UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of The Securities Exchange Act of 1934

Date of Report (Date of Earliest Event Reported): November 18, 2025

COGENT BIOSCIENCES, INC.

(Exact name of registrant as specified in its charter)

Delaware

001-38443

46-5308248

(State or other jurisdiction

of incorporation)

(Commission

File Number)

(I.R.S. Employer

Identification No.)

275 Wyman Street, 3rd Floor

Waltham, Massachusetts

02451

(Address of principal executive offices)

(Zip Code)

Registrant’s telephone number, including area code: (617) 945-5576

Not Applicable

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐	Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐	Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐	Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐	Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:


Title of each class	Trading Symbol(s)	Name of each exchange on which registered
Common stock, $0.001 Par Value	COGT	The Nasdaq Global Select Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 or Rule 12b-2 of the Securities Exchange Act of 1934.

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 13(a) of the Exchange Act. ☐

Item 1.01

Entry into a Material Definitive Agreement.

On November 18, 2025, Cogent Biosciences, Inc. (the “Company”) completed its previously-announced public offering (the “Offering”) of $230,000,000 aggregate principal amount of its 1.625% Convertible Senior Notes due 2031 (the “Notes”), including the exercise in full of the underwriters’ over-allotment option to purchase up to an additional $30.0 million principal amount of the Notes. The Notes were issued pursuant to, and are governed by, an indenture (the “Base Indenture”), dated as of November 18, 2025, between the Company and U.S. Bank Trust Company, National Association, as trustee (the “Trustee”), as supplemented by a first supplemental indenture (the “Supplemental Indenture,” and the Base Indenture, as supplemented by the Supplemental Indenture, the “Indenture”), dated as of November 18, 2025, between the Company and the Trustee.

The Notes are general, unsecured, senior obligations of the Company. The Notes will accrue interest payable semiannually in arrears on May 15 and November 15 of each year, beginning on May 15, 2026, at a rate equal to 1.625% per year. In addition, special interest will accrue on the Notes upon the occurrence of certain events relating to the Company’s failure to file certain reports with the U.S. Securities and Exchange Commission as provided in the Indenture and as described below. The Notes will mature on November 15, 2031 (the “Maturity Date”), unless earlier converted, redeemed or repurchased by the Company.

Noteholders may convert their Notes at their option only in the following circumstances: (1) during any calendar quarter (and only during such calendar quarter) commencing after the calendar quarter ending on March 31, 2026, if the last reported sale price per share of the Company’s common stock, $0.001 par value per share (the “Common Stock”), exceeds 130% of the conversion price for each of at least 20 trading days, whether or not consecutive, during the 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter; (2) during the five consecutive business days immediately after any 10 consecutive trading day period (such 10 consecutive trading day period, the “Measurement Period”) in which the trading price per $1,000 principal amount of Notes for each trading day of the Measurement Period was less than 98% of the product of the last reported sale price per share of the Common Stock on such trading day and the conversion rate on such trading day; (3) upon the occurrence of certain corporate events or distributions on the Common Stock, as described in the Indenture; (4) if the Company calls such Notes for redemption; and (5) at any time from, and including, August 15, 2031 until the close of business on the scheduled trading day immediately before the Maturity Date. The Company will settle conversions by paying or delivering, as applicable, cash, shares of Common Stock or a combination of cash and shares of Common Stock, at the Company’s election, based on the applicable conversion rate(s). The initial conversion rate is 22.2469 shares of Common Stock per $1,000 principal amount of Notes, which represents an initial conversion price of approximately $44.95 per share, and is subject to adjustment as described in the Indenture. If certain corporate events that constitute a “Make-Whole Fundamental Change” (as defined in the Indenture) occur, then the Company will in certain circumstances increase the conversion rate for a specified period of time.

The Notes will be redeemable, in whole or in part (subject to certain limitations described below), at the Company’s option at any time, and from time to time, on a redemption date on or after November 20, 2029 and on or before the 26th scheduled trading day immediately before the Maturity Date, at a cash redemption price equal to the principal amount of the Notes to be redeemed, plus accrued and unpaid interest, if any, to, but excluding, the redemption date, but only if the last reported sale price per share of the Common Stock exceeds 130% of the conversion price on (i) each of at least 20 trading days, whether or not consecutive, during the 30 consecutive trading days ending on, and including, the trading day immediately before the date the Company sends the related redemption notice; and (ii) the trading day immediately before the date the Company sends such notice. However, the Company may not redeem less than all of the outstanding Notes unless at least $75.0 million aggregate principal amount of Notes are outstanding and not called for redemption as of the time the Company sends the related redemption notice. In addition, calling any Note for redemption will constitute a “Make-Whole Fundamental Change” with respect to that Note, in which case the conversion rate applicable to the conversion of that Note will be increased in certain circumstances if it is converted after it is called for redemption.

If a “Fundamental Change” (as defined in the Indenture) occurs, then, subject to certain conditions and except as set forth in the Indenture, noteholders may require the Company to repurchase their Notes at a cash repurchase price equal to the principal amount of the Notes to be repurchased, plus accrued and unpaid interest, if any, to, but excluding, the fundamental change repurchase date. The definition in the Indenture of a Fundamental Change includes certain business combination transactions involving the Company and certain de-listing events with respect to the Common Stock.

The Notes will have customary provisions relating to the occurrence of “Events of Default” (as defined in the Indenture), which include the following: (i) certain payment defaults on the Notes (which, in the case of a default in the payment of interest on the Notes, will be subject to a 30-day cure period); (ii) the Company’s failure to send certain notices under the Indenture within specified periods of time; (iii) the Company’s failure to convert a Note in accordance with the Indenture within a specified period of time; (iv) the Company’s failure to comply with certain covenants in the Indenture relating to the Company’s ability to consolidate with or merge with or into, or sell, lease or otherwise transfer, in one transaction or a series of transactions, all or substantially all of the assets of the Company and its subsidiaries, taken as a whole, to another person; (v) a default by the Company in its other obligations or agreements under the Indenture or the Notes if such default is not cured or waived within 60 days after notice is given in accordance with the Indenture; (vi) certain defaults by the Company or any of its significant subsidiaries with respect to indebtedness for borrowed money of at least $20,000,000; (vii) certain final judgments being rendered against the Company or any of its significant subsidiaries for the payment of at least $20,000,000, where such judgments are not discharged or stayed within 60 days after date on which the right to appeal has expired or on which all rights to appeal have been extinguished; and (viii) certain events of bankruptcy, insolvency and reorganization involving the Company or any of its significant subsidiaries.

If an Event of Default involving bankruptcy, insolvency or reorganization events with respect to the Company (and not solely with respect to a significant subsidiary of the Company) occurs, then the principal amount of, and all accrued and unpaid interest, if any, on, all of the Notes then outstanding will immediately become due and payable without any further action or notice by any person. If any other Event of Default occurs and is continuing, then, the Trustee, by notice to the Company, or noteholders of at least 25% of the aggregate principal amount of Notes then outstanding, by notice to the Company and the Trustee, may declare the principal amount of, and all accrued and unpaid interest, if any, on, all of the Notes then outstanding to become due and payable immediately. However, notwithstanding the foregoing, the Company may elect, at its option, that the sole remedy for an Event of Default relating to certain failures by the Company to comply with certain reporting covenants in the Indenture consists exclusively of the right of the noteholders to receive special interest on the Notes for up to 365 days, at a rate per annum equal to 0.25% of the principal amount of the Notes for the first 180 days on which special interest accrues and, thereafter, at a rate per annum equal to 0.50% of the principal amount thereof.

The above descriptions of the Indenture and the Notes are summaries and are not complete. Copies of the Base Indenture, the Supplemental Indenture and the form of the certificate representing the Notes are filed as Exhibits 4.1, 4.2 and 4.3, respectively, to this Current Report on Form 8-K, and the above summaries are qualified in their entirety by reference to the terms of the Base Indenture, the Supplemental Indenture and the Notes set forth in such exhibits.

To the extent that any shares of Common Stock are issued upon conversion of the Notes, they will be issued in transactions anticipated to be exempt from registration under the Securities Act by virtue of Section 3(a)(9) thereof because no commission or other remuneration is expected to be paid in connection with conversion of the Notes and any resulting issuance of shares of Common Stock. Initially, a maximum of 7,419,340 shares of Common Stock may be issued upon conversion of the Notes based on the initial maximum conversion rate of 32.2580 shares of Common Stock per $1,000 principal amount of Notes, which is subject to customary anti-dilution adjustment provisions.

A copy of the opinion of Gibson, Dunn & Crutcher LLP, relating to the validity of the Notes and the Common Stock underlying the Notes in connection with the Offering, is filed as Exhibit 5.1 to this Current Report on Form 8-K.

Item 2.03

Creation of a Direct Financial Obligation or an Off-Balance Sheet Arrangement.

The disclosure set forth in Item 1.01 above is incorporated by reference into this Item 2.03.

Item 9.01

Financial Statements and Exhibits.

(d) Exhibits.


4.1		Indenture, dated as of November 18, 2025, between Cogent Biosciences, Inc. and U.S. Bank Trust Company, National Association, as trustee.

4.2		First Supplemental Indenture, dated as of November 18, 2025, between Cogent Biosciences, Inc. and U.S. Bank Trust Company, National Association, as trustee.

4.3		Form of certificate representing the 1.625% Convertible Senior Notes due 2031 (included as Exhibit A in Exhibit 4.2).

5.1		Opinion of Gibson, Dunn & Crutcher LLP.

23.1		Consent of Gibson, Dunn & Crutcher LLP (included in Exhibit 5.1).

104		Cover Page Interactive Data File (embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

Date: November 18, 2025

COGENT BIOSCIENCES, INC.

/s/ Evan Kearns

Evan Kearns

Chief Legal Officer and Corporate Secretary

Cogent Biosciences, Inc. 8-K