A gene therapy called LentiGlobin has shown promising results in patients with blood disorders like beta-thalassemia.
The results of two clinical trials published April 19 in the New England Journal of Medicine reported that participants with beta-thalassemia had significantly benefitted from the gene therapy where blood transfusions can be reduced or eliminated.
The studies enrolled 22 individuals aged 12 to 35 years who have been transfusion-dependent. Researchers defined transfusion dependency as having to receive eight transfusions per year or at least 100 milliliters per kilogram of body weight of red blood cells.
The process involved correcting the person's cells before it is reintroduced in the body. The patients were monitored for a period of 15 to 42 months. Overall, the need for blood transfusion was reduced by 73 percent in the enrolled patients.
No Side Effects
The researchers said no significant side effects were seen in the patients, and that most are consistent with transplants that use chemotherapy.
"We saw remarkable outcomes using LentiGlobin gene therapy, with most patients no longer needing monthly transfusions," said Dr. Alexis Thompson, the lead author of the study and a professor of pediatrics at Northwestern University Feinberg School of Medicine.
"These study results exceeded our expectations with clinical benefit for nearly all patients, and suggest that gene therapy may be an effective treatment for thalassemia in the future," Dr. Thompson said.
In both trials, the authors noted mild adverse effects including chemo-related episodes of veno-occlusive liver disease and mouth sores. However, they cautioned that long-term effects of the gene therapy are still unknown.
A Phase 3 clinical trial is currently underway, which is reported to include patients younger than 12 years old. Dr. Thompson said they needed to evaluate the effectiveness and safety of the gene therapy in a larger population.
She added that further studies on the gene therapy could open doors for the treatment of other blood disorders like sickle cell.
"There is room for improvement, as we'd like to see the elimination of dependency on transfusion even for patients with the most severe form of the disease; but there is also hope with protocol modifications we have introduced in our phase III trials," said Dr. Philippe Leboulch, the study director and lecturer in medicine at Harvard Medical School.
Beta-Thalassemia, A Genetic Disorder
Beta-thalassemia is an inherited disease that affects the production of hemoglobin in red blood cells. When hemoglobin count is low, the red blood cells carry insufficient levels of oxygen. This can lead to anemia, which causes shortness of breath and feeling tired or weak.
Treatment for beta-thalassemia requires blood transfusions. The frequency of the blood transfusion depends on whether the person has major, intermedia, or minor thalassemia. The more severe the condition is, the more frequent the person has to undergo transfusion.
The U.S. Centers for Disease Control and Prevention also recommends the supplementation of folic acid to help in the development of red blood cells.