Description of the business

12 Months Ended

Dec. 31, 2015

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Description of the business

1. Description of the business

bluebird bio, Inc. (the “Company” or “bluebird”) was incorporated in Delaware on April 16, 1992, and is headquartered in Cambridge, Massachusetts. The Company researches, develops, manufactures and plans to commercialize gene therapies for the treatment of severe genetic and rare diseases and in the field of T cell-based immunotherapy. Since its inception, the Company has devoted substantially all of its resources to its research and development efforts relating to its product candidates, including activities to manufacture product candidates, conduct clinical studies of its product candidates, perform preclinical research to identify new product candidates and provide general and administrative support for these operations.

On June 30, 2014, the Company acquired all of the outstanding capital stock of Precision Genome Engineering, Inc. (“Pregenen”) and in connection therewith, obtained the rights to Pregenen’s gene editing and cell signaling technology. See Note 11, “Business combinations,” for additional information.

In July 2014, the Company sold 3,450,000 shares of common stock (inclusive of 450,000 shares of common stock sold by the Company pursuant to the full exercise of an overallotment option granted to the underwriters in connection with the offering) through an underwritten public offering at a price of $34.00 per share. The aggregate net proceeds received by the Company from the offering were $109.8 million, net of underwriting discounts and commissions and offering expenses payable by the Company of approximately $7.5 million.

In December 2014, the Company sold 3,047,500 shares of common stock (inclusive of 397,500 shares of common stock sold by the Company pursuant to the full exercise of an overallotment option granted to the underwriters in connection with the offering) through an underwritten public offering at a price of $85.00 per share. The aggregate net proceeds received by the Company from the offering were $243.3 million, net of underwriting discounts and commissions and estimated offering expenses payable by the Company of approximately $15.8 million.

In June 2015, the Company sold 2,941,176 shares of common stock through an underwritten public offering at a price of $170.00 per share. The aggregate net proceeds received by the Company from the offering were $477.2 million, net of underwriting discounts and commissions and offering expenses of approximately $22.8 million.

As of December 31, 2015, the Company had cash, cash equivalents and marketable securities of $865.8 million. Although the Company has incurred recurring losses, the Company expects its cash, cash equivalents and marketable securities will be sufficient to fund current operations for at least the next twelve months.