What changed in this filing

/stocks — the workspaceLOADING

Item 9A. Controls and Procedures

2024-03-11 compared with 2023-03-09 · 355 added, 379 removed, 991 unchanged (43% of the section changed)

9 unchanged sentences

Our management is responsible for establishing and maintaining adequate internal control over financial reporting as defined in Rules 13a-15(f) and 15d-15(f) under the Exchange Act.

Our internal control over financial reporting is a process designed to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with GAAP.

Our internal control over financial reporting is a

process designed to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with U.S.

Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements.

Also, projections of any evaluation of effectiveness to future periods are subject to the risk that controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate.

Table of Conte n t s

Our management assessed the effectiveness of our internal control over financial reporting as of December 31, 2023 based on the criteria set forth by the Committee of Sponsoring Organizations of the Treadway Commission in its 2013 Internal Control - Integrated Framework.

1 unchanged sentence

Attestation Report of the Registered Public Accounting Firm

Our independent registered accounting firm will not be required to opine on the effectiveness of our internal control over financial reporting pursuant to Section 404 of Sarbanes-Oxley Act of 2002 until we are no longer either an “emerging growth company” as defined in the JOBS Act or a smaller reporting company as defined by Rule 12b-2 of the Securities Exchange Act of 1934, as amended, that does not otherwise also qualify as an “accelerated filer” or “large accelerated filer” for SEC reporting purposes.

Our independent registered accounting firm is not required to opine on the effectiveness of our internal control over financial reporting pursuant to Section 404 of Sarbanes-Oxley Act of 2002 until we are no longer either an “emerging growth company” as defined in the JOBS Act or a smaller reporting company as defined by Rule 12b-2 of the Exchange Act that does not otherwise also qualify as an “accelerated filer” or “large accelerated filer” for SEC reporting purposes.

Changes in Internal Control

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Other Information.

Not applicable.

(a) Not applicable.

(b) During the quarter ended December 31, 2023, no director or Section 16 officer adopted or terminated any Rule 10b5-1 trading arrangement or non-Rule 10b5-1 trading arrangement.

Disclosure Regarding Foreign Jurisdictions that Prevent Inspections.

Not applicable.

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Certain information required by Part III is incorporated by reference herein to our definitive proxy statement for our 2023 Annual Meeting of Stockholders (the “2023 Proxy Statement”) pursuant to Regulation 14A of the Exchange Act, which we intend to file not later than 120 days after the end of the fiscal year covered by this Annual Report on Form 10-K.

Certain information required by Part III is incorporated by reference herein to our definitive proxy statement for our 2024 Annual Meeting of Stockholders (“2024 Proxy Statement”) pursuant to Regulation 14A of the Securities Exchange Act of 1934, as amended (“Exchange Act”), which we intend to file not later than 120 days after the end of the fiscal year covered by this Annual Report on Form 10-K.

Directors, Executive Officers and Corporate Governance.

The information required by this item of Form 10-K will be included under the caption “Board of Directors and Corporate Governance” and subsections thereof including “--Nominees for Election as Class II Directors,” “--Directors Continuing in Office,” “--Family Relationships,” “--Classified Board of Directors,” and “--Board Committees--Audit Committee,” and under the caption “Executive Officers,” in our 2023 Proxy Statement, and is incorporated by reference herein..

The information required by this item of Form 10-K will be included under the caption “Board of Directors and Corporate Governance” and subsections thereof, including “—Nominees for Election as Class III Directors,” “—Directors Continuing in Office,” “—Family Relationships,” “—Classified Board of Directors,” and “—Board Committees—Audit Committee,” and under the caption “Executive Officers” in our 2024 Proxy Statement and is incorporated by reference herein.

We have adopted a written Code of Business Conduct, Scientific and Data Integrity, and Ethics (“Code of Conduct”) that applies to all of our employees, consultants, contractors, and directors.

17 unchanged sentences

2 - Ratification of Selection of Independent Registered Public Accounting Firm” in our 2024 Proxy Statement and is incorporated by reference herein.

Table of Conte n t s

Exhibits, Financial Statement Schedules.

4 unchanged sentences

Consolidated Statements of Operations and Comprehensive Loss

Consolidated Statements of Convertible Preferred Stock Stockholders’ Equity (Deficit)

Consolidated Statements of Stockholders’ Equity

Consolidated Statements of Cash Flows

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001-40631) , filed with the SEC on March 21, 2022)

10.1† Collaboration and License Agreement , dated February 9, 2021, between the Registrant and AbbVie Manufacturing Management Unlimited Company (incorporated by reference to Exhibit 10.1 of the Form S-1 filed by the Registrant on July 1, 2021 (File No.

10.1 † Exclusive License Agreement, dated November 13, 2020, by and between the Registrant and Memorial Sloan Kettering Cancer Center (incorporated by reference to Exhibit 10.2 of the Form S-1) filed by the Registrant on July 1, 2021 (File No.

333-257604) (the “Form S-1”)

10.2†* First Amendment to the Collaboration and License Agreement, dated February 21, 2023, between the Registrant and AbbVie Manufacturing Management Unlimited Company

10.3†* Side Letter to the Collaboration and License Agreement, dated January 30 , 2023, between the Registrant and AbbVie Manufacturing Management Unlimited Company

Table of Conte n t s

10.4† Exclusive License Agreement , dated November 13, 2020, by and between the Registrant and Memorial Sloan Kettering Cancer Center (incorporated by reference to Exhibit 10.2 of the Form S-1)

Sale and Assignment Agreement, dated January 31, 2020, by and between the Registrant and ProMab Biotechnologies, Inc.

45 unchanged sentences

Consent to Assignments, Licensing and Common Ownership and Invention Management Agreement for a Programmable DNA Restriction Enzyme for Genome Editing, dated December 15, 2016, by and among the Registrant and the other parties thereto (incorporated by reference to Exhibit 10.20 of the Form S-1)

Table of Conte n t s

Exclusive License Agreement, dated April 16, 2013, by and among the Registrant, The Regents of the University of California, and the University of Vienna (incorporated by reference to Exhibit 10.21 of the Form S-1)

22 unchanged sentences

Haurwitz, Ph.D .

(incorporated by reference to Exhibit 10.

34 of the Registrant’s Annual Report on Form 10-K for the fiscal year ended December 31, 2022 (File No.

001-40631), filed with the SEC on March 9, 2023)

Compensation Letter, dated February 20, 2024 , from the Registrant to Rachel E.

Haurwitz, Ph.D.

Officer Employment Agreement by and between the Registrant and Jason V.

8 unchanged sentences

Compensation Letter, dated February 16, 2023, from the Registrant to Jason V.

O’Byrne (incorporated by reference to Exhibit 10.

38 of the Registrant’s Annual Report on Form 10-K for the fiscal year ended December 31, 2022 (File No.

001-40631), filed with the SEC on March 9, 2023)

Compensation Letter, dated February 20, 2024, from the Registrant to Jason V.

10.38+ Officer Employment Agreement by and between the Registrant and Barbara G.

5 unchanged sentences

001-40631) , filed with the SEC on March 21, 2022)

Table of Conte n t s

Compensation Letter, dated February 16, 2023, from the Registrant to Barbara G.

McClung, J.D.

(incorporated by reference to Exhibit 10.

41 of the Registrant’s Annual Report on Form 10-K for the fiscal year ended December 31, 2022 (File No.

001-40631), filed with the SEC on March 9, 2023)

Compensation Letter, dated February 20, 2024, from the Registrant to Barbara G.

McClung, J.D.

10.42+ Officer Employment Agreement by and between the Registrant and Steven B.

7 unchanged sentences

Kanner, Ph.D.

(incorporated by reference to Exhibit 10.

44 of the Registrant’s Annual Report on Form 10-K for the fiscal year ended December 31, 2022 (File No.

001- 40631), filed with the SEC on March 9, 2023)

Compensation Letter, dated February 20, 2024, from the Registrant to Steven B.

Kanner, Ph.D.

Officer Employment Agreement by and between the Registrant and Ruhi Khan, dated November 8, 2021 (incorporated by reference to Exhibit 10.39 of the Registrant’s Annual Report on Form 10-K for the fiscal year ended December 31, 2021 (File No.

001-40631) , filed with the SEC on March 21, 2022)

10.46+†* Compensation Letter, dated February 11, 2022, from the Registrant to Ruhi Khan (incorporated by reference to Exhibit 10.40 of the Registrant’s Annual Report on Form 10-K for the fiscal year ended D ecember 31, 2021 (File No.

Compensation Letter, dated February 11, 2022, from the Registrant to Ruhi Khan (incorporated by reference to Exhibit 10.4 6 of the Registrant’s Annual Report on Form 10-K for the fiscal year ended December 31, 202 2 (File No.

001-40631), filed with the SEC on March 9 , 202 3 )

Compensation Letter, dated February 16, 2023, from the Registrant to Ruhi Khan (incorporated by reference to Exhibit 10.

47 of the Registrant’s Annual Report on Form 10-K for the fiscal year ended December 31, 2022 (File No.

001-40631), filed with the SEC on March 9, 2023)

Compensation Letter, dated February 20, 2024, from the Registrant to Ruhi Khan

2 unchanged sentences

001-40631) , filed with the SEC on March 21, 2022)

10.49+ Officer Employment Agreement by and between the Registrant and Syed Rizvi , M.D.

, dated January 18, 2022 (incorporated by reference to Exhibit 10.4 2 of the Registrant’s Annual Report on Form 10-K for the fiscal year ended December 31, 2021 (File No.

Officer Employment Agreement by and between the Registrant and Syed Rizvi, M.D., dated January 18, 2022 (incorporated by reference to Exhibit 10.42 of the Registrant’s Annual Report on Form 10-K for the fiscal year ended December 31, 2021 (File No.

001-40631) , filed with the SEC on March 21, 2022)

Compensation Letter, dated February 16, 2023, from the Registrant to Syed Rizvi, M.D.

(incorporated by reference to Exhibit 10.

50 of the Registrant’s Annual Report on Form 10-K for the fiscal year ended December 31, 2022 (File No.

001-40631), filed with the SEC on March 9, 2023)

Separation Letter, dated December 19, 2023, between the Registrant and Syed Rizvi, M.D.

Offer Letter, dated November 22 , 2023 , between the Registrant and T im Kelly

Officer Employment Agreement by and between the Registrant and Tim Kelly , dated Januar y 1 , 2024

10.56+ 2013 Equity Incentive Plan (as originally adopted) (incorporated by reference to Exhibit 99.1 of the Form S-8 filed by the Registrant on July 26, 2021 (File No.:

9 unchanged sentences

10.62+ 2021 Equity Incentive Plan of the Registrant (incorporated by reference to Exhibit 99.6 of the Form S-8)

10.58+ Form of Employee Stock Option Agreement under the 2021 Equity Incentive Plan of the Registrant (incorporated by reference to Exhibit 10.

5 0 of the Registrant’s Annual Report on Form 10-K for the fiscal year ended December 31, 2021 (File No.:

Form of Employee Stock Option Agreement under the 2021 Equity Incentive Plan of the Registrant (incorporated by reference to Exhibit 10.50 of the Registrant’s Annual Report on Form 10-K for the fiscal year ended December 31, 2021 (File No.:

333-258173) , filed with the SEC on March 21, 2022)

10.59+ Form of Non-Employee Director Stock Option Agreement under the 2021 Equity Incentive Plan of the Registrant (incorporated by reference to Exhibit 10.

51 of the Registrant’s Annual Report on Form 10-K for the fiscal year ended December 31, 2021 (File No.:

Form of Non-Employee Director Stock Option Agreement under the 2021 Equity Incentive Plan of the Registrant (incorporated by reference to Exhibit 10.51 of the Registrant’s Annual Report on Form 10-K for the fiscal year ended December 31, 2021 (File No.:

333-258173) , filed with the SEC on March 21, 2022)

10.60+ Form of Restricted Stock Unit Award Grant Notice and Restricted Stock Unit Award Agreement under the 2021 Equity Incentive Plan of the Registrant (incorporated by reference to Exhibit 10.

5 2 of the Registrant’s Annual Report on Form 10-K for the fiscal year ended December 31, 2021 (File No.:

Form of Restricted Stock Unit Award Grant Notice and Restricted Stock Unit Award Agreement under the 2021 Equity Incentive Plan of the Registrant (incorporated by reference to Exhibit 10.52 of the Registrant’s Annual Report on Form 10-K for the fiscal year ended December 31, 2021 (File No.:

333-258173) , filed with the SEC on March 21, 2022)

Table of Conte n t s

Form of Restricted Stock Unit Award Grant Notice and Restricted Stock Unit Award Agreement under the 2021 Equity Incentive Plan of the Registrant (incorporated by reference to Exhibit 10.1 of the Registrant’s Quarterly Report on Form 10-Q for the period ended September 30, 2022 (File No.:

4 unchanged sentences

10.69 Form of Indemnification Agreement between the Registrant and its directors and officers (incorporated by reference to Exhibit 10.50 of the Form S-1)

10.65 Promissory Note, dated November 27, 2018 made by Rachel E.

Haurwitz, Ph.D.

in favor of the Registrant (incorporated by reference to Exhibit 10.48 of the Form S-1)

10.66 Pledge and Security Agreement, dated November 27, 2018, by and between the Registrant and Rachel E.

Haurwitz, Ph.D.

(incorporated by reference to Exhibit 10.49 of the Form S-1)

10.67 Series C Preferred Stock Purchase Agreement, dated March 2, 2021, by and among the Registrant and the parties listed therein (incorporated by reference to Exhibit 10.59 of the Form S-1)

10.68 Third Amended and Restated Voting Agreement, dated March 2, 2021, by and among the Registrant and the parties listed therein (incorporated by reference to Exhibit 10.60 of the Form S-1)

10.69 First Amendment to Third Amended and Restated Voting Agreement, dated March 29, 2021, by and among the Registrant and the parties listed therein (incorporated by reference to Exhibit 10.61 of the Form S-1)

10.70 Second Amended and Restated Right of First Refusal and Co-Sale Agreement, dated March 2, 2021, by and among the Registrant and the parties listed therein (incorporated by reference to Exhibit 10.62 of the Form S-1)

10.71 Second Amended and Restated Investors’ Rights Agreement, dated March 2, 2021, by and among the Registrant and the investors listed therein (incorporated by reference to Exhibit 4.1 of the Form S-1)

10.70 Open Market Sale Agreement SM , dated August 9, 2022, by and between the Registrant and Jefferies LLC (incorporated by reference to Exhibit 1.2 to the Company’s Registration Statement on Form S-3 (File No.

333-266712) filed with the SEC on August 9, 2022)

10.71 Securities Purchase Agreement, dated June 29, 2023, by and between the Registrant and Pfizer, Inc.

(incorporated by reference to Exhibit 10.1 to the Form 8-K filed by the Registrant with the SEC on July 6, 2023)

10.72 Voting Agreement, dated June 29.

2023, by and between the Registrant and Pfizer, Inc.

(incorporated by reference to Exhibit 10.2 to the Form 8-K filed by the Registrant with the SEC on July 6, 2023)

21.1* List of Subsidiaries of the Registrant

6 unchanged sentences

Section 1350, as Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.

C lawback Policy

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.

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101.PRE* Inline XBRL Taxonomy Extension Presentation Linkbase Document

Table of Conte n t s

104 Cover Page Interactive Data File (formatted as inline XBRL and contained in Exhibit 101)

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# This certification is being furnished solely to accompany this Annual Report on Form 10-K pursuant to 18 U.S.C.

Section 1350, and is not being filed for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liability of that section, nor shall it be deemed incorporated by reference into any filing of the Registrant under the Securities Act of 1933, as amended, or the Securities Exchange Act of 1934, as amended, whether made before or after the date hereof, regardless of any general incorporation language in such filing.

Table of Conte n t s

Section 1350, and is not being filed for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (“Exchange Act”), or otherwise subject to the liability of that section, nor shall it be deemed incorporated by reference into any filing of the Registrant under the Securities Act of 1933, as amended, or the Exchange Act, whether made before or after the date hereof, regardless of any general incorporation language in such filing.

Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, as amended, the Registrant has duly caused this Annual Report on Form 10-K (this “Report”) to be signed on its behalf by the undersigned, thereunto duly authorized .

7 unchanged sentences

Haurwitz President and Chief Executive Officer ( Principal Executive Officer );

Director March 9, 2023

O’Byrne Chief Financial Officer (Principal Financial Officer & Principal Accounting Officer) March 9, 2023

March 11, 2024

O’Byrne Chief Financial Officer ( Principal Financial Officer & Principal Accounting Officer )

March 11, 2024

/s/ Scott Braunstein Director March 11, 2024

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/s/ Ran Zheng Director March 11, 2024

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INDEX TO CONSOLIDATED FINANCIAL STATEMENTS

3 unchanged sentences

Consolidated Statements of Operations and Comprehensive Loss

Consolidated Statements of Convertible Preferred Stock and Stockholders’ Equity

Consolidated Statements of Stockholders’ Equity

Consolidated Statements of Cash Flows

Notes to Consolidated Financial Statements

Table of Conte n t s

REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

2 unchanged sentences

We have audited the accompanying consolidated balance sheets of Caribou Biosciences, Inc.

and subsidiaries (the “Company”) as of December 31, 2022 and 2021, the related consolidated statements of operations and comprehensive loss, convertible preferred stock and stockholders' equity (deficit), and cash flows, for each of the two years in the period ended December 31, 2022, and the related notes (collectively referred to as the “financial statements”).

and subsidiaries (the "Company") as of December 31, 2023 and 2022, the related consolidated statements of operations and comprehensive loss, stockholders' equity, and cash flows, for each of the two years in the period ended December 31, 2023, and the related notes (collectively referred to as the "financial statements").

In our opinion, the financial statements present fairly, in all material respects, the financial position of the Company as of December 31, 2023 and 2022, and the results of its operations and its cash flows for each of the two years in the period ended December 31, 2023, in conformity with accounting principles generally accepted in the United States of America.

Change in Accounting Principle

As discussed in Note 2 to the financial statements, effective January 1, 2022, the Company adopted ASC No.

2016-02, Leases (Topic 842), using the modified retrospective approach.

Basis for Opinion

16 unchanged sentences

We have served as the Company's auditor since 2016.

Table of Conte n t s

CARIBOU BIOSCIENCES, INC.

22 unchanged sentences

Accrued expenses and other current liabilities 21,135 16,079

Lease liabilities, current 966 —

Operating lease liabilities, current

Deferred revenue ($ 2,487 and $ 150 from related party, respectively)

1 unchanged sentence

LONG-TERM LIABILITIES

Deferred revenue, net of current portion ($ 0 and $ 100 from related party)

15,954 22,032

Deferred rent and lease incentive liability — 2,097

Deferred revenue, net of current portion ($ 3,730 and $ 0 from related party, respectively)

MSKCC success payments liability 2,939 1,651

Lease liabilities, non-current 26,780 —

Other liabilities — 17

Operating lease liabilities, non-current

25,908 26,780

Deferred tax liabilities 557 381

2 unchanged sentences

STOCKHOLDERS’ EQUITY

Preferred stock, par value $ 0.0001 per share, 10,000,000 shares authorized at December 31, 2022 and 2021, respectively;

no shares issued and outstanding as of December 31, 2022 and 2021, respectively.

Common stock, par value $ 0.0001 per share, 300,000,000 shares authorized at December 31, 2023 and 2022, respectively;

1 unchanged sentence

Additional paid-in-capital 667,648 499,598

Accumulated other comprehensive loss ( 1,518 ) ( 135 )

Accumulated other comprehensive income (loss)

Accumulated deficit ( 299,285 ) ( 197,215 )

2 unchanged sentences

The accompanying notes are an integral part of these consolidated financial statements.

Table of Conte n t s

CARIBOU BIOSCIENCES, INC.

3 unchanged sentences

Years Ended December 31,

Licensing and collaboration revenue $ 13,851 $ 9,598

Licensing and collaboration revenue (including $ 2,393 and $ 0 , from related parties)

$ 34,477 $ 13,851

Operating expenses:

6 unchanged sentences

Change in fair value of the MSKCC success payments liability ( 1,288 ) 2,429

Gain on extinguishment of PPP Loan — 1,584

Other income, net 15,476 4,752

3 unchanged sentences

Net loss ( 102,070 ) ( 99,421 )

Other comprehensive loss:

Net unrealized loss on available-for-sale marketable securities ( 1,383 ) ( 135 )

Other comprehensive income (loss):

Net unrealized gain (loss) on available-for-sale marketable securities

1,548 ( 1,383 )

Net comprehensive loss $ ( 100,522 ) $ ( 100,804 )

2 unchanged sentences

The accompanying notes are an integral part of these consolidated financial statements.

Table of Conte n t s

CARIBOU BIOSCIENCES, INC.

AND ITS SUBSIDIARIES

Consolidated Statements of Convertible Preferred Stock and Stockholders’ Equity (Deficit)

Consolidated Statements of Stockholders’ Equity

(in thousands, except share amounts)

Convertible Preferred Stock Common Stock Additional

Capital Other Comprehensive

Income (Loss) Retained

Common Stock Additional

Capital Accumulated Other Comprehensive

Income (Loss)

Deficit Total

Stockholders’

Shares Amount Shares Amount

Shares Amount

BALANCE—December 31, 2021 60,263,158 $ 6 $ 485,748 $ ( 135 ) $ ( 97,794 ) $ 387,825

Issuance of Series C convertible preferred stock, net of issuance costs of $ 6.2 million

6,663,940 108,827 — — — — — —

Repayment of loan issued by stockholder — — — — 1,150 — — 1,150

Conversion of convertible preferred stock into common stock ( 14,430,522 ) ( 150,150 ) 26,234,654 3 150,147 — — 150,150

Issuance of common stock upon initial public offering, net of issuance costs of $ 28.6 million

— — 21,850,000 2 321,018 — — 321,020

Issuance of common stock upon employee stock plans 69,113 — 638 — — 638

Issuance of common stock on exercise of options 696,913 — 1,497 — — 1,497

5 unchanged sentences

Issuance of common stock on exercise of options 228,264 — 793 — — 793

Issuance of common stock on RSU release 78,596 — — — — —

Issuance of common stock in connection with public follow-on offering, net of offering expenses

22,115,384 2 134,423 — — 134,425

Issuance of common stock in connection with at-the-market offering, net of offering expenses 168,635 — 1,007 — — 1,007

Issuance of common stock pursuant to a private placement with Pfizer 4,690,431 — 17,290 — — 17,290

Stock-based compensation expense — — 13,750 — — 13,750

Other comprehensive loss — — — — — ( 1,383 ) — ( 1,383 )

Other comprehensive income — — — 1,548 — 1,548

Net loss — — — — ( 102,070 ) ( 102,070 )

1 unchanged sentence

The accompanying notes are an integral part of these consolidated financial statements.

Table of Conte n t s

CARIBOU BIOSCIENCES, INC.

7 unchanged sentences

Depreciation and amortization 3,525 1,622

Loss on disposal of property and equipment — 4

Change in fair value of equity securities 133 —

Gain on disposal of fixed assets ( 34 ) —

Non-cash consideration for licensing and collaboration revenue ( 61 ) ( 205 )

Change in fair value of equity securities 6 133

Stock-based compensation expense 13,750 11,716

1 unchanged sentence

Acquired in-process research and development — 600

Extinguishment of PPP Loan and accrued interest — ( 1,578 )

Amortization of premiums on marketable securities ( 797 ) 52

Accretion of discounts on investments in marketable securities, net

( 4,425 ) ( 797 )

Non-cash lease expense 2,048 2,019

8 unchanged sentences

Deferred revenue, current and long-term ( 16,943 ) ( 4,844 )

Deferred rent and lease incentive liability — 1,173

Operating lease liabilities ( 637 ) ( 403 )

3 unchanged sentences

CASH FLOWS FROM INVESTING ACTIVITIES:

Maturities of marketable securities 252,868 —

Proceeds from sales and maturities of marketable securities 338,188 252,868

Purchases of marketable securities ( 394,758 ) ( 339,063 )

3 unchanged sentences

CASH FLOWS FROM FINANCING ACTIVITIES:

Proceeds from initial public offering of common stock, net of offering costs — 321,020

Proceeds from issuance of Series C convertible preferred stock, net of issuance costs — 108,827

Proceeds from public follow-on public offering, net of offering expenses

Proceeds from issuance of common stock in a private placement with Pfizer 17,290 —

Proceeds from exercise of stock options and purchases of common stock under employee stock purchase plan 1,578 2,133

Repayment of promissory note — 1,150

Payments on capital lease — ( 119 )

Proceeds from issuance of common stock related to at-the-market offering, net of offering expenses 1,007 —

Net cash provided by financing activities 154,298 2,133

NET INCREASE (DECREASE) IN CASH, CASH EQUIVALENTS, AND RESTRICTED CASH ( 182,082 ) 224,513

NET DECREASE IN CASH, CASH EQUIVALENTS, AND RESTRICTED CASH

( 7,176 ) ( 182,082 )

CASH, CASH EQUIVALENTS, AND RESTRICTED CASH — BEGINNING OF PERIOD 58,384 240,466

7 unchanged sentences

SUPPLEMENTAL SCHEDULE OF NON-CASH INVESTING AND FINANCING ACTIVITIES:

Purchases of property and equipment unpaid at period end $ 1,223 $ 265

Extinguishment of PPP Loan and accrued interest $ — $ 1,578

Purchases of property and equipment included in accounts payable and accrued expenses $ 692 $ 1,223

Right-of-use-assets obtained in exchange for new operating lease liabilities $ — $ 26,249

Conversion of convertible preferred stock to common stock at closing of initial public offering $ — $ 150,150

The accompanying notes are an integral part of these consolidated financial statements.

Table of Conte n t s

CARIBOU BIOSCIENCES, INC.

4 unchanged sentences

Caribou Biosciences, Inc.

(the “Company” or “we”) is a clinical-stage C lustered R egularly I nterspaced S hort P alindromic R epeats (“CRISPR”) genome-editing biopharmaceutical company dedicated to developing transformative therapies for patients with devastating diseases.

Our genome-editing platform, including our novel chRDNA ( C RISPR h ybrid R NA- DNA , or “chRDNA,” pronounced “chardonnay”) technologies, enables superior editing precision to develop cell therapies that are armored to improve antitumor activity.

(“Company” or “we”) is a clinical-stage C lustered R egularly I nterspaced S hort P alindromic R epeats (“CRISPR”) genome-editing biopharmaceutical company dedicated to developing transformative therapies for patients with devastating diseases.

Our genome-editing platform, including our novel chRDNA ( C RISPR h ybrid R NA- DNA , or “chRDNA,” pronounced “chardonnay”) technology, enables more precise genome editing to develop cell therapies that are armored to improve antitumor activity.

We are advancing a pipeline of allogeneic, or off-the-shelf, cell therapies from our chimeric antigen receptor (“CAR”) T (“CAR-T”) cell and CAR-natural killer (“CAR-NK”) cell platforms as readily available therapeutic treatments for patients.

6 unchanged sentences

Our wholly owned subsidiaries hold interests in our equity investments and do not have operating activities.

Initial Public Offering

On July 22, 2021, our registration statement on Form S-1 (File No.

333-257604) relating to our initial public offering (“IPO”) of common stock became effective.

Our IPO closed on July 27, 2021, at which time we issued 19,000,000 shares of our common stock at a price of $ 16.00 per share.

On August 9, 2021, we issued and sold an additional 2,850,000 shares of our common stock to the IPO underwriters pursuant to the full exercise of their over-allotment option to purchase additional shares at the public offering price of $ 16.00 per share.

We received an aggregate of $ 349.6 million in gross proceeds and approximately $ 321.0 million in net proceeds from our IPO after deducting underwriting discounts and commissions and offering costs through the issuance of a total of 21,850,000 shares of our common stock.

Upon closing of our IPO, all outstanding shares of our convertible preferred stock converted into 26,234,654 shares of our common stock.

In connection with the completion of our IPO, on July 27, 2021, our Certificate of Incorporation was amended and restated to provide for 300,000,000 authorized shares of common stock with a par value of $ 0.0001 per share and 10,000,000 authorized shares of preferred stock with a par value of $ 0.0001 per share.

We have incurred net losses and negative cash flows from operations since our inception and we had an accumulated deficit of $ 197.2 million as of December 31, 2022.

We have incurred operating losses and negative cash flows from operations since our inception and we had an accumulated deficit of $ 299.3 million as of December 31, 2023.

During the year ended December 31, 2023, we incurred a net loss of $ 102.1 million and used $ 93.3 million of cash in operating activities.

We expect to continue to incur substantial losses, and our ability to achieve and sustain profitability will depend on the successful development, approval, and commercialization of our product candidates and on our achievement of sufficient revenue to support our cost structure.

We expect to continue to incur substantial losses, and our ability to achieve and sustain profitability will depend on the successful development, regulatory approval, and commercialization of our product candidates and on our generation of sufficient revenue to support our cost structure.

We may never achieve profitability and, unless and until we do, we will need to continue to raise additional capital.

Our management expects that existing cash, cash equivalents, and marketable securities of $ 372.4 million as of December 31, 2023, will be sufficient to fund our current operating plan for at least the next 12 months from the date of issuance of our consolidated financial statements.

In July and August of 2023, we issued and sold a total of 22,115,384 shares of our common stock in an underwritten follow-on public offering for total net proceeds of approximately $ 134.4 million, which included the full exercise of the underwriters’ right to purchase 2,884,615 additional shares of our common stock.

During the year ended December 31, 2023, we sold 168,635 shares of our common stock under the Open Market Sale Agreement SM (“ATM Sales Agreement”) with Jefferies LLC (“Jefferies”), at an average price per share of $ 7.32 for aggregate gross proceeds of $ 1.2 million ($ 1.0 million net of offering expenses).

In February 2024, we sold 1,594,171 shares of our common stock under the ATM Sales Agreement, at an average price per share of $ 7.33 for aggregate gross proceeds of $ 11.7 million ($ 11.3 million, net of offering expenses).

Summary of Significant Accounting Policies

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The consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“U.S.

GAAP”) and include the accounts of Caribou Biosciences, Inc.

and its wholly owned subsidiaries.

GAAP”) and include our and the accounts of our wholly owned subsidiaries.

All intercompany accounts and transactions are eliminated in consolidation.

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Forward Stock Split

In July 2021, our board of directors and stockholders approved an amendment to our certificate of incorporation to effect a forward split of the shares of our outstanding common stock at a ratio of 1.818 -for-1 (the “Forward Stock Split”), which became effective July 15, 2021.

The number of authorized shares was increased as a result of the Forward Stock Split, but the par values of the common stock and preferred stock were not adjusted.

All references to common stock, options to purchase common stock, common stock share data, per share data, and related information contained in the consolidated financial statements have been retrospectively adjusted to reflect the effect of the Forward Stock Split for all periods presented.

Use of Estimates

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and the reported amounts of revenue, income, and expenses during the applicable reporting period.

On an ongoing basis, we evaluate our estimates and assumptions, including those related to revenue recognition, common stock valuation, stock-based compensation expense, accrued expenses related to research and development activities, valuation of the Memorial Sloan Kettering Cancer Center (“MSKCC”) success payments liability, and income taxes.

On an ongoing basis, we evaluate our estimates and assumptions, including those related to revenue recognition, stock-based compensation expense, accrued expenses related to research

and development activities, valuation of the Memorial Sloan Kettering Cancer Center (“MSKCC”) success payments liability, operating lease right-of-use assets and liabilities, and income taxes.

Our management bases its estimates on historical experience and on various other assumptions that they believe to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources.

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Financial instruments that potentially subject us to concentration of credit risk consist of cash and cash equivalents, accounts receivable, contract assets, other receivables, and investments in marketable securities and equity securities.

Substantially all of our cash and cash equivalents are deposited in accounts at two financial institutions, and account balances may at times exceed federally insured limits.

Substantially all of our cash and cash equivalents are deposited in accounts at three financial institutions, and our account balances exceed federally insured limits.

We mitigate the risks by investing in high-grade instruments, limiting our exposure to one issuer, and we monitor the ongoing creditworthiness of the financial institutions and issuers.

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Contract Assets

Years Ended As of December 31,

December 31, 2022 December 31, 2021 2022 2021

Years Ended December 31, As of December 31,

2023 2022 2023 2022

Licensee A * 16.2 % 47.5 % 23.8 %

Licensee B, related party * * * *

Licensee C 57.4 % 41.4 % 36.6 % 45.1 %

71.9 % 57.4 % * 36.6 %

Total 71.9 % 73.6 % 47.5 % 60.4 %

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We monitor economic conditions to identify facts or circumstances that may indicate if any of our accounts receivable are not collectible or if the contract assets should be impaired.

No allowance for doubtful accounts or contract asset impairment was recorded as of December 31, 2022 or 2021.

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No allowance for credit losses or contract asset impairment was recorded as of December 31, 2023 or 2022.

Revenue Recognition

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nonrefundable upfront license fees, maintenance fees, milestones, and other contingent payments to us for the achievement of defined collaboration objectives and certain preclinical, clinical, regulatory, and sales-based events, as well as royalties on sales of any commercialized products.

We assess whether the promises in our arrangements with customers are considered distinct performance obligations that should be accounted for separately.

We assess whether the promises in our contracts with third parties are considered distinct performance obligations that should be accounted for separately.

Judgment is required to determine whether a license to our intellectual property is distinct from research and development services or participation on research or governance committees.

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We evaluate the measure of progress using the input method for each reporting period and, if necessary, adjust the measure of performance and related revenue recognition.

Certain of our license agreements as well as our license and collaboration agreement include contingent milestone payments.

Certain of our license agreements include contingent milestone payments.

Such milestone payments are typically payable when the collaborator or licensee achieves certain predetermined clinical, regulatory, and/or commercial milestones.

Milestone payments that are not within our control or the control of the collaborator or licensee, such as regulatory approvals, are not considered probable of being achieved until those approvals are received.

Milestone payments that are not within our control or the control of the licensee, such as regulatory approvals, are not considered probable of being achieved until those approvals are received.

At each reporting date, we reevaluate whether the milestones are considered probable of being reached, and we estimate the amount to be included in the transaction price by using the most likely amount method.

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Revenue for the material right for license renewals is recognized at the point in time that the annual license fee is paid by the licensee and the renewal period begins.

Customer payments are recorded as deferred revenue upon receipt or when due and may require deferral of revenue recognition to a future period until we satisfy our performance obligations under these arrangements.

Amounts payable to us are recorded as accounts receivable if invoiced or as contract assets when our right to consideration is unconditional.

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Payments received under third-party contracts are recorded as deferred revenue upon receipt or when due and may require deferral of revenue recognition to a future period until we satisfy our performance obligations under these contracts.

We record contract assets when payment is due under third-party contracts conditioned on future performance or the occurrence of other events.

Amounts payable to us are recorded as accounts receivable if invoiced and if our right to consideration is unconditional.

Fair Value Measurements

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We consider all highly liquid investments purchased with an original maturity of three months or less to be cash equivalents.

As of December 31, 2022 and 2021, cash and cash equivalents consisted of cash, money market funds, and commercial paper securities.

As of December 31, 2023 and 2022, cash and cash equivalents consisted of cash, money market funds, commercial paper securities, and U.S.

Treasury bills.

Restricted Cash

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The amortized cost of securities is adjusted for amortization of premiums and accretion of discounts to maturity, which are both recorded to interest income in the consolidated statements of operations and comprehensive loss.

Changes in the fair value of available-for-sale securities impact the consolidated statements of operations and comprehensive loss only when such securities are sold, or if an impairment is recognized.

Realized gains and losses on the sale of securities are determined by specific identification of each security’s cost basis.

We regularly review our investment portfolio to determine if any security is impaired, which would require us to record an impairment charge in the period any such determination is made.

In making this judgment, we consult with our investment managers and consider available quantitative and qualitative evidence in evaluating potential impairment of our investments on a quarterly basis.

If the cost of an individual investment exceeds its fair value, we evaluate, among other factors, general market conditions, the duration and extent to which the fair value is less than cost, and our intent and ability to hold the investment.

Once a decline in fair value is determined to be other-than-temporary, an impairment charge will be recorded to other expense, net, in the consolidated statements of operations and comprehensive loss and a new cost basis in the short-term investment will be established.

During the years ended December 31, 2022 and 2021, we did not record any impairment related to other-than-temporary declines in the fair value of our marketable securities.

When the fair value of a debt security declines below its amortized cost basis, any portion of that decline attributable to credit losses, to the extent expected to be nonrecoverable before the sale of the security, is recognized in our statement of operations.

When the fair value of a debt security declines below its amortized cost basis due to changes in interest rates, such amounts are recorded in other comprehensive loss, and are recognized in our statements of operations only if we sell or intend to sell the security before recovery of its cost basis.

Investments in Equity Securities

We may receive as consideration under our license agreements equity securities of private or public companies (an “investee”).

If we determine that we do have control over these investees under either the Variable Interest Entity (“VIE”) or voting models, we then determine if we have an ability to exercise significant influence via voting interests, board of director representation, or other business relationships.

If we determine that we do not have control over these investees under either the Variable Interest Entity (“VIE”) or voting models, we then determine if we have an ability to exercise significant influence via voting interests, board of director representation, or other business relationships.

If we conclude that we do not have an ability to exercise significant influence over an investee, we account for our investment at fair value and may elect to account for an equity security without a readily determinable fair value using a measurement alternative.

This measurement alternative allows us to measure the equity investment at its cost minus impairment, if any, plus or minus changes resulting from observable price changes in orderly transactions for the identical or a similar investment of the same issuer.

If we determine that we do have control over these companies under either voting or VIE models, we consolidate them in our consolidated financial statements.

As of December 31, 2023 and 2022, investments in equity securities, long-term, consisted primarily of our investment in the preferred stock of a private company, related party (Note 7).

We concluded that our shares of the private company’s preferred stock are not in substance common stock and, since these securities do not have readily determinable fair value, we account for our investment in the private company’s preferred stock using the alternative measurement method.

As of December 31, 2023 and 2022, we did not recognize any impairment loss related to this investment.

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Property and Equipment

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Under Financial Accounting Standards Board (“FASB”) Accounting Standards Update (“ASU”) No.

2016-02, Leases (Topic 842) and its associated amendments (“ASC 842”), we determine if an arrangement is a lease at inception.

2016-02, Leases (Topic 842) and its associated amendments, we determine if an arrangement is a lease at inception.

In addition, we determine whether a lease meets the classification criteria of a finance or operating lease at the lease commencement date considering whether:

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and (v) the underlying asset is such a specialized nature that it is expected to have no alternative use to the lessor at the end of the lease term.

As of December 31, 2022, our lease population consisted of real estate operating leases and we did not have any finance leases.

As of December 31, 2023, our leases consisted of real estate operating leases and we did not have any finance leases.

Operating leases are included in Operating lease right-of-use assets;

Lease liabilities, current;

and Lease liabilities, non-current in our consolidated balance sheets.

Operating lease liabilities, current;

and Operating lease liabilities, non-current in our consolidated balance sheets.

Right-of-use assets represent our right to use the underlying assets for the lease term and lease liabilities represent our obligation to make lease payments arising from the leases.

Operating lease right-of-use assets and liabilities are recognized at the lease commencement date based on the present value of lease payments over the lease term.

In determining the present value of lease payments, if the rate implicit in the lease is not readily determinable, we use our incremental borrowing rate based on the information available at the lease commencement date.

We determine the incremental borrowing rate based on an analysis of corporate bond yields with a credit rating similar to us.

In determining the present value of lease payments, if the rate implicit in the lease is not readily determinable, we would use our incremental borrowing rate based on the information available at the lease commencement date.

We would determine the incremental borrowing rate based on an analysis of corporate bond yields with a credit rating similar to ours.

The determination of our incremental borrowing rate requires management judgment, including development of a synthetic credit rating and cost of debt, as we currently do not carry any debt.

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Lease agreements with non-cancelable terms of less than 12 months are not recorded on our balance sheets.

Deferred Issuance Costs

Issuance costs, consisting of legal, accounting, audit, and filing fees relating to in-process equity financings, including our IPO, are capitalized.

Deferred issuance costs are offset against offering proceeds upon the completion of an

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equity financing or an offering.

In the event an equity financing or an offering is terminated or delayed, deferred issuance costs will be expensed immediately as a charge to general and administrative expenses in the consolidated statements of operations and comprehensive loss.

As of December 31, 2022 and 2021, we did not capitalize any issuance costs.

Convertible Preferred Stock

We recorded convertible preferred stock at fair value on the dates of issuance, net of issuance costs.

The convertible preferred stock was recorded outside of stockholders’ equity (deficit) because the preferred shares contain liquidation features outside of our control.

We elected not to adjust the carrying values of the convertible preferred stock to the liquidation preferences of such shares because it is uncertain whether or when an event would occur that would obligate us to pay the liquidation preferences to holders of shares of convertible preferred stock.

All outstanding convertible preferred stock converted into common stock in connection with the closing of our IPO and were reclassified to common stock and additional paid-in-capital.

MSKCC Success Payments Liability

Under the terms of our Exclusive License Agreement, dated November 13, 2020, with MSKCC (Note 4), we are obligated to make success payments and a change of control payment if our stock price increases by certain multiples of increasing value based on a comparison of the fair market value of our common stock with $ 5.1914 per share, adjusted for any future stock splits, during a specified time period.

The relevant time period commences when the first patient is dosed with our first CLL-1 product candidate (CB-012) in the first phase 1 clinical trial and ends upon the earlier of the third anniversary of approval of our biologics license application (“BLA”) by the FDA or 10 years from the date the first patient was dosed with our first CLL-1 product candidate in the first phase 1 clinical trial.

The success payments liability is accounted for under ASC 815, Derivatives and Hedging.

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To determine the estimated fair value of the MSKCC success payments liability, we use a Monte Carlo simulation methodology that models the future movement of stock prices based on several key variables.

This model requires significant estimates and assumptions in determining the estimated fair value of the MSKCC success payments liability at each balance sheet date.

The following variables were incorporated in the estimated fair value of the success payments liability:

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The computation of expected volatility was estimated using a combination of available information about the historical volatility of stocks of similar publicly traded companies for a period matching the expected term assumption and projected volatility.

The assumptions used to calculate the fair value of the MSKCC success payments liability are subject to a significant amount of judgment including the expected volatility that was estimated using available information about the historical volatility of stocks of publicly traded companies that are similar to us, the estimated term, and the estimated

number and timing of valuation measurement dates.

There are several valuation measurement dates that may trigger payments under the MSKCC Agreement and are considered in our valuation of the MSKCC success payments liability (Note 4).

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Research and development expenses are charged to expense as incurred.

Research and development expenses include certain payroll and personnel expenses;

Research and development expenses include those for certain payroll and personnel;

laboratory supplies;

consulting costs;

external clinical research and development expenses;

manufacturing;

external clinical;

and allocated overhead, including rent, equipment depreciation, and utilities.

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Generally, these agreements set forth the scope of work to be performed at a fixed fee, unit price or on a time and materials basis.

In the event we make advance payments for goods or services that will be used or rendered for future research and development activities, the payments are deferred and capitalized as a prepaid expense and recognized as expense as the

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goods are received or the related services are rendered.

These payments are evaluated for current or long-term classification based on when they are expected to be realized.

Acquisition of In-Process Research and Development Assets

We measure and recognize acquired in-process research and development assets, which include licenses, know-how, patents, and transaction fees, at cost.

We measure and recognize acquired in-process research and development assets, which include licenses, know-how, patents, and transaction fees, based on the cost to acquire the assets and the consideration is allocated to the items based on a relative fair value methodology.

Goodwill is not recognized in asset acquisitions.

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Stock-based compensation expense related to awards to employees is measured at the grant date based on the fair value of the award.

We determine the grant-date fair value of the options using the Black-Scholes option-pricing model.

The fair value of restricted stock units (“RSUs”) and performance-based RSUs (“PSUs”) awards is determined based on the number of units granted and the closing price of our common stock as of the grant-date.

The fair value of the award that is ultimately expected to vest is recognized as expense on a straight-line basis over the requisite service period of the awards, which is generally the vesting period, and is adjusted for pre-vesting forfeitures in the period in which the forfeitures occur.

We use the Black-Scholes valuation model as the method for determining the estimated fair value of stock options and stock purchases under our 2021 Employee Stock Purchase Plan (“ESPP”) with the following assumptions:

Fair Market Value of Common Stock — Prior to our IPO, the fair market value of our common stock was determined by our board of directors with assistance from management and external valuation experts.

Fair Market Value of Common Stock — Prior to our Initial Public Offering (“IPO”), the fair market value of our common stock was determined by our board of directors with assistance from management and external valuation experts.

Our approach to estimating the fair market value of our common stock was consistent with the methods outlined in the American Institute of Certified Public Accountants’ Practice Aid, Valuation of Privately-Held-Company Equity Securities Issued as Compensation.

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Treasury zero-coupon issued in effect at the time of grant for periods corresponding with the expected term of the award.

Stock-based compensation expense related to awards to non-employees, such as consultants, is recognized based on the then-current fair value at each grant date over the associated service period of the award, which is generally the vesting term, using the straight-line method.

The fair value of non-employee stock options and restricted stock awards is

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estimated using the Black-Scholes valuation model with assumptions generally consistent with those used for employee stock options.

We account for income taxes using the asset and liability method.

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We recognize fees earned from sources not considered to be within the normal course of business in other income within the statements of operations and comprehensive loss.

During the year ended December 31, 2022, we recognized $ 4.6 million of interest income from our short-term and long-term marketable securities.

Dur ing the year ended December 31, 2021, we recognized $ 0.1 million of other income mainly related to receiving corporate credit card rewards.

During the years ended December 31, 2023 and 2022, we recognized $ 15.3 million and $ 4.6 million of interest income from our short-term and long-term marketable securities, respectively .

Comprehensive Loss

Comprehensive loss is composed of net loss and other comprehensive income (loss).

Other comprehensive income (loss) consists primarily of unrealized gains and losses on available-for-sale marketable securities.

Other comprehensive income (loss) consists of unrealized gains and losses on available-for-sale marketable securities.

Net Loss Per Share

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Diluted net loss per share is computed by dividing the net loss by the sum of the weighted-average number of common shares outstanding during the period plus the dilutive effects of potentially dilutive securities outstanding during the period.

Potentially dilutive securities include convertible preferred shares, common stock options, and common shares subject to nonrecourse notes.

For all periods presented, diluted net loss per share is the same as basic net loss per share since the effect of including potential common shares is anti-dilutive.

Prior to the conversion of our preferred stock in connection with our IPO, we used the two-class method to calculate net loss per share.

Our convertible preferred stock contained participation rights in any dividend paid by us and was deemed to be a participating security.

Participating securities did not have a contractual obligation to share in losses.

As such, the net loss was attributed entirely to common stockholders.

Potentially dilutive securities include common stock options, RSUs issued and outstanding.

For all periods presented, diluted net loss per share is the same as basic net loss per share since the effect of including potential common shares is anti-dilutive.

Recent Accounting Pronouncements

From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board (the “FASB”) or other standard-setting bodies and adopted are by us as of the specified effective date.

In February 2016, the FASB issued ASU No.

2016-02, Leases (Topic 842).

This ASU requires a lessee to recognize in its statement of financial position a liability to make lease payments (the lease liability) and a right-of-use asset representing its right to use the underlying asset for the lease term.

We adopted the new standard as of January 1, 2022, using the modified retrospective approach with no impact to retained earnings.

Comparative periods were not adjusted and continue to be presented under the previous accounting guidance.

We elected the package of practical expedients permitted under the transition guidance, which allows us to carry forward the historical lease classification of contracts entered into prior to January 1, 2022.

Our adoption of the new standard impacted the consolidated balance sheets as follows (in thousands):

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January 1, 2022

Pre-ASC 842 Balance ASC 842 Adoption Impact Post-ASC 842 Balance

Operating lease right-of-use assets $ — $ 22,818 $ 22,818

Prepaid rent $ 291 $ ( 291 ) $ —

Accrued expenses and other current liabilities (1)

$ 13,136 $ 683 $ 13,819

Long-term operating lease liabilities $ — $ 23,941 $ 23,941

Deferred rent and lease incentive liability $ 2,097 $ ( 2,097 ) $ —

(1) Adjustment represents the current portion of operating lease liabilities of $ 0.8 million and reclassification of the current portion of the lease incentive liability of $ 0.1 million to reduce the operating lease right-of-use assets.

New Accounting Pronouncements Not Yet Adopted

From time to time, new accounting pronouncements are issued by FASB or other standard-setting bodies and adopted are by us as of the specified effective date.

In June 2016, the FASB issued ASU 2016-13, Financial Instruments—Credit Losses:

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ASU 2016-13 replaces the current incurred loss impairment approach with a methodology to reflect expected credit losses and requires consideration of a broader range of reasonable and supportable information to explain credit loss estimates.

This ASU is to be applied on a modified retrospective approach and is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2022, and interim reporting periods within fiscal years beginning after December 15, 2023.

This ASU is to be applied on a modified retrospective approach and is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2022.

Early adoption is permitted for all entities for fiscal years beginning after December 15, 2018, and interim periods therein.

We do not expect that the adoption of this ASU will have a significant impact on our consolidated financial statements.

We adopted ASU 2016-13 on January 1, 2023.

The impact of ASU 2016-13 on our financial statements and related disclosures was not material.

New Accounting Pronouncements Not Yet Adopted

In October 2023, the FASB issued ASU 2023-06, Disclosure Improvements:

Codification Amendments in Response to the SEC’s Disclosure Update and Simplification Initiative.

This ASU aligns the requirements in the ASC to the removal of certain disclosure requirements set out in Regulation S-X and Regulation S-K, announced by the U.S.

Securities and Exchange Commission (“SEC”).

The effective date for each amended topic in the ASC is either the date on which the SEC’s removal of the related disclosure requirement from Regulation S-X or Regulation S-K becomes effective, or on June 30, 2027, if the SEC has not removed the requirements by that date.

Early adoption is prohibited.

We are currently evaluating the impact of the adoption of this standard.

In November 2023, the FASB issued ASU 2023-07, Segment Reporting (Topic 280):

Improvements to Reportable Segment Disclosures.

This ASU requires public entities to disclose information about their reportable segments’ significant expenses and other segment items on an interim and annual basis.

Public entities with a single reportable segment are required to apply the disclosure requirements in ASU 2023-07, as well as all existing segment disclosures and reconciliation requirements in ASC 280 on an interim and annual basis.

ASU 2023-07 is effective for fiscal years beginning after December 15, 2023, and for interim periods within fiscal years beginning after December 15, 2024, with early adoption permitted.

We are currently evaluating the impact of the adoption of this standard.

In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740):

Improvements to Income Tax Disclosures.

This ASU requires public entities, on an annual basis, to provide disclosure of specific categories in the rate reconciliation, as well as disclosure of income taxes paid disaggregated by jurisdiction.

ASU 2023-09 is effective for fiscal years beginning after December 15, 2024, with early adoption permitted.

We are currently evaluating the impact the adoption of this standard.

Emerging Growth Company and Smaller Reporting Company Status

We are an emerging growth company, as defined in the Jumpstart Our Business Startups Act of 2012 (the “JOBS”) Act.

We are an emerging growth company, as defined in the Jumpstart Our Business Startups Act of 2012 Act (“JOBS” Act”).

Under the JOBS Act, emerging growth companies can delay adopting new or revised accounting standards issued subsequent to the enactment of the JOBS Act until such time as those standards apply to private companies.

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We are also a “smaller reporting company.” If we are a smaller reporting company at the time we cease to be an emerging growth company, we may continue to rely on exemptions from certain disclosure requirements that are available to smaller reporting companies.

Specifically, as a smaller reporting company, we may choose to present only the two most recent fiscal years of audited consolidated financial statements in our Annual Report on Form 10-K and, similar to emerging growth companies, smaller reporting companies have reduced disclosure obligations regarding executive compensation.

Specifically, as a smaller reporting company, we may choose to present only the two most

recent fiscal years of audited consolidated financial statements in our Annual Report on Form 10-K and, similar to emerging growth companies, smaller reporting companies have reduced disclosure obligations regarding executive compensation.

Fair Value Measurements and Fair Value of Financial Instruments

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Level 1—Quoted prices in active markets for identical assets or liabilities.

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Level 2—Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities, quoted prices in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.

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Our financial instruments consist of Level 1, Level 2, and Level 3 financial instruments.

We generally classify our marketable securities as Level 2.

We generally classify our marketable securities as Level 1 or Level 2.

Instruments are classified as Level 2 when observable market prices for identical securities that are traded in less active markets are used.

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For certain security types, additional inputs may be used, or some of the standard inputs may not be applicable.

Evaluators may prioritize inputs differently on any given day for any security based on market conditions, and not all inputs listed are available for use in the evaluation process for each security evaluation on any given day.

Changes in the ability to observe valuation inputs may result in a reclassification of levels of certain securities within the fair value hierarchy.

We recognize transfers into and out of levels within the fair value hierarchy in the period in which the actual event or change in circumstances that caused the transfer occurs.

No such transfers occurred during the year ended December 31, 2022 and 2021.

No such transfers occurred during the years ended December 31, 2023 and 2022.

Level 1 financial instruments are comprised of money market fund investments and U.S.

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Total Level 1 Level 2 Level 3

Money market fund investments (included in cash and cash equivalents) $ 27,693 $ 27,693 $ — $ —

Treasury bills ($ 23,527 included in cash and cash equivalents)

$ 262,439 $ 262,439 $ — $ —

Commercial paper ($ 9,759 included in cash and cash equivalents)

40,373 — 40,373 —

government agency bonds 40,185 — 40,185 —

Money market fund investments (included in cash and cash equivalents)

17,876 17,876 — —

Corporate debt securities

Treasury bills 91,966 91,966 — —

government agency bonds ($ 3,976 included in cash and cash equivalents)

11,531 — 11,531 —

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Total fair value of liabilities $ 2,939 $ — $ — $ 2,939

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Fair Value Measurements as of December 31, 2022

Total Level 1 Level 2 Level 3

Money market fund investments (included in cash and cash equivalents) $ 181,528 $ 181,528 $ — $ —

Commercial paper ($ 26,669 included in cash and cash equivalents)

$ 96,899 $ — $ 96,899 $ —

Corporate debt securities 38,649 — 38,649 —

Treasury bills 91,966 91,966 — —

government agency bonds 25,065 — 25,065 —

government agency bonds ($ 3,976 included in cash and cash equivalents)

63,659 — 63,659 —

Corporate debt securities

36,819 — 36,819 —

Money market fund investments (included in cash and cash equivalents)

27,693 27,693 — —

Total fair value of assets $ 317,036 $ 119,659 $ 197,377 $ —

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Total fair value of liabilities $ 1,651 $ — $ — $ 1,651

The fair value and amortized cost of cash equivalents and available-for-sale marketable securities by major security type as of December 31, 2022 and 2021 are presented in the following table (in thousands):

The fair value and amortized cost of cash equivalents and available-for-sale marketable securities by major security type as of December 31, 2023 and 2022 are presented in the following tables (in thousands):

As of December 31, 2023

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Losses Estimated

Money market investments (included in cash equivalents) $ 27,693 $ — $ — $ 27,693

Treasury bills ($ 23,527 included in cash and cash equivalents)

$ 262,328 $ 331 $ ( 220 ) $ 262,439

Commercial paper ($ 9,759 included in cash equivalents)

40,386 — ( 13 ) 40,373

government agency bonds ($ 3,976 included in cash and cash equivalents)

government agency bonds

40,295 1 ( 111 ) 40,185

Money market fund investments (included in cash equivalents)

17,876 — — 17,876

Corporate debt securities

Treasury bills 92,910 1 ( 945 ) 91,966

11,489 50 ( 8 ) 11,531

Total cash equivalents and marketable securities $ 372,374 $ 382 $ ( 352 ) $ 372,404

Classified as:

Cash equivalents $ 58,338

Cash and cash equivalents $ 51,162

Marketable securities, short-term 277,665

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Total cash equivalents and marketable securities $ 372,404

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As of December 31, 2022

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Losses Estimated

Money market investments (included in cash equivalents) $ 181,528 $ — $ — $ 181,528

Commercial paper ($ 26,669 included in cash equivalents)

97,024 6 ( 131 ) 96,899

government agency bonds 25,102 — ( 37 ) 25,065

Corporate debt securities 38,661 4 ( 16 ) 38,649

Treasury bills 92,910 1 ( 945 ) 91,966

government agency bonds ( 3,976 included in cash and cash equivalents)

63,926 25 ( 292 ) 63,659

Corporate debt securities 37,002 — ( 183 ) 36,819

Money market fund investments (included in cash equivalents)

$ 27,693 $ — $ — $ 27,693

Total cash equivalents and marketable securities $ 318,555 $ 32 $ ( 1,551 ) $ 317,036

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Total cash equivalents and marketable securities $ 317,036

As of December 31, 2022, our available-for-sale marketable securities had been in a continuous unrealized loss position, each for less than 12 months.

As of December 31, 2022, no significant facts or circumstances were present to indicate a deterioration in the creditworthiness of the issuers of the available-for-sale marketable securities we hold, and we have no requirement or intention to sell these securities before maturity or recovery of their amortized cost basis.

We considered the current and expected future economic and market conditions surrounding the COVID-19 pandemic and determined that our investments were not significantly impacted.

For each security with a fair value less than its amortized cost basis, we determined the decline in fair value below amortized cost basis to be immaterial, and therefore no other than temporary impairment loss has been recorded.

During the years ended December 31, 2022 and 2021, we did not recognize any impairment losses on our investments.

During the years ended December 31, 2023 and 2022, we reviewed our impaired marketable securities and concluded that the decline in fair value was not related to credit losses and is recoverable.

Accordingly, no allowance for credit losses was recorded and instead the unrealized losses are reported as a component of accumulated other comprehensive loss.

The following table presents the fair value of available-for-sale marketable securities by contractual maturities (in thousands):

December 31, 2023

Due in less than one year

Due in one to five years

The following table sets forth a summary of the changes in the fair value of our Level 3 financial liability (in thousands):

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Balance at December 31, 2023 $ 2,939

Our liability for the MSKCC success payments is carried at fair value and changes are recognized as expense or income as part of other income until the success payments liability is paid or expires (Note 4).

We recorded $ 2.4 million and $ 1.4 million change in fair value of the MSKCC success payments liability as a gain and loss, respectively, in other income (expense) in our consolidated statements of operations and comprehensive loss for the year ended December 31, 2022 and 2021, respectively.

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Our liability for the MSKCC success payments is carried at fair value and changes are recognized as expense or income as part of other income (expense) until the success payments liability is paid or expires (Note 4).

The table below summarizes key assumptions used in the valuation of MSKCC success payments liability:

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Expected volatility 79 %

Probability of achieving multiple of Initial Share Price 3.0 % to 10.6 %

Probability of achieving multiple of Initial Share Price (1)

5.2 % to 18.1 %

3.0 % to 10.6 %

Expected term (years) 3.7 to 5.2

(1) MSKCC is entitled to certain success payments if our common stock fair value increases by certain multiples of value based on a comparison of the fair market value of our common stock to $ 5.1914 per share, adjusted for any future stock splits (“Initial Share Price”), during a specified time period (Note 4).

The risk-free interest rate, expected volatility, and expected term assumptions depend on the estimated timing of our phase 1 clinical trial for our CB-012 product candidate utilizing the know-how, biological materials, and intellectual property licensed under the MSKCC Agreement and the estimated timing of marketing approval for this product candidate from the U.S.

The risk-free interest rate, expected volatility, and expected term assumptions depend on the initiation of our AMpLify phase 1 clinical trial for our CB-012 product candidate utilizing the know-how, biological materials, and intellectual property licensed under the Exclusive License Agreement, dated November 13, 2020, with MSKCC (“MSKCC Agreement”) and the estimated timing of marketing approval for this product candidate from the U.S.

Food and Drug Administration (“FDA”).

In addition, we incorporated the estimated number and timing of valuation measurement dates in the calculation of the MSKCC success payments liability.

A small change in the assumptions and other inputs, such as the fair value of our common stock, may have a relatively large change in the estimated valuation and associated liability and expense or income.

Significant Agreements

The Regents of the University of California and the University of Vienna

We entered into an Exclusive License Agreement, dated April 16, 2013 (as amended, the “UC/Vienna Agreement”) with The Regents of the University of California (“UC”) and the University of Vienna (“Vienna”) (together, “UC/Vienna”) wherein UC/Vienna granted us an exclusive worldwide license, with the right to sublicense, in all fields to the foundational CRISPR-Cas9 patent family co-owned by UC, Vienna, and Dr.

Emmanuelle Charpentier (the “CVC IP”).

We entered into an Exclusive License Agreement, dated April 16, 2013 (as amended, “UC/Vienna Agreement”) with The Regents of the University of California (“UC”) and the University of Vienna (“Vienna”) (together, “UC/Vienna”) wherein UC/Vienna granted us an exclusive worldwide license, with the right to sublicense, in all fields to the foundational

CRISPR-Cas9 patent family co-owned by UC, Vienna, and Dr.

Emmanuelle Charpentier (“CVC IP”).

Charpentier has not granted us any rights, either directly or indirectly.

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For the years ended December 31, 2023 and 2022, we reimbursed UC $ 2.3 million and $ 5.4 million, respectively, for prosecution and maintenance costs of the CVC IP, which were recorded in general and administrative expenses in our consolidated statements of operations and comprehensive loss.

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On December 15, 2016, we entered into a Consent to Assignments, Licensing and Common Ownership and Invention Management Agreement (“IMA”) relating to the CVC IP.

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Memorial Sloan Kettering Cancer Center

On November 13, 2020, we entered into an Exclusive License Agreement with MSKCC (the “MSKCC Agreement”), under which we exclusively licensed know-how, biological materials, and patent families relating to fully-human single-chain variable fragments targeting C-type lectin-like molecule-1 (“CLL-1”;

On November 13, 2020, we entered into the MSKCC Agreement, under which we exclusively licensed know-how, biological materials, and patent families relating to fully-human single-chain variable fragments targeting C-type lectin-like molecule-1 (“CLL-1”;

also known as CD371) for use in T cells, NK cells, and genome-edited induced pluripotent stem cells (“iPSCs”) for allogeneic CLL-1-targeted cell therapies (currently used in our CB-012 product candidate).

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At our option, success payments to MSKCC may be made in cash or common stock.

The relevant time period commences when the first patient is dosed with a licensed CLL-1 product candidate in the first phase 1 clinical trial and ends upon the earlier of the third anniversary from the approval of our, or our affiliate’s, or sublicensee’s biologics license application (“BLA”) by the FDA or 10 years from the date the first patient was dosed with a licensed CLL-1 product candidate in the first phase 1 clinical trial.

The relevant time period commences when the first patient is dosed with the first licensed CLL-1 product candidate (CB-012) in the first phase 1 clinical trial and ends upon the earlier of the third anniversary from the approval of our, or our affiliate’s, or sublicensee’s

biologics license application (“BLA”) by the FDA or 10 years from the date the first patient was dosed with a licensed CLL-1 product candidate in the first phase 1 clinical trial.

The aggregate success payments will not exceed $ 35.0 million.

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As of December 31, 2023 and 2022, the estimated fair value of the total success payments obligation to MSKCC was $ 2.9 million and $ 1.7 million, respectively, which was included in long-term liabilities in our consolidated balance sheets.

For the year ended December 31, 2022, we recognized $ 2.4 million of change in fair value of the MSKCC success payments liability, which was recorded in other income (expense) in our consolidated statements of operations and comprehensive loss.

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Intellia Therapeutics, Inc.

On July 16, 2014, we entered into a License Agreement (as amended, the “Intellia License Agreement”) with Intellia, LLC, to which Intellia Therapeutics, Inc.

On July 16, 2014, we entered into a License Agreement (as amended, “Intellia License Agreement”) with Intellia, LLC, to which Intellia Therapeutics, Inc.

(“Intellia”) is a successor in interest.

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provided, however, either party may terminate the agreement upon the occurrence of certain events.

On June 16, 2021, we entered into a leaseback agreement with Intellia (the “Leaseback Agreement”).

On June 16, 2021, we entered into a leaseback agreement with Intellia (“Leaseback Agreement”).

Pursuant to the Leaseback Agreement, in exchange for Intellia’s grant to us of an exclusive license to certain intellectual property relating to CRISPR-Cas9, including Cas9 chRDNAs, for use solely in the manufacture of our CB-010 product candidate, we paid Intellia an upfront cash payment of $ 1.0 million and will pay up to $ 23.0 million in potential future regulatory and sales milestones.

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On July 13, 2015, we and Pioneer Hi-Bred International, Inc.

(“Pioneer”) (now Corteva Agriscience), then a DuPont company (“DuPont”), entered into an Amended and Restated Collaboration and License Agreement (as amended, the “Pioneer Agreement”).

(“Pioneer”) (now Corteva Agriscience), then a DuPont company (“DuPont”), entered into an Amended and Restated Collaboration and License Agreement (as amended, “Pioneer Agreement”).

Under the terms of the Pioneer Agreement, we and Pioneer cross licensed CRISPR intellectual property portfolios.

Pioneer granted us an exclusive worldwide license, with the right to sublicense, to its CRISPR intellectual property in the field of research tools, as well as a non-exclusive worldwide license to such intellectual property in human and animal therapeutics, industrial biotechnology, certain agriculture segments, and other fields;

and we granted Pioneer an exclusive worldwide license, with the right to sublicense, to our CRISPR intellectual property, including the CVC IP, in a defined field of agriculture relating to specified row crops, as well as a non-exclusive worldwide license to the intellectual property in other agricultural applications, industrial biotechnology, nutrition and health, and other fields.

and we granted

Pioneer an exclusive worldwide license, with the right to sublicense, to our CRISPR intellectual property, including the CVC IP, in a defined field of agriculture relating to specified row crops, as well as a non-exclusive worldwide license to the intellectual property in other agricultural applications, industrial biotechnology, nutrition and health, and other fields.

The Pioneer Agreement continues until the expiration, abandonment, or invalidation of the last patent or patent application within the licensed intellectual property;

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We are eligible to receive milestone payments from Pioneer if certain regulatory and commercial milestones are met related to specified row crops, for a total of up to $ 22.4 million, as well as to receive low-single-digit percent royalties for sales of defined agricultural products and certain sublicensing revenues in that field.

In March 2021, we received a milestone payment of $ 0.3 million from Pioneer.

Initially, Pioneer owned the patents and patent applications developed under the collaboration, including the chRDNA patent family, and granted us an exclusive license to these patents and patent applications in the fields of research tools and therapeutics.

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In addition to the upfront payment, we are now obligated to pay all patent prosecution and maintenance costs for the chRDNA patent family;

up to $ 2.8 million in regulatory milestone payments for therapeutic

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products developed by us, our affiliates, or licensees that are covered by the chRDNA patent family;

up to $ 2.8 million in regulatory milestone payments for therapeutic products developed by us, our affiliates, or licensees that are covered by the chRDNA patent family;

up to $ 20.0 million in sales milestones over a total of four therapeutics products sold by us, our affiliates, or licensees that are covered by the chRDNA patent family;

and a low-single-digit percentage of licensing revenue we receive for licensing the chRDNA patent family after December 2020.

During the year ended December 31, 2022 and 2021, we incurred less than $ 0.1 million and $ 0.8 million, respectively, for payments we owe to Pioneer related to licensing revenues, which we recorded as a research and development expense in our consolidated statements of operations and comprehensive loss.

During the year ended December 31, 2023 we incurred no liability for payments owed to Pioneer for licensing revenues.

During the year ended December 31, 2022, we incurred $ 0.1 million, for payments we owe to Pioneer related to licensing revenues, which we recorded as a research and development expense in our consolidated statements of operations and comprehensive loss.

AbbVie Manufacturing Management Unlimited Company

On February 9, 2021, we entered into a Collaboration and License Agreement (as amended, the “AbbVie Agreement”) with AbbVie Manufacturing Management Unlimited Company (“AbbVie”).

Pursuant to the AbbVie Agreement, AbbVie selects one target or, for a dual CAR-T cell product, two targets (each selection, a “Program Slot”) to develop collaboration CAR-T cell products (and corresponding licensed products).

For each of AbbVie’s two Program Slots (or up to four Program Slots, if AbbVie elects to expand the number as set forth below), we are collaborating to develop one or more collaboration allogeneic CAR-T cell products directed toward the single cancer target or target combination chosen by AbbVie as described in an applicable research plan, utilizing our Cas12a chRDNA genome-editing and cell therapy technologies.

We granted AbbVie an exclusive (even as to us), royalty-bearing, worldwide license, with the right to grant sublicenses, under our Cas12a chRDNA and cell therapy intellectual property, as well as certain genome-editing technology that we may gain rights to in the future and intellectual property that may be developed under the collaboration, solely for AbbVie to develop, commercialize, manufacture, and otherwise exploit the collaboration CAR-T cell products in the field of human diagnostics, prophylactics, and therapeutics.

Under the terms of the AbbVie Agreement, we conduct certain preclinical research, development, and manufacturing activities under the collaboration, including certain activities for the manufacture and supply of licensed product for AbbVie’s phase 1 clinical trials.

AbbVie reimburses us for all such activities, including reimbursement for time spent by employees at a designated FTE rate.

The duration of the collaboration is not fixed.

Under the terms of the AbbVie Agreement, AbbVie has selected its initial Program Slot and has reserved two additional targets, which AbbVie may choose to be used or substituted into the two Program Slots or used for the third or fourth Program Slots if AbbVie expands the number of Program Slots during the collaboration.

During the collaboration, AbbVie may expand from two Program Slots to a total of four Program Slots by paying us an additional $ 15.0 million for each Program Slot, provided that AbbVie must make such payment within the earlier of (a) 60 calendar days following completion of the phase 1 clinical trials for the initial collaboration CAR-T cell product and (b) December 31, 2025.

Under the terms of the AbbVie Agreement, we are eligible to receive up to $ 150.0 million in future developmental and regulatory milestone payments for each Program Slot and up to $ 200.0 million in sales-based milestones for each Program Slot.

We are also eligible to receive global royalties on net sales of licensed products sold by AbbVie, its affiliates, and sublicensees in the high-single-digit to low-teens percent range, subject, in certain instances, to various reductions.

The term of the AbbVie Agreement continues in force and effect until the date of expiration of the last royalty term of the last country in which a licensed product is exploited.

On a licensed product-by-licensed product and country-by-country basis, the royalty term is the period of time beginning on the first commercial sale of a licensed product in a country and ending on the latest of the following three dates:

(a) the expiration, invalidation, revocation, cancellation, or abandonment date of the last patent that includes a valid claim to either (i) the collaboration CAR-T cell product in the licensed product or (ii) the method of making the collaboration CAR-T product in the licensed product in such country (in the case of (ii), only for so long as no biosimilar product is commercially available in such country);

(b) 10 years from the date of the first commercial sale of such licensed product in such country;

and (c) the expiration date of regulatory exclusivity for such licensed product in such country.

The AbbVie Agreement may be terminated during the term by either party for an uncured material breach or bankruptcy by the other party.

Additionally, AbbVie may terminate the AbbVie Agreement, in its entirety or on a licensed product-by-licensed product basis, effective immediately upon written notice to us, if AbbVie in good faith believes that it is not advisable for AbbVie to continue to exploit the collaboration CAR-T cell products or licensed products as a result of a perceived serious safety issue.

AbbVie may also terminate the AbbVie Agreement in its entirety at its sole discretion upon 90 days’ prior written notice to us.

The transaction price we received under the AbbVie Agreement associated with the first two Program Slots consisted of a $ 30.0 million upfront cash payment and the estimated variable consideration related to our performance of preclinical, development, and manufacturing activities under the collaboration and the developmental and regulatory

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milestone payments.

On February 9, 2021, we entered into a Collaboration and License Agreement (as amended, “AbbVie Agreement”) with AbbVie Manufacturing Management Unlimited Company (“AbbVie”).

Pursuant to the AbbVie Agreement, AbbVie selected one target or, for a dual CAR-T cell product, two targets (each selection, a “Program Slot”) to develop collaboration CAR-T cell products (and corresponding licensed products).

Under the terms of the AbbVie Agreement, we conducted certain preclinical research and development activities under the collaboration.

AbbVie reimbursed us for all such activities, including reimbursement for time spent by employees at a designated rate.

On September 26, 2023, we received notice from AbbVie that AbbVie elected to terminate the AbbVie Agreement.

By mutual agreement with AbbVie, termination of the AbbVie Agreement became effective on October 25, 2023.

The transaction price we received under the AbbVie Agreement associated with the first two Program Slots consisted of a $ 30.0 million upfront, non-refundable and non-creditable, cash payment and the estimated variable consideration related to our performance of preclinical research, development, and manufacturing activities under the collaboration and the developmental and regulatory milestone payments.

We constrain the estimated variable consideration if we assess that it is probable that a significant reversal in the amount of cumulative revenue recognized may occur in future periods.

We constrained all developmental and regulatory milestone payments as of December 31, 2022.

The transaction price is reevaluated at the end of each reporting period and as changes in circumstances occur.

We determined that the licenses we granted to AbbVie and our participation in the joint governance committee are not capable of being distinct from the preclinical research, development, and manufacturing activities and therefore are combined into one performance obligation.

We recognize revenue based on the measure of progress using an estimated cost-based input method each reporting period.

We received an upfront cash payment of $ 30.0 million from AbbVie during the year ended December 31, 2021.

We recognized short-term deferred revenue in the amount of $ 9.4 million and long-term deferred revenue in the amount of $ 13.3 million related to these payments in our consolidated balance sheets as of December 31, 2022.

We recognized short-term deferred revenue in the amount of $ 8.3 million and long-term deferred revenue in the amount of $ 19.1 million related to this upfront cash payment in our consolidated balance sheets as of December 31, 2021.

We recognized $ 8.0 million and $ 4.0 million in revenue for the year ended December 31, 2022 and 2021, respectively, relating to the AbbVie Agreement.

As of December 31, 2022 we had no amounts recorded in accounts receivable and as of December 31, 2021 we recorded $ 1.0 million in accounts receivable in our consolidated balance sheets.

As of December 31, 2022 and 2021 we had $ 0.9 million and $ 0.2 million, respectively, in contract assets in our consolidated balance sheets.

The transaction price was reevaluated at the end of each reporting period and as changes in circumstances occurred.

We determined that the licenses we granted to AbbVie and our participation in the joint governance committee were not capable of being distinct from the preclinical research, development, and manufacturing activities and therefore were combined into one performance obligation.

We recognized revenue based on the measure of progress using an estimated cost-based input method each reporting period.

Upon to receipt of the termination notice, we stopped performing preclinical research and development services under the AbbVie Agreement and determined that our performance obligation to AbbVie was substantially completed as of September 30, 2023.

Consequently, the remaining $ 20.8 million of deferred revenue from the $ 30.0 million upfront cash payment was recognized upon satisfaction of the performance obligation during the year ended December 31 2023.

We had no long-term or short-term deferred revenue related to the upfront cash payment in our consolidated balance sheets as of December 31, 2023.

We had short-term deferred revenue of $ 9.4 million and long-term deferred revenue of $ 13.3 million related to the upfront cash payment in our consolidated balance sheets as of December 31, 2022.

During the year ended December 31, 2023, we recognized $ 24.8 million in licensing and collaboration revenue associated with the AbbVie Agreement, of which $ 22.7 million had been included in deferred revenue as of the beginning of the period.

During the year ended December 31, 2022, we recognized $ 8.0 million in licensing and collaboration revenue associated with the AbbVie Agreement.

As of December 31, 2023 and 2022, we had no amounts recorded in accounts receivable in our consolidated balance sheets.

As of December 31, 2023, we had no contract assets in our consolidated balance sheets.

As of December 31, 2022, we had $ 0.9 million in contract assets in our consolidated balance sheets.

Disaggregation of Revenue

We disaggregate revenue by geographical market based on the location of research and development activities of our licensees and collaborators.

The following is a summary of revenue by geographic location for the years ended December 31, 2022 and 2021, (in thousands):

The following table is a summary of revenue by geographic location for the years ended December 31, 2023 and 2022, (in thousands):

Years Ended December 31,

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Total $ 34,477 $ 13,851

During the year ended December 31, 2022, we recognized $ 5.9 million of revenue related to performance obligations satisfied at a point in time, and we recognized $ 8.0 million of revenue related to performance obligations satisfied over time.

During the year ended December 31, 2023, we recognized $ 8.4 million of revenue related to performance obligations satisfied at a point in time, and we recognized $ 26.1 million of revenue related to performance obligations satisfied over time that included $ 24.8 million in licensing and collaboration revenue associated with the AbbVie Agreement, of which $ 22.7 million had been included in deferred revenue as of the beginning of the period.

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Contract assets are rights to consideration in exchange for a license that we have granted to a licensee when the right is conditional on something other than the passage of time.

Our contract asset balances represent research costs related to the AbbVie Agreements, as well as royalties and milestone payments from our other license agreements that are unbilled as of the end of a reporting period.

Our contract asset balances represent reimbursable research costs related to the AbbVie Agreement, as well as royalties and milestone payments from our other license agreements that are unbilled as of the end of a reporting period.

Contract liabilities consist of deferred revenue and relate to amounts invoiced to, or advance consideration received from, licensees that precede our satisfaction of the associated performance obligations.

Our deferred revenue primarily results from the upfront payment received relating to the performance obligation that is satisfied over time under the AbbVie Agreement.

The remaining deferred revenue relates to upfront payments received under license agreements

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that also include non-refundable annual license fees, which are accounted for as material rights for license renewals and are recognized at the point in time annual license fees are paid by the licensees and the renewal periods begin.

As of December 31, 2023, our deferred revenue balance primarily resulted from the upfront payment received relating to our performance obligation to Pfizer, Inc.

As of December 31, 2022 our deferred revenue balance primarily result from the upfront payment received relating to our performance obligations under the now-terminated AbbVie Agreement.

The remaining deferred revenue relates to upfront payments received under license agreements that also include nonrefundable annual license fees, which are accounted for as material rights for license renewals and are recognized at the point in time annual license fees are paid by the licensees and the renewal periods begin.

The following table presents changes in our contract assets and liabilities during the year ended December 31, 2023 (in thousands):

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Deferred revenue, current and long-term $ 25,891 $ 12,981 $ ( 29,923 ) $ 8,949

Unbilled accounts receivable increased during the year ended December 31, 2022, primarily due to the increase in unbilled research costs.

Deferred revenue decreased during the year ended December 31, 2022, primarily due to a higher amount of revenue recognized compared to the amount of additional billings during the year ended December 31, 2022.

During the years ended December 31, 2022 and 2021, we recognized $ 5.0 million and $ 0.1 million of revenue, respectively, which were included in the opening contract liabilities balances at the beginning of the respective periods.

Unbilled accounts receivable decreased during the year ended December 31, 2023, primarily due to the decrease in unbilled research costs under the AbbVie Agreement.

Deferred revenue decreased during the year ended December 31, 2023, primarily due to the recognition of deferred revenues related to the satisfaction of our performance obligation to AbbVie as a result of AbbVie’s termination of the AbbVie Agreement, offset by the $ 7.5 million allocated to the Pfizer information sharing committee (Notes 4 and 7).

During the years ended December 31, 2023 and 2022, we recognized $ 23.2 million and $ 5.0 million of revenue, respectively, which was included in the opening contract liabilities balances at the beginning of the respective periods.

Transaction Prices Allocated to Remaining Performance Obligations

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Total $ 2,286 $ 2,215

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Prepaid expenses and other current assets consisted of the following (in thousands):

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Prepaid insurance 993 1,568

Prepaid rent — 468

Other 1,220 1,119

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Depreciation and amortization expenses related to property and equipment were $ 3.5 million and $ 1.6 million, for the years ended December 31, 2023, and 2022, respectively.

Accrued expenses and other current liabilities consisted of the following as of December 31, 2022 and 2021, respectively (in thousands):

Accrued expenses and other current liabilities consisted of the following (in thousands):

2023 December 31,

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Related Party Transactions

Private Company, Related Party

On May 15, 2020, we entered into an Exclusive License Agreement, as amended, with a private company, related party (as amended, the “Private Company License Agreement”), under which we granted the private company an exclusive worldwide license to certain CRISPR intellectual property rights and know-how in a defined field.

As consideration for the exclusive license, the private company issued to us 7,500,000 shares of convertible preferred stock with an estimated fair value of $ 7.5 million, which was the price paid for similar shares by another investor, and which was an arm’s length transaction.

This represents a material voting interest in the private company and entitles us to hold one of the four private company’s board of director seats and to jointly vote with another stockholder on a second board of director seat.

As of December 31, 2022, we have appointed one of the four directors of the private company.

We concluded that the private

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company is a variable interest entity and that we are not its primary beneficiary based on our representation on its board of directors.

As the private company’s convertible preferred stock is not in substance common stock, we record this investment using the measurement alternative in accordance with ASC 321, Investments - Equity Securities.

Under the measurement alternative, our investment in the private company’s convertible preferred stock was initially recorded at its estimated fair value, but the carrying value may be adjusted through earnings upon an impairment or when there is an observable price change involving the same or a similar investment with the private company.

As of each of December 31, 2022 and 2021, the carrying value of the investment was $ 7.5 million.

Edge Animal Health

On May 15, 2020, we entered into an Exclusive License Agreement for Veterinary Therapeutics (as amended, “Edge chRDNA License Agreement”) with Edge Animal Health (“Edge”), a private company, related party, under which we granted Edge an exclusive worldwide license to Cas9 and Cas12a chRDNA intellectual property rights and know-how in the defined field of veterinary therapeutics.

As consideration for this exclusive license, Edge issued to us 7,500,000 shares of convertible preferred stock with an estimated fair value of $ 7.5 million, which was the price paid for similar shares by another investor, and which was an arm’s length transaction.

This represents a material voting interest in Edge and entitles us to hold one of the four board of director seats.

As of December 31, 2023, we had appointed one of the four Edge directors.

We concluded that Edge is a variable interest entity and that we are not its primary beneficiary based on our representation on its board of directors.

As Edge’s convertible preferred stock is not in substance common stock, we recorded this investment using the measurement alternative.

As of each of December 31, 2023 and 2022, the carrying value

of the Edge investment was $ 7.5 million.

There have been no changes to the carrying value of the investment during the years ended December 31, 2023 and 2022.

We did not recognize any revenue in connection with the Private Company License Agreement for each of the years ended December 31, 2022 and 2021.

Loan to our President and Chief Executive Officer

In November 2018, our president and chief executive officer entered into a promissory note (the “Note”) with us for $ 1.1 million, at an interest rate of 3.04 %, secured by 409,795 shares of our common stock owned by our president and chief executive officer and was determined to be non-recourse for accounting purposes.

In June 2021, the Note was repaid by our president and chief executive officer and recognized as an increase in additional paid in capital of $ 1.2 million.

Paycheck Protection Program Loan

On May 6, 2020, we entered into a promissory note with WebBank (the “Lender”) pursuant to the Paycheck Protection Program for a total amount of $ 1.6 million (the “PPP Loan”).

On May 22, 2021, our PPP Loan was forgiven in full by the SBA and, at that time, we recognized a PPP Loan extinguishment gain of $ 1.6 million in our consolidated statements of operations and comprehensive loss.

On May 16, 2023, we entered into an Exclusive License Agreement for Veterinary Therapeutics (CRISPR-Cas9) (“Edge Cas9 License Agreement”), under which we granted Edge an exclusive worldwide license to certain CRISPR-Cas9 intellectual property rights in the field of veterinary therapeutics.

Previously, on May 15, 2020, we had entered into an Option for an Exclusive License under which Edge could exercise its option within three years upon payment of a total of $ 1.2 million, which Edge paid, and we entered into the Edge Cas9 License Agreement.

We recognized $ 1.2 million of revenue in connection with the Edge Cas9 License Agreement during the twelve months ended December 31, 2023.

We did no t recognize any revenue in connection with the Edge Cas9 License Agreement in 2022.

Pfizer Investment

On June 29, 2023, we entered into a Securities Purchase Agreement (“Securities Purchase Agreement”) with Pfizer, pursuant to which we, in a private placement transaction, issued and sold to Pfizer 4,690,431 shares of our common stock, par value $ 0.0001 per share, at a purchase price of $ 5.33 per share, for aggregate gross proceeds of approximately $ 25.0 million (“Pfizer Investment”).

The issuance and sale of the shares to Pfizer closed on June 30, 2023.

We granted certain registration rights to Pfizer under the Securities Purchase Agreement covering the resale of the shares.

Unless otherwise agreed by Pfizer, we agreed to use the proceeds from the Pfizer Investment solely in connection with (i) the development program for our allogeneic anti-BCMA CAR-T cell therapy known as CB-011 that is being evaluated in our CaMMouflage clinical trial and/or (ii) any other single-targeted anti-BCMA CAR-T cell therapy using an anti-BCMA single-chain variable fragment owned or controlled by us (collectively, cell therapies described in clauses (i) and (ii) are referred to as a “BCMA Product Candidate”), for 36 months beginning on June 29, 2023.

On June 29, 2023, in connection with the Pfizer Investment, we and Pfizer also entered into an Information Rights Agreement, having a thirty-six ( 36 )-month term.

Under the Information Rights Agreement, we granted Pfizer a thirty ( 30 )-calendar day right of first negotiation (“ROFN”) if we commence or engage with any third party with respect to a potential grant of rights to develop and/or commercialize a BCMA Product Candidate, including, without limitation, a license agreement, a co-promotion/co-commercialization agreement, a profit share agreement, a joint venture agreement, or an asset sale agreement (a “Grant of Program Rights”).

If we and Pfizer do not reach an agreement with respect to a Grant of Program Rights within the 30-day period, then we may pursue negotiations and enter into an agreement with any third party.

If we and such third party do not reach agreement on the Grant of Program Rights within a specified time period, Pfizer’s right of first negotiation will be reinstated.

Under the Information Rights Agreement, we also agreed to grant Pfizer the right to designate one representative to serve on our scientific advisory board (“SAB”).

Through an information sharing committee, we provide calendar quarter updates to Pfizer regarding the development program for a BCMA Product Candidate.

Additionally, we agreed to provide Pfizer access to any preclinical or interim or final clinical data (including raw data) and results generated as part of the development program for a BCMA Product Candidate at the same time that we provide such data to a third party (other than to our service providers or the FDA or other regulatory authorities), subject to certain confidentiality exceptions.

On June 29, 2023, we and Pfizer also entered into a Voting Agreement, pursuant to which, for a period of 12 months, Pfizer agreed to cause our voting securities that Pfizer beneficially owns (within the meaning of Rules 13d-3 or 13d-5 under the Securities Exchange Act of 1934, as amended (“Exchange Act”)) in excess of 4.99 % of our then issued and outstanding voting securities to be voted (i) with respect to any matter directly relating to remuneration of directors, directors’ insurance, or indemnification or release from liability of directors, in a manner proportionally consistent with the votes properly cast for and against by holders of voting securities not beneficially owned by Pfizer, and (ii) with respect to any other matter in which Pfizer shall have the right to vote such voting securities, in accordance with the recommendation of our board of directors or any applicable committee thereof.

We recorded the issuance of our common stock at its estimated fair value of $ 17.5 million, which reflects a discount for the lack of marketability of the shares.

The remaining $ 7.5 million of the aggregate purchase price was allocated to the Information Rights Agreement, which represented a contract with a customer under ASC 606.

We concluded that the information sharing committee represents the only performance obligation under the Information Rights Agreement.

The ROFN does not provide Pfizer with a material right and is therefore not a performance obligation.

We recognize revenue over time as the measure of progress which we believe best depicts the obligations to Pfizer.

The information sharing committee will meet quarterly over the 36-month term of the Information Rights Agreement, which results in recognition of the transaction price over the 36-month term.

During the twelve months ended December 31, 2023, we recognized $ 1.2 million of revenue from Pfizer.

As of December 31, 2023, there was approximately $ 6.2 million of related party deferred revenue ($ 2.5 million included in current liabilities and $ 3.7 million included in long-term liabilities) related to our performance obligation to Pfizer.

Operating Lease Obligations

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To complete certain leasehold improvements, the lessor has agreed to provide us a tenant improvement allowance of $ 1.8 million.

The leasehold improvements constructed are presented under property and equipment on our consolidated balance sheets and are depreciated on a straight-line basis over the remaining lease term.

The components of lease costs, which are included in our statements of operations and comprehensive loss, are as follows (in thousands):

Year Ended December 31, 2022

The leasehold improvements constructed are presented under property and equipment on our consolidated balance sheets and are depreciated on a straight-line basis over the shorter of remaining lease term or estimated useful life.

The components of lease costs, which are included in our statements of operations and comprehensive loss, were as follows (in thousands):

Years Ended December 31,

Operating lease cost (1)

$ 7,628 $ 7,337

Short-term lease cost 250 83

Total lease cost $ 7,878 $ 7,420

(1) Includes $ 2.2 million of variable lease cost related to operating expenses and taxes for the year ended December 31, 2022.

Supplemental information related to our leases is as follows (in thousands):

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Year Ended December 31, 2022

(1) Includes $ 2.5 million and $ 2.2 million of variable lease cost related to operating expenses and taxes for the years ended December 31, 2023, and 2022, respectively.

Supplemental information related to our leases was as follows (in thousands):

Years Ended December 31,

Cash paid for amounts included in the measurement of lease liabilities:

Operating cash flows from operating leases $ 3,732 $ 3,468

As of December 31, 2022, the weighted-average remaining lease term was 8.3 years for our corporate office and laboratory leases, and the weighted-average discount rate was 11.3 %.

The following table summarizes the weighted-average remaining lease term and weighted-average discount rate for our corporate laboratory and office leases:

Years Ended December 31,

Weighted-average remaining lease term (years)

Weighted-average discount rate

11.3 % 11.3 %

The following table summarizes a maturity analysis of our operating lease liabilities showing the aggregate lease payments as of December 31, 2023:

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(1) Reflects an offset of $ 1.0 million related to incentives expected to be received in 2024.

(2) Reflects an offset of $ 0.6 million related to incentives expected to be received in 2024.

Commitments and Contingencies

Research and Development Agreements

We enter into various agreements in the ordinary course of business, such as those with suppliers, CROs, CMOs, and clinical trial sites.

These agreements provide for termination at the request of either party, generally with less than one-year notice and are, therefore, cancellable contracts and, if cancelled, are not anticipated to have a material effect on our consolidated financial condition, results of operations, or cash flows.

Research, Manufacturing, and License Agreements

We enter into various agreements in the ordinary course of business, such as those with CMOs, suppliers, CROs, clinical trial sites, licensors, assignors, and the like.

These agreements provide for termination by either party in certain circumstances, generally with less than one-year notice and are, therefore, cancellable contracts and, if cancelled, are not anticipated to have a material effect on our consolidated financial condition, results of operations, or cash flows.

Some of these agreements include contingent payments that will become payable if and when certain development, regulatory, clinical, and/or commercial milestones are achieved by us.

As of December 31, 2023, the satisfaction and timing of such contingent payments is uncertain and is not reasonably estimable.

Guarantees and Indemnifications

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Significant judgment by us is required to determine both probability and the estimated amount.

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On February 10, 2023, a putative class action lawsuit was filed in the U.S.

District Court for the Northern District of California against our company and certain of our officers and current and former members of our board of directors ( Greenhalgh v.

On April 11, 2023, a putative class action lawsuit was filed in the U.S.

District Court for the Northern District of California against our company and certain of our officers and current and former members of our board of directors, B ergman v.

Caribou Biosciences, Inc., et al.

, Case Number 3:23-cv-00609-VC).

The complaint challenges disclosures regarding our company’s business, operations, and prospects, specifically with respect to the alleged durability of CB-010’s therapeutic effect and the product candidate’s clinical and commercial prospects, in alleged violation of Sections 11 and 15 of the Securities Act and Sections 10(b) and 20(a) of the Securities Exchange Act of 1934, as amended.

The complaint seeks an unspecified amount of damages on behalf of a putative class of purchasers of our company’s securities during the class period of July 23, 2021, through December 9, 2022, as well as interest and reasonable fees and costs.

We believe that this lawsuit is without merit.

Convertible Preferred Stock

There were no shares of convertible preferred stock authorized or outstanding as of December 31, 2022 and 2021.

In connection with the closing of our IPO on July 27, 2021, all outstanding shares of convertible preferred stock, including the Series C preferred stock issued in March 2021, were converted into shares of common stock.

Our amended and restated certificate of Incorporation, which was approved by the board of directors and stockholders in connection with our IPO, authorizes the issuance of 10,000,000 shares of preferred stock with par value of $ 0.0001 upon the closing of our IPO.

Common stock reserved for future issuance, on an as-converted basis, consists of the following:

, Case Number 4:23-cv-01742-YGR (“Bergman Case”).

The Bergman complaint challenges disclosures regarding our company’s business, operations, and prospects, specifically with respect to the alleged durability of CB-010’s therapeutic effect and the product candidate’s clinical and commercial prospects, in alleged violation of Sections 11 and 15 of the Securities Act of 1933, as amended (“Securities Act”) and Sections 10(b) and 20(a) of the Exchange Act.

On September 18, 2023, plaintiffs filed an amended complaint adding the IPO underwriters as defendants and making substantially the same allegations as the original complaint.

On November 14, 2023, we filed a motion to dismiss the amended complaint for failure to state a claim.

Motion to dismiss briefing was completed on February 21, 2024, and oral argument on the motion is scheduled for April 23, 2024.

We intend to vigorously defend the claims asserted against us.

On March 22, 2023, a putative class action lawsuit was filed in Superior Court of the State of California for the County of Alameda against our company and certain of our officers and current and former members of our board of directors, Lowry v.

Caribou Biosciences, Inc., et al.

, Case Number T23-1084 (“Lowry Case”).

The Lowry Case challenges disclosures regarding our company’s business, operations, and prospects, specifically with respect to the alleged durability of CB-010’s therapeutic effect and the product candidate’s clinical and commercial prospects, in alleged violation of Sections 11 and 15 of the Securities Act.

The allegations and claims in the Lowry Case are substantially similar to the Securities Act claims asserted in the Bergman Case.

On April 26, 2023, we filed a motion to stay the Lowry Case during the pendency of the parallel federal court litigation in the Bergman Case, and, on July 11, 2023, our motion to stay was denied.

On September 11, 2023, plaintiff filed an amended complaint making substantially the same allegations as the original complaint.

On November 9, 2023, we filed a motion to dismiss the amended complaint on the grounds that our certification of incorporation mandates that Securities Act claims against us be brought in federal court.

On February 28, 2024, the court granted our motion to dismiss and ordered the case dismissed.

Common stock reserved for future issuance, consisted of the following:

December 31, 2023 As of

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Stock options, authorized for future issuance 5,952,012 5,833,979

Stock available under the Employee Stock Purchase Plan 1,044,518 511,000

Restricted stock units 256,146 —

Stock available under our employee stock purchase plan 1,516,355 1,044,518

Unvested restricted stock units and performance-based restricted stock units 205,357 256,146

Total common stock reserved for future issuance 17,084,128 13,867,717

Shelf Registration Statement

On August 9, 2022, we filed a shelf registration statement on Form S-3 (“Shelf Registration Statement”) with the U.S.

Securities and Exchange Commission (“SEC”).

On August 9, 2022, we filed a shelf registration statement on Form S-3 (“Shelf Registration Statement”) with the SEC.

The Shelf Registration Statement allows us to sell from time to time up to $ 400.0 million of common stock, preferred stock, debt securities, warrants, rights, or units comprised of any combination of these securities, for our own account in one or more offerings (including the $ 100.0 million of common stock reserved for our at-the-market equity offering program described below).

The SEC declared the Shelf Registration Statement effective on August 16, 2022.

The terms of any offering under the Shelf Registration Statement will be established at the time of such offering and will be described in a prospectus supplement to the Shelf Registration Statement filed with the SEC prior to the completion of any such offering.

The terms of any offering under the Shelf Registration Statement are established at the time of such offering as described in a prospectus supplement to the Shelf Registration Statement filed with the SEC prior to the completion of any such offering.

In July and August 2023, we issued and sold a total of 22,115,384 shares of our common stock in an underwritten follow-on public offering at a price to the public of $ 6.50 per share, which included the full exercise of the underwriters’ right to purchase 2,884,615 additional shares of our common stock.

The total gross proceeds from the offering were approximately $ 143.7 million ($ 134.4 million net of underwriting discounts and commissions and offering expenses).

The shares were issued pursuant to the Shelf Registration Statement.

At-the-market Equity Offering Program

On August 9, 2022, we also entered into an Open Market Sale Agreement SM with Jefferies LLC (“Jefferies”) with respect to an at-the-market (“ATM”) equity offering program, pursuant to which, through Jefferies as sales agent, we may from time to time, sell shares of our common stock having an aggregate offering price of up to $ 100.0 million in gross proceeds under the Shelf Registration Statement.

As of December 31, 2022, there have been no sales under the ATM equity offering program and the full capacity remained available for issuance.

On August 9, 2022, we entered into an ATM Sales Agreement with Jefferies with respect to an at-the-market (“ATM”) equity offering program, pursuant to which, through Jefferies as sales agent, we may from time to time, sell shares of our common stock having an aggregate offering price of up to $ 100.0 million in gross proceeds under the Shelf Registration Statement.

As of December 31, 2023, we sold 168,635 shares of our common stock under the ATM Sales Agreement at an average price per share of $ 7.32 for aggregate gross proceeds of $ 1.2 million ($ 1.0 million net of offering expenses).

Stock-Based Compensation

Equity Incentive Plans

In July 2021, our board of directors adopted and our stockholders approved the 2021 Equity Incentive Plan (the “2021 Plan”) that became effective on July 22, 2021.

We reserved 5,200,000 shares of common stock for issuance under

Table of Conte n t s

the 2021 Plan.

In July 2021, our board of directors adopted and our stockholders approved the 2021 Equity Incentive Plan (“2021 Plan”) that became effective on July 22, 2021.

We reserved 5,200,000 shares of common stock for issuance under the 2021 Plan.

In addition, 934,562 shares available for issuance under the 2013 Equity Incentive Plan, adopted in 2013 and amended and restated in 2019, were transferred into the 2021 Plan.

In addition, any shares subject to awards under the 2013 Plan that terminate, expire, or lapse for any reason without the delivery of shares, or are reacquired or withheld (or not issued) to satisfy a tax withholding obligation or the purchase or exercise price, will be added to the 2021 Plan.

The 2021 Plan also provides that the number of shares initially reserved and available for issuance will automatically increase each January 1, beginning on January 1, 2022 and ending on January 1, 2031, by an amount equal to the lesser of (a) 5 % of the shares of common stock outstanding on the last day of the immediately preceding fiscal year, and (b) such smaller number of shares of stock as determined by our Board.

No more than 56,000,000 shares of stock may be issued upon the exercise of incentive stock options under the 2021 Plan.

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Grant Date Fair Value

During the year ended December 31, 2022, we granted 1,409,475 stock options to employees and non-employees with a weighted-average grant date fair value of $ 5.82 .

During the year ended December 31, 2021, we granted 4,860,623 stock options to employees and non-employees with a weighted-average grant date fair value of $ 7.39 .

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We estimated the fair value of each employee and non-employee stock option award on the grant date using the Black-Scholes option-pricing model based on the following assumptions for the years ended December 31, 2022 and 2021:

During the year ended December 31, 2023, we granted 3,524,616 stock options to employees with a weighted-average grant date fair value of $ 3.88 .

During the year ended December 31, 2022, we granted 1,409,475 stock options to employees with a weighted-average grant date fair value of $ 5.82 .

We estimated the fair value of each employee and stock option award on the grant date using the Black-Scholes option-pricing model based on the following assumptions:

Years Ended December 31,

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Expected dividend yield 0.0 % 0.0 %

As of December 31, 2022, there was $ 26.5 million of unrecognized stock-based compensation expense related to employee and non-employee stock options that is expected to be recognized over a weighted-average period of 2.7 years.

As of December 31, 2023, there was $ 25.8 million of unrecognized stock-based compensation expense related to employee and stock options that is expected to be recognized over a weighted-average period of 2.5 years.

Restricted Stock Units

During the year ended December 31, 2022, we granted 200,058 restricted stock units (“RSUs”) and 59,781 performance-based RSUs (“PSUs”) under the 2021 Plan.

During the year ended December 31, 2023, we granted 75,000 RSUs and no PSUs under the 2021 Plan.

A summary of the status of and change in unvested RSUs and PSUs as of December 31, 2023 was as follows:

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Unvested, January 1, 2022

259,839 10.07

( 3,693 ) 9.90

Unvested, December 31, 2022 256,146 $ 10.07

Granted 75,000 5.88

Vested ( 78,596 ) 10.04

Forfeited ( 47,193 ) 10.37

Unvested, December 31, 2023 205,357 $ 8.49

The PSUs were granted to our executive officers and will vest if and when a certain milestone is reached within a specific time period, contingent upon the executive officer remaining an employee at that time.

The PSUs were granted to our executive officers and will vest contingent upon the achievement of a clinical milestone for CB-010 during a performance period ending December 31, 2024, and an executive officer’s continued employment during the performance period.

As of December 31, 2023, the achievement of this milestone was not considered probable and, therefore, no stock-based compensation was recorded.

As of December 31, 2022, the total unrecognized stock-based compensation expense related to unvested RSUs was $ 1.6 million, which is expected to be recognized over the remaining weighted-average vesting period of 2.1 years.

As of December 31, 2023, the total unrecognized stock-based compensation expense related to unvested RSUs was $ 0.8 million, which is expected to be recognized over the remaining weighted-average vesting period of one years.

As of December 31, 2023, there was approximately $ 0.6 million of unrecognized stock-based compensation expense related to unvested PSUs.

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In July 2021, our board of directors adopted and our stockholders approved the ESPP, which became effective on July 22, 2021.

The ESPP is intended to qualify as an employee stock purchase plan under Section 423 of the Internal Revenue Code of 1986, as amended (the “Tax Code”).

The ESPP is intended to qualify as an employee stock purchase plan under Section 423 of the Internal Revenue Code of 1986, as amended (“Tax Code”).

We reserved 511,000 shares of our common stock for employee purchases under the ESPP.

The number of shares of common stock reserved for issuance under the ESPP will be automatically increased each January 1, beginning on January 1, 2022 and ending on January 1, 2031 by an amount equal to the lesser of (a) 1% of the shares of common stock outstanding on the last day of the immediately preceding fiscal year, and (b) such smaller number of shares of stock as determined by our Board;

The number of shares of common stock reserved for issuance under the ESPP will be automatically increased each January 1, beginning on January 1, 2022 and ending on January 1, 2031 by an amount equal to the lesser of (a) 1 % of the shares of common stock outstanding on the last day of the immediately preceding fiscal year, and (b) such smaller number of shares of stock as determined by our board of directors;

provided that the maximum number of shares that may be issued under the ESPP is 10,000,000 shares.

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At the end of each purchase period, employees are able to purchase shares at 85 % of the lower of the fair market value of our common stock at the beginning of the offering period or at the end of each applicable offering period.

The first offering period commenced on August 16, 2021 and ended on February 15, 2022.

We have issued 69,113 shares of common stock under the ESPP as of December 31, 2022.

We recorded $ 0.3 million in accrued liabilities related to contributions withheld as of December 31, 2022.

Table of Conte n t s

We issued 207,567 shares of common stock under the ESPP as of December 31, 2023.

We recorded $ 0.5 million and $ 0.3 million in accrued liabilities related to contributions withheld as of December 31, 2023 and December 31, 2022, respectively.

Stock-Based Compensation Expense

We recorded stock-based compensation expense related to employee and non-employee equity-based award grants in our consolidated statements of operations and comprehensive loss for the years ended December 31, 2022 and 2021 as follows (in thousands):

We recorded stock-based compensation expense related to employee equity-based awards grants in our consolidated statements of operations and comprehensive loss as follows (in thousands):

Years Ended December 31,

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Total $ 13,750 $ 11,716

Stock-based compensation expense related to employees was $ 11.6 million and $ 3.4 million, for the years ended December 31, 2022 and 2021, respectively.

Stock-based compensation expense related to non-employees was $ 0.1 million for the year ended December 31, 2022 and less than $ 0.1 million for the year ended December 31, 2021.

401(k) Savings Plan

In 2017, we established a defined-contribution savings plan under Section 401(k) of the Tax Code.

In 2017, we established a defined-contribution savings plan under Section 401(k) of the Internal Revenue Code of 1986, as amended (“Tax Code”).

Our 401(k) plan is available to all employees and allows participants to defer a portion of their annual compensation on a pretax basis subject to applicable laws.

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Effective income tax rate — % — %

Table of Conte n t s

For the years ended December 31, 2023 and 2022, our tax provision for (benefit from) income taxes consisted of the following (in thousands):

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Deferred income taxes:

Federal — 317

State 177 ( 95 )

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As of December 31, 2023, a valuation allowance of $ 96.2 million was recorded against our deferred tax assets.

Table of Conte n t s

As of December 31, 2023, we had federal NOL carryforwards of $ 103.8 million, which do not expire.

As of December 31, 2023, we had state NOL carryforwards of $ 172.7 million, which may be available to offset future state income, and which expire at various years beginning with 2036.

As of December 31, 2022, we generated federal research and development tax credit carryforwards of $ 8.8 million, which will begin to expire in 2037.

As of December 31, 2023, we generated federal tax credit carryforwards of $ 14.2 million, which will begin to expire in 2037.

As of December 31, 2023, we had state credit carryforwards of $ 5.6 million available to reduce future tax liabilities, which do not expire.

Beginning January 1, 2022, the Tax Cuts and Jobs Act enacted in 2017 eliminates the option to deduct research and development expenditures in the current year and requires taxpayers to capitalize and amortize pursuant to IRC Section 174.

As a result, we recognized an increase in our deferred tax assets due to the capitalization of $ 84.9 million, net of current year amortization.

Given such amount was offset by our valuation allowance, there were no material impacts to the financial statements outside of the deferred tax table.

Beginning January 1, 2022, the Tax Cuts and Jobs Act of 2017 eliminated the option to deduct research and development expenditures in the current year and requires taxpayers to capitalize and amortize pursuant to Section 174 of the Tax Code.

As a result, we have capitalized research and development costs of $ 102.6 million and $ 93.9 million for the years ended December 31, 2023 and 2022, respectively.

We will amortize these costs for tax purposes over five years if the research and development was performed in the United States and over 15 years if the research and development was performed outside the United States.

Under Section 382 of the Tax Code, the ability to utilize NOL carryforwards or other tax attributes, such as research tax credits, in any taxable year may be limited if we have experienced an “ownership change.” Generally, a Section 382 ownership change occurs if there is a cumulative increase of more than 50 percentage points in the stock ownership of one or more stockholders or groups of stockholders who own at least 5 % of a corporation’s stock within a specified testing period.

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There are no ongoing examinations by taxing authorities at this time.

During August 2022, the CHIPS and Science Act (“CHIPS Act”) and Inflation Reduction Act (“IRA”) were enacted, neither of which are expected to have a material impact to our financial statements.

Also, effective as of January 1, 2022, the California net operating loss deduction and temporary limit on business credits have been reinstated in accordance with Senate bill 113.

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The American Rescue Plan Act (“ARA”) was signed into law on March 11, 2021.

We do not expect the ARA to have a material impact on our financial statements but given potential changes to IRC Section 162(m) will take place in 2027, we will continue to monitor and assess.

The following table shows the change in deferred tax valuation for the periods indicated:

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Because we were in a net loss position for all periods presented, basic net loss per share is the same as diluted net loss per share for all periods, as the inclusion of all common stock equivalents outstanding would have been anti-dilutive.

Potentially dilutive securities that were not included in the diluted per share calculations because they would be anti-dilutive were, as of December 31, 2022, and 2021 as follows:

Potentially dilutive securities that were not included in the diluted per share calculations because they would be anti-dilutive were as follows:

Stock options outstanding 9,410,404 6,733,074

RSUs and PSUs issued and outstanding 256,146 —

Shares committed under ESPP 49,109 18,804

RSUs issued and outstanding

153,000 256,146

Shares available under ESPP

134,276 49,109

9,697,680 7,038,329

Subsequent Events

We did not have any subsequent events as of the filing date of this Annual Report on Form 10-K, except as disclosed in Note 10.

On February 28, 2024, the Superior Court of the State of California for the County of Alameda granted our motion to dismiss the putative class action lawsuit filed against our company and certain of our officers and current and former members of our board of directors, Lowry v.

Caribou Biosciences, Inc., et al.

, Case Number T23-1084 (“Lowry Case”), and the court ordered the case dismissed.

Compared sentence by sentence after normalising whitespace, quotation marks, case and digits, so re-formatting and restated figures do not read as changed language. Wording changes appear as one removal and one addition. The current filing and the prior one are authoritative.

What changed 10-K

Item 9A. Controls and Procedures