[S-8 POS] Kronos Bio, Inc. SEC Filing

Rhea-AI Filing Summary

Kronos Bio, Inc. (NASDAQ: KRON) filed five Post-Effective Amendments to previously effective Form S-8 registration statements in order to deregister all unsold shares that had been reserved for issuance under the company’s 2017 Equity Incentive Plan, 2020 Equity Incentive Plan, and 2020 Employee Stock Purchase Plan.

The administrative action follows the closing of the June 20, 2025 merger in which Concentra Merger Sub IV, Inc., a wholly-owned subsidiary of Concentra Biosciences, LLC, merged with and into Kronos Bio. Each outstanding common share was converted into the right to receive $0.57 in cash plus one non-transferable contingent value right (CVR). As Kronos now operates as a wholly-owned subsidiary of Concentra, all public offerings under the referenced S-8 statements have been terminated in accordance with prior undertakings, and the effectiveness of the statements has been withdrawn.

The filing is purely procedural: it eliminates the registration of roughly 34 million shares that remained unissued across the five plans, confirms that no additional equity will be issued, and finalises the company’s transition away from public-company status.

Insights

Corporate Governance Expert

TL;DR: Administrative S-8 withdrawal—confirms completed take-private; no further equity issuance.

This Post-Effective Amendment is a routine housekeeping step that follows the June 20, 2025 completion of Kronos Bio’s cash-and-CVR merger with Concentra Biosciences. By deregistering the ~34 million shares that remained available under three equity plans, the company ends all SEC-registered employee-equity programs and formally switches off the underlying shelf capacity. For legacy investors, the economic impact occurred at closing ($0.57 + CVR); today’s filing merely tidies the SEC record. Material impact on valuation or future cash flows is therefore negligible.

As filed with the Securities and Exchange Commission on June 20, 2025

Registration No. 333-278125

Registration No. 333-270564

Registration No. 333-262993

Registration No. 333-254620

Registration No. 333-249424

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

POST-EFFECTIVE AMENDMENT NO. 1 TO FORM S-8 REGISTRATION STATEMENT NO. 333-278125

POST-EFFECTIVE AMENDMENT NO. 1 TO FORM S-8 REGISTRATION STATEMENT NO. 333-270564

POST-EFFECTIVE AMENDMENT NO. 1 TO FORM S-8 REGISTRATION STATEMENT NO. 333-262993

POST-EFFECTIVE AMENDMENT NO. 1 TO FORM S-8 REGISTRATION STATEMENT NO. 333-254620

POST-EFFECTIVE AMENDMENT NO. 1 TO FORM S-8 REGISTRATION STATEMENT NO. 333-249424

FORM S-8

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

KRONOS BIO, INC.

(Exact name of registrant as specified in its charter)

Delaware		82-1895605
(State or other jurisdiction of incorporation or organization)		(IRS employer identification number)

301 Binney Street, 2nd Floor East

Cambridge, MA 02142

(Address of Principal Executive Offices, including Zip Code)

2017 Equity Incentive Plan (Prior Plan)

2020 Equity Incentive Plan

2020 Employee Stock Purchase Plan

(Full title of the Plans)

Michael Hearne

Chief Financial Officer

Kronos Bio 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

Michael R. Patrone, Esq.

Amanda J. Gill, Esq.

Goodwin Procter LLP

New York Times Bldg

620 8th Ave

New York, NY 10018

(212) 813-8800

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 Kronos Bio, 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. 333-249424) pertaining to the registration of (i) 3,433,122 Shares issuable under the 2017 Equity Incentive Plan (the “2017 Plan”), (ii) 12,075,323 Shares issuable under the 2020 Equity Incentive Plan (the “2020 Plan”) and (iii) 688,000 Shares issuable under the 2020 Employee Stock Purchase Plan (the “ESPP”).

• Registration Statement on Form S-8 (No. 333-254620) pertaining to the registration of (i) 2,801,675 Shares issuable under the 2020 Plan and (ii) 560,335 Shares issuable under the ESPP.

• Registration Statement on Form S-8 (No. 333-262993) pertaining to the registration of (i) 2,828,994 Shares issuable under the 2020 Plan and (ii) 565,798 Shares issuable under the ESPP.

• Registration Statement on Form S-8 (No. 333-270564) pertaining to the registration of (i) 2,848,371 Shares issuable under the 2020 Plan and (ii) 569,674 Shares issuable under the ESPP.

• Registration Statement on Form S-8 (No. 333-278125) pertaining to the registration of (i) 2,947,329 Shares issuable under the 2020 Plan and (ii) 589,465 Shares issuable under the ESPP.

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 May 1, 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 IV, Inc., a Delaware corporation and wholly owned subsidiary of Parent (“Merger Sub”). Pursuant to the Merger Agreement, on June 20, 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 $0.57 in cash per Share, plus one non-transferrable 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 June 20, 2025. No other person is required to sign these Post-Effective Amendment to the Registration Statements in reliance on Rule 478 of the Securities Act of 1933, as amended.

KRONOS BIO, INC.

/s/ Michael Hearne

Name: Michael Hearne

Title: Chief Financial Officer

FAQ

Why did Kronos Bio (KRON) file Post-Effective Amendments to its S-8 registrations?

The company completed a merger on June 20, 2025 and is removing approximately 34 million unissued shares from registration because no further public issuance will occur.

How much cash did KRON shareholders receive in the Concentra Biosciences merger?

Each common share was converted into the right to receive $0.57 in cash plus one contingent value right.

Which equity plans are affected by the deregistration?

The 2017 Equity Incentive Plan, 2020 Equity Incentive Plan, and 2020 Employee Stock Purchase Plan are all terminated for public issuance.

Does the filing have any impact on KRON’s financial statements or future dilution?

No. It is an administrative step that prevents any additional equity dilution; the economic effects of the merger have already occurred.

Is KRON still a publicly traded company after this filing?

No. Following the merger, Kronos Bio became a wholly-owned subsidiary of Concentra Biosciences and its public offerings were terminated.