bluebird bio Announces Pricing of Public Offering of Common Stock

CAMBRIDGE, Mass.--(BUSINESS WIRE)--bluebird bio, Inc. (Nasdaq: BLUE), a clinical-stage biotechnology company committed to developing potentially transformative gene therapies for severe genetic diseases and cancer, today announced the pricing of an underwritten public offering of 3,243,244 shares of its common stock at a public offering price of $185 per share, before underwriting discounts. In addition, bluebird bio has granted the underwriters a 30-day option to purchase up to an additional 486,486 shares of common stock. All of the shares in the offering are to be sold by bluebird bio.

Goldman Sachs & Co. LLC, BofA Merrill Lynch, J.P. Morgan Securities LLC and Cowen are acting as joint book-running managers of the offering. The offering is expected to close on or about December 15, 2017, subject to customary closing conditions.

bluebird bio anticipates the total gross proceeds from the offering (before deducting underwriters’ discounts and commissions and estimated offering expenses) will be approximately $600 million, excluding any exercise of the underwriters’ option to purchase additional shares.

The shares are being offered by bluebird bio pursuant to an automatically effective shelf registration statement that was previously filed with the Securities and Exchange Commission (SEC). A preliminary prospectus supplement relating to and describing the terms of the offering was filed with the SEC on December 11, 2017. The final prospectus supplement relating to the offering will be filed with the SEC and will be available on the SEC’s website at www.sec.gov. When available, copies of the final prospectus supplement and the accompanying prospectus relating to these securities may also be obtained by contacting one of the following: Goldman Sachs & Co. LLC, Attn: Prospectus Department, 200 West Street, New York, NY 10282, telephone: [phone], facsimile: [phone], email: [e-mail]; BofA Merrill Lynch, NC1-004-03-43, 200 North College Street, 3rd floor, Charlotte, NC 28255-0001, Attn: Prospectus Department, email: [e-mail]; J.P. Morgan Securities LLC, c/o Broadridge Financial Solutions, 1155 Long Island Avenue, Edgewood, NY 11717, or by telephone at [phone]; or Cowen and Company, LLC, c/o Broadridge Financial Services, 1155 Long Island Avenue, Edgewood, NY, 11717, Attn: Prospectus Department, by telephone at [phone] or by fax at [phone].

This press release shall not constitute an offer to sell or the solicitation of an offer to buy, nor shall there be any sale of, these securities in any state or jurisdiction in which such offer, solicitation or sale would be unlawful prior to the registration or qualification under the securities laws of such state or jurisdiction.

About bluebird bio, Inc.

With its lentiviral-based gene therapies, T cell immunotherapy expertise and gene editing capabilities, bluebird bio has built an integrated product platform with broad potential application to severe genetic diseases and cancer. bluebird bio's gene therapy clinical programs include its Lenti-D™ product candidate, currently in a Phase 2/3 study, called the Starbeam Study, for the treatment of cerebral adrenoleukodystrophy, and its LentiGlobin® product candidate, currently in five clinical studies for the treatment of transfusion-dependent β-thalassemia, also known as β-thalassemia major, and severe sickle cell disease. bluebird bio's oncology pipeline is built upon the company's leadership in lentiviral gene delivery and T cell engineering, with a focus on developing novel T cell-based immunotherapies, including chimeric antigen receptor (CAR T) and T cell receptor (TCR) therapies. bluebird bio's lead oncology programs, bb2121 and bb21217, are anti-BCMA CAR T programs partnered with Celgene. bb2121 and bb21217 are each currently being studied in Phase 1 trials for the treatment of relapsed/refractory multiple myeloma. bluebird bio also has discovery research programs utilizing megaTALs/homing endonuclease gene editing technologies with the potential for use across the company's pipeline.

bluebird bio has operations in Cambridge, Massachusetts, Seattle, Washington, Durham, North Carolina and Europe.

LentiGlobin and Lenti-D are trademarks of bluebird bio, Inc.

Forward-Looking Statements
This release contains “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, including statements regarding the anticipated final terms, timing and completion of the proposed offering, and bluebird bio’s existing product candidates and research programs. Any forward-looking statements are based on management’s current expectations of future events and are subject to a number of risks and uncertainties that could cause actual results to differ materially and adversely from those set forth in or implied by such forward-looking statements. These risks and uncertainties include, but are not limited to, risks and uncertainties related to market conditions and satisfaction of customary closing conditions related to the proposed public offering, that the preliminary results from our clinical trials will not continue or be repeated in our ongoing clinical trials, the risk of cessation or delay of any of the ongoing or planned clinical studies and/or our development of our product candidates, the risk of a delay in the enrollment of patients in our clinical studies, the risks that the changes we have made in the LentiGlobin drug product manufacturing process or the HGB-206 clinical study protocol will not result in improved patient outcomes, risks that the current or planned clinical studies of the LentiGlobin drug product will be insufficient to support regulatory submissions or marketing approval in the United States and European Union, risks that the current clinical study of Lenti-D will be insufficient to support regulatory submissions or marketing approval in the United States and European Union, the risk that our collaborations, including the collaboration with Celgene, will not continue or will not be successful, and the risk that any one or more of our product candidates will not be successfully developed, approved or commercialized. There can be no assurance that bluebird bio will be able to complete the proposed public offering on the anticipated terms, or at all. For a discussion of other risks and uncertainties, and other important factors, any of which could cause our actual results to differ from those contained in the forward-looking statements, see the section entitled “Risk Factors” in our annual report on Form 10-K and our most recent quarterly report on Form 10-Q, as well as discussions of potential risks, uncertainties, and other important factors in our subsequent filings with the Securities and Exchange Commission. All information in this press release is as of the date of the release, and bluebird bio undertakes no duty to update this information unless required by law.