On May 26, 2016, the first ex vivo gene therapy, autologous CD34+ cells encoding the human ADA cDNA sequence, was approved by the European Commission for the treatment of severe combined immunodeficiency due to ADA deficiency (ADA-SCID), in patients who cannot be treated by a bone marrow transplant because they do not have a suitable, matched, related donor.24,25 Children born with ADA-SCID do not have a healthy, fully functioning immune system and as a consequence, are unable to fight off everyday infections.24,25

The therapy is an autologous CD34+ enriched cell fraction that contains CD34+ cells transduced with retroviral vector that encodes for the human ADA cDNA sequence.26 It replaces defective ADA in immune cells.27

*Brand name: Strimvelis®.