iTeos completes merger with Concentra; S-8 registrations withdrawn

Rhea-AI Filing Summary

iTeos Therapeutics, Inc. filed post-effective amendments to withdraw and remove any unissued and unsold securities previously registered under multiple Form S-8 registration statements. The company states that on July 18, 2025 it entered into a Merger Agreement with Concentra Biosciences, LLC and its subsidiary Merger Sub, and that on August 29, 2025 Merger Sub was merged into iTeos with iTeos surviving as a wholly owned subsidiary of Parent. In the Merger each outstanding common share (with limited exceptions) converted into $10.047 in cash plus one non-transferable contractual contingent value right (CVR). As a result, all offerings under the listed registration statements were terminated and the registrant removed the unsold registered securities from registration.

Positive

• Per-share cash consideration of $10.047 for each outstanding common share (subject to enumerated exceptions)
• Completed transaction converting the company into a wholly owned subsidiary, which resolves strategic uncertainty
• Post-effective amendments filed to remove unsold securities, demonstrating compliance with registration undertakings

Negative

• iTeos became a wholly owned subsidiary, meaning its common shares are no longer publicly traded
• Contractual contingent value rights are non-transferable and the filing provides no terms here, leaving future value uncertain
• All prior offerings under the listed registration statements were terminated, eliminating those share issuance programs

Insights

M&A Specialist

TL;DR: iTeos was acquired; shareholders received $10.047 cash plus a CVR and the company’s outstanding registration statements were terminated.

The filing confirms a completed acquisition by Concentra Biosciences through a merger that left iTeos as a private, wholly owned subsidiary. The clear, per-share cash consideration of $10.047 is disclosed and a non-transferable CVR was issued for each share, indicating contingent upside beyond the cash consideration. Post-effective amendments withdraw unsold shares from multiple Form S-8 registrations, consistent with the termination of public equity offerings following the change in control. This is a material corporate action that ends iTeos’s status as an independent public registrant.

Corporate Governance Expert

TL;DR: The company completed a change of control, removed registered but unsold securities, and ceased public offering activity as required by prior undertakings.

The document documents compliance with registration undertakings by filing post-effective amendments to remove any unissued, unsold securities under the referenced S-8 registration statements. The merger effective date and the conversion mechanics for shares are explicitly stated, and the CEO-level signature indicates appropriate corporate authorization. The filing provides no details on CVR terms or any remaining obligations, so governance implications tied to contingent payments remain unspecified in this filing.

As filed with the Securities and Exchange Commission on August 29, 2025

Registration No. 333-240144

Registration No. 333-254670

Registration No. 333-263791

Registration No. 333-270545

Registration No. 333-277687

Registration No. 333-285550

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

POST-EFFECTIVE AMENDMENT NO. 1 TO FORM S-8 REGISTRATION STATEMENT NO. 333-240144

POST-EFFECTIVE AMENDMENT NO. 1 TO FORM S-8 REGISTRATION STATEMENT NO. 333-254670

POST-EFFECTIVE AMENDMENT NO. 1 TO FORM S-8 REGISTRATION STATEMENT NO. 333-263791

POST-EFFECTIVE AMENDMENT NO. 1 TO FORM S-8 REGISTRATION STATEMENT NO. 333-270545

POST-EFFECTIVE AMENDMENT NO. 1 TO FORM S-8 REGISTRATION STATEMENT NO. 333-277687

POST-EFFECTIVE AMENDMENT NO. 1 TO FORM S-8 REGISTRATION STATEMENT NO. 333-285550

FORM S-8

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

ITEOS THERAPEUTICS, INC.

(Exact name of registrant as specified in its charter)

Delaware		84-3365066
(State or other jurisdiction of incorporation or organization)		(IRS employer identification number)

321 Arsenal Street

Watertown, Massachusetts 02472

(Address of Principal Executive Offices, including Zip Code)

iTeos Therapeutics, Inc. 2019 Stock Option and Grant Plan

iTeos Therapeutics, Inc. 2020 Stock Option and Incentive Plan

iTeos Therapeutics, Inc. 2020 Employee Stock Purchase Plan

(Full title of the Plans)

Michael Hearne

Chief Financial Officer

iTeos Therapeutics, Inc.

4747 Executive Drive, Suite 210

San Diego, California 92121

(858) 281-5372

(Name, Address and Telephone Number, including Area Code, of Agent for Service)

Copies to:

Ryan A. Murr

Gibson, Dunn & Crutcher LLP

One Embarcadero Center Suite 2600

San Francisco, California 94111

(415) 393-8200

William Michener

Nicholas Roper

Ropes & Gray LLP

800 Boylston Street

Boston, MA 02199

(617) 951-7000

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See definitions of “large accelerated filer, “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

Large accelerated filer		☐		Accelerated filer		☐
Non-accelerated filer		☒		Smaller reporting company		☒
				Emerging growth company		☒

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act.  ☐

EXPLANATORY NOTE

DEREGISTRATION OF UNSOLD SECURITIES

These Post-Effective Amendments (the “Post-Effective Amendments”) filed by iTeos Therapeutics, Inc., a Delaware corporation (the “Registrant”), to deregister all shares of the Registrant’s common stock, $0.001 par value per share (the “Shares”), remaining unissued under the following Registration Statements on Form S-8 (each, a “Registration Statement”, and collectively, the “Registration Statements”) filed by the Registrant with the U.S. Securities and Exchange Commission (the “Commission”).

	•	Registration Statement on Form S-8 (No. 333-240144) pertaining to the registration of (i) 3,323,378 Shares issuable under the 2019 Stock Option and Grant Plan (the “2019 Plan”), (ii) 1,151,680 Shares outstanding and 2,658,138 Shares issuable under the 2020 Stock Option and Incentive Plan (the “2020 Plan”) and (iii) 317,484 Shares issuable under the 2020 Employee Stock Purchase Plan (the “2020 ESPP”).
	•	Registration Statement on Form S-8 (No. 333-254670) pertaining to the registration of (i) 1,752,237 Shares issuable under the 2020 Plan and (ii) 350,447 Shares issuable under the 2020 ESPP.
	•	Registration Statement on Form S-8 (No. 333-263791) pertaining to the registration of 1,773,300 Shares issuable under the 2020 Plan.
	•	Registration Statement on Form S-8 (No. 333-270545) pertaining to the registration of 1,780,560 Shares issuable under the 2020 Plan.
	•	Registration Statement on Form S-8 (No. 333-277687) pertaining to the registration of 1,791,904 Shares issuable under the 2020 Plan.
	•	Registration Statement on Form S-8 (No. 333-285550) pertaining to the registration of 1,828,402 Shares issuable under the 2020 Plan.

The Registrant is filing these Post-Effective Amendments to withdraw and remove any unissued and unsold securities issuable by Registration pursuant to the above-referenced Registration Statements.

On July 18, 2025, the Registrant entered into an Agreement and Plan of Merger (the “Merger Agreement”) with Concentra Biosciences, LLC, a Delaware limited liability company (“Parent”), and Concentra Merger Sub VIII, Inc., a Delaware corporation and wholly owned subsidiary of Parent (“Merger Sub”). Pursuant to the Merger Agreement, on August 29, 2025, Merger Sub was merged with and into the Registrant with the Registrant surviving as a wholly owned subsidiary of Parent (the “Merger”). In the Merger, each share of Common Stock (the “Shares”) (other than (i) Shares owned or held in the Company’s treasury immediately prior to the Effective Time, (ii) Shares owned directly or indirectly by Parent or Merger Sub immediately prior to the Effective Time and (iii) Shares held by any stockholder of the Registrant who properly exercised appraisal rights under Delaware law) was converted into the right to receive (i) $10.047 per Share in cash and (ii) one non-transferable contractual contingent value right for each Share.

As a result of the Merger, the Registrant has terminated all offerings of its securities pursuant to the Registration Statements. In accordance with an undertaking made by the Registrant in each of the Registration Statements to remove from registration, by means of a post-effective amendment, any of the securities that had been registered for issuance that remain unsold at the termination of the offerings, the Registrant hereby removes from registration all such securities registered under the Registration Statements that remain unsold as of the date hereof and terminates the effectiveness of the Registration Statements.

SIGNATURE

Pursuant to the requirements of the Securities Act of 1933, the Registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-8 and has duly caused these Post-Effective Amendments to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of San Diego, State of California, on August 29, 2025. No other person is required to sign these Post-Effective Amendments to the Registration Statements in reliance on Rule 478 of the Securities Act of 1933, as amended.

ITEOS THERAPEUTICS, INC.

/s/ Michael Hearne

Name: Michael Hearne

Title: Chief Financial Officer

FAQ

What did iTeos (ITOS) shareholders receive in the merger?

Each outstanding common share (except treasury shares, shares owned by Parent/Merger Sub, and properly appraising stockholders) was converted into $10.047 in cash plus one non-transferable contractual contingent value right (CVR).

When did the merger become effective for iTeos?

The filing states the merger occurred on August 29, 2025, following a Merger Agreement dated July 18, 2025.

What happened to iTeos’s registered but unsold securities under the Form S-8 filings?

The registrant filed post-effective amendments to withdraw and remove all unissued and unsold securities from the referenced registration statements and terminated their effectiveness.

Did the filing disclose the terms of the CVRs?

No. The filing confirms issuance of one non-transferable CVR per share but does not provide the CVR terms or contingent payment triggers.

Who signed the filing for iTeos?

The filing is signed by Michael Hearne, Chief Financial Officer of iTeos Therapeutics, Inc.