Caribou Biosciences, Inc. 10-Q

Item 2. Unregistered Sales of Equity Securities and Use of Proceeds. Unregistered Sales of Equity Securities for the Three Months Ended March 31, 2023 There were no unregistered sales of equity securities during the three months ended March 31, 2023. Use of Proceeds from our IPO The net proceeds from our IPO, after deducting underwriting discounts and commissions and offering expenses of $28.6 million, were $321.0 million. We are holding a significant portion of the balance of the net proceeds from our IPO in money market mutual funds, U.S. Treasury bills, corporate debt securities, and U.S. government agency bonds. There has been no material change in our planned use of the net proceeds from our IPO described in the final prospectus for our IPO filed on July 23, 2021 with the SEC pursuant to Rule 424(b)(4) of the Securities Act. 30 Table of Contents Item 6. Exhibits. Exhibit Number Description 3.1 Amended and Restated Certificate of Incorporation of Caribou Biosciences, Inc. (incorporated by reference to Exhibit 3.1 to the Current Report on Form 8-K filed by the Registrant with the SEC on July 28, 2021) 3.2 Amended and Restated Bylaws of Caribou Biosciences, Inc. (incorporated by reference to Exhibit 3.2 to the Current Report on Form 8-K filed by the Registrant with the SEC on July 28, 2021) 4.1 Description of Common Stock (incorporated by reference to Exhibit 4.1 to the Form 10-K filed by the Registrant on March 21, 2022) 10.1† First Amendment to the Collaboration and License Agreement, dated February 21, 2023, between the Registrant and AbbVie Manufacturing Management Unlimited Company (incorporated by reference to Exhibit 10.2 to the Form 10-K filed by the Registrant with the SEC on March 9, 2023) 10.2† Side Letter to the Collaboration and License Agreement, dated January 30, 2023, between the Registrant and AbbVie Manufacturing Management Unlimited Company (incorporated by reference to Exhibit 10.3 to the Form 10-K filed by the Registrant with the SEC on March 9, 2023) 10.3+ Compensation Letter, dated February 16, 2023, from the Registrant to Rachel E. Haurwitz, Ph.D. (incorporated by reference to Exhibit 10.34 to the Form 10-K filed by the Registrant with the SEC on March 9, 2023) 10.4+ Compensation Letter, dated February 16, 2023, from the Registrant to Jason V. O’Byrne (incorporated by reference to Exhibit 10.38 to the Form 10-K filed by the Registrant with the SEC on March 9, 2023) 10.5+ Compensation Letter, dated February 16, 2023, from the Registrant to Barbara G. McClung, J.D. (incorporated by reference to Exhibit 10.41 to the Form 10-K filed by the Registrant with the SEC on March 9, 2023) 10.6+ Compensation Letter, dated February 16, 2023, from the Registrant to Steven B. Kanner, Ph.D. (incorporated by reference to Exhibit 10.44 to the Form 10-K filed by the Registrant with the SEC on March 9, 2023) 10.7+ Compensation Letter, dated February 16, 2023, from the Registrant to Ruhi Khan (incorporated by reference to Exhibit 10.47 to the Form 10-K filed by the Registrant with the SEC on March 9, 2023) 10.8+ Compensation Letter, dated February 16, 2023, from the Registrant to Syed Rizvi, M.D. (incorporated by reference to Exhibit 10.50 to the Form 10-K filed by the Registrant with the SEC on March 9, 2023) 31.1* Certification of Principal Executive Officer Pursuant to Rules 13a-14(a) and 15d-14(a) under the Exchange Act, as Adopted Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002. 31.2* Certification of Principal Financial Officer Pursuant to Rules 13a-14(a) and 15d-14(a) under the Exchange Act, as Adopted Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002. 32.1** Certification of Principal Executive Officer Pursuant to 18 U.S.C. Section 1350, as Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002. 32.2** Certification of Principal Financial Officer Pursuant to 18 U.S.C. Section 1350, as Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002. 101.INS* Inline XBRL Instance Document – the instance document does not appear in the Interactive Data File because XBRL tags are embedded within the Inline XBRL document. 101.SCH* Inline XBRL Taxonomy Extension Schema Document 101.CAL* Inline XBRL Taxonomy Extension Calculation Linkbase Document 101.DEF* Inline XBRL Taxonomy Extension Definition Linkbase Document 101.LAB* Inline XBRL Taxonomy Extension Label Linkbase Document 101.PRE* Inline XBRL Taxonomy Extension Presentation Linkbase Document 104* Cover Page Interactive Data File (embedded within the Inline XBRL document) ______________________________________________ * Filed herewith. ** Furnished herewith. † Indicates certain portions of this document that constitute confidential information have been redacted in accordance with Regulation S-K, Item 601(b)(10) 31 Table of Contents + Indicates management contract or compensatory plan 32 Table of Contents SIGNATURES Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized. Caribou Biosciences, Inc. Date: May 9, 2023 By: /s/ Rachel E. Haurwitz Rachel E. Haurwitz President and Chief Executive Officer (Principal Executive Officer) Date: May 9, 2023 By: /s/ Jason V. O'Byrne Jason V. O’Byrne Chief Financial Officer (Principal Financial Officer) 33