Gene therapy: current status and future prospects

The ability to successfully introduce foreign genes into eukaryotic cells has made possible a new approach to the treatment of human disease. Gene therapy is now being brought to bear on genetic, malignant, and infectious diseases. In this review, we summarize the status of the field through an analysis of clinical protocols involving transfer of marker or therapeutic gene(s) into various somatic cell targets. Many of these trials will begin to examine whether or not patients with diseases that are unresponsive to conventional therapeutic interventions (e.g., pharmaceutical, surgical) will show benefit solely from somatic cell-based gene therapies. In other trials, the gene therapies are meant to complement or bolster the effect of conventional treatments. Although the field of gene therapy is now entering the clinical arena, we will also attempt to summarize certain shortcomings and technical hurdles that will need to be overcome for its eventual widespread use.