Gene therapy

Findings by SBU Alert

This is a translation of version 1, published on October 23, 1999. The latest version of this report is not available in English.

Research in gene therapy has increased dramatically during the past 15 years, particularly in the United States. The research has encompassed the development of gene delivery vectors (carriers) for gene transfer, both viral and non-viral, gene transfer to cells in culture, animal experiments, and clinical trials.

Preliminary results from animal experiments approximately 10 years ago led to the first transfer of a foreign gene to a human in 1989, and to clinical gene therapy trials the following year. Since then, nearly 400 clinical trials have been registered. Studies have yet to show any distinct clinical benefits to patients.

The difficulty in most studies has been an insufficient transfer of genes to the relevant target cells. Hence, it is too early to predict the benefits and potential risks to patients who undergo gene therapy. The effectiveness and potential complications will vary widely depending on the nature of the disease and the transfer method used.

Alert has found there is poor* scientific evidence available on the risks of gene therapy. No* scientific evidence is available concerning patient benefits or the cost effectiveness of gene therapy. Currently, gene therapy should be considered experimental and without specific clinical applications.

*This assessment by SBU Alert uses a 4-point scale to grade the quality and evidence of the scientific documentation. The grades indicate: (1) good, (2) moderate, (3) poor, or (4) no scientific evidence on the subject.

This summary is based on a report prepared at SBU in collaboration with Prof Stefan Karlsson, MD PhD, Lund University, and Assoc Prof Edvard Smith, MD PhD, Karolinska Institutet.

Alert is a joint effort by the Swedish Council on Technology Assessment in Health Care (SBU), the Medical Products Agency, the National Board of Health and Welfare, and the Federation of Swedish County Councils.

References

• Andersson, W.F. Human gene therapy. Nature 1998;392(suppl):25-30.
• Brenner, M. Gene marking. Hum Gene Ther 1996;7:1927-36.
• Health Council of the Netherlands. Gene therapy. No 1997/12E.Rijswik, 1997.
• Smith, E. Genterapi. Förväntningar och förverkligande. Läkartidningen 1996;93(5):349-50.
• Verma, IM., Somia, N. Gene therapy ? promises, problems and prospects. Nature 1997;389(6648):239-42.