UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13D

(Amendment No. 1)

Under the Securities Exchange Act of 1934

EQRx, Inc.

(Name of Issuer)

Eli Casdin 

c/o Casdin Capital LLC

1350 Avenue of the Americas, Suite 2600

New York, New York 10019

(212) 897-5430

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

Common stock, par value $0.0001 per share

(Title of Class of Securities)

26886C107

(CUSIP Number)

November 23, 2022

(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.  ¨

Note: Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See §240.13d-7 for other parties to whom copies are to be sent.

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

The shares of Common Stock reported on this Statement were acquired in connection with the consummation of the transactions contemplated by the Agreement and Plan of Merger, dated August 5, 2021, by and among CM Life Sciences III Inc. (“CMLS III” or the “Company”), Clover III Merger Sub Inc. (“Merger Sub”) and EQRx, Inc. (“EQRx”) (as so amended and may be further amended from time to time, the “Merger Agreement”). Pursuant to the terms of the Merger Agreement, Merger Sub merged with and into EQRx with EQRx surviving the merger as a wholly owned subsidiary of CMLS III, which was renamed “EQRx International, Inc.” (the “Merger” and together with the other transactions contemplated by the Merger Agreement, the “Business Combination”).

The shares of Common Stock reported on this Statement were acquired for investment purposes. The Reporting Persons expect to evaluate on an ongoing basis the Company’s financial condition and prospects and their respective interests in, and intentions with respect to, the Company and their respective investments in the securities of the Company, which review may be based on various factors, including the Company’s business and financial condition, results of operations and prospects, general economic and industry conditions, the securities markets in general and those for the Company’s securities in particular, as well as other developments and other investment opportunities. Accordingly, each Reporting Person reserves the right to change its intentions, as it deems appropriate. In particular, each Reporting Person may, subject to any restrictions on the Reporting Persons pursuant to the agreements entered into in connection with the Business Combination, at any time and from time to time, in the open market, in privately negotiated transactions or otherwise, increase its holdings in the Company or dispose of all or a portion of the securities of the Company that such Reporting Person now owns or may hereafter acquire, including sales pursuant to the exercise of the registration rights provided for in the Registration Rights Agreement (as defined below). In addition, the Reporting Persons may engage in discussions with management and members of the Company’s board of directors regarding the Company, including, but not limited to, the Company’s business and financial condition, results of operations and prospects.

In connection with the acquisition of the Common Stock included in this Statement, the Reporting Persons entered into an Amended and Restated Registration Rights Agreement, dated as of December 17, 2021, by and among CMLS III, certain Reporting Persons and the other parties thereto (the “Registration Rights Agreement”) setting forth, among other things, certain rights and restrictions pertaining to the ownership and disposition of Common Stock by such Reporting Persons and their controlled affiliates. A copy of the Registration Rights Agreement is included as Exhibit 1 to this Statement.

Except as set forth above in this Item 4, the Reporting Persons have no present plans or proposals that relate to, or that would result in, any of the actions specified in clauses (a) through (j) of Item 4 of Schedule 13D under the Act.

On November 23, 2022, Mr. Casdin, a director of the Issuer, notified the Issuer of his decision to step down from the Board of Directors of the Issuer, effective as of November 23, 2022. Mr. Casdin’s decision was not the result of any disagreement with the Issuer on matters related to the Issuer’s operations, policies or practices.

The information set forth in the facing pages of this Schedule 13D with respect to the shared beneficial ownership of Common Stock by the Reporting Persons is incorporated by reference into this Item 5.

The information set forth in Items 2, 3 and 4 is hereby incorporated by reference into this Item 5.

(a) The aggregate number of shares of Common Stock and the percentage of total outstanding shares of Common Stock beneficially owned by the Reporting Persons is set forth below. References to percentage ownerships of shares of Common Stock in this Statement are based upon the 488,433,373 shares of Common Stock stated to be outstanding as of November 4, 2022 in the Company’s 10-Q filed with the Securities and Exchange Commission on November 10, 2022. The filing of this Statement shall not be construed as an admission that a Reporting Person beneficially owns those shares held by any other Reporting Person.

(b) Eli Casdin has shared power to vote or to direct the vote and shared power to dispose or to direct the disposition of 56,297,042 of the Common Stock reported in (a) above.

(c) Casdin Capital, LLC has shared power to vote or to direct the vote and shared power to dispose or to direct the disposition of 39,527,669 of the Common Stock reported in (a) above.

(c) Casdin Partners GP, LLC and CPMF have shared power to vote or to direct the vote and shared power to dispose or to direct the disposition of 30,214,933 of the Common Stock reported in (a) above.

The Reporting Persons have not effected any transactions in the Company’s Common Stock during the past 60 days.

No person other than the Reporting Persons is known to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, the Common Stock beneficially owned by the Reporting Persons.

The information set forth in Items 2, 3, 4 and 5 is hereby incorporated by reference into this Item 6. The Reporting Persons are party to the following contracts, agreements and understanding with respect to securities of the Company:

Registration Rights Agreement

In connection with the execution of the Business Combination Agreement, the Company, CMLS Holdings III and certain other parties thereto (collectively, the “rights holders”) entered into the Amended and Restated Registration Rights Agreement which amends and restates in its entirety the existing registration rights agreement, dated April 6, 2021, by and between the Company and the parties thereto. Pursuant to the terms of the Amended and Restated Registration Rights Agreement, the Company is to prepare and file with the SEC, no later than 30 days after the Closing Date, a shelf registration statement for an offering to be made on a continuous basis from time to time with respect to the resale of the registrable shares under the Amended and Restated Registration Rights Agreement. The Company is further required to use commercially reasonable efforts to cause such shelf registration statement to be declared effective as soon as possible after filing, but in no event later than the earlier of 60 days following the filing date thereof and five business days after the SEC notifies the Company that it will not review such registration statement, subject to extension in the event that the registration is subject comments from the SEC.

In addition, pursuant to the terms of the Amended and Restated Registration Rights Agreement and subject to certain requirements and customary conditions, including with regard to the number of demand rights that may be exercised, the rights holders may demand at any time or from time to time, that the Company file a registration statement on Form S-1 or Form S-3 to register certain shares of the Company’s Class A common stock held by such rights holders. The Amended and Restated Registration Rights Agreement will also provide the rights holders with “piggy-back” registration rights, subject to certain requirements and customary conditions. The Company will bear the expenses incurred in connection with the filing of any such registration statement.

This summary description does not purport to be complete, and is qualified in its entirety by reference to the Registration Rights Agreement, a copy of which is filed as Exhibit 1 to this Statement.

Insider Letter

CMLS III, CMLS Holdings III and each insider and CMLS Holdings III entered into the Insider Letter providing for a lock-up in relation to CMLS Holdings II’s Class B common stock (as defined in the Insider Letter) of CMLS III or any shares of Class A common stock (as defined in the Insider Letter) of CMLS II until the earlier of (a) one year after the completion of CMLS’s initial business combination and (b) subsequent to the business combination, (x) if the closing price of the Class A common stock equals or exceeds $12.00 per share (as adjusted for stock splits, stock dividends, reorganizations, recapitalizations, and the like) for any 20 trading days within any 30-day trading day period commencing at least 180 days after CMLS’s initial business combination or (y) the date following the completion of CMLS’s initial business combination on which CMLS completes a liquidation, merger, capital stock exchange, reorganization or other similar transaction that results in all of CMLS’s stockholders having the right to exchange their shares of Class A common stock for cash securities or other property. CMLS Holdings II and each insider also agreed not to transfer any private placement warrants (or any share of Class A common stock issued or issuable upon the exercise of the private placement warrants), until 30 days after the completion of a business combination.

This summary description does not purport to be complete, and is qualified in its entirety by reference to the Insider Letter, a copy of which is filed as Exhibit 2 to this Statement.

Item 7

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.

EXHIBIT INDEX

EXHIBIT A

JOINT FILING AGREEMENT

PURSUANT TO RULE 13d-1(k)

The undersigned acknowledge and agree that the foregoing statement on Schedule 13D is filed on behalf of each of the undersigned and that all subsequent amendments to this statement on Schedule 13D shall be filed on behalf of each of the undersigned without the necessity of filing additional joint filing agreements. The undersigned acknowledge that each shall be responsible for the timely filing of such amendments, and for the completeness and accuracy of the information concerning him or it contained herein and therein, but shall not be responsible for the completeness and accuracy of the information concerning the others, except to the extent that he or it knows or has reason to believe that such information is inaccurate.