CAMBRIDGE, Mass.--(BUSINESS WIRE)--bluebird bio, Inc. (Nasdaq: BLUE) today announced that it has commenced an underwritten public offering of $400 million of its common stock. bluebird bio also intends to grant the underwriters a 30-day option to purchase up to an additional fifteen percent (15%) of the shares of common stock offered in the public offering. All of the shares in the proposed 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 and Wells Fargo Securities is acting as co-manager of the proposed offering. The offering is subject to market and other conditions, and there can be no assurance as to whether or when the offering may be completed, or as to the actual size or terms of the offering.

About bluebird bio, Inc.

With its lentiviral-based gene therapies, T cell immunotherapy expertise and gene editing capabilities, bluebird bio has built a pipeline with broad potential application in severe genetic diseases and cancer.

bluebird bio's gene therapy clinical programs include investigational treatment for cerebral adrenoleukodystrophy, and treatment of transfusion-dependent ?-thalassemia, also known as ?-thalassemia major, and severe sickle cell disease.

bluebird bio's oncology pipeline is built upon the company's 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. The company’s lead oncology programs are anti-BCMA CAR T programs partnered with Celgene.

bluebird bio’s discovery research programs include utilizing megaTAL/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 Zug, Switzerland.