2005: Gene therapy is growing teenage, what have we learned?

Molecular biology of recombinant DNA exists since about thirty years. In the last twenty years this know-how has been progressively applied to medicine. We can distinguish four major periods: a) the era of 'genes as probes' (started in the 80ties) where molecular genetics has been first used for precise diagnostics of monogenic diseases; (b) the era of 'genes as factories' (started in the 90ties), where genes transferred into cell cultures have permitted the industrial production of biopharmaceuticals; (c) the era of 'genes as drugs' (coming into clinics in the 90ties) where gene transfer into human tissues and organs should permit the cure or treatment of otherwise untreatable diseases. The era of 'genes as drugs', better known as 'era of gene therapy' has indeed started to enter clinical trials in 1990. Fifteen years later we can count over 900 trials and about 4500 experimentally treated patients. In spite of that, gene therapy is still far from being widely clinically applicable, in spite of a recent commercialisation of a gene medicine in China. This report summarizes which are the basic ingredients and players in somatic gene therapy, and what have been the achievements and frustrations in this research field. The conclusions are that the potential of this approach is indeed very high, although this is no longer collectively perceived by the medical field.