Europe – Precautionary marketing suspension of thalassaemia medicine Zynteglo

The company that markets the gene therapy medicine Zynteglo for treating the rare blood condition beta thalassaemia has suspended sales pending investigation of a safety concern.

The company, bluebird bio, notified EMA that a related medicine it was developing, which uses the same technology as Zynteglo, may have been associated with a case of cancer. Although no cases of cancer have been reported with Zynteglo itself, the company suspended marketing of Zynteglo until the possibility that the same risk might apply to the licensed medicine has been investigated.

The concern arose with the medicine, bb1111, intended to treat another blood disorder, sickle cell disease. This medicine uses the same viral vector as Zynteglo, based on a type of virus known as a lentivirus, to insert a working gene into the patient’s blood cells. One patient treated with bb1111 developed acute myeloid leukaemia, a cancer of the blood, that might have been related to treatment, and a different blood disorder, myelodysplastic syndrome, was reported in another patient…