Gene therapy is comparable or better than other treatments when it comes to brain blood flow
Results from the study compare well to previous studies measuring the impact of other treatments for sickle cell disease, including the drug hydroxyurea or blood transfusions. Hydroxyurea, the most common treatment for sickle cell disease, has only a small effect on brain blood flow, and while blood transfusions have a stronger positive impact on brain blood flow, the effect is transient because the patient must continually receive new transfusions for it to last. The researchers found gene therapy has a more substantial and long-lasting protective effect on the brain than either of these treatments.
Bone marrow transplants also normalize brain blood flow over the long term. While gene therapy and bone marrow transplantation were not compared directly in the study, the results suggest both treatments produce a similar return to normal blood flow in the brain that is durable over time.
This study of three patients provides preliminary evidence for gene therapy’s effect on stroke risk and requires follow-up studies to confirm the result. However, it adds to a growing body of evidence that gene therapy should be considered as a treatment option to protect brain health in patients with sickle cell disease.
The study provides support for new clinical trials for sickle cell disease gene therapy to include patients at risk for stroke. Historically, given the high-risk nature of their disease, these individuals have been excluded from gene therapy trials.
“We now have emerging data to at least evaluate the efficacy of gene therapy in patients with a risk of or history of stroke,” Sharma said. “Until now, we only had one option that had a long-term impact on blood flow in the brain: bone marrow transplantation. But now we may also have gene therapy as another viable method to protect against neurovascular disease in people with sickle cell disease.”
Authors and funding
The study’s other authors are Jane Hankins and Ranganatha Sitaram, St. Jude; Jaap-Jan Boelens and Maria Cancio, Memorial Sloan Kettering Cancer Center; Radhika Peddinti and James Labelle, University of Chicago Medicine; Lawrence Rispoli, Sarah Costa, Sharon Peled and Andrea Wiethoff, Novartis Institutes for Biomedical Research; and Sarah Sloan, Novartis Pharma AG.
The study was supported by Novartis Pharmaceuticals Corporation, USA.
