• Early results in one group exceed initial therapeutic target
• Patients (small number in Ph I currently) appear to remain stable for up to two years
• LentiGlobin is being studied in both sickle cell disease and β-thalassemia
• LentiGlobin granted orphan drug status in both sickle cell disease and β-thalassemia

Bluebird bio, Inc. (Nasdaq: BLUE) on 6/15/2018 announced new interim data from the ongoing HGB-206 Phase 1 multicenter clinical study of LentiGlobin investigational gene therapy in patients with severe sickle cell disease (SCD) will be presented in an oral presentation on Saturday, June 16 at the 23rd Congress of the European Hematology Association (EHA) by Julie Kanter, M.D., Medical University of South Carolina, Charleston, South Carolina.

“The consistent production of increased amounts of anti-sickling HbAT87Q in the Group C patients reflects the substantial positive impact of the changes introduced with the amended HGB-206 study protocol and refined manufacturing process. All four Group C patients with greater than or equal to three months follow-up are making over 30 percent anti-sickling HbAT87Q. The first patient treated, now with six months of follow-up, is producing over 60 percent anti-sickling HbAT87Q with a normal total hemoglobin level of 14.2 g/dL,” said David Davidson, M.D., chief medical officer, bluebird bio. “The upward trajectory in Group C at these early time points suggests the potential for these patients to exceed the initially proposed therapeutic target of 30 percent anti-sickling HbAT87Q. We continue to define the development plan with regulatory authorities, and with further follow-up, we hope to see even higher levels of HbAT87Q, as well as sustained clinical benefit for patients.”

“The early data from Group C patients are very exciting and provide increasing confidence that LentiGlobin has the potential to deliver transformative benefit to patients. The longer-term data from patients treated earlier in the study show that levels of anti-sickling HbAT87Q in patients with SCD treated with LentiGlobin remain stable for at least two years,” said Dr. Kanter, a lead investigator of the HGB-206 study. “Treatment options that can address the underlying cause of sickle cell disease are limited and LentiGlobin gene therapy has the potential to prevent or substantially reduce damaging symptoms associated with this debilitating disease.”

HGB-206 is an ongoing, open-label study designed to evaluate the safety and efficacy of LentiGlobin gene therapy for the treatment of adults with severe SCD. Patients in this study are divided into three cohorts: A, B and C. Patients in Group A were treated under the original study protocol. Patients in Group B were treated under an amended study protocol that included a refined Drug Product (DP) manufacturing process intended to increase DP vector copy number (VCN) as well as changes to improve engraftment of gene-modified stem cells. Patients in both Group A and B had DP made from stem cells collected using bone marrow harvest. Patients in Group C were also treated under the amended study protocol, but received LentiGlobin gene therapy made from stem cells collected from peripheral blood after mobilization with plerixafor rather than via bone marrow harvest.

LentiGlobin works by inserting a functional human beta-globin gene into a patient’s own hematopoietic stem cells outside the body (ex vivo) and then transplanting those modified cells into the patient’s blood stream through infusion, also known as autologous stem cell transplantation.Bluebird bio is currently testing LentiGlobin in both sickle cell disease and β-thalassemia. The FDA has granted  LentiGlobin orphan drug status for both  β-thalassemia and sickle cell disease. Bluebird currently has four ongoing studies evaluating LentiGlobin in  β-thalassemia and sickle cell disease.