Gene therapy treats transfusion-dependent beta-thalassemia.
Gene therapy is a technique that modifies a person’s genes to prevent, treat, or cure a disease. Gene therapies work by a variety of mechanisms, including replacing a disease-causing gene with a healthy version of the gene, inactivating a disease-causing gene, or introducing a new or modified gene or genes into the body. Findings from a phase 3 clinical trial suggest that beti-cel gene therapy successfully treats transfusion-dependent beta-thalassemia.
Beti-cel is a gene therapy that works by adding a modified form of the beta-globin gene into a recipient’s own blood cell-producing stem cells. This process relies on transduction, the process by which foreign DNA is introduced into a cell by a virus or viral vector. Beti-cel therapy is designed to facilitate the production of normal, healthy hemoglobin and obviate the need for transfusions.
Thalassemia is a class of inherited blood disorders that affect the genes for hemoglobin, the oxygen-carrying component of the red blood cells. Hemoglobin, which consists of two proteins (alpha and beta) becomes incorporated into red blood cells during their maturation. Insufficient production of either the alpha or beta proteins due to genetic defect impairs oxygen transport via the red blood cells, inducing anemia and often necessitating blood transfusions.
The study involved 22 people (ages 4 to 34 years) with transfusion-dependent beta-thalassemia. Prior to receiving the gene therapy, each of the participants underwent chemotherapy to temporarily halt their red blood cell production. The investigators administered beti-cel intravenously and monitored the recipients for an average of 30 months.
They found that 20 of the 22 participants, including six who were under the age of 12 years, no longer required blood transfusions after receiving the gene therapy, typically within one month of administration. Four of the participants experienced adverse events related to the gene therapy, but most events were mild except for one event in which the participant developed thrombocytopenia, a condition in which blood platelet levels are too low.
These findings suggest that beti-cel gene therapy successfully treats transfusion-dependent beta-thalassemia and opens the door for more gene therapy strategies and applications in the future. Learn more about gene therapy in this episode featuring world-renowned geneticist Dr. George Church.