Gene therapy enters the pharma market: The short story of a long journey

Approximately 20 years ago, gene therapy was first introduced when Michael Blaese and colleagues applied ex vivo modified autologous T cells to children suffering from adenosine deaminase deficiency (ADA-SCID), a Mendelian genetic error that causes severe combined immunodeficiency syndrome (Blaese et al, 1995). The investigators used retroviral vectors; the most advanced gene delivery system at that time. They transferred a normal copy of adenosine deaminase that, according to the intrinsic features of retroviruses, stably integrated into the cellular genome.While this study demonstrated a proof of concept, years of tremendous efforts both in basic and translational research followed before the first clear evidence for a cure of SCID patients through gene therapy could be reported (Cavazzana-Calvo et al, 2012).