Background: This article presents the main conclusions and the recommendations of a multidisciplinary group of experts appointed by the Norwegian Centre for Health Technology Assessment to assess the potential of gene therapy in clinical medicine.
Materials and methods: Clinical gene therapy protocols, ongoing or completed with published results, if any, were identified through a systematic survey of descriptive protocols and publications.
Results: So far 3,000-4,000 patients have been treated with gene therapy strategies in more than 400 clinical trials. In Norway the six first patients have been treated with gene therapy at The Norwegian Radium Hospital as part of two approved protocols for treatment of cancer. Gene therapy today is dominated by preclinical and clinical research. Most of the gene therapy protocols identified are in early phases (phases I and II) with few patients in each study; only three of the protocols represent phase III studies. Apart from the use of soluble antisense oligonucleotides against cytomegalovirus, gene therapy is not an established treatment modality today. In early clinical studies, however, promising results have been seen in treatment of cancer, in certain forms of cardiovascular diseases and also in a subgroup of inherited severe combined immunodeficiency.
Interpretation: The expert group recommends that it is now important to build up national competence in the field in two ways: 1) by building up infrastructure in selected milieus; 2) by starting a national programme for gene therapy research including both preclinical and clinical research. The article also considers ethical and legislative aspects and emphasises that gene therapy should continue to be carefully monitored for side effects.