A patient with the genetic blood disorder beta-thalassaemia has been successfully treated using genetically-altered stem cells, according to US and French researchers. The genetically-altered stem cells now contribute one third of the patient's beta-globin - a key component of haemoglobin, which blood cells need to carry oxygen.
Since childhood, the 21-year-old man had required monthly blood transfusions to cope with his beta-thalassaemia, which leads to decreased beta-globin production. But the stem cell treatment allowed him to go without blood transfusions for 21 months.
'For the first time, a patient with severe beta-thalassaemia is living without the need for transfusions over a sustained period of time. These results are not only important due to the tremendous medical need that exists for thalassaemia patients around the world, but also represents a significant step forward for the field of autologous stem cell therapy as an emerging therapeutic modality', said Professor Marina Cavazzana-Calvo of the University of Paris and Necker-Enfants Malades Hospital, Paris, who was lead co-author of the study.
Professor Cavazzana-Calvo and her team harvested stem cells from the patient's bone marrow and infected them with LentiGlobin - a virus containing the beta globin gene. These cells were then transfused back into the patient's bloodstream where they proliferated. The cause of the proliferation is unknown. But the US and French researchers found some of the genetically-altered stem cells had also turned on a gene called HMGA2. Unexpected genetic changes have been a concern in the past, as this could potentially lead to cancer.
'We must be very cautious, but the signs are that the impact of the HMGA2 gene will be benign', said Dr Philippe Leboulch of the University of Paris and Harvard University who led the study.
'For beta-thalassemia, we have worked intensely for almost 20 years to design, develop and manufacture LentiGlobin to provide a sustained high-level haemoglobin production, resulting in a major clinical benefit. It has been very rewarding to follow this patient as his life has dramatically improved since receiving our treatmentÊ¹, said Dr Leboulch.
The research was published in Nature.