Deerfield reports 2.88% stake in Cogent Biosciences

Cogent Biosciences, Inc. reports that a group of Deerfield entities and James E. Flynn have filed an amended Schedule 13G reflecting their current ownership of Cogent common stock.

Rhea-AI Filing Summary

Cogent Biosciences, Inc. reports that a group of Deerfield entities and James E. Flynn have filed an amended Schedule 13G reflecting their current ownership of Cogent common stock. Deerfield Mgmt, L.P., Deerfield Management Company, L.P., Deerfield Partners, L.P. and James E. Flynn each report beneficial ownership of 5,006,104 shares of common stock, representing 2.88% of the outstanding class. Voting and dispositive authority over these shares is reported on a shared basis among the reporting persons, and they state that they now hold 5 percent or less of this class of securities.

Key Figures

Shares beneficially owned: 5,006,104 shares Percent of class: 2.88% Shared voting power: 5,006,104 shares +2 more

5 metrics

Shares beneficially owned 5,006,104 shares Common stock of Cogent Biosciences reported by each Deerfield entity and James E. Flynn

Percent of class 2.88% Beneficial ownership percentage of Cogent Biosciences common stock for each reporting person

Shared voting power 5,006,104 shares Number of Cogent Biosciences shares over which each reporting person has shared power to vote

Shared dispositive power 5,006,104 shares Number of Cogent Biosciences shares over which each reporting person has shared power to dispose

Ownership threshold status 5 percent or less Item 5 disclosure that the group owns 5 percent or less of the class

Key Terms

beneficially owned, shared power to vote, shared power to dispose, Schedule 13G, +1 more

5 terms

beneficially owned financial

"Amount beneficially owned: Deerfield Mgmt, L.P. - 5,006,104 shares"

Beneficially owned describes securities or assets where a person has the economic rights and control—such as the right to receive dividends and to direct voting—even if legal title is held in another name. Think of it like having the keys and using a car that’s registered to someone else: you get the benefits and make decisions. Investors care because beneficial ownership reveals who truly controls value and voting power, affecting corporate decisions and takeover dynamics.

shared power to vote financial

"Shared power to vote or to direct the vote: Deerfield Mgmt, L.P. - 5,006,104"

shared power to dispose financial

"Shared power to dispose or to direct the disposition of: Deerfield Mgmt, L.P. - 5,006,104"

Schedule 13G regulatory

"If a group has filed this schedule pursuant to 1(c) or 1(d), attach an exhibit"

A Schedule 13G is a formal document that investors file with the government when they acquire a large ownership stake in a company, usually for investment purposes rather than control. It helps keep the public informed about who owns significant parts of a company's shares, which can influence how the company is managed and how investors make decisions. Filing this schedule is important for transparency and understanding the ownership landscape of publicly traded companies.

joint filing agreement regulatory

"Exhibit A. Joint Filing Agreement."

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What stake in Cogent Biosciences (COGT) is reported in this Schedule 13G/A?

The filing reports beneficial ownership of 5,006,104 Cogent Biosciences common shares, representing 2.88% of the outstanding class. This ownership is reported jointly by Deerfield entities and James E. Flynn.

Who are the reporting persons in the Cogent Biosciences (COGT) Schedule 13G/A?

The reporting persons are Deerfield Mgmt, L.P., Deerfield Management Company, L.P., Deerfield Partners, L.P. and James E. Flynn. They file jointly with shared voting and dispositive power over the reported shares.

What percentage of Cogent Biosciences (COGT) does Deerfield report owning?

Each reporting person discloses beneficial ownership of 2.88% of Cogent Biosciences’ common stock. The filing also notes that they own 5 percent or less of this class of securities.

How is voting power over Cogent Biosciences (COGT) shares allocated in this filing?

The reporting persons disclose shared power to vote and shared power to dispose of 5,006,104 Cogent Biosciences shares. They report no sole power to vote or dispose of any shares individually.

Where are the Deerfield reporting persons in the Cogent Biosciences (COGT) filing organized?

Deerfield Mgmt, L.P., Deerfield Management Company, L.P. and Deerfield Partners, L.P. are Delaware limited partnerships, while James E. Flynn is a United States citizen, as disclosed in the filing.

What does Item 5 indicate about Deerfield’s ownership in Cogent Biosciences (COGT)?

Item 5 states that the reporting persons hold 5 percent or less of Cogent Biosciences’ common stock. Consistent with this, they report a current beneficial ownership level of 2.88% of the class.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Available on EDGAR 08/13/2026 - 04:11 PM Accepted by SEC EDGAR 08/13/2026 - 04:10 PM Learn about SEC filing dates

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 2)

Cogent Biosciences, Inc.

(Name of Issuer)

Common Stock

(Title of Class of Securities)

19240Q201

(CUSIP Number)

06/30/2026

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

Rule 13d-1(b)

Rule 13d-1(c)

Rule 13d-1(d)

schemaVersion:

SCHEDULE 13G

CUSIP Number(s): 19240Q201

1

Names of Reporting Persons

Deerfield Mgmt, L.P.

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 5,006,104.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 5,006,104.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

5,006,104.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

2.88 %

12

Type of Reporting Person (See Instructions)

PN

Comment for Type of Reporting Person: Comprised of shares of common stock held by Deerfield Partners, L.P., of which Deerfield Mgmt, L.P. is the general partner.

SCHEDULE 13G

CUSIP Number(s): 19240Q201

1

Names of Reporting Persons

Deerfield Management Company, L.P.

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 5,006,104.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 5,006,104.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

5,006,104.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

2.88 %

12

Type of Reporting Person (See Instructions)

PN

Comment for Type of Reporting Person: Comprised of shares of common stock held by Deerfield Partners, L.P. of which Deerfield Management Company, L.P. is the investment advisor.

SCHEDULE 13G

CUSIP Number(s): 19240Q201

1

Names of Reporting Persons

Deerfield Partners, L.P.

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 5,006,104.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 5,006,104.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

5,006,104.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

2.88 %

12

Type of Reporting Person (See Instructions)

PN

SCHEDULE 13G

CUSIP Number(s): 19240Q201

1

Names of Reporting Persons

James E. Flynn

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 5,006,104.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 5,006,104.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

5,006,104.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

2.88 %

12

Type of Reporting Person (See Instructions)

IN

Comment for Type of Reporting Person: Comprised of shares of common stock held by Deerfield Partners, L.P.

SCHEDULE 13G

Item 1.
(a)	Name of issuer: Cogent Biosciences, Inc.
(b)	Address of issuer's principal executive offices: 275 Wyman Street, 3rd Floor, Waltham, Massachusetts 02451
Item 2.
(a)	Name of person filing: James E. Flynn, Deerfield Mgmt, L.P., Deerfield Management Company, L.P. and Deerfield Partners, L.P.
(b)	Address or principal business office or, if none, residence: James E. Flynn, Deerfield Mgmt, L.P., Deerfield Management Company, L.P. and Deerfield Partners, L.P., 345 Park Avenue South, 12th Floor, New York, NY 10010
(c)	Citizenship: Deerfield Mgmt, L.P., Deerfield Management Company, L.P. and Deerfield Partners, L.P. - Delaware limited partnerships; James E. Flynn - United States citizen
(d)	Title of class of securities: Common Stock
(e)	CUSIP No.: 19240Q201
Item 3.	If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:
(a)	Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);
(b)	Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);
(c)	Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);
(d)	Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);
(e)	An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);
(f)	An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);
(g)	A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);
(h)	A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
(i)	A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);
(j)	A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J). If filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J), please specify the type of institution:
(k)	Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).
Item 4.	Ownership
(a)	Amount beneficially owned: Deerfield Mgmt, L.P. - 5,006,104 shares Deerfield Management Company, L.P. - 5,006,104 shares Deerfield Partners, L.P. - 5,006,104 shares James E. Flynn - 5,006,104 shares
(b)	Percent of class: Deerfield Mgmt, L.P. - 2.88% Deerfield Management Company, L.P. - 2.88% Deerfield Partners, L.P. - 2.88% James E. Flynn - 2.88%
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: All Reporting Persons - 0
	(ii) Shared power to vote or to direct the vote: Deerfield Mgmt, L.P. - 5,006,104 Deerfield Management Company, L.P. - 5,006,104 Deerfield Partners, L.P. - 5,006,104 James E. Flynn - 5,006,104
	(iii) Sole power to dispose or to direct the disposition of: All Reporting Persons - 0
	(iv) Shared power to dispose or to direct the disposition of: Deerfield Mgmt, L.P. - 5,006,104 Deerfield Management Company, L.P. - 5,006,104 Deerfield Partners, L.P. - 5,006,104 James E. Flynn - 5,006,104
Item 5.	Ownership of 5 Percent or Less of a Class.
	Ownership of 5 percent or less of a class
Item 6.	Ownership of more than 5 Percent on Behalf of Another Person.
	Not Applicable
Item 7.	Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
	Not Applicable
Item 8.	Identification and Classification of Members of the Group.
	If a group has filed this schedule pursuant to §240.13d-1(b)(1)(ii)(J), so indicate under Item 3(j) and attach an exhibit stating the identity and Item 3 classification of each member of the group. If a group has filed this schedule pursuant to §240.13d-1(c) or §240.13d-1(d), attach an exhibit stating the identity of each member of the group. See Exhibit B
Item 9.	Notice of Dissolution of Group.
	Not Applicable

Item 10.

Certifications:

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under § 240.14a-11.

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.

Deerfield Mgmt, L.P.

Signature:	/s/ Jonathan Isler
Name/Title:	Jonathan Isler, Attorney-In-Fact
Date:	08/13/2026

Deerfield Management Company, L.P.

Signature:	/s/ Jonathan Isler
Name/Title:	Jonathan Isler, Attorney-In-Fact
Date:	08/13/2026

Deerfield Partners, L.P.

Signature:	/s/ Jonathan Isler
Name/Title:	Jonathan Isler, Attorney-In-Fact
Date:	08/13/2026

James E. Flynn

Signature:	/s/ Jonathan Isler
Name/Title:	Jonathan Isler, Attorney-In-Fact
Date:	08/13/2026

Exhibit Information

Exhibit A. Joint Filing Agreement. Exhibit B. Item 8 Statement. Exhibit C. Power of Attorney (1). (1) Power of Attorney previously filed as Exhibit 24 to a Form 3 with regard to BiomX Inc. filed with the Securities and Exchange Commission on March 19, 2024 by Deerfield Private Design Fund V, L.P., Deerfield Healthcare Innovations Fund II, L.P., Deerfield Mgmt V, L.P., Deerfield Mgmt HIF II, L.P., Deerfield Management Company, L.P. and James E. Flynn.