[Form 4] Summit Therapeutics Inc. Insider Trading Activity

Rhea-AI Filing Summary

Summit Therapeutics (SMMT) Co‑Chief Executive Officer and director Mahkam Zanganeh, a 10% owner, reported multiple share purchases dated 10/21/2025 tied to a private placement at $18.74 per share. Reported acquisitions include 266,808 shares by the Mahkam Zanganeh Revocable Trust, 26,680 shares for an immediate family member, and 13,980,789 shares by her spouse. The filing notes the transaction was pursuant to a definitive agreement and is anticipated to close on or about October 23, 2025. The report includes a standard disclaimer of beneficial ownership for certain indirect holdings.

Insights

Securities lawyer

Insider reports private placement purchases at $18.74; neutral.

The reporting person, a director, co‑CEO, and 10% owner of Summit Therapeutics, disclosed multiple acquisitions dated 10/21/2025 at $18.74 per share via a private placement under a definitive agreement. Portions were allocated to a revocable trust, an immediate family member, and the spouse.

The disclosure includes a customary disclaimer that indirect holdings are reported without admitting beneficial ownership beyond any pecuniary interest. The filing states the transaction is anticipated to close on or about October 23, 2025.

Because this is a Form 4 reporting insider purchases linked to a private placement, it is administrative in nature. Actual market impact depends on closing and any subsequent filings that detail settlement and ownership updates.

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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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^*

Zanganeh Mahkam

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

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 her 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/ Mahkam Zanganeh	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’s Co-CEO report on Form 4?

Mahkam Zanganeh reported acquisitions of common stock dated 10/21/2025 in a private placement at $18.74 per share.

How many SMMT shares were reported as acquired by related parties?

Reported amounts include 266,808 shares by a revocable trust, 26,680 by an immediate family member, and 13,980,789 by her spouse.

What price per share was disclosed for the SMMT private placement?

The purchase price disclosed was $18.74 per share.

When is the private placement expected to close?

The transaction is anticipated to close on or about October 23, 2025.

Does the Form 4 include a beneficial ownership disclaimer?

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

What roles does Mahkam Zanganeh hold at SMMT?

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