The Thalassaemia International Federation (TIF) has been informed through official communication by both the European Medicines Agency (EMA) and bluebird bio that the latter has placed Phase 1/2 and Phase 3 Studies of LentiGlobin gene therapy (bb1111) for sickle cell disease (SCD) on a temporary suspension, due to 2 recently reported cases of haematologic malignancies among patients who received the treatment in SCD clinical trials.
Bluebird bio implemented the suspension as one patient treated with bb1111 was diagnosed with acute myeloid leukaemia, a type of blood cancer, and a second patient developed a different blood disorder, referred to as myelodysplastic syndrome (MDS). Investigations have already been initiated by bluebird to determine if there is any relationship to these unexpected serious adverse reactions with the use of BB305 lentiviral vector in the manufacture of LentiGlobin gene therapy for SCD.
No cases of cancer have been reported so far with the ZYNTEGLO™ gene therapy treatment in patients with thalassaemia. Nevertheless, since the viral vector (BB305) used to manufacture ZYNTEGLO™ is the same as the one used in Lentiglobin gene therapy for SCD, the company has decided to temporarily suspend the treatment of patients with ZYNTEGLO™.
ZYNTEGLO™ was given conditional marketing authorization by the EMA in 2019, for patients with transfusion-dependent-β-thalassaemia aged 12 years and older who do not have a beta0/beta0 genotype and no matched sibling donor available. This was based on the results from 24 participants, 83% of whom have reached blood transfusion independency, with a high safety profile.
TIF is following these developments very closely and it will be informing its global patient and healthcare professionals’ communities on any updates.
TIF also expresses its sincere hopes that there is a positive outcome of the affected patients’ current situation.