[Form 4] Summit Therapeutics Inc. Insider Trading Activity

Rhea-AI Filing Summary

Summit Therapeutics (SMMT) Co‑CEO, director, and 10% owner Robert W. Duggan reported acquisitions of common stock. He acquired 13,980,789 shares at $18.74 in a private placement pursuant to a definitive agreement dated October 21, 2025, anticipated to close on or about October 23, 2025. He also acquired 266,808 shares indirectly at $18.74 and purchased 26,680 shares at $18.74.

Following these transactions, he beneficially owned 570,073,879 shares directly and 25,724,474 shares indirectly via a trust, with additional indirect holdings of 76,680, 31,000, and 10,199,776 shares through family and related trusts.

Insights

Equity Financing & Governance Analyst

Large insider-led share acquisition via private placement; capital inflow with dilution and ownership concentration considerations.

The reporting person, a Director, 10% Owner, and Co‑Chief Executive Officer of Summit Therapeutics Inc. (SMMT), reported acquiring 13,980,789 shares of common stock at $18.74 per share on 10/21/2025 via a private placement. Additional acquisitions include 266,808 shares at $18.74 through a revocable trust and a separate purchase of 26,680 shares at $18.74 by an immediate family member of the spouse. The filing notes the private placement is anticipated to close on or about 10/23/2025.

Following these transactions, directly held common stock is reported at 570,073,879 shares, with additional indirect holdings disclosed across several trusts and family accounts. The filer disclaims beneficial ownership of certain indirect holdings except to the extent of pecuniary interest. These acquisitions indicate new shares issued to the insider and related parties at a stated price, which implies equity issuance and ownership concentration effects.

Key items to watch are the consummation of the private placement on or about 10/23/2025, any accompanying disclosure of aggregate financing size, and subsequent updates to ownership and governance. Also monitor any future filings clarifying total shares issued and any related agreements tied to this placement.

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

OMB APPROVAL

OMB Number:			3235-0287
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hours per response:			0.5

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^*

DUGGAN ROBERT W

(Last) (First) (Middle)

C/O SUMMIT THERAPEUTICS INC.

601 BRICKELL KEY DRIVE SUITE 1000

(Street)

MIAMI FL 33131

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Summit Therapeutics Inc. [ SMMT ]

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

X	Director	X	10% Owner
X	Officer (give title below)		Other (specify below)
	Co-Chief Executive Officer

3. Date of Earliest Transaction (Month/Day/Year)
10/21/2025

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	10/21/2025		A		13,980,789(1)	A	$18.74	570,073,879	D
Common Stock	10/21/2025		A		266,808(1)	A	$18.74	25,724,474(2)	I	By the Mahkam Zanganeh Revocable Trust, with the Spouse of Reporting Person as Trustee
Common Stock	10/21/2025		P		26,680(1)	A	$18.74	76,680(2)	I	Immediate family member of Spouse
Common Stock								31,000(2)	I	By Spouse
Common Stock								10,199,776(2)	I	By the Shaun Zanganeh Irrevocable Trust, with the Spouse of Reporting Person as Trustee

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

Explanation of Responses:

1. Acquired in a private placement transaction pursuant to the terms of a definitive agreement, dated as of October 21, 2025, pursuant to which the Issuer agreed to sell shares of common stock to the Reporting Person and certain other parties at a purchase price of $18.74 per share. The transaction is anticipated to close on or about October 23, 2025.

2. The Reporting Person disclaims beneficial ownership of these securities, except to the extent of his pecuniary interest therein, if any, and the inclusion of these securities in this report shall not be deemed an admission of beneficial ownership of all of the reported securities for purposes of Section 16 or for any other purpose.

Remarks:

	/s/ Robert W. Duggan	10/23/2025
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What did SMMT insider Robert W. Duggan report on Form 4?

He acquired 13,980,789 shares at $18.74 in a private placement dated October 21, 2025, with closing anticipated on or about October 23, 2025.

Were there additional SMMT share purchases by Robert W. Duggan?

Yes. He acquired 266,808 shares indirectly at $18.74 and purchased 26,680 shares at $18.74.

How many SMMT shares does Robert W. Duggan own after these transactions?

He beneficially owned 570,073,879 shares directly and 25,724,474 shares indirectly via a trust, plus other indirect holdings of 76,680, 31,000, and 10,199,776 shares.

What is the price per share for the private placement reported by SMMT?

The reported purchase price was $18.74 per share.

What roles does Robert W. Duggan hold at Summit Therapeutics (SMMT)?

He is Co‑Chief Executive Officer, a Director, and a 10% Owner.

Does the filing note any disclaimer about indirect holdings?

Yes. It states the reporting person disclaims beneficial ownership of certain securities except to the extent of any pecuniary interest.