bluebirdbio® bluebird bio, Inc. 2020 Annual Report UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 ___________________________________________________________________________ FORM 10-K ___________________________________________________________________________ (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2020 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-35966 ___________________________________________________________________________ bluebird bio, Inc. (Exact Name of Registrant as Specified in Its Charter ___________________________________________________________________________ Delaware 13-3680878 (State or Other Jurisdiction of (IRS Employer Incorporation or Organization) Identification No.) 60 Binney Street Cambridge, Massachusetts 02142 (Address of Principal Executive Offices) (Zip Code) (339) 499-9300 (Registrant’s Telephone Number, Including Area Code) ___________________________________________________________________________ Securities registered pursuant to Section 12(b) of the Act: Title of each class Trading Symbol(s) Name of each exchange on which registered Common Stock, $0.01 par value per share BLUE The NASDAQ Stock Market LLC Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes ☒ No ¨ Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act. Yes ¨ No ☒ Indicate by check mark whether the registrant: (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes ☒ No ¨ Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§ 232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yes ☒ No ¨ Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer”, “accelerated filer”, “smaller reporting company”, and “emerging growth company” in Rule 12b-2 of the Exchange Act. Large accelerated filer ☒ Accelerated filer ☐ Non-accelerated filer ☐ Smaller reporting company ☐ Emerging growth company ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐ Indicate by check mark whether the registrant has filed a report on and attested to its management's assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report. ☒ Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Act). Yes ☐ No ☒ The aggregate market value of common stock held by non-affiliates of the registrant based on the closing price of the registrant’s common stock as reported on the Nasdaq Global Select Market on June 30, 2020, the last business day of the registrant’s most recently completed second quarter, was $4,040,592,242. As of February 18, 2021, there were 67,141,044 shares of the registrant’s common stock, par value $0.01 per share, outstanding. DOCUMENTS INCORPORATED BY REFERENCE Portions of the registrant’s definitive Proxy Statement relating to its 2021 Annual Meeting of Stockholders are incorporated by reference into Part III of this Annual Report on Form 10-K where indicated. Such Proxy Statement will be filed with the U.S. Securities and Exchange Commission within 120 days after the end of the fiscal year to which this report relates. Table of Contents Page PART I. Item 1. Business 1 Item 1A. Risk Factors 38 Item 1B. Unresolved Staff Comments 71 Item 2. Properties 71 Item 3. Legal Proceedings 72 Item 4. Mine Safety Disclosures 72 PART II. Item 5. Market for Registrant’s Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities 73 Item 6. Selected Financial Data 74 Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations 75 Item 7A. Quantitative and Qualitative Disclosures About Market Risks 95 Item 8. Financial Statements and Supplementary Data 95 Item 9. Changes in and Disagreements with Accountants on Accounting and Financial Disclosure 95 Item 9A. Controls and Procedures 95 Item 9B. Other Information 98 PART III. Item 10. Directors, Executive Officers and Corporate Governance 99 Item 11. Executive Compensation 99 Item 12. Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters 99 Item 13. Certain Relationships and Related Transactions and Director Independence 99 Item 14. Principal Accountant Fees and Services 99 PART IV. Item 15. Exhibits and Financial Statement Schedules 100 Item 16. Form 10-K Summary 100 Signatures FORWARD-LOOKING STATEMENTS This Annual Report on Form 10-K contains forward-looking statements that involve risks and uncertainties, as well as assumptions that, if they never materialize or prove incorrect, could cause our results to differ materially from those expressed or implied by such forward-looking statements. We make such forward-looking statements pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995 and other federal securities laws. All statements other than statements of historical facts contained in this Annual Report on Form 10-K are forward-looking statements. In some cases, you can identify forward-looking statements by words such as “anticipate,” “believe,” “contemplate,” “continue,” “could,” “estimate,” “expect,” “intend,” “may,” “plan,” “potential,” “predict,” “project,” “seek,” “should,” “target,” “would,” or the negative of these words or other comparable terminology. These forward-looking statements include, but are not limited to, statements about: • the initiation, timing, progress and results of our preclinical and clinical studies, and our research and development programs; • our ability to advance product candidates into, and successfully complete, clinical studies; • our ability to advance our viral vector and drug product manufacturing capabilities, and to ensure adequate supply of our viral vectors and drug products; • the timing or likelihood of regulatory filings and approvals for our product candidates; • the timing or success of commercialization of our approved product, and any future approved products; • our ability to obtain adequate pricing and reimbursement of our approved product, and any future approved products; • the implementation of our business model, strategic plans for our business, product candidates and technology; • the scope of protection we are able to establish and maintain for intellectual property rights covering our approved product, product candidates and technology; • estimates of our expenses, future revenues, capital requirements and our needs for additional financing; • the potential benefits of strategic collaboration agreements and our ability to enter into strategic arrangements; • our ability to maintain and establish collaborations and licenses; • developments relating to our competitors and our industry; • the impact of the COVID-19 pandemic; • the timing and results of our investigation into the cause of recent safety events in our HGB-206 clinical study, and whether there is a relationship with the use of our lentiviral vector in the manufacture of LentiGlobin for SCD; • the timing, effects, costs, and benefits, including the tax treatment of the planned separation of our portfolio of products and programs into two independent, publicly-traded companies; and • other risks and uncertainties, including those listed under Part I, Item 1A. Risk Factors. Any forward-looking statements in this Annual Report on Form 10-K reflect our current views with respect to future events or to our future financial performance and involve known and unknown risks, uncertainties and other factors that may cause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by these forward-looking statements. Factors that may cause actual results to differ materially from current expectations include, among other things, those listed under Part I, Item 1A. Risk Factors and elsewhere in this Annual Report on Form 10-K. Given these uncertainties, you should not place undue reliance on these forward-looking statements. Except as required by law, we assume no obligation to update or revise these forward-looking statements for any reason, even if new information becomes available in the future. This Annual Report on Form 10-K also contains estimates, projections and other information concerning our industry, our business, and the markets for certain diseases, including data regarding the estimated size