The same lentivirus, known as LentiGlobin® BB305, was previously used in the Northstar Study, which enrolled adults who are transfusion-dependent and diagnosed with beta-thalassemia major. Early data
from the Northstar Study shows that patients with non-β0
genotypes and ≥12 months of follow-up have stopped regular transfusions; patients with β0
genotypes and ≥12 months of follow-up had a median reduction in transfusion volume of 63%. Prior to the Northstar Study, three patients were treated in a gene therapy clinical study in France using a similar lentiviral vector between 2006 and 2011. None of the patients have experienced serious, unexpected side effects. However, not all short and long term risks are known at this time, and the patients continue to be followed by their physicians.