​Interim results from a clinical trial conducted by Prof. Marina Cavazzana and her team at the Necker Children's Hospital in partnership with the Imagine Institute, and those from an international multicenter trial conducted in the United States, Thailand and Australia have shown that a gene therapy can improve the health of or cure patients with beta thalassemia. The two trials employed the same therapeutic product called LentiGlobin, developed at Harvard University in Boston (USA) and the CEA's François Jacob Institute of Biology (France) by Professor Philippe Leboulch in partnership with the American company he founded: bluebird bio.

For these phase I/II trials, the researchers harvested hematopoietic stem cells from patients and transduced a corrective gene into them using the LentiGlobin BB305 vector. The patients underwent myeloablation and thereafter had the corrected cells infused into them. Once returned to the patients, these therapeutic stem cells produced red blood cells with sufficient quantities of functional hemoglobin. According to beta thalassemia severity, the LentiGlobin gene therapy either freed patients from transfusion (12 of 13 patients with non-beta0/beta0 alleles) or reduced transfusion volume (-73%) and frequency (3 of 9 patients with beta0/beta0 alleles or with two copies of the IVS1-110 mutation). With a cumulative follow-up of 15 to 42 months, the patients in the two trials have reported no adverse events and have returned to their professional or scholastic activities.

These results have been shared through a press release.