The US FDA has approved the gene therapy betibeglogene autotemcel (Zynteglo) for adult and pediatric patients with beta-thalassemia who require regular red blood cell transfusions. Functional copies of the mutated gene are inserted into patient’s hematopoietic stem cells via a replication-defective lentivirus. A one-time gene therapy cost $2.8 million. Adverse events such as abdominal pain, hot flush, dyspnea, tachycardia, noncardiac chest pain, and cytopenias were noted.