STOCK TITAN

Summit Therapeutics (SMMT) Co-CEO Robert Duggan buys 3.81M shares in open market

Filing Impact
(Very High)
Filing Sentiment
(Very Positive)
Form Type
4

Rhea-AI Filing Summary

Summit Therapeutics Inc. Co-Chief Executive Officer and director Robert W. Duggan reported an open-market purchase of 3,810,000 shares of common stock at $13.12 per share. After this transaction, he directly holds 573,883,879 shares of Summit Therapeutics common stock.

The filing also lists indirect holdings attributed to entities and individuals related to him, including 10,199,776 shares held by the Shaun Zanganeh Irrevocable Trust, 25,824,474 shares held by the Mahkam Zanganeh Revocable Trust, 31,000 shares held by his spouse, and 76,680 shares held by an immediate family member of his spouse. He disclaims beneficial ownership of these indirect holdings except to the extent of any pecuniary interest.

Positive

  • None.

Negative

  • None.
Insider DUGGAN ROBERT W
Role Co-Chief Executive Officer
Bought 3,810,000 shs ($49.99M)
Type Security Shares Price Value
Purchase Common Stock 3,810,000 $13.12 $49.99M
holding Common Stock -- -- --
holding Common Stock -- -- --
holding Common Stock -- -- --
holding Common Stock -- -- --
Holdings After Transaction: Common Stock — 573,883,879 shares (Direct, null); Common Stock — 25,824,474 shares (Indirect, By the Mahkam Zanganeh Revocable Trust, with the Spouse of Reporting Person as Trustee)
Footnotes (1)
  1. [object Object]
Shares purchased 3,810,000 shares Open-market purchase of Summit Therapeutics common stock
Purchase price $13.12 per share Price paid for 3,810,000 common shares
Direct holdings after transaction 573,883,879 shares Common stock directly held following the reported purchase
Shaun Zanganeh Irrevocable Trust holdings 10,199,776 shares Indirect holdings related to reporting person
Mahkam Zanganeh Revocable Trust holdings 25,824,474 shares Indirect holdings related to reporting person
Spouse holdings 31,000 shares Indirect holdings by spouse of reporting person
Immediate family member holdings 76,680 shares Indirect holdings by immediate family member of spouse
open-market purchase financial
"transaction_action":"open-market purchase""
An open-market purchase is when an investor or a company buys shares on a public stock exchange at the going market price, rather than through a private deal. It matters to investors because these purchases change how many shares are available, can push the stock price up or signal confidence from large buyers, and often affect per-share metrics like earnings—think of it like someone buying lots of apples off a grocery shelf, reducing supply and potentially raising the price.
beneficial ownership financial
"The Reporting Person disclaims beneficial ownership of these securities"
Beneficial ownership means the person or entity that actually enjoys the benefits of owning shares or other assets — such as receiving dividends, voting rights, or price gains — even if the legal title is held in another name. For investors it matters because knowing who truly controls and profits from a company reveals who can influence decisions, exposes potential conflicts of interest or hidden concentration of power, and affects transparency and risk in the stock.
pecuniary interest financial
"except to the extent of his pecuniary interest therein, if any"
Section 16 regulatory
"for purposes of Section 16 or for any other purpose"
Section 16 is a U.S. securities law rule that governs the trading and disclosure obligations of company insiders — typically officers, directors and large shareholders — to promote transparency and deter unfair profit-taking. It requires insiders to publicly report their stock trades and allows companies or the issuer to reclaim quick, short-term profits from certain insider trades, like a scoreboard and a refund policy that help investors see and limit possible insider advantage.
indirect ownership financial
""ownership_type": "indirect", "ownership_code": "I""
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SEC Form 4
FORM 4UNITED 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
Estimated average burden
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 FLORIDA 33131

(City)(State)(Zip)

UNITED STATES

(Country)
2. Issuer Name and Ticker or Trading Symbol
Summit Therapeutics Inc. [ SMMT ]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
XDirectorX10% Owner
XOfficer (give title below)Other (specify below)
Co-Chief Executive Officer
2a. Foreign Trading Symbol
3. Date of Earliest Transaction (Month/Day/Year)
06/12/2026
6. Individual or Joint/Group Filing (Check Applicable Line)
XForm filed by One Reporting Person
Form filed by More than One Reporting Person
4. If Amendment, Date of Original Filed (Month/Day/Year)

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)
CodeVAmount(A) or (D)Price
Common Stock06/12/2026P3,810,000A$13.12573,883,879D
Common Stock25,824,474(1)IBy the Mahkam Zanganeh Revocable Trust, with the Spouse of Reporting Person as Trustee
Common Stock76,680(1)IImmediate family member of Spouse
Common Stock31,000(1)IBy Spouse
Common Stock10,199,776(1)IBy 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)
CodeV(A)(D)Date ExercisableExpiration DateTitleAmount or Number of Shares
Explanation of Responses:
1. 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. Duggan06/12/2026
** Signature of Reporting PersonDate
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.
* Form 4: SEC 1474 (03-26)

FAQ

What insider transaction did Summit Therapeutics (SMMT) report for Robert W. Duggan?

Summit Therapeutics reported that Robert W. Duggan completed an open-market purchase of 3,810,000 shares of common stock at $13.12 per share. This filing reflects a significant direct addition to his equity position in the company.

How many Summit Therapeutics (SMMT) shares does Robert W. Duggan hold after the latest Form 4?

After the reported transaction, Robert W. Duggan directly holds 573,883,879 shares of Summit Therapeutics common stock. The Form 4 also discloses additional indirect holdings through trusts, his spouse, and an immediate family member of his spouse.

At what price did Robert W. Duggan buy Summit Therapeutics (SMMT) shares?

Robert W. Duggan purchased 3,810,000 Summit Therapeutics common shares at a price of $13.12 per share. The transaction is classified as an open-market purchase under the Form 4 insider trading code for non-derivative securities.

Does Robert W. Duggan disclaim beneficial ownership of some Summit Therapeutics (SMMT) shares?

Yes. The filing states he disclaims beneficial ownership of the indirectly held securities, except to the extent of his pecuniary interest, if any. This means he does not concede full beneficial ownership of those indirect positions for Section 16 or other purposes.