FDA Approves Zynteglo for Rare Blood Disorder

Red blood cells flowing through an artery

FDA approves Bluebird Bio gene therapy: Zynteglo, which treats rare blood disorder beta thalassemia

The Bluebird Bio gene therapy treats beta thalassemia, which is a rare blood disorder. It provides one-time treatment options, which can eliminate the standard regular blood transfusion requirements.

The wholesale price of Bluebird is $2.8 million for the wholesale of the product, Zynteglo, which makes it among the most expensive therapies available. However, biotech claims they have come up with a reimbursement plan, which will allow the patients to get benefits from the therapy.

Beta Thalassemia

Beta thalassemia is a blood disorder passed from parents to children, which causes the level of haemoglobin in the blood to drop. This low level of haemoglobin can lead to dizziness, fatigue, weakness, and bone problems.

When the disease is in its severe form, patients require RBC transfusion for as long as they live. Bluebird estimated that 1300 to 1500 people in the US have transfusion-dependent beta-thalassemia. Furthermore, although transfusions are a treatment option, it can lead to other problems. For example, excessive iron build-up in the organs and however, drugs are available to combat it, they too have their own side effects.

Zynteglo Production and Trial

The patient’s own stem cells are used to make Zynteglo. They are harvested from the bone marrow and modified genetically to produce a haemoglobin component. After that, the engineered cells are infused into the patients again.

Zynteglo was tested in two single-arm, open-label phase 3 studies. Bluebird enrolled forty-one patients, which included both kids and adults with transfusion-dependent beta-thalassemia. The aim of the study was to demonstrate transfusion independence. It was defined by the maintenance of pre-determined haemoglobin levels, which did not require any transfusions for at least twelve months.

Thirty-six participants could be evaluated and 89% of them could achieve transfusion independence. Therefore, the therapy also proves that the effects can be long-lasting. Moreover, Bluebird said the results are durable regarding the last patient follow-up. The longest follow-up is of four years.

Hence, despite the $2.8 million price, the positive long-term results prevent patients from being burdened by regular blood transfusions.


Please enter your comment!
Please enter your name here