Sickle-Cell Gene Therapy From Bluebird Bio Appears Encouraging In Early Results

The first patient with severe sickle cell disease (SCD) to be treated with LentiGlobin BB305, produced by Bluebird Bio, seems to working effectively so far, researchers said today.

LentiGlobin BB305 works by correcting the underlying gene defect which causes sickle-cell disease. It helps the body make enough functional hemoglobin to lower severity of or even eliminate symptoms.

The compound inserts a corrected rendition of the hemoglobin gene into patients’ blood stem cells through means of a non-harmful virus.

Sickle-cell disease, also known as sickle-cell anaemia, is a hereditary blood disorder, characterized by an abnormality in the oxygen-carrying haemoglobin molecule in red blood cells. The abnormality leads to a tendency for the cells to assume a rigid, sickle-like shape under certain circumstances.

Sickle-cell disease is associated with a number of acute and chronic health problems, such as severe infections, attacks of severe pain (“sickle-cell crisis”), and stroke, and an increased risk of death.

Almost 300,000 children are born with a form of sickle-cell disease every year, mostly in sub-Saharan Africa, but also in other parts of the world such as the West Indies and in people of African origin elsewhere in the world.

Presenting at the European Hematology Association meeting in Vienna, Bluebird Bio researchers reported the young French patient has not needed a life-sustaining blood transfusion for more than three months. His body was producing 45 percent so-called anti-sickling hemoglobin at six months.

LentiGlobin BB305 treatment has also shown promissing results in the blood disorder beta-thalassemia, in which a genetic defect prevents the production of hemoglobin. Researchers presented updated data on two patients with the disease. As of May have been free of blood transfusions for 14 months to 16 months.

Researchers cautioned that it is not possible to draw any firm conclusions from a one-patient study of such short duration.