bluebird bio, Inc., based in Somerville, Massachusetts, is a biotechnology company that develops gene therapies for severe genetic disorders. The company is owned by investment funds managed by The Carlyle Group and SK Capital Partners.

One of the company's approved drugs is betibeglogene autotemcel (Zynteglo), which treats transfusion-dependent beta thalassemia (TDT), a rare genetic blood disorder, and has been approved for use by the European Medicines Agency. The company has been criticized for the $1.8 million cost of the drug, which is the second most expensive drug in the world.

The company is developing LentiGlobin gene therapy for the treatment of sickle cell disease and cerebral adrenoleukodystrophy. It is also developing T cell product candidates to treat acute myeloid leukemia, Merkel-cell carcinoma, diffuse large B-cell lymphoma, and MAGEA4 solid tumors.

The company was founded as Genetix Pharmaceuticals in April 1992 by MIT faculty members Philippe Leboulch and Irving London.

From 2001 to 2005, Walter Ogier was chief executive officer of Genetix. At that time, the company was focused on the development of LentiglobinTM for the treatment of sickle cell disease and thalassemia major (beta-thalassemia), the two most globally prevalent severe human genetic diseases.

In September 2010, preliminary results of clinical trials of LentiglobinTM at Hospital Necker in Paris, France, were published in Nature by Marina Cavazzana and company founder Philippe Leboulch. Stable transfusion (21 months) independence was successfully achieved by a patient with severe beta-thalassemia who had been treated with Lentiglobin 2 years earlier. This represented the first-ever long term correction of a major human genetic disease by gene therapy.

Also in September 2010, the company was renamed bluebird bio and Nick Leschly was named chief executive officer.

In June 2013, the company became a public company via an initial public offering, raising $116 million.