The first gene therapy to treat a rare blood disorder is one step closer to approval Friday following a recommendation by European officials.
Lentiglobin, the gene therapy for beta-thalassemia developed by Cambridge, Mass.-based Bluebird Bio, was recommended for approval by the Committee for Medicinal Products for Human Use (CHMP), the drug-reviewing arm of the European Medicines Agency. A final approval decision is expected within the next three months.
Lentiglobin is Bluebird’s first gene therapy, and if approved, will be marketed under the brand name Zynteglo.
There are dozens of biotech and pharma companies developing gene therapies for rare diseases today, but Bluebird was a pioneer. The first data from beta-thalassemia patients treated with lentiglobin were presented in 2014. Five years later, the gene therapy is on the cusp of approval.
Beta-thalassemia is a rare, inherited blood disease caused by a mutation in the beta-globin gene, which in turn, leads to the production of impaired red blood cells and severe anemia. Regular blood transfusions are the only effective treatment for beta-thalassemia patients today.
Bluebird’s lentiglobin, administered once, uses an inactivated virus to insert a healthy, working copy of the beta-globin gene into patient’s bone marrow. Once implanted, healthy red blood cells are produced and the need for chronic blood transfusions is eliminated or substantially reduced. Before lentiglobin can be manufactured and administered, patients must have stem cells harvested from their body and undergo chemotherapy to ready their bone marrow to receive the gene therapy.
“The goal of treatment with Zynteglo is to enable patients with transfusion-dependent beta-thalassemia to produce hemoglobin at sufficient levels to allow lifelong independence from blood transfusions,” Bluebird Chief Medical Officer David Davidson said in a statement.
He added: “The positive CHMP opinion for Zynteglo is a crucial step toward providing what would be the first one-time gene therapy for people living with transfusion-dependent beta-thalassemia. We share this achievement with the community, patients and clinical investigators whose dedication made it possible. We look forward to the upcoming decision from the European Commission.”
Bluebird’s marketing submission to European regulators is based largely on a lentiglobin clinical trial in which eight of 10 beta-thalassemia patients followed for nearly three years were no longer dependent on transfusions. Bluebird also submitted data from subsequent clinical trials showing improvements made to lentiglobin led to larger increases in the production of healthy hemoglobin.