In the latest issue of the New England Journal Medicine, there is a report on the success of Bluebird Bio’s gene therapy for sickle cell disease. The report summarizes the results from a 13-year-old boy with the βS/βS genotype who had a history of numerous vasoocclusive crises who in May 2014 received an infusion of Bluebird Bio’s LentiGlobin BB305.
More than 15 months after transplantation, no sickle cell disease–related clinical events or hospitalization had occurred. Further, all medications, including pain medication, were discontinued. The boy reported full participation in normal academic and physical activities.
The patient’s complete blood counts were stable, reticulocyte counts decreased, and circulating erythroblasts were not detected.
Because the gene therapy included a session in which the patient underwent myeloablation with intravenous busulfan, some side effects associated with that chemotherapeutic agent were expected.
Grade 3 and 4 events included grade 4 neutropenia, grade 3 anemia, grade 3 thrombocytopenia, and grade 3 infection with Staphylococcus epidermidis (with positive results on blood culture), all of which resolved with standard measures. All these events resolved over time.
No adverse events related to the LentiGlobin BB305–transduced stem cells were reported.
The researchers concluded that this case report provides proof of concept for this approach and may help to guide the design of future clinical trials of gene therapy for sickle cell disease.
Additional data on LentiGlobin treatment in sickle cell disease is currently being collected in a multicenter, phase 1/2 clinical study in the United States.
In December 2016, we talked with one the investigators, Marina Cavazzana, MD, PhD, of the Hôpital Universitaire Necker-Enfants Malades, Paris, France about bluebird bio’s gene therapy to treat β-thalassemia and sickle cell disease.
Ribeil J-A, Hacein-Bey-Abina S, Payen E, et al. Gene Therapy in a Patient with Sickle Cell Disease. New Engl J Med 2017;376:848-855. DOI: 10.1056/NEJMoa1609677