BlueBird Bio Update On LG001 Study

"Professor Cavazzana summarized results from HGB-205, an ongoing clinical study using LentiGlobin® BB305 for the treatment of beta-thalassemia major and severe sickle cell disease, which were presented earlier this year at the Annual Congress of the European Hematology Association. She also provided an update on subject 1003, a patient with beta-thalassemia major treated by Professor Cavazzana in 2007 in the LG001 study using the first-generation HPV569 lentiviral vector. Following approximately seven years of transfusion independence, subject 1003 has recently required two blood transfusions after experiencing clinical symptoms of anemia. Importantly, both the expression of HbAT87Q and the vector copy number in peripheral blood leukocytes, a measure of the persistence of the gene therapy, have remained largely unchanged. The safety profile for both vectors is consistent with autologous transplantation, with no gene-therapy related serious adverse events. Development of bluebird bio's approach to treating hemoglobinopathies was guided by the data collected from the LG001 study, a pioneering clinical study that served to highlight both the potential for gene therapy as an intervention in beta-thalassemia as well as the need for an improved lentiviral vector. To this end, Professor Cavazzana also discussed the advances in the design of lentiviral vectors for hemoglobinopathy gene therapies -- specifically the evolution from the first-generation HPV569 lentiviral vector to bluebird bio's current lentiviral vector, BB305, which results in substantially improved vector copy number and HbAT87Q expression. "