) shall be subject to the same terms and conditions (including vesting, forfeiture and acceleration provisions) that were applicable to the corresponding 2025 Option immediately prior to the Effective Time; provided, that (i) the Converted Option Consideration shall vest and become payable 50% upon the date that closing occurs pursuant to the Merger Agreement (the "Closing Date") and 50% upon the date that is nine months following the Closing Date and (ii) in the event that the holder of a Converted Option experiences an Involuntary Termination (as defined in the Merger Agreement) following the Closing Date but prior to the date that is nine months following the Closing Date, such holder's Converted Option Consideration shall immediately vest and become payable without any further action on the part of Parent or any other person.

	/s/ Rodney Young, Attorney-in-Fact	03/05/2026
	** Signature of Reporting Person	Date
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FAQ

What insider transactions did RAPT (RAPT) CEO Brian Wong report?

Brian Wong reported multiple dispositions of employee stock options and common stock. The transactions reflect equity being cashed out or converted in connection with RAPT’s merger, rather than open-market buying or selling, and are tied directly to terms in the merger agreement.

What price did RAPT (RAPT) shareholders receive in the GSK tender offer?

Shareholders received $58.00 per share in cash for each RAPT common share. This offer price was paid without interest and subject to applicable tax withholding, as Purchaser completed a tender offer and subsequent merger to acquire all outstanding RAPT common stock.

How were RAPT (RAPT) employee stock options treated in the merger?

All outstanding RAPT stock options vested immediately before the merger’s effective time. Options with exercise prices below $58.00 were cancelled and converted into cash rights equal to the number of option shares multiplied by the difference between the offer price and each option’s exercise price.

What happened to unvested RAPT (RAPT) options granted after March 1, 2025?

Unvested options granted after March 1, 2025 became cash-based awards of the acquirer. These converted awards pay the option consideration 50% at closing and 50% nine months later, with accelerated vesting if the holder experiences an involuntary termination during that period.

Did RAPT (RAPT) adjust share and option counts before the merger?

Yes. RAPT adjusted share and option counts for a 1-for-8 reverse stock split effective June 16, 2025. Both the number of shares and related option exercise prices were recalculated to reflect this split before applying the merger’s cash-out and conversion mechanics.

Why does this Form 4 for RAPT (RAPT) reference a Merger Agreement?

The Form 4 reports securities transacted under a Merger Agreement with GlaxoSmithKline entities. It documents how the CEO’s common shares and stock options were tendered, cancelled for cash, or converted into new cash-based awards as part of the completed acquisition.