bluebird bio, Inc., based in Somerville, Massachusetts, is a biotechnology company that develops gene therapies for severe genetic disorders. The company's only - in the European Union - approved drug is betibeglogene autotemcel, which treats transfusion-dependent beta thalassemia, 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. Wikipedia