Michel Detheux - 29 Aug 2025 Form 4 Insider Report for iTeos Therapeutics, Inc. (ITOS)

Reporting relationship: Chief Executive Officer, Director
Issuer ticker: ITOS
Reported as of: 29 Aug 2025
Net transaction value: $0
SEC form: 4
Accepted by SEC: 29 Aug 2025, 16:30:29 UTC
Prior SEC filing: 18 Jul 2025
Next SEC filing: 12 Jun 2026
Source filing: View source filing
Reporting owner signature: /s/ Adi Osovsky, as Attorney-in-Fact

Key filing fact

Michel Detheux filed Form 4 for iTeos Therapeutics, Inc. (ITOS) on 29 Aug 2025.

Key facts

This page summarizes Michel Detheux's Form 4 filing for iTeos Therapeutics, Inc. (ITOS).
9 reported transactions and 7 derivative rows are listed below.
Accepted by SEC: 29 Aug 2025, 16:30.

Change

Previous filing in this sequence was filed on 18 Jul 2025.
Current net transaction value: $0.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (1)

CIK 0001816196 Primary reporting owner

Detheux Michel

Relationship: Chief Executive Officer, Director
Address: C/O ITEOS THERAPEUTICS, INC., 321 ARSENAL STREET, WATERTOWN
Signature: /s/ Adi Osovsky, as Attorney-in-Fact
Signature date: 29 Aug 2025

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

ITOS transaction

Common Stock

Disposition pursuant to a tender of shares in a change of control transaction

Transaction value
Shares: -153,903
Change %: -100%
Price
Shares after: 0
Date: 29 Aug 2025
Ownership: Direct
Footnotes: F1, F2, F3

ITOS transaction

Common Stock

Disposition pursuant to a tender of shares in a change of control transaction

Transaction value
Shares: -94,027
Change %: -100%
Price
Shares after: 0
Date: 29 Aug 2025
Ownership: By MG3A
Footnotes: F1, F4

Reported derivative securities

Options, warrants, convertible securities, or similar derivative positions disclosed in the filing.

ITOS transaction Derivative

Stock Option (Right to Buy)

Disposed to Issuer

Transaction value
Shares: -14,185
Change %: -100%
Price
Shares after: 0
Date: 29 Aug 2025
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 14,185
Exercise price: $7.05
Footnotes: F5, F6

ITOS transaction Derivative

Stock Option (Right to Buy)

Disposed to Issuer

Transaction value
Shares: -444,815
Change %: -100%
Price
Shares after: 0
Date: 29 Aug 2025
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 444,815
Exercise price: $7.05
Footnotes: F5, F6

ITOS transaction Derivative

Stock Option (Right to Buy)

Disposed to Issuer

Transaction value
Shares: -94,336
Change %: -100%
Price
Shares after: 0
Date: 29 Aug 2025
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 94,336
Exercise price: $4.24
Footnotes: F6

ITOS transaction Derivative

Stock Option (Right to Buy)

Disposed to Issuer

Transaction value
Shares: -50,128
Change %: -100%
Price
Shares after: 0
Date: 29 Aug 2025
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 50,128
Exercise price: $4.24
Footnotes: F6

ITOS transaction Derivative

Stock Option (Right to Buy)

Disposed to Issuer

Transaction value
Shares: -17,544
Change %: -100%
Price
Shares after: 0
Date: 29 Aug 2025
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 17,544
Exercise price: $6.16
Footnotes: F6

ITOS transaction Derivative

Stock Option (Right to Buy)

Disposed to Issuer

Transaction value
Shares: -185,000
Change %: -100%
Price
Shares after: 0
Date: 29 Aug 2025
Ownership: By MG3A
Underlying class: Common Stock
Underlying amount: 185,000
Exercise price: $4.24
Footnotes: F4, F6

ITOS transaction Derivative

Stock Option (Right to Buy)

Disposed to Issuer

Transaction value
Shares: -52,700
Change %: -100%
Price
Shares after: 0
Date: 29 Aug 2025
Ownership: By MG3A
Underlying class: Common Stock
Underlying amount: 52,700
Exercise price: $6.16
Footnotes: F4, F6

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Section 16 status

Michel Detheux is no longer subject to Section 16 filing requirements. Form 4 or Form 5 obligations may still apply in specific circumstances.

Explanation of responses 6 footnotes

Footnote F1

This Form 4 reports securities disposed of pursuant to the terms of the Agreement and Plan of Merger (the "Merger Agreement"), dated as of July 18, 2025, by and among iTeos Therapeutics, Inc. (the "Company"), Concentra Biosciences LLC ("Parent"), and Concentra Merger Sub VIII, Inc., a wholly-owned subsidiary of Parent ("Merger Sub"), pursuant to which Parent completed a tender offer for shares of common stock of the Company ("Shares") and thereafter, the Merger Sub merged with and into the Company (the "Merger"). At the effective time of the Merger (the "Effective Time"), each issued and outstanding Share was canceled and converted into the right to receive (i) $10.047 in cash per share (the "Cash Amount"); plus (ii) one non-transferable contractual contingent value right per share (each, a "CVR"), without interest and subject to applicable withholding of taxes.

Footnote F2

The amount reported in Column 4 includes 108,875 restricted stock units of the Company ("Company Restricted Stock Units," and each such restricted stock unit, a "Company Restricted Stock Unit"). Pursuant to the actions of the of the Compensation and Leadership Development Committee of the Board of Directors of the Company (the "Committee") and in accordance with the terms of the Merger Agreement, at the Effective Time, by virtue of the Merger and without any action on the part of the holders, (A) each Company Restricted Stock Unit that was held by a Company service provider who was subject to an individual employment or other agreement and/or a Company severance and change in control plan or agreement that provides for accelerated vesting of time-based equity awards upon the occurrence of a sale of the Company or a qualifying termination of employment or service in connection with, or

Footnote F3

(Continued from footnote 2) within a specified time following, a sale of the Company (each such Company Restricted Stock Unit, an "Accelerated Vesting Restricted Stock Unit") that was then outstanding but not then vested became immediately vested in full and (B) each Accelerated Vesting Restricted Stock Unit that was then outstanding was canceled and, in exchange therefor, the holder of such canceled Company Restricted Stock Unit became entitled to receive in consideration of the cancellation of such Company Restricted Stock Unit (x) an amount in cash without interest, subject to any applicable tax withholding, equal to the Cash Amount and (y) one CVR.

Footnote F4

MG3A is a Belgian partnership of which the reporting person is the manager and the reporting person's spouse is the successor manager.

Footnote F5

Pursuant to the actions of the of the Committee and in accordance with the terms of the Merger Agreement, at the Effective Time, by virtue of the Merger and without any action on the part of the holders, each option to purchase Shares from the Company ("Company Stock Options," and each such option, a "Company Stock Option") that was then outstanding but not then vested or exercisable and that was held by a Company service provider who was subject to an individual employment or other agreement and/or a Company severance and change in control plan or agreement that provides for accelerated vesting of time-based equity awards upon the occurrence of a sale of the Company or a qualifying termination of employment or service in connection with, or within a specified time following, a sale of the Company became immediately vested and exercisable in full.

Footnote F6

In accordance with the terms of the Merger Agreement, at the Effective Time, by virtue of the Merger and without any action on the part of the holders, each Company Stock Option that had an exercise price per share that is less than the Cash Amount (each, an "In-the-Money Option") that was then outstanding was canceled and, in exchange therefor, the holder of such canceled In-the-Money Option became entitled to receive in consideration of the cancellation of such In-the-Money Option (x) an amount in cash without interest, subject to any applicable tax withholding, equal to the product obtained by multiplying (1) the excess of the Cash Amount over the exercise price per Share underlying such In-the-Money Option by (2) the number of Shares underlying such In-the-Money Option as of immediately prior to the Effective Time and (y) one CVR for each Share underlying such In-the-Money Option.