blue-20240926

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

______________________________________________

SCHEDULE 14A

(Rule 14a-101)

INFORMATION REQUIRED IN PROXY STATEMENT

SCHEDULE 14A INFORMATION

Proxy Statement Pursuant to Section 14(a) of the

Securities Exchange Act of 1934

(Amendment No. )

______________________________________________

Filed by the Registrant x Filed by a party other than the Registrant ¨

Check the appropriate box:


¨			Preliminary Proxy Statement

¨			Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2))

x			Definitive Proxy Statement

¨			Definitive Additional Materials

¨			Soliciting Material under §240.14a-12

bluebird bio, Inc.

(Name of Registrant as Specified in its Charter)

(Name of Person(s) Filing Proxy Statement, if Other Than the Registrant)

Payment of Filing Fee (Check all boxes that apply):

No fee required.

Fee paid previously with preliminary materials.

Fee computed on table in exhibit required by Item 25(b) per Exchange Act Rules 14a-6(i)(1) and 0-11.

September 26, 2024

Dear Stockholder:

You are cordially invited to attend the 2024 Annual Meeting of Stockholders (the "Annual Meeting") of bluebird bio, Inc. The Annual Meeting will be held on November 6, 2024 at 8.30 a.m. EST at the offices of the Company, at 455 Grand Union Boulevard, Somerville, Massachusetts. As always, we encourage you to vote your shares prior to the Annual Meeting.

Details regarding admission to the Annual Meeting and the business to be conducted are more fully described in the accompanying Notice of Annual Meeting and Proxy Statement.

At this Annual Meeting, the agenda includes the election of three Class II directors for three-year terms ("Proposal 1"), the approval of named executive officer compensation by a non-binding advisory vote ("Proposal 2"), the approval of an amendment to our Amended and Restated Certificate of Incorporation, as amended (the "Amended and Restated Certificate of Incorporation") to provide for the exculpation of officers for certain breaches of fiduciary duty to the extent permitted by the General Corporation Law of the State of Delaware ("Proposal 3"), the approval of amendments to our Amended and Restated Certificate of Incorporation to effect a reverse stock split of our common stock at a ratio ranging from any whole number between 1-for-15 and 1-for-20, as determined by our Board of Directors in its discretion ("Proposal 4"), the approval of an amendment and restatement of our 2023 Incentive Award Plan to, among other things, increase the number of shares of our common stock authorized for issuance thereunder ("Proposal 5"), the ratification of the appointment of Ernst & Young LLP as our independent registered public accounting firm for the fiscal year ending December 31, 2024 ("Proposal 6"), and the approval of an adjournment of the Annual Meeting, if necessary, to solicit additional proxies if there are not sufficient votes at the time of the Annual Meeting to approve Proposal 3, Proposal 4 and/or Proposal 5 ("Proposal 7").

Under Securities and Exchange Commission rules, we are providing access to the proxy materials for the Annual Meeting to stockholders via the Internet. Accordingly, you can access the proxy materials and vote at www.proxyvote.com. Instructions for accessing the proxy materials and voting are described below and in the Notice of Internet Availability of Proxy Materials that you received in the mail. Your vote is very important. Whether or not you plan to attend the Annual Meeting, please carefully review the enclosed proxy statement and then cast your vote, regardless of the number of shares you hold. If you are a stockholder of record, you may vote over the Internet, by telephone, or, if you request to receive a printed set of the proxy materials, by completing, signing, dating and mailing the accompanying proxy card in the return envelope. Submitting your vote via the Internet or by telephone or proxy card will not affect your right to vote at the Annual Meeting if you decide to attend the Annual Meeting. If your shares are held in street name (held for your account by a broker or other nominee), you will receive instructions from your broker or other nominee explaining how to vote your shares, and you will have the option to cast your vote by telephone or over the Internet if your voting instruction form from your broker or nominee includes instructions and a toll-free telephone number or Internet website to do so. In any event, to be sure that your vote will be received in time, please cast your vote by your choice of available means at your earliest convenience.

We hope that you will join us on November 6, 2024. Your continuing interest in bluebird is very much appreciated.

Sincerely,

Andrew Obenshain

President & Chief Executive Officer

NOTICE OF 2024 ANNUAL MEETING OF STOCKHOLDERS


Date			November 6, 2024
Time			8:30 a.m. Eastern Time
Place			455 Grand Union Boulevard, Somerville, Massachusetts 02145
Record Date			September 16, 2024. Only stockholders of record at the close of business on the record date are entitled to receive notice of, and to vote at, the Annual Meeting. A complete list of such stockholders will be open to the examination of any stockholder for a period of ten days prior to the Annual Meeting for a purpose germane to the meeting by sending an email to investor@bluebirdbio.com, stating the purpose of the request and providing proof of ownership of Company stock.
Purpose			•To elect John O. Agwunobi, Elisabeth Leiderman and Andrew Obenshain as Class II members of the Board of Directors, to serve until the Company’s 2027 Annual Meeting of Stockholders and until their successors are duly elected and qualified ("Proposal 1");
			•To approve, on a non-binding, advisory basis, the compensation paid to the Company’s named executive officers ("Proposal 2");
			•To approve an amendment to the Company's Amended and Restated Certificate of Incorporation to provide for the exculpation of officers for certain breaches of fiduciary duty to the extent permitted by the General Corporation Law of the State of Delaware ("Proposal 3");
			•To approve amendments to the Company's Amended and Restated Certificate of Incorporation to effect a reverse stock split of our common stock at a ratio ranging from any whole number between 1-for-15 and 1-for-20, as determined by our Board of Directors in its discretion ("Proposal 4");
			•To approve an amendment and restatement of the Company's 2023 Incentive Award Plan to, among other things, increase the number of shares of our common stock authorized for issuance thereunder ("Proposal 5");
			•To ratify the selection of Ernst & Young LLP as the Company’s independent registered public accounting firm for the fiscal year ending December 31, 2024 ("Proposal 6");
			•To approve an adjournment of the Annual Meeting, if necessary, to solicit additional proxies if there are not sufficient votes at the time of the Annual Meeting to approve Proposal 3, Proposal 4 and/or Proposal 5 ("Proposal 7"); and
			•To transact any other business that may properly come before the meeting or any adjournment thereof.
Meeting Admission			All stockholders as of the record date, or their duly appointed proxies, may attend the Annual Meeting. If you attend, you will be asked to present valid picture identification such as a driver’s license or passport. If your bluebird stock is held in a brokerage account or by a bank or other nominee, you are considered the beneficial owner of shares held in street name, and this proxy statement is being forwarded to you by your broker or nominee. As a result, your name does not appear on our list of stockholders. If your stock is held in street name, in addition to picture identification, you should bring with you a letter or account statement showing that you were the beneficial owner of the stock on the record date, in order to be admitted to the Annual Meeting.
Proxy Voting			If you are a stockholder of record, please vote via the Internet or, for shares held in street name, please submit the voting instruction form you receive from your broker or nominee, as soon as possible so your shares can be voted at the Annual Meeting. You may submit your voting instruction form by mail. If you are a stockholder of record, you may also vote by telephone or by submitting a proxy card by mail. If your shares are held in street name, you will receive instructions from your broker or other nominee explaining how to vote your shares, and you may also have the choice of instructing the record holder as to the voting of your shares over the Internet or by telephone. Follow the instructions on the voting instruction form you received from your broker or nominee.
Corporate Headquarters			455 Grand Union Boulevard, Somerville, Massachusetts 02145

By order of the Board of Directors,

Joseph Vittiglio

Chief Legal and Business Officer and Secretary

Somerville, Massachusetts

September 26, 2024

BLUEBIRD BIO, INC.

455 GRAND UNION BOULEVARD

SOMERVILLE, MASSACHUSETTS 02145

PROXY STATEMENT

FOR THE 2024 ANNUAL MEETING OF STOCKHOLDERS

TO BE HELD ON NOVEMBER 6, 2024

AT 8:30 AM EST

GENERAL INFORMATION

When are this proxy statement and the accompanying materials scheduled to be sent to stockholders?

We have elected to provide access to our proxy materials to our stockholders via the Internet. Accordingly, on or about September 26, 2024, we will begin mailing a Notice of Internet Availability of Proxy Materials and the proxy materials, including the Notice of 2024 Annual Meeting of Stockholders, this proxy statement and accompanying proxy card or, for shares held in street name (held for your account by a broker or other nominee), voting instruction form, and the Annual Report on Form 10-K for the year ended December 31, 2023 (the "Annual Report") will be made available to stockholders on the Internet on the same date.

Why did I receive a Notice of Internet Availability of Proxy Materials instead of a full set of proxy materials?

Pursuant to rules adopted by the Securities and Exchange Commission (SEC), we are providing access to our proxy materials over the Internet rather than printing and mailing the proxy materials. We believe electronic delivery will expedite the receipt of materials and will help lower our costs and reduce the environmental impact of our annual meeting materials. Therefore, a Notice of Internet Availability will be mailed to holders of record and beneficial owners of our common stock starting on or around September 26, 2024. The Notice of Internet Availability will provide instructions as to how stockholders may access and review the proxy materials, including the Notice of Annual Meeting, proxy statement, proxy card and Annual Report, on the website referred to in the Notice of Internet Availability or, alternatively, how to request that a copy of the proxy materials, including a proxy card, be sent to them by mail. The Notice of Internet Availability will also provide voting instructions. In addition, stockholders of record may request to receive the proxy materials in printed form by mail or electronically by e-mail on an ongoing basis for future stockholder meetings. Please note that, while our proxy materials are available at the website referenced in the Notice of Internet Availability, and our Notice of Annual Meeting, proxy statement and Annual Report are available on our website, no other information contained on either website is incorporated by reference in or considered to be a part of this document.


Important Notice Regarding the Availability of Proxy Materials for the Annual Meeting to Be Held on November 6, 2024
The Notice of 2024 Annual Meeting of Stockholders, Proxy Statement and our Annual Report on Form 10-K for the fiscal year ended December 31, 2023, are available at investor.bluebirdbio.com.

Who is soliciting my vote?

The Board of Directors of bluebird bio, Inc. is soliciting your vote for the 2024 Annual Meeting of Stockholders (the "Annual Meeting").

When is the record date for the Annual Meeting?

The Board has fixed the record date for the Annual Meeting as of the close of business on September 16, 2024.

How many votes can be cast by all stockholders?

A total of 193,913,585 shares of our common stock were outstanding on September 16, 2024, and entitled to be voted at the meeting. Each share of common stock is entitled to one vote on each matter.

How do I vote?

If you are a stockholder of record and your shares are registered directly in your name, you may vote:

•By Internet. Access the website of our tabulator, Broadridge, at: www.proxyvote.com, using the voter control number printed on the furnished proxy card. Your shares will be voted in accordance with your instructions. You must specify how you want your shares voted or your Internet vote cannot be completed and you will receive an error message. If you vote on the Internet, you may also request electronic delivery of future proxy materials.

•By Telephone. Call 1-800-690-6903 toll-free from the U.S., U.S. territories and Canada, and follow the instructions on the enclosed proxy card. Your shares will be voted in accordance with your instructions. You must specify how you want your shares voted or your telephone vote cannot be completed.

•By Mail. Complete and mail a proxy card in the enclosed postage prepaid envelope to Broadridge. Your proxy will be voted in accordance with your instructions. If you sign and return the enclosed proxy but do not specify how you want your shares voted, they will be voted FOR the director nominees named herein to our Board, FOR the non-binding advisory resolution approving the compensation of the named executive officers, FOR the approval of the amendment to the Amended and Restated Certificate of Incorporation to provide for exculpation of officers for certain breaches of fiduciary duty to the extent permitted by the General Corporation Law of the State of Delaware, FOR the approval of amendments to the Amended and Restated Certificate of Incorporation to effect a reverse stock split of our common stock at a ratio ranging from any whole number between 1-for-15 and 1-for-20, as determined by our Board of Directors in its discretion, FOR the approval of the amendment and restatement of the 2023 Incentive Award Plan to, among other things, increase the number of shares of common stock authorized for issuance thereunder, FOR the ratification of Ernst & Young LLP as our independent registered public accounting firm for the fiscal year ending December 31, 2023, and FOR the approval of an adjournment of the Annual Meeting, if necessary, to solicit additional proxies if there are not sufficient votes at the time of the Annual Meeting to approve Proposal 3, Proposal 4 and/or Proposal 5, and will be voted according to the discretion of the proxy holder upon any other business that may properly be brought before the meeting and at all adjournments and postponements thereof. If you are mailed or otherwise receive or obtain a proxy card or voting instruction form, and you choose to vote by telephone or by Internet, you do not have to return your proxy card or voting instruction form.

•In Person. If you are a stockholder of record, you may vote in person at the Annual Meeting.

Whether or not you plan to attend the meeting, we urge you to vote by proxy.

If your shares of common stock are held in street name (held for your account by a broker or other nominee), you will receive instructions on how to vote from your broker or other nominee. You must follow their instructions in order for your shares to be voted. Internet and telephone voting also may be offered to stockholders owning shares through certain banks and brokers. As a beneficial owner, you are invited to attend the Annual Meeting. However, since you are not a stockholder of record, you may not vote your shares in person at the Annual Meeting unless you request and obtain a legal proxy from the organization that holds your shares.

What are the Board’s recommendations on how to vote my shares?

Our Board recommends a vote:

Proposal 1: FOR the election of John O. Agwunobi, Elisabeth Leiderman and Andrew Obenshain as Class II directors (page 7)

Proposal 2: FOR the approval, on a non-binding, advisory basis, of the compensation of our named executive officers (page 22)

Proposal 3: FOR the approval of the amendment to our Amended and Restated Certificate of Incorporation to provide for the exculpation of officers for certain breaches of fiduciary duty to the extent permitted by the General Corporation Law of the State of Delaware (page 23)

Proposal 4: FOR the approval of amendments to our Amended and Restated Certificate of Incorporation to effect a reverse stock split of our common stock at a ratio ranging from any whole number between 1-for-15 and 1-for-20, as determined by our Board of Directors in its discretion (page 41)

Proposal 5: FOR the approval of the amendment and restatement of our 2023 Incentive Award Plan to, among other things, increase the number of shares of common stock authorized for issuance thereunder (page 50)

Proposal 6: FOR ratification of the selection of Ernst & Young LLP as our independent registered public accounting firm (page 61); and

Proposal 7: FOR the approval of an adjournment of the Annual Meeting, if necessary, to solicit additional proxies if there are not sufficient votes at the time of the Annual Meeting to approve Proposal 3, Proposal 4 and/or Proposal 5 (page 62)

Who pays the cost for soliciting proxies?

We will pay the cost for the solicitation of proxies by the Board. The solicitation of proxies will be made primarily by mail and through Internet access to materials. Proxies may also be solicited personally, by telephone, fax or e-mail by employees of bluebird without any remuneration to such individuals other than their regular compensation. We will also reimburse brokers, banks, custodians, other nominees and fiduciaries for forwarding these materials to their principals to obtain the authorization for the execution of proxies.

Will my shares be voted if I do not return my proxy?

If your shares are registered directly in your name, your shares will not be voted if you do not vote over the Internet, by telephone, by returning your proxy or by ballot at the Annual Meeting. If your shares are held in street name, your bank, broker or other nominee may under certain circumstances vote your shares if you do not timely return your proxy. Banks, brokers and other nominees can vote customers’ unvoted shares on routine matters, but cannot vote such shares on non-routine matters. If you do not timely return a proxy to your bank, broker or other nominee to vote your shares, your bank, broker or other nominee may, on routine matters, either vote your shares or leave your shares unvoted. Your bank, broker or other nominee cannot vote your shares on any non-routine matter. The election of directors (Proposal 1), the non-binding advisory vote to approve named executive officer compensation (Proposal 2), the approval of the amendment to our Amended and Restated Certificate of Incorporation to provide for the exculpation of officers for certain breaches of fiduciary duty to the extent permitted by the General Corporation Law of the State of Delaware (Proposal 3) and the approval of the amendment and restatement of our 2023 Incentive Award Plan to, among other things, increase the number of shares of common stock authorized for issuance thereunder (Proposal 5) are non-routine matters. The approval of amendments to our Amended and Restated Certification of Incorporation to effect a reverse stock split of our common stock at a ratio ranging from any whole number between 1-for-15 and 1-for-20, as determined by our Board of Directors in its discretion (Proposal 4), the ratification of the appointment of our independent registered public accounting firm (Proposal 6) and the approval of an adjournment of the Annual Meeting, if necessary, to solicit additional proxies if there are not sufficient votes at the time of the Annual Meeting to approve Proposal 3, 4 or 5 (Proposal 7) are routine matters. We encourage you to provide voting instructions to your bank, broker or other nominee by giving your proxy to them. This ensures that your shares will be voted at the Annual Meeting according to your instructions. You should receive directions from your bank, broker or other nominee about how to submit your proxy to them at the time you receive this proxy statement.

Can I change my vote?

You may revoke your proxy at any time before it is voted by notifying the Secretary in writing, by returning a signed proxy with a later date, by transmitting a subsequent vote over the Internet or by telephone prior to the close of the Internet voting facility or the telephone voting facility, or by attending the Annual Meeting and voting in person. If your stock is held in street name, you must contact your broker or nominee for instructions as to how to change your vote.

How is a quorum reached?

The presence, in person or by proxy, of holders of at least a majority of the total number of outstanding shares entitled to vote is necessary to constitute a quorum for the transaction of business at the Annual Meeting. Shares held of record by stockholders or brokers, bankers or other nominees who do not return a signed and dated proxy or attend the Annual Meeting in person will not be considered present or represented at the Annual Meeting and will not be counted in determining the presence of a quorum. Abstentions and broker non-votes, if any, will be counted for purposes of determining whether a quorum is present for the transaction of business at the meeting.

What vote is required to approve each item and how are votes counted?

Votes cast by proxy or in person at the Annual Meeting will be counted by the persons appointed by bluebird to act as tabulators for the meeting. A broker non-vote occurs when a nominee holding shares for a beneficial owner does not vote on a particular proposal because the nominee does not have discretionary voting power with respect to that item and has not received instructions from the beneficial owner.

Proposal 1 – Election of three Class II director nominees

For the election of the three Class II director nominees, each director nominee presented must be elected by a majority of the votes cast in person or by proxy at the Annual Meeting. Director nominees are elected by a majority vote for non-contested director elections. Because the number of director nominees properly nominated for the Annual Meeting does not exceed the number of positions on the Board to be filled by election at the Annual Meeting, this election of directors is non-contested. To elect a director nominee to the Board, the votes cast FOR the director nominee must exceed the votes cast AGAINST. Only FOR and AGAINST votes will affect the outcome. Abstentions will have no effect on the outcome of the vote on Proposal 1. Proposal 1 is a non-routine matter. Therefore, if your shares are held by your bank, broker or other nominee in street name and you do not vote your shares, your bank, broker or other nominee cannot vote your shares on Proposal 1. Shares held in street name by banks, brokers or nominees who indicate on their proxies that they do not have authority to vote the shares on Proposal 1 will not be counted as votes FOR or AGAINST any director nominee and will be treated as broker non-votes. As a result, broker non-votes will have no effect on the outcome of the vote on Proposal 1.

Proposal 2 – Non-binding advisory vote on named executive officer compensation

For the non-binding advisory vote on named executive officer compensation, the votes cast FOR must exceed the votes cast AGAINST to approve, on a non-binding advisory basis, the compensation of our named executive officers. Only FOR and AGAINST votes will affect the outcome. Abstentions will have no effect on the outcome of the vote on Proposal 2. Proposal 2 is a non-routine matter. Therefore, if your shares are held by your bank, broker or other nominee in street name and you do not vote your shares, your bank, broker or other nominee cannot vote your shares on Proposal 2. Shares held in street name by banks, brokers or nominees who indicate on their proxies that they do not have authority to vote the shares on Proposal 2 will not be counted as votes FOR or AGAINST the proposal and will be treated as broker non-votes. As a result, broker non-votes will have no effect on the outcome of the vote on Proposal 2.

Proposal 3 – Approval of the amendment to our Amended and Restated Certificate of Incorporation to provide for the exculpation of officers for certain breaches of fiduciary duty

For the approval of the amendment to our Amended and Restated Certificate of Incorporation to provide for the exculpation of officers for certain breaches of fiduciary duty to the extent permitted by the General Corporation Law of the State of Delaware, the holders of at least a majority of the outstanding shares of our common stock entitled to vote at the Annual Meeting must vote FOR this proposal. Proposal 3 is a non-routine matter. Therefore, if your shares are held by your bank, broker or other nominee in street name and you do not vote your shares, your bank, broker or other nominee cannot vote your shares on Proposal 3. Abstentions and broker non-votes will have the effect of votes AGAINST Proposal 3.

Proposal 4 – Approval of amendments to our Amended and Restated Certificate of Incorporation to effect a reverse stock split of our common stock at a ratio ranging from any whole number between 1-for-15 and 1-for-20, as determined by our Board of Directors in its discretion

For the approval of amendments to our Amended and Restated Certificate of Incorporation to effect a reverse stock split of our common stock at a ratio ranging from any whole number between 1-for-15 and 1-for-20, as determined by our Board of Directors in its discretion, the holders of at least a majority of the outstanding shares of our common stock entitled to vote at the Annual Meeting must vote FOR this proposal. Proposal 4 is a routine matter. Therefore, if your shares are held by your bank, broker or other nominee in street name and you do not vote your shares, your bank, broker or other nominee may vote your shares on Proposal 4. Therefore, we do not expect any broker non-votes with respect to this proposal. Abstentions will have the same effect as an AGAINST vote on Proposal 4.

Proposal 5 - Approval of the amendment and restatement of our 2023 Incentive Award Plan to, among other things, increase the number of shares of our common stock authorized for issuance thereunder.

For the approval of the amendment and restatement of our 2023 Incentive Award Plan, the votes cast FOR must exceed the votes cast AGAINST. Only FOR and AGAINST votes will affect the outcome. Abstentions will have no effect on the

outcome of the vote on Proposal 5. Proposal 5 is a non-routine matter. Therefore, if your shares are held by your bank, broker or other nominee in street name and you do not vote your shares, your bank, broker or other nominee cannot vote your shares on Proposal 5. Shares held in street name by banks, brokers or nominees who indicate on their proxies that they do not have authority to vote the shares on Proposal 5 will not be counted as votes FOR or AGAINST the proposal and will be treated as broker non-votes. As a result, broker non-votes will have no effect on the outcome of the vote on Proposal 5.

Proposal 6 – Ratification of selection of Ernst & Young LLP as our independent registered public accounting firm

For the ratification of the selection of Ernst & Young LLP as our independent registered public accounting firm for our 2024 fiscal year, the votes cast FOR must exceed the votes cast AGAINST. Only FOR and AGAINST votes will affect the outcome. Abstentions will have no effect on the outcome of Proposal 6. Proposal 6 is a routine matter. Therefore, if your shares are held by your bank, broker or other nominee in street name and you do not vote your shares, your bank, broker or other nominee may vote your shares on Proposal 6. Therefore, we do not expect any broker non-votes with respect to this proposal.

Proposal 7 – Approval of an adjournment of the Annual Meeting, if necessary, to solicit additional proxies if there are not sufficient votes at the time of the Annual Meeting to approve Proposal 3, Proposal 4 and/or Proposal 5

For the approval of an adjournment of the Annual Meeting, if necessary, to solicit additional proxies if there are not sufficient votes at the time of the Annual Meeting to approve Proposal 3, Proposal 4 and/or Proposal 5, the votes cast FOR must exceed the votes cast AGAINST. Only FOR and AGAINST votes will affect the outcome. Abstentions will have no effect on the voting of Proposal 7. Proposal 7 is a routine matter. Therefore, if your shares are held by your bank, broker or other nominee in street name and you do not vote your shares, your bank, broker or other nominee may vote your shares on Proposal 7. Therefore, we do not expect any broker non-votes with respect to this proposal.

If the Annual Meeting is adjourned or postponed for any purpose, at any subsequent reconvening of the meeting, your proxy will be voted in the same manner as it would have been voted at the original convening of the Annual Meeting unless you withdraw or revoke your proxy. Your proxy may be voted in this manner even though it may have been voted on the same or on any other matter at a previous session of the Annual Meeting.

Could other matters be decided at the Annual Meeting?

bluebird does not know of any other matters that may be presented for action at the Annual Meeting. Should any other business come before the meeting, the persons named on the enclosed proxy will have discretionary authority to vote the shares represented by such proxies in accordance with their best judgment. If you hold shares through a broker, bank or other nominee as described above, they will not be able to vote your shares on any other business that comes before the Annual Meeting unless they receive instructions from you with respect to such matter.

What happens if the meeting is postponed or adjourned?

Your proxy may be voted at the postponed or adjourned meeting. You will still be able to change your proxy until it is voted.

How can I find out the results of the voting at the Annual Meeting?

Preliminary voting results will be announced at the Annual Meeting. Final voting results will be published in a Current Report on Form 8-K that we expect to file with the SEC within four business days after the Annual Meeting. If final voting results are not available to us in time to file a Form 8-K within four business days after the Annual Meeting, we intend to file a Form 8-K to publish preliminary results and, within four business days after the final results are known to us, file an amended Form 8-K to publish the final results.

What does it mean if I receive more than one proxy card or voting instruction form?

It means that you have multiple accounts at the transfer agent or with brokers. Please complete and return all proxy cards or voting instruction forms to ensure that all of your shares are voted.

Who should I call if I have any additional questions?

If you hold your shares directly, please call Joseph Vittiglio, Secretary of the Company, at (339) 499-9300. If your shares are held in street name, please contact the telephone number provided on your voting instruction form or contact your broker or nominee holder directly.

PROPOSAL 1

ELECTION OF DIRECTORS

In accordance with Delaware law and our certificate of incorporation and By-laws, our Board is divided into three classes of approximately equal size. The members of each class are elected to serve a three-year term with the term of office of each class ending in successive years. John O. Agwunobi, Elisabeth Leiderman and Andrew Obenshain are the Class II directors whose terms expire at this Annual Meeting. Each of John O. Agwunobi, Elisabeth Leiderman and Andrew Obenshain has been nominated for and has agreed to stand for re-election to the Board to serve as a Class II director of the Company until the 2027 Annual Meeting and until his or her successor is duly elected and qualified.

Our By-laws provide for a majority voting standard for the election of directors in uncontested elections, which provides that to be elected, a director nominee must receive a greater number of votes FOR his or her election than votes AGAINST such election. The number of votes cast with respect to that director’s election excludes abstentions and broker non-votes with respect to that director’s election. In contested elections where the number of director nominees exceeds the number of directors to be elected, the voting standard will be a plurality of the shares present in person or by proxy and entitled to vote. In an uncontested election, if a director nominee who already serves as a director is not elected and no successor is elected, the resignation policy in our Corporate Governance Guidelines provides that such director will offer to tender his or her resignation to the Board. Our Nominating and Corporate Governance Committee will make a recommendation to the Board on whether to accept or reject the resignation, or whether to take some other action. The Board will act on the Nominating and Corporate Governance Committee’s recommendation and publicly disclose its decision within 90 days from the date of the certification of the election results.

It is intended that, unless you give contrary instructions, shares represented by proxies solicited by the Board will be voted for the election of the two director nominees listed below. We have no reason to believe that any director nominee will be unable to serve, or for good cause will not serve, if elected at the Annual Meeting. In the event that one or more director nominees is unexpectedly unable to serve, or for good cause will not serve, proxies may be voted for another person designated as a substitute nominee by the Board, or the Board may reduce its size. Information relating to each director nominee and for each continuing director, including his or her period of service as a director of bluebird, principal occupation and other biographical material is shown below. Pursuant to the By-laws, the Board has fixed the number of directors at nine as of the date of the Annual Meeting, and we have one vacancy. Vacancies on the Board are filled exclusively by the affirmative vote of a majority of the remaining directors, even if less than a quorum is present, and not by the stockholders. Your proxy cannot be voted for a greater number of persons than the number of director nominees named in this proxy statement.

THE BOARD UNANIMOUSLY RECOMMENDS THAT YOU VOTE

FOR

EACH OF THE FOLLOWING DIRECTOR NOMINEES FOR CLASS II DIRECTOR:

JOHN O. AGWUNOBI

ELISABETH LEIDERMAN

ANDREW OBENSHAIN

(PROPOSAL 1 ON YOUR PROXY CARD)

CORPORATE GOVERNANCE

Board Composition

We currently have eight directors and the terms of office of the directors are divided into three classes:


			Class I			Term expiring 2026
			Class II			Current term expiring 2024, if elected, subsequent term expiring 2027
			Class III			Term expiring 2025

At each Annual Meeting, the successors to directors whose terms will then expire shall serve from the time of election and qualification until the third Annual Meeting following election and until their successors are duly elected and qualified. A resolution of the Board may change the authorized number of directors. Any additional directorships resulting from an increase in the number of directors will be distributed among the three classes so that, as nearly as possible, each class will consist of one-third of the directors. This classification of the Board may have the effect of delaying or preventing changes in control or management of our company.

Our directors as of September 16, 2024 are as set forth below.

CLASS II DIRECTOR NOMINEES:


John O. Agwunobi, M.D.
Other Current Board Experience:						Previous Board Experience within the Last Five Years:
Ensign Group Inc. (ENSG)						Herbalife Nutrition Inc. (HLF)
U.S. African Development Foundation (USADF)						Magellan Health Inc. (MGLN)
The Akkermansia Company (private)
Professional Highlights:
Dr. Agwunobi was Chief Executive Officer and Chairman of the Board of Herbalife Nutrition Inc. from 2020 to 2022. Previously, Dr. Agwunobi served as Co-President of Herbalife from May 2018 to 2020. He also served as Chief Health and Nutrition Officer at Herbalife, responsible for training, education, science strategy and product development from 2016 to 2018. Prior to joining Herbalife, Dr. Agwunobi was an independent consultant, advising a number of privately-held health-related companies, including serving as an advisory board member of Shopko Stores Operating Co., LLC on behalf of the private equity firm Sun Capital Partners. From September 2007 to April 2014, Dr. Agwunobi served as Senior Vice President and President of Health and Wellness for Wal-Mart (NYSE: WMT) in the United States where he grew the business and provided insight and advice on the company’s health reform position. From December 2005 to September 2007, he served as the Assistant Secretary of Health for the U.S. Department of Health and Human Services, where he was responsible for disease prevention and health promotion. His responsibilities included the oversight of the Centers for Disease Control, National Institute of Health, the U.S. Food and Drug Administration, the Office of the U.S. Surgeon General, and numerous other public health offices and programs. Dr. Agwunobi also serves on the Board of the Ensign Group, Inc. and the Board of the U.S. African Development Foundation.
Key Qualifications and Expertise:
Dr. Agwunobi has significant experience as a senior executive and board member in the health and wellness field. In addition, he has deep expertise in public health programs and governmental agencies relevant to the healthcare industry, from his prior service and experience with the public sector. The insights he has developed from these roles provides our Board with important perspectives on the issues facing our company.


Elisabeth Leiderman, M.D.
Other Current Board Experience:						Previous Board Experience within the Last Five Years:
Autolus Therapeutics (AUTL)						None
Professional Highlights:
Since June 2024, Dr. Leiderman has served as Chief Financial Officer and Corporate Development Officer at Dewpoint Therapeutics, a biotechnology company applying biomolecular condensates to drug discovery. From November 2022 to November 2023, Dr. Leiderman served as Chief Financial Officer and Chief Business Officer at Atsena Therapeutics, a clinical-stage gene therapy company. Before joining Atsena, from September 2020 to October 2022, Dr. Leiderman was Chief Financial Officer and Head of Corporate Development at Decibel Therapeutics, a clinical stage biotechnology company developing novel gene therapeutics for restoration of hearing loss and balance disorders. From January 2020 to August 2020, Dr. Leiderman served as Chief Business Officer for Complexa, Inc., a clinical stage biopharmaceutical company focused on life-threatening fibrosis and inflammatory diseases. Prior to Complexa, Dr. Leiderman was Senior Vice President, Head of Corporate Development at Fortress Biotech from November 2016 to November 2019. Earlier in her career from 2007 to 2016, Dr. Leiderman developed her transaction and capital markets expertise in the healthcare investment banking groups at Nomura, Credit Suisse, Jefferies and UBS. Dr. Leiderman began her career in medical affairs at AstraZeneca, where she analyzed product and industry trends related to the central nervous system. Since December 2023, Dr. Leiderman has served on the Board of Directors of Autolus Therapeutics and is a member of the Audit Committee. Dr. Leiderman earned an M.D. from the American Medical Program at Tel Aviv University, an M.B.A. from The Wharton School at the University of Pennsylvania and a B.A. from The University of Pennsylvania.
Key Qualifications and Expertise:
Dr. Leiderman has over 20 years of experience in finance, strategy and business development in the life sciences industry. She is an "audit committee financial expert" with particular experience in matters faced by the audit committee of a life sciences company.


Andrew Obenshain
Other Current Board Experience:						Previous Board Experience within the Last Five Years:
Biotechnology Innovation Organization (BIO) (private)						None
Professional Highlights:
Since November 2021, Mr. Obenshain has served as bluebird's President and Chief Executive Officer. Mr. Obenshain previously served as bluebird's President, Severe Genetic Diseases from August 2020 to November 2021, and as bluebird's Senior Vice President, Head of Europe from 2016 to August 2020. Prior to that, from September 2015 to September 2016, Mr. Obenshain was the general manager of France and Benelux at Shire Pharmaceuticals, Inc. and from 2007 to 2015, he held roles of increasing responsibility at Genzyme/Sanofi. Mr. Obenshain received his M.B.A. from Northwestern University's Kellogg School of Management, and his B.A. in genetics, cell and developmental biology from Dartmouth College.
Key Qualifications and Expertise:
Mr. Obenshain has deep operating and historical experience with our Company gained from serving as our President, Chief Executive Officer and in other roles. Mr. Obenshain also has significant management experience in the biotechnology and pharmaceutical fields.

CONTINUING DIRECTORS:


Charlotte Jones-Burton, M.D., M.S.
Other Current Board Experience:						Previous Board Experience within the Last Five Years:
American Kidney Fund (private)						None
Women of Color in Pharma (private)
Professional Highlights:
Since May 2024, Dr. Jones-Burton has been Director and Head of Life Science Product Development and Strategy at 2Flo Ventures, an emerging venture capital firm and startup studio focused on the discovery, development, and commercialization of healthcare solutions. From January 2022 to November 2023, Dr. Jones-Burton served as Senior Vice President, Product Development and Strategy at Chinook Therapeutics, a clinical-stage biotechnology company discovering, developing and commercializing precision medicines for rare, severe kidney diseases. Prior to her role at Chinook Therapeutics she was VP, Global Clinical Development Head, Nephrology at Otsuka Pharmaceutical Development & Commercialization, Inc. from September 2019 to December 2021. From October 2016 until September 2019, Dr. Jones-Burton held various positions at Bristol-Myers Squibb Company with increasing responsibilities, most recently as Executive Director, Full Development Team Leader of Cardiovascular, Anti-Thrombosis. Prior to that, Dr. Jones-Burton was with Merck & Co. from 2007 to May 2011. With more than 20 years of experience as a clinical development leader, internal medicine and nephrology physician and academician, Dr. Jones-Burton is dedicated to creating healthier communities through drug development, patient advocacy and people engagement. Dr. Jones-Burton is also active in numerous professional associations and organizations and founded Women of Color in Pharma (WOCIP), a non-profit professional society focused women of color in the pharmaceutical industry. Dr. Jones-Burton earned a medical degree and Master of Science degree in Epidemiology and Preventive Medicine, with a concentration in Clinical Research, from the University of Maryland School of Medicine. Dr. Jones-Burton's postgraduate training included an internal medicine residency and a nephrology fellowship at the University of Maryland Medical Systems.
Key Qualifications and Expertise:
Dr. Jones-Burton has extensive experience as an executive in the pharmaceutical industry in drug development, physician and patient engagement and advocacy. The insights she has developed in her work, together with her involvement in professional service organizations, also provide her with important perspectives on the issues facing our company in the development and potential commercialization of our therapies, as well as matters of diversity, equity and inclusion.


Michael Cloonan
Other Current Board Experience:						Previous Board Experience within the Last Five Years:
Sionna Therapeutics (private)						Certego Therapeutics (private)
Professional Highlights:
Since May 2021, Mr. Cloonan has served as President and Chief Executive Officer of Sionna Therapeutics, where he leads company strategy and operations. From May 2017 to April 2021, Mr. Cloonan served as Chief Operating Officer at Sage Therapeutics, where he led all business functions (commercial, medical affairs, government affairs, business development, technical operations, strategy and program management) as well as general and administrative functions. Prior to Sage, Mr. Cloonan served in various business and commercial roles at Biogen for fourteen years, including most recently as Senior Vice President, U.S. Commercial, where he was the general manager of the multi-billion-dollar multiple sclerosis, hemophilia, and spinal muscular atrophy franchises. Prior to Biogen, Mr. Cloonan worked at Bain & Company as a consultant specializing in healthcare. Mr. Cloonan earned his M.B.A. from the Darden Graduate School of Business Administration at the University of Virginia and a B.A. from College of the Holy Cross.
Key Qualifications and Expertise:
Mr. Cloonan has extensive operating experience gained from serving as President and Chief Executive Officer at Sionna and leadership roles at Sage and Biogen.


Nick Leschly
Other Current Board Experience:						Previous Board Experience within the Last Five Years:
Synlogic, Inc. (SYBX)						Proclara Biosciences, Inc. (private)
2seventy bio, Inc. (TSVT)
Biotechnology Innovation Organization (BIO) (private)
Professional Highlights:
Mr. Leschly is Chairman of the Board of 2seventy bio, Inc., a cell and gene therapy company, and from November 2021 to March 2024, Mr. Leschly served as its Chief Executive Officer. Mr. Leschly previously served as bluebird's President and Chief Executive Officer from October 2010 to November 2021. Formerly a partner of Third Rock Ventures, L.P. since its founding in 2007 until 2010, Mr. Leschly played an integral role in the overall formation, development and business strategy of several of Third Rock’s portfolio companies, including Agios Pharmaceuticals, Inc. and Edimer Pharmaceuticals, Inc. Prior to joining Third Rock, he worked at Millennium Pharmaceuticals, Inc. (now a subsidiary of Takeda), leading several early-stage drug development programs and served as the product and alliance leader for VELCADE. Mr. Leschly also founded and served as Chief Executive Officer of MedXtend Corporation. He received his B.S. in molecular biology from Princeton University and his M.B.A. from The Wharton School of the University of Pennsylvania.
Key Qualifications and Expertise:
Mr. Leschly has deep operating and historical experience with our Company gained from serving as our President, Chief Executive Officer and member of the Board. In addition, Mr. Leschly also has significant experience in the venture capital industry and drug research and development.


Richard Paulson
Other Current Board Experience:						Previous Board Experience within the Last Five Years:
Karyopharm Therapeutics, Inc. (KPTI)						None
Sequent AG (private)
Professional Highlights:
Since 2021, Mr. Paulson has been President, Chief Executive Officer and Director at Karyopharm Therapeutics, a commercial-stage pharmaceutical company. Previously, Mr. Paulson was Executive Vice President of Ipsen Pharmaceuticals and Chief Executive Officer of Ipsen North America from 2018 to 2021 where he focused on innovative therapies and specialty care for oncology, neuroscience and rare diseases. Before joining Ipsen, Mr. Paulson work at Amgen for 10 years holding various leadership positions across Europe and North America. Mr. Paulson received his M.B.A. from the University of Toronto and his B.Com in marketing and finance from the University of Saskatchewan.
Key Qualifications and Expertise:
Mr. Paulson has deep operating experience gained from serving as President, Chief Executive Officer and Director at Karyopharm and leadership roles at Ipsen and Amgen. Mr. Paulson also has significant experience in sales, marketing, and market access in the biotechnology and pharmaceutical fields.


Najoh Tita-Reid
Other Current Board Experience:						Previous Board Experience within the Last Five Years:
CMI Marketing, Inc. (private)						None
Professional Highlights:
Since November 2023, Ms. Tita-Reid has served as Chief Brand and Experience Officer at Mars Petcare, to lead brand, experience, digitalization and technology to drive business transformation. From April 2021 to October 2023, Ms. Tita-Reid served as Global Chief Marketing Officer for Logitech, a global manufacturer of computer peripherals, software and services, where she led the global marketing function. Prior to this role, Ms. Tita-Reid served as Global Commercial Marketing Head from June 2020 to March 2021 and on the Global Marketing Reinvention team from February 2020 to May 2020 at Logitech. Previously, Ms. Tita-Reid served as Global Chief Marketing Officer and Executive Board Member for Hero-AG, a family-run healthy food company, from August 2017 to January 2020. In this role, she developed the organization’s marketing function and brand strategy and built the first global innovation pipeline while overseeing the R&D, innovation, sustainability and quality functions. Prior to Hero-AG, Ms. Tita-Reid held leadership positions at Bayer PLC, where she served as Vice President-Country Division Head for Consumer Care in the UK and Ireland from 2014 to 2017 and Merck & Co, Inc., where she served in various roles from 2011 to 2014, including General Manager for Western Europe from 2013 to 2014. Earlier in her career, Ms. Tita-Reid spent 19 years at Procter & Gamble, where she managed a number of consumer brands in the baby and feminine care categories, spearheaded multi-cultural marketing strategy across 15 billion-dollar brands, and led the multi-brand business unit for Hispanic and African American consumers. During her tenure, Ms. Tita-Reid trained and developed the P&G marketing function on ethnic marketing, and created breakthrough marketing strategies. Ms. Tita-Reid graduated with a Bachelor of Arts from Spelman College and holds an M.B.A. from Fuqua School of Business at Duke University.
Key Qualifications and Expertise:
Ms. Tita-Reid has extensive experience as a multi-faceted executive with global marketing expertise, she has a record of strategic and operational ingenuity and transformation across complex organizations and a breadth of experience across the US and Europe.


Mark Vachon (Chair of the Board)
Other Current Board Experience:						Previous Board Experience within the Last Five Years:
Beacon Mobility (private)						Charitable Health and Retirement Trust (private)
Clergy Trust of Boston (private)						Klöckner Pentaplast Group (private)
Panoramic Health (private)						Numotion (private)
Professional Highlights:
Mr. Vachon served as President and Executive Vice President at Change Healthcare Holdings, Inc. from November 2016 to April 2018. For over 30 years, Mr. Vachon held a variety of leadership positions across the General Electric organization, and was a company officer beginning in 1999 and a member of GE’s Corporate Executive Council. Mr. Vachon was President and CEO of GE Healthcare Americas from 2009 to 2010, and prior to that he was President and CEO of Global Diagnostics Imaging, GE Healthcare, between 2006 and 2009. Between 2003 and 2006, Mr. Vachon was Executive Vice President and CFO of GE Healthcare. Mr. Vachon holds a B.S. in Finance from Northeastern University and an M.A. from Boston College.
Key Qualifications and Expertise:
Mr. Vachon's corporate leadership experience and financial expertise make him a valuable contributor to our Board. In addition, Mr. Vachon has extensive experience in executive operating roles and in the healthcare field on a global basis. He is an "audit committee financial expert" with particular experience in matters faced by the audit committee of a life sciences company.

Identifying and Evaluating Director Nominees

Our Board is responsible for selecting its own members. The Board delegates the selection and nomination process to the Nominating and Corporate Governance Committee, with the expectation that other members of the Board, and of management, will be requested to take part in the process as appropriate.

Generally, our Nominating and Corporate Governance Committee identifies candidates for director nominees in consultation with management, through the use of search firms or other advisors, and through the recommendations submitted by stockholders or through such other methods as the Nominating and Corporate Governance Committee deems to be helpful in identifying candidates. Once candidates have been identified, our Nominating and Corporate Governance

Committee confirms that the candidates meet all of the minimum qualifications for director nominees established by the Nominating and Corporate Governance Committee. The Nominating and Corporate Governance Committee may gather information about the candidates through interviews, detailed questionnaires, background checks or any other means that the Nominating and Corporate Governance Committee deems to be appropriate in the evaluation process. The Nominating and Corporate Governance Committee then meets as a group to discuss and evaluate the qualities and skills of each candidate, both on an individual basis and taking into account the overall composition and needs of our Board. Based on the results of the evaluation process, the Nominating and Corporate Governance Committee recommends candidates for the Board’s approval as director nominees for election to the Board. Elisabeth Leiderman, one of our Class II directors, was recommended by a third-party search firm.

Director Qualifications and Diversity

Our Nominating and Corporate Governance Committee will consider, among other things, the following qualifications, skills and attributes when recommending candidates for the Board’s selection as director nominees for the Board and as candidates for appointment to the Board’s committees: a director nominee shall have the highest personal and professional integrity, shall have demonstrated exceptional ability and judgment, and shall be effective, in conjunction with the other director nominees to the Board, in collectively serving the long-term interests of the stockholders.

In evaluating proposed director candidates, our Nominating and Corporate Governance Committee may consider, in addition to the minimum qualifications and other criteria for board membership approved by the Board from time to time, all facts and circumstances that it deems appropriate or advisable, including, among other things, diversity considerations, the skills of the proposed director candidate, his or her depth and breadth of professional experience or other background characteristics, his or her independence, and the needs of the Board. While we do not have a formal policy with respect to diversity, our Nominating and Corporate Governance Committee believes that it is essential that the members of the Board represent diverse viewpoints. Our Nominating and Corporate Governance Committee believes that the backgrounds and qualifications of our directors, considered as a group, should provide a composite mix of experience, knowledge and abilities that will allow our Board to promote our strategic objectives and fulfill its responsibilities to our stockholders, and considers diversity of gender, race, national origin, education, professional experience, and differences in viewpoints and skills when evaluating proposed director candidates.

Our Nominating and Corporate Governance Committee’s priority in selecting directors is identification of persons who will further the interests of our Company through his or her established record of professional accomplishment, the ability to contribute positively to the collaborative culture among directors, and professional and personal experiences and expertise relevant to our growth strategy. The Nominating and Corporate Governance Committee will consider candidates recommended by stockholders. The policy adopted by the Nominating and Corporate Governance Committee provides that candidates recommended by stockholders are given appropriate consideration in the same manner as other candidates.

The expertise and experience, characteristics and committee assignments for each of our directors are summarized in the table below:

Director Nominees

Continuing Directors

Agwunobi

Leiderman

Obenshain

Cloonan

Jones-Burton

Leschly

Paulson

Tita-Reid

Vachon

Expertise & Experience

Public Company Experience

International Business Experience

Corporate Governance Experience

Capital Allocation / Corporate Financing Experience

Financial Literacy / Expertise

Information Services & Technology Experience

Legal / Regulatory / Public Policy Experience

Marketing / Sales / Business Development Experience

Risk Management Experience

Strategic Planning Experience

Human Resource, Executive Compensation, and Talent Management Experience

Senior Leadership Experience

Cybersecurity / Data Privacy

ESG and Climate Risks

Industry Experience

Shareholder Advocacy

Director Characteristics

Independence

Term expiring

2024

2026

2025

2026

Age

Director Since

2017

2021

2024

2022

2010

2023

2021

2014

Gender

Ethnic or Racial Diversity

Committee Composition

Audit Committee

Chair

Compensation Committee

Chair

Nominating & Corporate Governance Committee

Chair

The following Board Diversity Matrix presents our Board diversity statistics in accordance with Nasdaq Rule 5606, as self-disclosed by our directors.


Board Diversity Matrix as of September 26, 2024
Part I: Gender Identity	Female	Male	Non-Binary	Did Not Disclose Gender
Directors (9 total)	3	6	-	-
Part II: Demographic Background	Female	Male	Non-Binary	Did Not Disclose Gender
African American or Black	2	1	-	-
Alaskan Native or Native American	-	-	-	-
Asian	-	-	-	-
Hispanic or Latinx	-	-	-	-
Native Hawaiian or Pacific Islander	-	-	-	-
White	1	5	-	-
Two or More Races or Ethnicities	-	-	-	-
LGBTQ+	-
Did Not Disclose Demographic Background	-

Board Independence

Our Board has determined, upon the recommendation of our Nominating and Corporate Governance Committee, that each of our directors, other than Andrew Obenshain who serves as our President and Chief Executive Officer, and Nick Leschly, who served as our President and Chief Executive Officer from October 2010 to November 2021, has no relationship that would interfere with the exercise of independent judgment in carrying out the responsibilities of a director and is independent within the meaning of the director independence standards of the Nasdaq Stock Market rules. At least annually, our Board evaluates all relationships between us and each director in light of relevant facts and circumstances for the purposes of determining whether a relationship exists that would interfere with the exercise of independent judgment in carrying out the responsibilities of a director. Based on this evaluation, our Board makes an annual determination of whether each director is independent within the meaning of Nasdaq, and the SEC independence standards.

Board Meetings and Attendance

Our Board held four meetings during the fiscal year ended December 31, 2023. In the fiscal year ended December 31, 2023, each of our directors attended at least 75% of the meetings of the Board and the committees of the Board, in the period for which he or she served.

We encourage our directors to attend the Annual Meeting of Stockholders. Of the eight members of our Board at the time of last year’s Annual Meeting, six attended the meeting.

Board Committees

Our Board has established three standing committees: the Audit Committee, the Compensation Committee and the Nominating and Corporate Governance Committee, each of which is comprised solely of independent directors, and is described more fully below. Each of the Audit Committee, Compensation Committee and Nominating and Corporate Governance Committee operates pursuant to a written charter and each committee reviews and assesses the adequacy of its charter and submits its charter to the Board for approval on an annual basis. The charters for the Audit Committee, Compensation Committee and Nominating and Corporate Governance Committee are all available on our website www.bluebirdbio.com in the Investors & Media—Corporate Governance section. Our Board establishes additional committees from time to time.

Audit Committee

Our Audit Committee is currently composed of Dr. Agwunobi, Dr. Leiderman and Mr. Vachon, with Dr. Leiderman serving as chair of the committee. Our Board has determined that each member of the Audit Committee meets the independence requirements of Rule 10A-3 under the Securities Exchange Act of 1934, as amended, and the applicable listing standards of Nasdaq. Our Board has determined that Dr. Leiderman and Mr. Vachon are “audit committee financial experts” within the meaning of the SEC regulations and applicable listing standards of Nasdaq. During the fiscal year ended December 31, 2023, the Audit Committee met five times. The report of the Audit Committee is included in this Proxy Statement under Report of the Audit Committee. The Audit Committee’s responsibilities include:

•appointing, approving the compensation of, and assessing the independence of our independent registered public accounting firm;

•approving audit and permissible non-audit services, and the terms of such services, to be provided by our independent registered public accounting firm;

•reviewing the audit plan (both internal and external) with the independent registered public accounting firm and members of management responsible for performing our internal audit and preparing our financial statements;

•reviewing and discussing with management and the independent registered public accounting firm our annual and quarterly financial statements and related disclosures, including critical audit matters as well as critical accounting policies and practices used by us;

•reviewing the adequacy of our internal control over financial reporting;

•overseeing the qualifications, independence and performance of our internal audit function;

•establishing policies and procedures for the receipt and retention of accounting-related complaints and concerns;

•recommending, based upon the Audit Committee’s review and discussions with management and the independent registered public accounting firm, whether our audited financial statements shall be included in our Annual Report on Form 10-K;

•monitoring the integrity of our financial statements and our compliance with legal and regulatory requirements as they relate to our financial statements and accounting matters;

•preparing the Audit Committee report required by the rules of the SEC to be included in our annual proxy statement;

•reviewing all related party transactions for potential conflict of interest situations and approving all such transactions;

•monitoring compliance with our investment policy;

•monitoring information security matters and risks, including those regarding data privacy and cybersecurity;

•overseeing our enterprise risk assessment program; and

•reviewing quarterly earnings releases.

Compensation Committee

Our Compensation Committee is currently composed of Dr. Leiderman, Ms. Tita-Reid and Mr. Vachon, with Mr. Vachon serving as chair of the committee. Our Board has determined each member of the Compensation Committee is “independent” as defined under the applicable listing standards of Nasdaq. In addition, each member qualifies as a non-employee director, as defined in Rule 16b-3 of the Securities Exchange Act. During the fiscal year ended December 31, 2023, the Compensation Committee met four times. The Compensation Committee’s responsibilities include, as applicable:

•reviewing and approving corporate goals and objectives relevant to the compensation of our Chief Executive Officer;

•evaluating the performance of our Chief Executive Officer in light of such corporate goals and objectives and determining the compensation of our Chief Executive Officer;

•reviewing and approving the compensation of our other executive officers and certain other members of senior management;

•appointing, compensating and overseeing the work of any compensation consultant, legal counsel or other advisor retained by the Compensation Committee;

•conducting the independence assessment outlined in Nasdaq rules with respect to any compensation consultant, legal counsel or other advisor retained by the Compensation Committee;

•annually reviewing and reassessing the adequacy of the committee charter in its compliance with the listing requirements of Nasdaq;

•reviewing and establishing our overall management compensation, philosophy and policy, including practices regarding competitive pay opportunity and program design;

•overseeing and administering our compensation and similar plans;

•reviewing and approving our policies and procedures for the grant of equity-based awards;

•reviewing and making recommendations to the Board with respect to director compensation;

•reviewing and discussing with management the compensation discussion and analysis to be included in our annual proxy statement or Annual Report on Form 10-K;

•reviewing and discussing with the Board corporate succession plans for our Chief Executive Officer and other key executives;

•overseeing the application of our policies for clawback or recoupment of incentive compensation;

•overseeing our strategies, policies and practices with respect to human capital management, diversity, equity, inclusion; and

•overseeing the management of risks relating to our compensation policies and programs.

Historically, our Compensation Committee has made most of the significant adjustments to annual compensation, determined cash incentive and equity awards and established new performance objectives at one or more meetings held during the first and last quarters of the year. However, our Compensation Committee also considers matters related to individual compensation, such as compensation for new executive hires, as well as high-level strategic issues, such as the efficacy of our compensation strategy, potential modifications to that strategy and new trends, plans or approaches to compensation, at various meetings throughout the year. Generally, the Compensation Committee’s process consists of two related elements: the determination of compensation levels and the establishment of performance objectives for the current year. For executives other than our Chief Executive Officer, our Compensation Committee solicits and considers evaluations and recommendations submitted to the Compensation Committee by our Chief Executive Officer. In the case of our Chief Executive Officer, the evaluation of his performance is conducted by the Compensation Committee, which determines any adjustments to his compensation as well as awards to be granted. For all executives and directors as part of its deliberations, the Compensation Committee may review and consider, as appropriate, materials such as financial reports and projections, operational data, tax and accounting information, tally sheets that set forth the total compensation that may become payable to executives in various hypothetical scenarios, executive and director stock ownership information, company stock performance data, analyses of historical executive compensation levels and current Company-wide compensation levels and recommendations of our People & Culture management team. In addition, in 2023, the Compensation Committee engaged the Human Capital Solutions practice of Aon plc ("Aon") to assist in making decisions regarding the amount and types of compensation to provide our executive officers and non-employee directors. For more information, see Executive Officer and Director Compensation - Role of Our Independent Compensation Consultant below. Aon reports directly to the Compensation Committee. The Compensation Committee has considered the adviser independence factors required SEC rules as they relate to Aon and has determined that Aon's work does not raise a conflict of interest. The Compensation Committee may delegate its authority to grant certain equity awards to certain individuals to our Chief Executive Officer and in 2023, delegated such authority to Mr. Obenshain.

Nominating and Corporate Governance Committee

Our Nominating and Corporate Governance Committee is composed of Dr. Agwunobi, Dr. Jones-Burton, and Ms. Tita-Reid, with Dr. Agwunobi serving as chair of the committee. Our Board has determined that each member of the Nominating and Corporate Governance Committee is “independent” as defined under the applicable listing standards of Nasdaq. During the fiscal year ended December 31, 2023, the Nominating and Corporate Governance Committee met two times. The Nominating and Corporate Governance Committee’s responsibilities include:

•developing and recommending to the Board for its approval criteria for membership of the Board and its committees;

•establishing procedures for identifying and evaluating Board candidates, including candidates recommended by stockholders;

•identifying individuals qualified to become members of the Board;

•recommending to the Board the persons to be nominated for election as directors and to each of the committees of the Board;

•developing and recommending to the Board a set of corporate governance guidelines; and

•overseeing the evaluation of the Board.

The Nominating and Corporate Governance Committee oversees an annual self-evaluation process of the Board and its committees with the assistance of an external advisor specializing in strategic planning and organizational development. The results of the self-evaluation are presented to the Nominating and Corporate Governance Committee, which determines what actions, if any, to present to the Board and the other committees to further enhance the performance and effectiveness of the Board and its committees.

Independent Director Meetings

In addition to the meetings of the committees of the Board described above, in connection with the Board meetings, the independent directors met four times in executive session during the fiscal year ended December 31, 2023. The Chair of the Board presides at these executive sessions. The Audit Committee and the Board have established a procedure whereby interested parties may make their concerns known to independent directors, which is described on our website.

Leadership Structure and Risk Oversight

Our Corporate Governance Guidelines provide that the Board shall fill the Chair of the Board and Chief Executive Officer positions based on the Board's view of what is in the Company's best interest. The roles of Chair of the Board and Chief Executive Officer are currently separate, with Mr. Vachon serving as Chair and Mr. Obenshain serving as Chief Executive Officer. Our Board believes that separation of the positions of Chair and Chief Executive Officer reinforces the independence of the Board from management, creates an environment that encourages objective oversight of management’s performance and enhances the effectiveness of the Board as a whole. The Board retains the flexibility to change its leadership structure from time to time as appropriate based on its view of the best interests of the Company.

We face a number of risks in our business, including risks related to commercial operations and our ability to obtain reimbursement for our approved products; competition; manufacturing and supply chain; growth and capacity expansion in the United States; research and development; regulatory reviews and approvals; intellectual property filings, prosecution, maintenance and challenges; the establishment and maintenance of strategic alliances; litigation and government investigations; and the ability to access additional funding for our business; among other risks. Our management is responsible for the day-to-day management of the risks that we face, while our Board, as a whole and through its committees, has responsibility for the oversight of risk management.

Our Board performs its oversight role by using several different levels of review. Our Chair meets regularly with our Chief Executive Officer and other executive officers to discuss our strategy and material risks. Members of senior management attend the quarterly Board meetings, present on strategic matters involving our business, and are available to address any questions or concerns raised by the Board on risk management-related issues and any other matters. Our Board reviews the risks, including any environmental, social or governance risks, associated with our business strategies periodically throughout the year as part of its consideration of undertaking any such business strategies. Moreover, our Audit Committee oversees enterprise risk management and discusses guidelines and policies that govern the process by which the Company's exposure to risk is assessed and managed by management.

Each of the committees of our Board also oversees the management of our risk that falls within the committee’s areas of responsibility. In performing this function, each committee has full access to management, as well as the ability to engage advisors. The Audit Committee oversees our enterprise risk management program as it relates to our operations by identifying the primary risks associated with our operations and corporate functions, receiving periodic updates on activities to manage such risks, and providing reports to the Board regarding such activities. In carrying out its responsibilities for the oversight of operational risk management, members of the Audit Committee regularly discuss with management our risk exposures in the areas of financial reporting, internal controls, information security, and our legal and regulatory compliance programs, and the steps we take to manage them. Our Chief Financial Officer, our Chief Legal & Business Officer, and our Chief Compliance Officer all periodically provide reports to the Audit Committee and are responsible for identifying, evaluating and implementing risk management controls and methodologies to address any identified risks. Our Audit Committee also meets privately with representatives from our independent registered public accounting firm as part of its oversight of our risk management. The Compensation Committee assists the Board in fulfilling its oversight responsibilities with respect to the management of risks arising from our compensation policies and programs and succession planning for our executive officers, and evaluates potential risks associated with independent director compensation for consideration by the full Board. The Nominating and Corporate Governance Committee assists the Board in fulfilling its oversight responsibilities with respect to the management of risks associated with Board organization, membership and structure, succession planning for our directors, and corporate governance.

Compensation Committee Interlocks and Insider Participation

Mr. Vachon, Dr. Leiderman and Ms. Tita-Reid served as members of our Compensation Committee during the year ended December 31, 2023. None of the members of our Compensation Committee have at any time been one of our officers or employees. None of our executive officers currently serves, or in the past fiscal year has served, as a member of the board of directors or on a compensation committee of any entity that has one or more executive officers serving on our Board or Compensation Committee. For a description of transactions between us and members of our Compensation Committee and affiliates of such members, please see Certain Relationships and Related Party Transactions.

Code of Business Conduct and Ethics and Corporate Governance Guidelines

We have adopted a Code of Business Conduct and Ethics for our directors, officers and employees, including our President and Chief Executive Officer, Principal Financial Officer, Principal Accounting Officer, and Controller (or persons performing an equivalent function). We provide mandatory online training for our employees with respect to the Code of Business Conduct and Ethics on an annual basis to ensure understanding and the importance of adhering to such guidelines. A copy of our Code of Business Conduct and Ethics may be accessed free of charge by visiting the Company’s website at

www.bluebirdbio.com and going to the Investors & Media—Corporate Governance section or by requesting a copy in writing from Joseph Vittiglio, Secretary, at our Somerville, Massachusetts office. We intend to post on our website any amendment to, or waiver under, a provision of the Code of Business Conduct and Ethics that applies to our President and Chief Executive Officer, Principal Financial Officer, Principal Accounting Officer, or Controller (or persons performing an equivalent function) within four business days following the date of such amendment or waiver.

A copy of the Corporate Governance Guidelines may also be accessed free of charge by visiting the website at www.bluebirdbio.com and going to the Investors & Media—Corporate Governance section or by requesting a copy from Joseph Vittiglio, Secretary, at our Somerville, Massachusetts office.

Our Social Responsibility Efforts

For patients and society to benefit from our therapies, we believe they must be available to those who will benefit from them. To enable access to our products, we are continuing to engage in discussions with stakeholders across the healthcare system, including public and private payers, patient advocates and organizations, professional societies, and healthcare providers. These discussions are part of a broader ongoing dialogue exploring pathways for bringing our products to patients at a sustainable cost.

In addition, as a leading gene therapy company, the way we operate, the work we do, and the support we provide to our local communities is tied to our desire to extend and improve the lives of our patients. We are committed to patient advocacy and community endeavors that promote and improve the understanding of severe genetic disease. Our company participates in charitable activities relevant to our business and linked to our mission, vision and values.

We view our employees as our most valuable asset and we believe that by creating a positive culture together we can drive positive business and patient impact. We demonstrate this by providing a comprehensive benefits package. In addition, we believe in helping our employees to continue to grow at bluebird through leadership development, and Employee Resource Groups that provide a strong focus on diversity, equity and inclusion. We also provide equity compensation to all of our employees and offer an employee stock purchase plan to promote employee ownership of our shares and to allow employees to share in our success. Our employees are highly engaged which is due, in part, to the creation of an environment where our team thrives through professional development, total rewards, a robust diversity, equity, inclusion and belonging strategy and a successful ESG strategy and approach.

EXECUTIVE OFFICERS

The following table sets forth information regarding our executive officers as of September 16, 2024:

Name

Age

Position(s)

Executive Officers:

Andrew Obenshain (1)

President, Chief Executive Officer and Director (Principal Executive Officer)

O. James Sterling

Chief Financial Officer (Principal Financial Officer and Principal Accounting Officer)

Richard A. Colvin, M.D., Ph.D.

Chief Medical Officer

Thomas J. Klima

Chief Commercial and Operating Officer

Joseph Vittiglio

Chief Legal and Business Officer

__________

(1) Andrew Obenshain is also a director and his biographical information appears on page 9.

O. James Sterling – Mr. Sterling has served as our Chief Financial Officer since June 2024. Previously, Mr. Sterling served as Chief Financial Officer of Renalytix plc from November 2018 to June 2024, where he led the finance department. From 2015 to 2018, Mr. Sterling served as managing partner of Renwick Capital LLC. Prior to that, he served as a managing director at investment banks Brock Capital Group LLC and Aleutian Capital Group. Mr. Sterling is currently a director of Star Mountain Lower Middle-Market Capital Corp. Mr. Sterling received his B.A. from Boston University and an M.B.A. from Columbia Business School.

Richard A. Colvin, M.D., Ph.D. – Dr. Colvin has served as our Chief Medical Officer since October 2022. Previously, Dr. Colvin was our interim Chief Medical Officer from March 2021 through September 2022 and our Vice President and head of severe genetic diseases clinical research and development from January 2020 to March 2021. Dr. Colvin joined us in 2018 as Vice President, Medical Lead Thalassemia Program, for the successful European submission and approval of the Company’s beti-cel gene therapy for the treatment of patients with beta-thalassemia. Dr. Colvin is on faculty at Harvard Medical School and also sees patients as a Clinical Associate in Medicine, Infectious Diseases Clinic, at Massachusetts General Hospital Chelsea Health Care Center. Prior to joining bluebird, Dr. Colvin was an executive director in translational medicine at Novartis, where he led anti-infective drug development programs for the treatment of patients with certain infections from 2014 to 2018. Previously, Dr. Colvin completed his clinical and research fellowships in the Mass General Brigham Infectious Diseases Program and completed his internship and residency at the Brigham and Women’s Hospital. Dr. Colvin received his M.D. and Ph.D. from Duke University School of Medicine and his B.S. in Biology from Cornell University.

Thomas J. Klima – Mr. Klima has served as our Chief Operating Officer since September 2022 and our Chief Commercial Officer since May 2021. Prior to joining bluebird, Mr. Klima served as Chief Commercial Officer at Gamida Cell Ltd. from January 2019 to December 2020, where he led the strategic vision and commercial growth transforming its R&D organization to a commercially ready company. In 2018, Mr. Klima served as senior vice president of global commercial planning and operations at Atara Biotherapeutics. From 2015 to 2017, Mr. Klima served as senior vice president and chief commercial officer at Navidea Biopharmaceuticals Ltd. (acquired by Cardinal Health). Before that, Mr. Klima served as head of sales and commercial operations at Algeta U.S. (acquired by Bayer Healthcare) from 2012 to 2015. Before Algeta, he held various commercial leadership positions at Dendreon from 2009 to 2012. Mr. Klima began his pharmaceutical career at Eli Lilly where he held several positions of increasing responsibility from 2000 to 2009. Mr. Klima received a B.A. in Business Administration and Marketing from Western State College.

Joseph Vittiglio, Esq. – Mr. Vittiglio has served as our Chief Legal and Business Officer since January 2023. Prior to joining bluebird, Mr. Vittiglio served as Chief Business and Legal Officer at Finch Therapeutics from December 2020 to December 2022 where he guided its initial public offering in 2021. Prior to joining Finch, Mr. Vittiglio was the General Counsel and Chief Business Officer for AMAG Pharmaceuticals from August 2015 to November 2020 where he led its legal and business initiatives, including its successful sale to private equity investors and multiple out-licensing and partnership collaborations. Prior to AMAG, Mr. Vittiglio held leadership roles at Flexion Therapeutics, AVEO Pharmaceuticals, and Oscient Pharmaceuticals. Mr. Vittiglio began his career as a corporate and securities attorney at Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C. Mr. Vittiglio received a B.A. in International Relations from Tufts University and a J.D. from Northeastern University School of Law.

PROPOSAL 2

NON-BINDING ADVISORY VOTE ON NAMED EXECUTIVE OFFICER COMPENSATION

Our Board is committed to excellence in governance. As part of that commitment, and as required by Section 14A(a)(1) of the Securities Exchange Act, our Board is providing our stockholders with an opportunity to approve, on a non-binding advisory basis, the compensation of our named executive officers. At the Company's 2021 annual meeting of stockholders, the stockholders approved a frequency of "once every year" for the non-binding, advisory vote to approve the compensation of our named executive officers. Therefore, the next such advisory vote will be held at the Company's annual meeting of stockholders in 2025.

As described below under Executive Officer and Director Compensation, we have developed a compensation policy that is designed to attract and retain key executives responsible for our success and motivate management to enhance long-term stockholder value. We believe our compensation policy strikes an appropriate balance between the implementation of responsible, measured compensation practices and the effective provision of incentives for our named executive officers to exert their best efforts for our success.

For the reasons discussed above, the Board unanimously recommends that our stockholders vote in favor of the following resolution:

“RESOLVED, that the Company’s stockholders approve, on an advisory (non-binding) basis, the compensation of the Company's named executive officers, as disclosed in the Company’s Proxy Statement for the 2024 Annual Meeting of Stockholders pursuant to the compensation disclosure rules of the Securities and Exchange Commission, including the Summary Compensation Table and the other compensation tables and narrative discussion.”

As this vote is advisory, it will not be binding upon the Board or the Compensation Committee and neither our Board nor the Compensation Committee will be required to take any action as a result of the outcome of this vote. However, our Board and the Compensation Committee value the opinions of our stockholders, and the Compensation Committee will carefully consider the outcome of this vote when considering future executive compensation policies.

THE BOARD UNANIMOUSLY RECOMMENDS THAT YOU VOTE

FOR

THE NON-BINDING ADVISORY RESOLUTION APPROVING THE COMPENSATION OF OUR NAMED EXECUTIVE OFFICERS

(PROPOSAL 2 ON YOUR PROXY CARD)

PROPOSAL 3

AMENDMENT OF AMENDED AND RESTATED CERTIFICATION OF INCORPORATION TO PROVIDE FOR THE EXCULPATION OF OFFICERS FOR CERTAIN BREACHES OF FIDUCIARY DUTY TO THE EXTENT PERMITTED BY THE GENERAL CORPORATION LAW OF THE STATE OF DELAWARE

General

As part of its continuing review of our corporate governance standards and practices, the Board unanimously approved and declared advisable, subject to stockholder approval, an amendment and restatement (the “Exculpation Amendment”) to the Company’s Amended and Restated Certificate of Incorporation to reflect developing law. A copy of the Exculpation Amendment, which would add a new Article XI to the Amended and Restated Certificate of Incorporation, is attached to this Proxy Statement as Appendix A.

Effective August 1, 2022, Section 102(b)(7) of the General Corporation Law of the State of Delaware (the “DGCL”) was amended (“Amended 102(b)(7)”) to enable a corporation to include in its certificate of incorporation a provision exculpating certain corporate officers from liability for breach of the fiduciary duty of care in certain circumstances. Previously, Section 102(b)(7) of the DGCL provided for the ability to exculpate directors only and our Amended and Restated Certificate of Incorporation currently limits the monetary liability of our directors in certain circumstances consistent with Section 102(b)(7) of the DGCL. Amended 102(b)(7) allows for the exculpation of certain officers only in connection with direct claims brought by stockholders, including class actions, but would not eliminate officers’ monetary liability for breach of fiduciary duty claims brought by the corporation itself or for derivative claims brought by stockholders in the name of the corporation. Further, Amended 102(b)(7) does not permit a corporation to exculpate covered officers from liability for breach of the duty of loyalty, acts or omissions not in good faith or that involve intentional misconduct or a knowing violation of law, or any transaction in which the officer derived an improper personal benefit. Under Amended 102(b)(7), the officers who may be exculpated include a person who (i) is the president, chief executive officer, chief operating officer, chief financial officer, chief legal officer, controller, treasurer or chief accounting officer of the corporation at any time during the course of conduct alleged in the action or proceeding to be wrongful, (ii) is or was identified in the corporation's public filings with the SEC because such person is or was one of the most highly compensated executive officers of the corporation, or (iii) has consented to services of process in Delaware by written agreement (the “Covered Officers”).

Effect of the Exculpation Amendment

The proposed Exculpation Amendment would allow for the exculpation of our officers to the fullest extent permitted by the DGCL. As described above, this currently means that the proposed Exculpation Amendment would allow for the exculpation of Covered Officers only in connection with direct claims brought by stockholders, including class actions, but would not eliminate such officers’ monetary liability for breach of fiduciary duty claims brought by the corporation itself or for derivative claims brought by stockholders in the name of the corporation. Further, the Exculpation Amendment would not limit the liability of Covered Officers for any breach of the duty of loyalty to the corporation or its stockholders, any acts or omissions not in good faith or which involve intentional misconduct or a knowing violation of the law, or any transaction from which a Covered Officer derived an improper personal benefit.

Rationale for Adoption of the Exculpation Amendment

Our Board believes that adopting the Exculpation Amendment would better position the Company to attract top officer candidates and retain our current officers. The Exculpation Amendment would also more closely align the protections available to our officers with those already available to our directors. We believe that failing to adopt the Exculpation Amendment could impact our recruitment and retention of exceptional officer candidates who conclude that the potential exposure to liabilities, costs of defense, and other risks of proceedings exceeds the benefits of serving as an officer of the Company.

In addition, adopting the Exculpation Amendment would enable the officers to exercise their business judgment in furtherance of the interests of the stockholders without the potential for distraction posed by the risk of personal liability. The nature of the role of officers often requires them to make decisions on crucial matters. Frequently, officers must make decisions in response to time-sensitive opportunities and challenges, which can create substantial risk of investigations, claims, actions, suits, or proceedings seeking to impose liability based on hindsight, especially in the current litigious environment and regardless of merit. Limiting our current and prospective officers’ concern about personal risk would empower officers to best exercise their business judgment in furtherance of stockholder interests and better position the Company to retain our current officers and attract top officer candidates. Enhancing our ability to retain and attract experienced officers is in the best interests of the Company and its stockholders and we should seek to assure such persons that exculpation under certain circumstances is available. Certain of our officers would stand to benefit if Proposal 3 is adopted, as it could reduce their potential monetary liability for certain breaches of fiduciary duties.

If our stockholders approve the Exculpation Amendment, our Board has authorized our officers to file a Certificate of Amendment with the Delaware Secretary of State, which we anticipate doing as soon as practicable following stockholder approval of the Amendment at the Annual Meeting, and the Certificate of Amendment would become effective upon acceptance by the Delaware Secretary of State.

If our stockholders do not approve the Exculpation Amendment, the Certificate of Amendment will not be filed with the Delaware Secretary of State. However, even if our stockholders approve the Exculpation Amendment, our Board retains discretion under Delaware law to determine when to file the Certificate of Amendment with the Delaware Secretary of State and to abandon the Exculpation Amendment notwithstanding prior stockholder approval of the Exculpation Amendment.

THE BOARD UNANIMOUSLY RECOMMENDS THAT YOU VOTE

FOR

THE APPROVAL OF THE AMENDMENT TO OUR AMENDED AND RESTATED CERTIFICATE OF INCORPORATION TO PROVIDE FOR THE EXCULPATION OF OFFICERS FOR CERTAIN BREACHES OF FIDUCIARY DUTY TO THE EXTENT PERMITTED BY THE GENERAL CORPORATION LAW OF THE STATE OF DELAWARE

(PROPOSAL 3 ON YOUR PROXY CARD)

EXECUTIVE OFFICER AND DIRECTOR COMPENSATION

Overview of Executive Officer Compensation

Our Compensation Committee is responsible for overseeing the total compensation of our senior management team, which consists of our executive officers and certain other senior managers. In this capacity, our Compensation Committee designs, implements, reviews and approves all compensation for our Chief Executive Officer and our other executive officers. This section discusses the principles underlying our policies and decisions with respect to the compensation of our named executive officers, and all material factors relevant to an analysis of these policies and decisions. Our named executive officers for the fiscal year ended December 31, 2023 and relevant positions, were:

•Andrew Obenshain, our Chief Executive Officer and Principal Executive Officer;

•Thomas J. Klima, our Chief Commercial and Operating Officer; and

•Richard A. Colvin, M.D., Ph.D., our Chief Medical Officer.

Compensation Philosophy

Our Compensation Committee believes a well-designed compensation program should align executive interests with the drivers of growth and stockholder returns by supporting the Company’s achievement of its primary business goals, and our ability to attract and retain employees whose talents, expertise, leadership, and contributions are expected to sustain growth and drive long-term stockholder value. Consequently, we maintain an ongoing commitment to corporate governance principles and strong performance orientation in our compensation program. Our Compensation Committee regularly reviews our compensation policies and program design overall, to ensure that they are aligned with the interests of our stockholders and our business goals, and that the total compensation paid to our employees is fair, reasonable and competitive. The market for qualified and talented executives in the biopharmaceutical industry is highly competitive and we compete for talent with many companies that have greater resources than we do.

Overview of Our Compensation Programs

Key elements of our executive compensation programs include the following:

Compensation Element

Purpose

Features

Base salary

To attract and retain highly skilled executives

Fixed component of pay to provide financial stability, based on responsibilities, experience, individual contributions

Short Term Incentive

Annual incentive program

To promote and reward the achievement of our key short-term strategic and business goals; to motivate and attract executives

Variable component of pay based on annual quantitative and qualitative company performance goals and, for our executives other than our Chief Executive Officer, individual performance goals

At-Risk Compensation

Long-term equity incentive compensation

To encourage executives to focus on long-term performance; to promote retention; to reward outstanding company and individual performance

Typically subject to multi-year vesting based on continued service and are primarily in the form of stock options and restricted stock units, the value of which depends on the performance of our common stock price, in order to align employee interests with those of our stockholders over the longer-term.

We also introduced performance-vesting restricted stock unit grants for our Chief Executive Officer in 2021, and for our other executives in 2024, to further tie executive compensation to stock price performance.

Long Term Incentive

Role of Compensation Committee

Each year, as part of its oversight of broader human capital management, our Compensation Committee reviews and establishes the levels of each element of total compensation for our employees, including our senior executives. As part of this process, our Compensation Committee reviews the mix of compensation elements to ensure our performance-based compensation is an appropriate proportion of overall compensation and is aligned with our business goals and strategy. The specific performance factors our Compensation Committee considers when determining the compensation of our named executive officers include:

•key research and development achievements, including advances in our gene addition platform in the fields of severe genetic diseases;

•initiation and progress of clinical studies for our product candidates;

•expansion of our manufacturing and operational capabilities, including our commercial readiness and capacity planning;

•achievement of regulatory milestones, including regulatory filings for marketing approval;

•achievement of commercialization milestones, including pricing and reimbursement approval, engagement of qualified treatment centers, and number of patients treated in the commercial context;

•establishment and maintenance of key strategic relationships and new business initiatives, including financings;

•development of organizational capabilities, success in hiring and growth management initiatives; and

•leadership skills, and the ability to drive decisions that positively impact the business overall, including through financial acumen, business judgment and strategic planning.

Our senior executives, including our named executive officers, are also evaluated based on factors such as individual, strategic, and demonstrated enterprise leadership achievements. These performance factors are considered by our Compensation Committee in connection with our annual performance reviews described below and are a critical component in the determination of annual incentive awards for our executives.

Our Compensation Committee, with input from the Board and our Chief People Officer, evaluates our Chief Executive Officer’s individual performance and determines whether to change his base salary, grant him an annual equity award and/or change his target percentage cash award under our annual incentive program.

Role of Our Compensation Consultants

For 2023, our Compensation Committee engaged Aon as its independent compensation consultant to advise on executive and Board compensation matters including: overall compensation program design, peer group development and updates, and collection of market data to inform our compensation programs for our executives and directors. We develop our compensation programs after reviewing publicly available compensation data and we also subscribe to Aon’s various global annual and specialized life sciences and general industry surveys on an ongoing basis. Aon advised the Compensation Committee on all of the principal aspects of executive compensation, including executive new hire compensation arrangements. Aon consultants attend meetings of the Compensation Committee when requested to do so. Aon reports directly to our Compensation Committee and not to management, although it meets with management for purposes of gathering information for its analyses and recommendations. Our Compensation Committee has assessed the independence of Aon consistent with SEC regulations and NASDAQ listing standards and has concluded that the engagement of Aon does not raise any conflict of interest.

Elements of Compensation

Base Salary

We provide base salaries to our named executive officers to compensate them with a fair and competitive base level of compensation for services rendered during the year. Our Compensation Committee typically determines the base salary for each executive based on the executive’s responsibilities, experience and, if applicable, the base salary level of the executive prior to joining bluebird. In addition, our Compensation Committee reviews and considers the level of base salary paid by companies in our peer group for similar positions. Our Compensation Committee's assessment of our named executive officers' base salary takes into account our compensation objectives and philosophy to retain highly qualified executives, to motivate them to achieve our business goals, and to reward them for superior short- and long-term performance.

At the beginning of 2023, our Compensation Committee reviewed the compensation for our Chief Executive Officer and each of our other named executive officers. With respect to Mr. Obenshain, our Compensation Committee reviewed his overall compensation and determined to increase his annual base salary from $643,750 to $682,400. This determination was based on his critical role at the Company, market conditions, company performance throughout 2022 in meeting key milestones and objectives, as well as consideration of the critical upcoming execution and risk inflection points throughout 2023. The Compensation Committee also approved merit increases in base salary for each of our other named executive officers serving at that time based on several factors including the Company's performance against the 2022 company goals, and each named executive officer's achievement of individual goals in 2022, as well as a consideration of the market conditions and a comparison of the executives' base salaries to similarly situated executives in our peer group. The table below sets forth the adjustments to the base salary, in dollars and as a percentage, for each of our named executive officers:


Name	2022 Base Salary ($)	2023 Base Salary ($)	Aggregate Increase (%)
Andrew Obenshain	643,750	682,400	6.0
Thomas J. Klima	460,000	480,000	4.4
Richard A. Colvin	480,000	490,000	2.1

In December 2023, our Compensation Committee and our Board reviewed the base salaries of our named executive officers, including our Chief Executive Officer. Taking into account the Company's performance in 2023 and the need to provide a competitive base level of salary balanced against financial discipline, the Compensation Committee and the Board determined that each named executive officer, including our Chief Executive Officer, would receive increases to their base salaries of between 4% - 7%, as set forth in the table below, effective January 1, 2024.


Name	2023 Base Salary ($)	2024 Base Salary ($)	Aggregate Increase (%)
Andrew Obenshain	682,400	730,000	6.98
Thomas J. Klima	480,000	511,000	6.46
Richard A. Colvin	490,000	510,000	4.08

Annual Incentive Program

At the end of 2022, our Board approved the Company's corporate goals for 2023. Consistent with past practice, the Company's annual incentive program for 2023 was structured based on Company-wide achievement of the Company's corporate goals and our employees' achievement of their individual goals during 2023. For 2023, our employees, including our named executive officers, had the opportunity to earn cash incentive awards calculated as a percentage of pre-established bonus targets based on the Company's performance against the Company's corporate goals and such employee's individual performance against their own pre-established individual goals.

For fiscal year 2023, the incentive award for our Chief Executive Officer and each of our other named executive officers was based 100% on the Company's performance relative to the pre-established company goals, with an individual multiplier of 0 - 1.5x based on individual performance. Our Compensation Committee, however, reserves the discretion to adjust upward or downward any cash incentive award as it deems appropriate, provided that bonuses are capped at 150% of target amounts.

The table below summarizes the pre-established 2023 Company goals, their relative weighting, and level of achievement for each Company goal as approved by the Board in December 2023.

2023 Company goals

Weighting

2023 Company performance assessment (weighted assessment)

Deliver for Patients

75%

80% (60)

–Complete target number of patient starts across ZYNTEGLO and SKYSONA programs

–Expand QTC network

–Achieve timely disposition of drug product

–Submit lovo-cel BLA by target date and begin commercial preparation, including marketing plans and manufacturing capacity

The Board recognized the Company's achievements in receiving FDA approval of LYFGENIA, while simultaneously executing on the commercial launches of ZYNTEGLO and SKYSONA. Additionally, the Company made significant progress in expanding its QTC network and completing patient starts for ZYNTEGLO and SKYSONA in 2023. However, the Board also acknowledged certain regulatory delays and delays in drug product disposition.

People & Business

25%

100% (25)

–Meet targets for cash runway, employee engagement, and employee diversity

The Board recognized that the Company achieved its goals with respect to employee diversity. The Company ended the year with positive employee engagement, as evidenced by a comprehensive employee engagement survey, and achieved a turnover rate lower than the industry average. The Board also acknowledged challenges with respect to the Company's cash runway, including because the Company did not receive a priority review voucher in connection with the approval of LYFGENIA, but noted progress as the Company worked toward a year-end equity raise.

Total

100%

85%

The pre-established individual goals and individual performance against those goals in 2023 applicable to our named executive officers were as follows:


Name	2023 individual performance assessment (multiplier)	2023 individual goals
Andrew Obenshain	100% (1x)	Cross-functional leadership in guiding the organization to accomplish each of the corporate goals
Thomas J. Klima	100% (1x)	Leadership in preparing the organization for commercial launches in the United States and ongoing operational efficiency
Richard A. Colvin	100% (1x)	Leadership in guiding the organization through late-stage development programs in severe genetic disease and associated regulatory interactions as well as overseeing the continued efforts towards the filing and approval of the lovo-cel BLA

The table below shows each named executive officer’s target incentive award under the 2023 annual incentive program as a percentage of the named executive officer’s annual base salary in 2023, the target incentive award opportunity in dollars for 2023 and the actual incentive awards to our named executive officers for 2023 performance, which were paid in March 2024.


Name	2023 Target Incentive Award (% of 2023 Base Salary)(1)	2023 Target Incentive Award Opportunity ($)	Actual Total 2023 Incentive Award Amount ($)
Andrew Obenshain	60%	409,440	348,024
Thomas J. Klima	45%	216,000	183,600
Richard A. Colvin	45%	220,500	187,425

(1) Target Incentive Awards as a percentage of base salary did not change in 2023.

In 2024, our Compensation Committee approved changes to the 2024 annual incentive program, providing that the award for our Chief Executive Officer will be based 100% on the Company's performance against the corporate goals and the award for our other named executive officers will be based 80% on the Company's performance against the corporate goals and 20% on such executive officer's performance against his or her individual goals.

Long-Term Incentive Awards

Our long-term incentive equity awards are generally in the form of stock options and restricted stock units, which deliver equivalent value while using fewer authorized shares. Beginning in 2021, we granted performance-based restricted stock units based on relative total shareholder return to our Chief Executive Officer, and beginning in 2024, we extended these grants to our other executive officers, in each case to further tie executive compensation to stock price performance and in response to stockholder feedback. We typically make equity award grants to each of our executive officers upon commencement of employment, and annually in conjunction with our review of their individual performance. Additional equity award grants may be made in connection with a promotion, or as a special incentive. Our executives benefit from stock options only if our stock price increases through the creation of stockholder value, and the value of restricted stock units increase as our stock price increases. Accordingly, we believe stock options and restricted stock units provide meaningful incentives to our executives to achieve increases in the value of our stock over time, while performance-based restricted stock units further align our executive officers' interests with long-term stockholders' interests and company performance. In addition, the vesting feature of our long-term incentive grants contributes to executive retention by providing an incentive to our executives to remain employed by us during the vesting period.

All equity awards to our executive officers are approved by our Compensation Committee. The size of equity awards varies among our executive officers based on their positions, competitive market data, and annual performance assessments. All stock options granted by bluebird have exercise prices equal to the fair market value of our common stock on the date of grant, so that the recipient will not realize any value from his or her options unless our share price increases above the stock price on the date of grant. Accordingly, this portion of our executive officers’ compensation is at risk and is directly aligned with stockholder value creation.

As part of the ongoing review of our compensation strategy and practices, the Compensation Committee determines the appropriate mix of the type of equity awards, based in part on recommendations from Aon, its independent compensation consultant. Because of the volatility of our stock price in relation to when equity grants are made, our equity compensation guidelines set forth aggregate grant targets reflecting stock options plus restricted stock units based on number of shares (rather than value of the equity grants), and these guidelines are developed based on and in reference to our equity

grant data for our peer companies. The target mix for annual long-term incentive equity grants to our executive officers is generally split approximately one-half in stock options and one-half in restricted stock units (including performance-based restricted stock units). The Compensation Committee believes that this deliberate mix of equity ensures that compensation remains tied to stock performance and promotes retention. The Compensation Committee may adjust the mix of award types or approve different award types as part of the overall compensation strategy. Awards made in connection with a new, extended or expanded employment relationship may involve a different mix of equity awards, depending on the Compensation Committee’s assessment of the total compensation package being offered.

In addition, long-term equity incentive grants of stock options and restricted stock units to our executive officers typically vest over four years, which we believe provides an incentive to our executives to add value to the Company over the long-term and to remain with bluebird. Typically, the stock options we grant to our executives have a ten-year term and vest as to 25% of the shares on the first anniversary of the date of grant and then the remaining shares vest in equal monthly installments thereafter until the fourth anniversary of such date. Vesting of option grants to employees ceases upon termination of employment and exercise rights typically cease three months following termination of employment, except in the case of death or disability. Prior to the exercise of an option, the stock option holder does not have any rights as a stockholder with respect to the shares subject to such option, including voting rights or the right to receive dividends or dividend equivalents. Annual restricted stock units granted to our executives generally vest in equal annual installments beginning on or about the first anniversary of the day of grant, until the fourth anniversary of such date.

2023 Equity Awards

In 2023, we granted our Chief Executive Officer a performance-based restricted stock unit award, to further align our Chief Executive Officer's compensation with stockholder experience (the "2023 Performance-Based RSU Award"). This 2023 Performance-Based RSU Award is earned based on total shareholder return compared to a selected group of companies that are considered relevant peers across business segment and size metrics, with a focus on industry classifications, revenue, and market capitalization, and which was developed in consultation with Aon (our "Named Peer Group"). The multiplier used to determine the number of earned restricted stock units could range between 0% and 200%, with a threshold achievement level at -25th percentile (as compared to the peer median) required to earn any restricted stock units, target achievement level equal to the peer median, and a ceiling achievement level at the +50th percentile (as compared to the peer median). The 2023 Performance-Based RSU Award, to the extent earned, vest in full on approximately the third anniversary of the grant date on the date performance achievement is certified by our Compensation Committee, subject to Mr. Obenshain's continued service. For 2023, the target number of shares subject to this 2023 Performance-Based RSU Award is 101,400 shares. Under the terms of this award, the number of performance-based restricted stock units earned is calculated by multiplying the target number of performance-based restricted stock units by a performance multiplier.

In its design of the performance-based restricted stock units, the Compensation Committee considered various design elements and alternative approaches including milestone-based approaches. Given the stage of the Company, early in its commercial product launches, the Compensation Committee felt that an overall relative stock performance metric best captures the value inflections that would potentially be unlocked through exceptional company performance, and is fully aligned with stockholder interests. Furthermore, a three-year measurement period provides an incentive for our executives to take a long-term view with respect to company performance.

In connection with the annual review of our named executive officers’ performance during 2022 and consistent with our compensation philosophy, in 2023 our Compensation Committee approved the annual long-term equity incentive awards granted to our named executive officers serving at that time as set forth in the table below:


	2023 Option Award		2023 RSU Award		2023 Performance-Based RSU Award
Name	# Shares	Grant date fair value	# Shares	Grant date fair value	Target # Shares	Grant Date Fair value
Andrew Obenshain	338,000	$1,142,440	67,600	$345,436	101,400	$518,154
Thomas J. Klima	110,000	$371,800	55,000	$281,050	—	$—
Richard A. Colvin	110,000	$371,800	55,000	$281,050	—	$—

2024 Equity Awards

In connection with the annual review of our named executive officers' performance during 2023, the Compensation Committee has approved the annual long-term equity incentive award amounts set forth in the table below in respect of our named executive officers:


	2024 Option Award	2024 RSU Award Time-Based Vesting(1)	2024 RSU Award Performance-Based Vesting (1)(2)
Name	# Shares	# Shares	Target # Shares
Andrew Obenshain	650,000	130,000	195,000
Thomas J. Klima	199,000	50,000	50,000
Richard A. Colvin	199,000	50,000	50,000

(1) We anticipate issuing the RSUs and performance-based RSUs approved during the 2024 annual review cycle during the second half of 2024.

(2) Similar to the 2023 Performance-Based RSU Award granted to Mr. Obenshain, each performance-based restricted stock award granted to our named executive officers in 2024 is earned based on relative total shareholder return compared to our Named Peer Group. The multiplier used to determine the number of earned performance-based restricted stock units ranges between 0% and 200%, with a threshold achievement level at the 25th percentile (as compared to the peer median) and target achievement level equal to the peer median. These performance-based restricted stock units, to the extent earned, will vest in full on approximately the third anniversary of the grant date, subject to the named executive officer's continued service.

The equity awards granted to our named executive officers, and the grant date fair values of those awards presented above and shown in the Summary Compensation Table below were determined in accordance with Financial Accounting Standards Board (FASB), Accounting Standards Codification (ASC), Topic 718.

Benefits and Other Compensation

Other compensation to our executives consists primarily of the broad-based benefits we provide to all full-time employees in the United States, including medical, dental and vision insurance, group life and disability insurance, an employee stock purchase plan and a 401(k) plan. Pursuant to our employee stock purchase plan, employees, including our named executive officers, have an opportunity to purchase our common stock at a discount on a tax-qualified basis through payroll deductions. The employee stock purchase plan is designed to qualify as an “employee stock purchase plan” under Section 423 of the Internal Revenue Code. The purpose of the employee stock purchase plan is to encourage our employees, including our named executive officers, to become our stockholders and better align their interests with those of our other stockholders. Pursuant to our 401(k) plan, employees, including our named executive officers, may elect to defer a portion of their current compensation up to the statutorily prescribed annual limit (which was $22,500 in 2023), with additional salary deferrals not to exceed $30,000 available to those employees 50 years of age or older, and to have the amount of this deferral contributed to our 401(k) plan. We make discretionary matching contributions and other employer contributions on behalf of eligible employees under our 401(k) plan. For fiscal year 2023, we matched a portion of eligible employee contributions equal to 100% of the first 4% of eligible contributions pursuant to our 401(k) plan’s matching formula.

Currently, we do not view perquisites or other personal benefits as a significant component of our executive compensation program. Accordingly, we do not provide perquisites to our named executive officers, except in situations where we believe it is appropriate to assist an individual in the performance of his or her duties, to make him or her more efficient and effective, and for recruitment and retention purposes. All future practices with respect to perquisites or other personal benefits will be approved and subject to periodic review by our Compensation Committee.

Certain executives, including our named executive officers, may be entitled to certain severance and/or change in control protections pursuant to their employment agreements, which are described below under Executive Officer and Director Compensation—Employment Arrangements with Our Named Executive Officers. Our goal in providing severance and change in control benefits is to offer sufficient cash continuity protection such that our executives will focus their full time and attention on the requirements of the business rather than the potential implications for their respective position. We prefer to have certainty regarding the potential severance amounts payable to the named executive officers, rather than negotiating severance at the time that a named executive officer’s employment terminates.

Anti-Hedging and Anti-Pledging Policies; Insider Trading Policy

Our insider trading policy expressly prohibits short sales and derivative transactions of our stock by our named executive officers, directors and specified other employees, including short sales of our securities, including short sales “against the box”; purchases or sales of puts, calls or other derivative securities of the Company or any derivative securities that provide the economic equivalent of ownership of any of our securities or an opportunity, direct or indirect, to profit from any change in the value of our securities; or other hedging or monetization transactions accomplished through the use of prepaid variable forwards, equity swaps, collars and exchange funds. In addition, our insider trading policy expressly prohibits our named executive officers, directors and specified other employees from purchasing our securities on margin, borrowing against Company securities held in a margin account, or pledging our securities as collateral for a loan.

Clawback Policy

In 2023, we adopted our Policy for Recovery of Erroneously Awarded Compensation (the “Policy”), which amended and restated our prior clawback policy and is intended to comply with SEC and Nasdaq listing standards. Accordingly, as set forth in the Policy, the Company is required to recover certain erroneously paid incentive-based compensation of its current and former executive officers in the event the Company is required to prepare a qualifying accounting restatement.

Share Ownership Guidelines

In 2017, our Compensation Committee and Board adopted share ownership guidelines applicable to our non-employee directors and our senior executive officers, including our Chief Executive Officer, to further align the interests of the leadership of the Company with those of our stockholders. The equity ownership guidelines are as set forth on the table below:


Covered Individuals						Applicable Stock Ownership Guideline
Chief Executive Officer						3x base salary
Other Senior Executive Officer						1x base salary
Non-Employee Director						3x annual cash retainer for service on the Board

Covered individuals and newly appointed or elected persons have five years to achieve the guideline. The following forms of equity will count toward the ownership guidelines: shares owned outright, vested but unexercised “in-the-money” stock options, and fifty percent of unvested restricted stock units. All senior executive officers and directors are currently meeting or are working to achieve these guidelines within the five-year time period.

Executive Compensation

Summary Compensation Table

The following table sets forth the total compensation awarded to, earned by and paid during the fiscal years ended December 31, 2023 and December 31, 2022 for each of our named executive officers.


Name and Principal Position	Year	Salary ($)	Option awards ($)(1)	Stock awards ($)(1)	Non-equity incentive plan compensation ($)(2)	All other compensation ($)(3)	Total ($)
Andrew Obenshain...........................	2023	681,657	1,142,440	863,590	348,024	13,470	3,049,181
Chief Executive Officer	2022	643,390	421,830	351,000	386,280	12,200	1,814,700
Thomas J. Klima................................	2023	479,615	371,800	281,050	183,600	13,470	1,329,535
Chief Commercial and Operating Officer	2022	435,769	325,232	267,050	207,000	12,200	1,247,251
Richard A. Colvin ..............................	2023	489,808	371,800	281,050	187,425	14,170	1,344,253
Chief Medical Officer	2022	467,639	374,297	294,240	216,000	12,600	1,364,776

(1) The amounts reported in the Option awards and Stock awards columns above represent the aggregate grant date fair value of the stock options and restricted stock units granted to such named executive officers during 2022 and 2023 as computed in accordance with FASB ASC 718, not including any estimates of forfeitures related to service-based vesting conditions. See note 16 of Notes to Consolidated Financial Statements in our Annual Report on Form 10-K for the year ended December 31, 2023 for a discussion of assumptions made by the Company in determining the aggregate grant date fair value of our stock option and restricted stock unit awards. Note that the amounts reported in these columns reflect the accounting cost for these stock options and restricted stock units, and do not correspond to the actual economic value that may be received by the named executive officers from the stock options and restricted stock units. We also granted performance-based restricted stock unit awards to Mr. Obenshain in 2022 and 2023. The grant date fair value computed in accordance with FASB ASC 718 of these awards based on probable outcome as of the grant date is equal to their maximum grant date fair values.

(2) Amounts represent cash payment under our annual cash incentive program earned in respect of 2022 and 2023, based on achievement of performance goals. Please see the description of the annual cash incentive program under which bonuses were paid to the named executive officers in the "Annual Incentive Program" section above.

(3) Amounts represent employer matching contributions to the executive’s 401(k) plan account and certain other employee fringe benefits.

Outstanding Equity Awards at Fiscal Year End

The following table sets forth information concerning the outstanding equity awards held by each of the named executive officers as of December 31, 2023.


		Option Awards				Stock Awards
Name	Award Grant Date	Number of securities underlying unexercised options ((#) exercisable)	Number of securities underlying unexercised options (#) unexercisable)	Option exercise price ($/share)	Option expiration date	Number of shares or units of stock that have not vested (#)	Market value of shares or units of stock that have not vested ($)(1)	Equity incentive plan awards: number of unearned shares, units or other rights that have not vested (#)	Equity incentive plan awards: market or payout value of unearned shares, units or other rights that have not vested ($)(1)
Andrew Obenshain	12/1/2016	17,721	—	$34.20	12/1/2026
	2/1/2018	9,353	—	$102.24	2/1/2028
	2/1/2019	7,827	—	$67.06	2/1/2029
	3/2/2020	6,705	186 (2)	$36.78	3/2/2030
	3/2/2020					862 (3)	1,190
	11/2/2020	15,918	4,756 (4)	$26.45	11/2/2030
	11/2/2020					2,585 (5)	3,567
	2/16/2021	43,889	16,331 (6)	$14.17	2/16/2031
	2/16/2021					15,059 (7)	20,781
	8/2/2021	240,655	160,888 (8)	$12.76	8/2/2031
	8/2/2021					100,387 (9)	138,534
	2/1/2022	41,250	48,750 (4)	$7.80	2/1/2032
	2/1/2022					13,500 (5)	18,630
	2/1/2022							27,000 (10)	37,260
	3/1/2023	—	338,000 (4)	$5.11	3/1/2033
	3/1/2023					67,600 (5)	93,288
	3/1/2023							101,400 (10)	139,932

Thomas J. Klima	6/1/2021	64,812	35,573 (11)	$15.50	6/1/2031
	6/1/2021					25,096 (5)	34,632
	2/1/2022	22,910	27,090 (4)	$7.80	2/1/2032
	2/1/2022					18,750 (5)	25,875
	9/1/2022	6,874	15,126 (4)	$6.55	9/1/2032
	9/1/2022					8,250 (5)	11,385
	3/1/2023	—	110,000 (4)	$5.11	3/1/2033
	3/1/2023					55,000 (5)	75,900

Richard A. Colvin	11/1/2018	11,134	—	$64.83	11/1/2028
	3/2/2020	4,305	124 (2)	$36.78	3/2/2030
	3/2/2020					555 (3)	766
	2/16/2021	5,835	2,195 (6)	$14.17	2/16/2031
	2/16/2021					2,009 (7)	2,772
	3/1/2021	27,573	12,580 (4)	$14.99	3/1/2031
	3/1/2021					10,039 (5)	13,854
	2/1/2022	12,100	14,300 (4)	$7.80	2/1/2032
	2/1/2022					9,975 (5)	13,766
	11/1/2022	16,250	43,750 (4)	$6.35	11/1/2032
	11/1/2022					22,500 (5)	31,050
	3/1/2023	—	110,000 (4)	$5.11	3/1/2033
	3/1/2023					55,000 (5)	75,900

(1) All unvested stock options and restricted stock awards were granted under our 2013 Stock Option and Incentive Plan, 2023 Incentive Award Plan, or our 2021 Inducement Plan. The market value of restricted stock units that have not vested is based on the closing price of $1.38 per share for our common stock on December 31, 2023, as reported on the NASDAQ Global Select Market.

(2) The shares underlying these options vest as follows: 25% vested on January 4, 2021, with the remainder of the shares vesting in equal monthly installments over the following three years through January 4, 2024, subject to the grantee's continued service with us through each applicable vesting date.

(3) These restricted stock unit awards vest in four equal annual installments of 25% starting on January 4, 2021 through January 4, 2024, subject to the grantee's continued service with us through each applicable vesting date.

(4) The shares underlying these options vest as follows: 25% vest on the one-year anniversary of the grant date, with the remainder of the shares vesting in equal monthly installments over the following three years, subject to the grantee's continued service with us through each applicable vesting date.

(5) These restricted stock unit awards vest in four equal annual installments of 25% starting on the one-year anniversary of the award grant date, subject to the grantee's continued service with us through each applicable vesting date.

(6) The shares underlying these options vest as follows: 25% vested on January 4, 2022, with the remainder of the shares vesting in equal monthly installments over the following three years through January 4, 2025, subject to the grantee's continued service with us through each applicable vesting date.

(7) These restricted stock unit awards vest in four equal annual installments of 25% starting on January 4, 2022 through January 4, 2025, subject to the grantee's continued service with us through each applicable vesting date.

(8) This performance-based option was earned based on performance criteria related to the separation of 2seventy bio. Subject to achievement of the performance criteria, the shares underlying this option vest as follows: 25% vested on August 2, 2022, with the remainder of the shares vesting in equal monthly installments over the following three years through August 2, 2025, subject to the grantee's continued service with us through each applicable vesting date.

(9) This performance-based restricted stock unit award was earned based on performance criteria related to the separation of 2seventy bio. Subject to achievement of the performance criteria, the PSU vests in four equal annual installments of 25% starting on August 2, 2022 through August 2, 2025, subject to the grantee's continued service with us through each applicable vesting date.

(10) These performance-based restricted stock unit awards are earned based on relative total shareholder return compared to a peer group of companies in the Standard & Poor Biotechnology Index and, to the extent earned, will vest approximately three years from the grant date, subject to the grantee's continued service with us on the applicable vesting date.

(11) The shares underlying this option vest as follows: 25% vested on May 10, 2022, with the remainder of the shares vesting in equal monthly installments over the following three years through May 10, 2025, subject to the grantee's continued service with us through each applicable vesting date.

Employment Arrangements with our Named Executive Officers

Andrew Obenshain. We have entered into an employment agreement, effective as of January 7, 2021, with Mr. Obenshain providing for his employment as the Company’s President, Severe Genetic Disease. Mr. Obenshain currently serves as our Chief Executive Officer and Principal Executive Officer. Under his agreement Mr. Obenshain was initially entitled to receive a base salary of $435,000 (which has been subsequently increased as described above), subject to adjustment at the discretion of the Compensation Committee. Mr. Obenshain is also currently eligible for an annual cash incentive award targeted at 60% of his annual base salary. Mr. Obenshain is eligible to participate in our employee benefit plans, subject to the terms of those plans.

Thomas J. Klima. We have entered into an employment agreement, effective as of April 20, 2021, with Mr. Klima providing for his employment as the Company’s Chief Commercial Officer. Mr. Klima currently serves as our Chief Commercial and Operating Officer. Under his agreement Mr. Klima is entitled to receive a base salary of $400,000 (which has been subsequently increased as described above), subject to adjustment at the discretion of the Compensation Committee. Mr. Klima is also eligible for an annual cash incentive award targeted at 45% of his annual base salary. Mr. Klima's employment agreement also provides for an initial grant of stock options and restricted stock units and his eligibility to participate in our employee benefit plans, subject to the terms of those plans.

Richard A. Colvin. We have entered into an employment agreement, effective as of October 31, 2022, with Dr. Colvin providing for his employment as the Company’s Chief Medical Officer. Under his agreement Dr. Colvin is entitled to receive a base salary of $480,000 (which has been subsequently increased as described above), subject to adjustment at the discretion of the Compensation Committee. Dr. Colvin is also eligible for an annual cash incentive award targeted at 45% of his annual base salary. Dr. Colvin is eligible to participate in our employee benefit plans, subject to the terms of those plans.

These employment agreements also contain provisions that provide for certain payments and benefits in the event of an involuntary termination of employment. In addition, the named executive officers may be entitled to accelerated vesting of their outstanding and unvested awards in certain circumstances as described below.

Involuntary termination of employment

Pursuant to their employment agreements, each named executive officer is eligible to receive certain payments and benefits in the event his employment is terminated by us without “cause” (as defined in the employment agreements) or in the event he terminates his employment with “good reason” (as defined in the employment agreements). Upon the timely execution of a severance agreement, including a general release of claims, each named executive officer is eligible to receive the following payments and benefits:

•12 months of base salary continuation; and

•if he elects to continue his or her group healthcare benefits, to the extent authorized by and consistent with COBRA, we will pay the named executive officer a monthly cash payment equal to the monthly employer contribution we would have made to provide him health insurance if he had remained employed by us until the earlier of (1) 12 months following the date of termination, or (2) the end of the named executive officer’s COBRA health continuation period.

Involuntary termination of employment in connection with a sale event

In addition, in the event that any of our named executive officers terminates his or her employment with us for good reason or his or her employment with us is terminated by us without "cause", in either case within 12 months following a “sale event” (as defined in the 2013 Stock Option and Incentive Plan (now referred to as a "change in control" under the 2023 Incentive Award Plan)), he or she will be entitled to receive the following payments and benefits (in lieu of the payments and benefits described above) upon the timely execution of a severance agreement, including a general release of claims:

•a lump sum cash payment equal to one times the sum of (1) the named executive officer’s then-current base salary (or base salary in effect immediately prior to the sale event, if higher) and (2) the named executive officer’s target annual cash incentive compensation; and

•if he or she elects to continue his or her group healthcare benefits, to the extent authorized by and consistent with COBRA, we will pay the named executive officer a monthly cash payment equal to the monthly employer contribution we would have made to provide him or her health insurance if he or she had remained employed by us until the earlier of (1) 12 months following the date of termination or (2) the end of the named executive officer’s COBRA health continuation period; and

•all stock options and other stock-based awards granted to the named executive officer after the date of his or her employment agreement will become fully exercisable and non-forfeitable as of the date of the named executive officer’s termination.

Pay vs. Performance

In accordance with rules adopted by the Securities and Exchange Commission pursuant to the Dodd-Frank Wall Street Reform and Consumer Protection Act of 2010, we provide the following disclosure regarding executive compensation for our principal executive officers (“PEOs”) and Non-PEO named executive officers ("Non-PEO NEOs") and Company performance for the fiscal years listed below. The Compensation Committee did not consider the pay versus performance disclosure below in making its pay decisions for any of the years shown.


Year	Summary Compensation Table Total for PEO 1¹ ($)	Summary Compensation Table Total for PEO 21 ($)	Compensation Actually Paid to PEO 1¹˒²˒³ ($)	Compensation Actually Paid to PEO 21,2,3 ($)	Average Summary Compensation Table Total for Non-PEO NEOs1 ($)	Average Compensation Actually Paid to Non-PEO NEOs1,2,3 ($)	Value of Initial Fixed $100 Investment based on4	Net Income ($ Thousands)
							TSR ($)
2023	3,049,181	-	(608,619)	-	1,336,894	179,961	5.35	(205,904)
2022	1,814,700	-	(136,947)	-	1,353,832	850,656	26.80	(266,578)
2021	9,258,001	7,332,683	5,104,693	1,650,578	3,075,681	1,462,375	38.70	(819,378)

(1) Nick Leschly was our PEO until his resignation on November 4, 2021 (PEO 2). Andrew Obenshain has been our PEO since November 4, 2021 (PEO 1). The individuals comprising the Non-PEO NEOs for each year presented are listed below.


2021	2022	2023
Gina Consylman	Thomas J. Klima	Thomas J. Klima
Jason Cole	Richard A. Colvin	Richard A. Colvin
Thomas J. Klima	Jason Cole
William D. Baird, III
Philip Gregory

(2) The amounts shown for the "Compensation Actually Paid" columns have been calculated in accordance with Item 402(v) of Regulation S-K and do not reflect compensation actually earned, realized, or received by the Company’s NEOs. These amounts reflect the Summary Compensation Table Total with certain adjustments as described in footnote 3 below. On November 4, 2021, the Company completed the spin-off of 2seventy bio, Inc. All equity awards granted before January 1, 2021 were bifurcated into awards based in both Company stock and 2seventy bio, Inc. stock. The impact of this

conversion has been incorporated into the calculation of Compensation Actually Paid in accordance with the methodologies disclosed in our Annual Report on Form 10-K for the year ended December 31, 2023.

(3) The "Compensation Actually Paid" columns reflect the exclusions and inclusions of certain amounts for the PEOs and the Non-PEO NEOs as set forth below for the most recent fiscal year. Equity values are calculated in accordance with FASB ASC Topic 718. Amounts in the Exclusion of Stock Awards and Option Awards column are the totals from the Stock Awards and Option Awards columns set forth in the Summary Compensation Table. The fair values of RSUs, PSUs, and stock options included in the "Compensation Actually Paid" to our PEOs and the "Average Compensation Actually Paid" to our Non-PEO NEOs columns are calculated at the required measurement dates, consistent with the approach used to value the awards at the grant date as described in our Annual Report on Form 10-K for the year ended December 31, 2023. Any changes to the RSU and PSU fair values are based on our updated stock price at the respective measurement dates and updated performance metric projections (for PSUs). Changes to the stock option fair values are based on the updated stock price at the respective measurement dates, in addition to updated expected option life, volatility, dividend yield and risk-free rate assumptions. For all years presented, the meaningful increases or decreases in the year-end stock option fair value from the fair value on the grant date were primarily driven by changes in the stock price.


Year	Summary Compensation Table Total for PEO 1($)	Exclusion of Stock Awards and Option Awards for PEO 1 ($)	Inclusion of Equity Values for PEO 1 ($)	Compensation Actually Paid to PEO 1 ($)
2023	3,049,181	(2,006,030)	(1,651,770)	(608,619)


Year	Average Summary Compensation Table Total for Non-PEO NEOs ($)	Average Exclusion of Stock Awards and Option Awards for Non-PEO NEOs ($)	Average Inclusion of Equity Values for Non-PEO NEOs ($)	Average Compensation Actually Paid to Non-PEO NEOs ($)
2023	1,336,894	(652,850)	(504,083)	179,961

The amounts in the Inclusion of Equity Values in the tables above are derived from the amounts set forth in the following tables:


Year	Year-End Fair Value of Equity Awards Granted During Year That Remained Unvested as of Last Day of Year for PEO 1 ($)	Change in Fair Value from Last Day of Prior Year to Last Day of Year of Unvested Equity Awards for PEO 1($)	Vesting-Date Fair Value of Equity Awards Granted During Year that Vested During Year for PEO 1 ($)	Change in Fair Value from Last Day of Prior Year to Vesting Date of Unvested Equity Awards that Vested During Year for PEO 1 ($)	Fair Value at Last Day of Prior Year of Equity Awards Forfeited During Year for PEO 1 ($)	Total - Inclusion of Equity Values for PEO 1 ($)
2023	595,914	(1,814,736)	-	(432,948)	-	(1,651,770)

Year	Average Year-End Fair Value of Equity Awards Granted During Year That Remained Unvested as of Last Day of Year for Non-PEO NEOs ($)	Average Change in Fair Value from Last Day of Prior Year to Last Day of Year of Unvested Equity Awards for Non-PEO NEOs ($)	Average Vesting-Date Fair Value of Equity Awards Granted During Year that Vested During Year for Non-PEO NEOs ($)	Average Change in Fair Value from Last Day of Prior Year to Vesting Date of Unvested Equity Awards that Vested During Year for Non-PEO NEOs ($)	Average Fair Value at Last Day of Prior Year of Equity Awards Forfeited During Year for Non-PEO NEOs ($)	Total - Average Inclusion of Equity Values for Non-PEO NEOs ($)
2023	171,167	(540,934)	-	(134,316)	-	(504,083)

(4) Assumes $100 was invested for the period starting December 31, 2020, through the end of the listed year. Historical stock performance is not necessarily indicative of future stock performance.

Relationship Between PEOs and Non-PEO NEO Compensation Actually Paid and Company Total Shareholder Return (“TSR”)

The following chart sets forth the relationship between Compensation Actually Paid to our PEOs, the average of Compensation Actually Paid to our Non-PEO NEOs, and the Company’s cumulative TSR over the three most recently completed fiscal years.

Relationship Between PEOs and Non-PEO NEO Compensation Actually Paid and Net Income

The following chart sets forth the relationship between Compensation Actually Paid to our PEOs, the average of Compensation Actually Paid to our Non-PEO NEOs, and our Net Income during the three most recently completed fiscal years.

Director Compensation

The Compensation Committee of our Board is responsible for making recommendations to our Board on appropriate compensation levels and arrangements for our non-employee directors, ensuring they are consistent with our compensation policy and remain competitive with our peer companies. The Compensation Committee reviews our non-employee director compensation on an annual basis. In making recommendations, the Compensation Committee takes various factors into consideration, including:

•Non-employee directors’ responsibilities and the form and amount of compensation paid to directors at our peer companies;

•Ability to retain and attract the most qualified and experienced non-employee directors to oversee the management of our business operations; and

•Advice of an independent compensation consultant to review our non-employee director compensation program and promote alignment with market practice and stockholder interests.

Our goal is to appropriately compensate non-employee directors for their leadership and expertise while aligning non-employee director interests with those of our stockholders. In line with this goal, our non-employee director compensation policy is underpinned by the same philosophy and principles that govern our executive compensation program. The Compensation Committee generally targeted non-employee director compensation near the 50th percentile of compensation paid non-employee directors with the companies in our peer group.

Our non-employee director compensation program is designed to:

✓ Align non-employee director and stockholder interests through grants of non-statutory stock option awards and restricted stock units;

✓ Encourage a vested interest in our long-term business performance through stock ownership requirements;

✓ Align non-employee director compensation with our peer companies of comparable stage of development, market capitalization and size;

✓ Ensure a robust non-employee director compensation governance framework is in place; and

✓ Help us attract and retain talent for Board service to support the long-term value of the Company.

Based on these considerations, our Board has adopted a non-employee director compensation policy, which provides for annual cash retainers. The non-executive chair of our Board and the chair of each of our committees is entitled to greater compensation for his or her services than other members of our Board, which we believe is commensurate with the additional time commitment and additional responsibility required by the position held and is consistent with the compensation practices of our peer group companies. On April 18, 2023, our Board amended the non-employee director compensation policy to increase the cash retainers payable for service on our Audit Committee. The table below sets forth the cash retainer applicable to our directors in 2023 following such amendment.


Annual cash retainers under the Non-Employee Director Compensation Policy						2023 Cash Retainer ($)

SEC Form DEF 14A filed by bluebird bio Inc.