[SCHEDULE 13D/A] iTeos Therapeutics, Inc. SEC Filing

Rhea-AI Filing Summary

iTeos Therapeutics, Inc. was acquired pursuant to an Offer and merger described in this Schedule 13D/A. The Offer, which began August 1, 2025, expired on August 29, 2025, and Merger Sub accepted for purchase 32,226,407 shares tendered and not withdrawn, representing approximately 72.17% of the outstanding common stock. On August 29, 2025, Merger Sub merged with and into the Issuer under Delaware law and the Issuer became a wholly owned subsidiary of Concentra. The reporting persons state they beneficially own an aggregate of 10,000 shares, which the filing reports as 100% of the outstanding shares for the reporting persons' class. The amendment updates Items 4, 5 and 7 and lists related exhibits, including the Merger Agreement and Schedule TO materials.

Positive

• Offer accepted for 32,226,407 shares, representing approximately 72.17% of outstanding common stock
• Statutory merger completed on August 29, 2025, making iTeos a wholly owned subsidiary of Concentra
• Comprehensive exhibit list included (Merger Agreement, Schedule TO, Offer to Purchase, transmittal forms)

Negative

• None.

Insights

Financial Analyst

TL;DR The offer closed and a controlling stake was acquired, creating a change of control; transaction size and completion are material to shareholders.

The filing reports that the tender offer accepted 32,226,407 shares, or ~72.17% of iTeos common stock, and that Merger Sub completed a Section 251(h) merger on August 29, 2025, leaving the issuer as a wholly owned subsidiary of Concentra. This constitutes a definitive change of control and is material to valuation, liquidity, and governance of iTeos equity. The amendment also restates beneficial ownership disclosures showing the reporting persons aggregate beneficial ownership of 10,000 shares as reported on the cover pages and updates exhibits documenting the offer and merger.

Corporate Governance Expert

TL;DR The Schedule 13D/A documents a completed takeover via tender offer and merger, terminating public control and consolidating ownership under Concentra.

The disclosure confirms consummation of the previously announced Merger Agreement and a post-offer statutory merger under Delaware law. The resulting structure — iTeos as a wholly owned subsidiary of Concentra — ends independent public governance. The filing updates Items 4, 5 and 7 and attaches governance and transactional exhibits such as the Merger Agreement, Schedule TO materials, letters of transmittal, and a joint filing agreement among reporting persons.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

(Amendment No. 2)

ITeos Therapeutics, Inc.

(Name of Issuer)

Common Stock, par value $0.001 per share

(Title of Class of Securities)

46565G104

(CUSIP Number)

Kevin Tang
4747 Executive Drive, Suite 210
San Diego, CA, 92121
858-200-3830

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

08/29/2025

(Date of Event Which Requires Filing of This Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§ 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box.

The information required on the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

SCHEDULE 13D

CUSIP No. 46565G104

1

Name of reporting person

TANG CAPITAL MANAGEMENT, LLC

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

WC

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 10,000.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 10,000.00

11

Aggregate amount beneficially owned by each reporting person

10,000.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

100 %

14

Type of Reporting Person (See Instructions)

OO

SCHEDULE 13D

CUSIP No. 46565G104

1

Name of reporting person

KEVIN TANG

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

WC

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 10,000.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 10,000.00

11

Aggregate amount beneficially owned by each reporting person

10,000.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

100 %

14

Type of Reporting Person (See Instructions)

IN

SCHEDULE 13D

CUSIP No. 46565G104

1

Name of reporting person

TANG CAPITAL PARTNERS, LP

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

WC

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 10,000.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 10,000.00

11

Aggregate amount beneficially owned by each reporting person

10,000.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

100 %

14

Type of Reporting Person (See Instructions)

PN

SCHEDULE 13D

CUSIP No. 46565G104

1

Name of reporting person

TANG CAPITAL PARTNERS INTERNATIONAL, LP

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

WC

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 0.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 0.00

11

Aggregate amount beneficially owned by each reporting person

0.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

0 %

14

Type of Reporting Person (See Instructions)

PN

SCHEDULE 13D

CUSIP No. 46565G104

1

Name of reporting person

TANG CAPITAL PARTNERS III, INC

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

WC

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

NEVADA

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 0.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 0.00

11

Aggregate amount beneficially owned by each reporting person

0.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

0 %

14

Type of Reporting Person (See Instructions)

CO

SCHEDULE 13D

CUSIP No. 46565G104

1

Name of reporting person

TANG CAPITAL PARTNERS IV, INC

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

WC

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

NEVADA

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 0.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 0.00

11

Aggregate amount beneficially owned by each reporting person

0.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

0 %

14

Type of Reporting Person (See Instructions)

CO

SCHEDULE 13D

CUSIP No. 46565G104

1

Name of reporting person

CONCENTRA BIOSCIENCES, LLC

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

AF

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 10,000.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 10,000.00

11

Aggregate amount beneficially owned by each reporting person

10,000.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

100 %

14

Type of Reporting Person (See Instructions)

OO

SCHEDULE 13D

CUSIP No. 46565G104

1

Name of reporting person

CONCENTRA MERGER SUB VIII, INC

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

AF

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 0.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 0.00

11

Aggregate amount beneficially owned by each reporting person

0.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

0 %

14

Type of Reporting Person (See Instructions)

CO

SCHEDULE 13D

Item 1.	Security and Issuer
(a)	Title of Class of Securities: Common Stock, par value $0.001 per share
(b)	Name of Issuer: ITeos Therapeutics, Inc.
(c)	Address of Issuer's Principal Executive Offices: 321 Arsenal Street, Bldg 312, Floor 3, Suite 301, Watertown, MASSACHUSETTS , 02472.
Item 1 Comment: This Schedule 13D/A (this "Statement") amends the Schedule 13D (the "Original Schedule 13D") filed on June 12, 2025, as amended on July 22, 2025. Items 4, 5 and 7 of the Statement are hereby amended and supplemented to the extent hereinafter expressly set forth. Except as amended hereby, the original disclosure set forth in the Statement shall remain unchanged. All capitalized terms used and not expressly defined herein have the respective meanings ascribed to such terms in the Original Schedule 13D.
Item 4.	Purpose of Transaction
	Item 4 of the Schedule 13D is amended by adding the following: Closing of the Merger: As previously disclosed, each of Concentra, the Issuer and Merger Sub entered into the Merger Agreement, which provides for an Offer by Merger Sub for all of the Issuer's Common Stock. The Offer commenced on August 1, 2025. On August 29, 2025, the Offer expired and Merger Sub accepted for purchase a total of 32,226,407 shares tendered and not withdrawn, representing approximately 72.17% of the total shares of the Issuer issued and outstanding. Following the expiration of the Offer, Merger Sub merged with and into the Issuer on August 29, 2025, pursuant to Section 251(h) of the Delaware General Corporation Law, and, among other things, each share of common stock of Merger Sub issued and outstanding immediately before the Effective Time automatically converted into the right to receive the Offer Price, with the Issuer surviving as a wholly owned subsidiary of Concentra.
Item 5.	Interest in Securities of the Issuer
(a)	The information previously provided in response to Item 5 is hereby amended and restated by replacing the text thereof in its entirety with the following: The information set forth in the cover pages of this Schedule 13D is hereby incorporated by reference into this Item 5. As of the date hereof the Reporting Persons beneficially own an aggregate of 10,000 shares of the Issuer's Common Stock, representing 100% of the outstanding shares.
(b)	See item 5(a) above.
(c)	Except as described in this Amendment No. 2, there have been no transactions in the Issuer's Common Stock during the past 60 days by the Reporting Persons.
(d)	No person other than a Reporting Person has the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, Common Stock beneficially owned by the Reporting Persons.
(e)	Not applicable.
Item 7.	Material to be Filed as Exhibits.
	Exhibit 1: Joint Filing Agreement by and among the Reporting Persons (filed as Exhibit 1 of the 13D filed on June 12, 2025 by the Reporting Persons with respect to the Common Stock of the Issuer). Exhibit 2: Schedule A: Transactions during the past 60 days (filed as Exhibit 2 of the 13D filed on June 12, 2025 by the Reporting Persons with respect to the Common Stock of the Issuer). Exhibit 3: Agreement and Plan of Merger, dated as of July 18, 2025, by and among iTeos Therapeutics, Inc., Concentra Biosciences, LLC, and Concentra Merger Sub VIII, Inc. (filed as Exhibit 2.1 of the Issuer's Current Report filed on Form 8-K on July 21, 2025). Exhibit 4: Schedule TO (filed by Concentra on August 1, 2025). Exhibit 5: Offer to Purchase, dated August 1, 2025 (filed as Exhibit (a)(1)(A) to the Schedule TO filed by Concentra on August 1, 2025). Exhibit 6: Form of Letter of Transmittal (filed as Exhibit (a)(1)(B) to the Schedule TO filed by Concentra on August 1, 2025). Exhibit 7: Form of Letter to Brokers, Dealers, Commercial Banks, Trust Companies and Other Nominees (filed as Exhibit (a)(1)(C) to the Schedule TO filed by Concentra on August 1, 2025). Exhibit 8: Form of Letter to Clients for Use by Brokers, Dealers, Commercial Banks, Trust Companies and Other Nominees (filed as Exhibit (a)(1)(D) to the Schedule TO filed by Concentra on August 1, 2025). Exhibit 9: Confidentiality Agreement, dated June 10, 2025, between iTeos and TCM (filed as Exhibit (d)(2) to the Schedule TO filed by Concentra on August 1, 2025). Exhibit 10: Limited Guaranty, dated July 18, 2025 (filed as Exhibit (d)(3) to the Schedule TO filed by Concentra on August 1, 2025). Exhibit 11: Joint Filing Agreement, dated September 3, 2025, by and among the Reporting Persons.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

TANG CAPITAL MANAGEMENT, LLC

Signature:	/s/ Kevin Tang
Name/Title:	Manager
Date:	09/03/2025

KEVIN TANG

Signature:	/s/ Kevin Tang
Name/Title:	Self
Date:	09/03/2025

TANG CAPITAL PARTNERS, LP

Signature:	/s/ Kevin Tang
Name/Title:	Manager, Tang Capital Management, LLC, General Partner
Date:	09/03/2025

TANG CAPITAL PARTNERS INTERNATIONAL, LP

Signature:	/s/ Kevin Tang
Name/Title:	Manager, Tang Capital Management, LLC, General Partner
Date:	09/03/2025

TANG CAPITAL PARTNERS III, INC

Signature:	/s/ Kevin Tang
Name/Title:	Chief Executive Officer
Date:	09/03/2025

TANG CAPITAL PARTNERS IV, INC

Signature:	/s/ Kevin Tang
Name/Title:	Chief Executive Officer
Date:	09/03/2025

CONCENTRA BIOSCIENCES, LLC

Signature:	/s/ Kevin Tang
Name/Title:	Chief Executive Officer
Date:	09/03/2025

CONCENTRA MERGER SUB VIII, INC

Signature:	/s/ Kevin Tang
Name/Title:	Chief Executive Officer
Date:	09/03/2025

FAQ

What happened in the iTeos (ITOS) Schedule 13D/A filing?

The filing reports that the tender offer expired August 29, 2025 with acceptance of 32,226,407 shares (≈72.17%) and that Merger Sub merged into iTeos, leaving iTeos as a wholly owned subsidiary of Concentra.

How many shares were accepted in Concentra's offer for ITOS?

Merger Sub accepted for purchase 32,226,407 shares, representing approximately 72.17% of the issuer's outstanding common stock.

Did the merger for iTeos close and when did it become effective?

Yes. The filing states the merger was effected on August 29, 2025 pursuant to Section 251(h) of the Delaware General Corporation Law.

What beneficial ownership do the reporting persons claim in the filing?

The reporting persons state they beneficially own an aggregate of 10,000 shares, which the cover pages report as 100% of the class for those reporting persons.

What exhibits are attached to this Schedule 13D/A?

Noted exhibits include the Agreement and Plan of Merger, Schedule TO, Offer to Purchase, forms of transmittal and letters to brokers/clients, a Confidentiality Agreement, a Limited Guaranty, and a Joint Filing Agreement.