The aim of the WHO Expert Group on International Nonproprietary Names is to designate one generic name for each pharmaceutical substance to avoid confusion of use among regulatory authorities, drug manufacturers, health professionals and patent authorities. The International Nonproprietary Names (INN) system was initiated in 1950 and, at present, over 7000 names have been designated for pharmaceutical substances.

Gene transfer is a complex and rapidly developing area leading to a variety of potential clinical products. More than 600 currently approved trials have been, or are being, carried out and it is expected that within a few years several gene transfer products will be commercially available. There is, therefore, a need to consider how gene transfer medicinal products will be named.

FDA recommendations for such a nomenclature focus on two points. Firstly, the name should indicate clearly that the product is a vector carrying a gene (as opposed to a protein) to be transferred for therapeutic purposes. Secondly, FDA recommends that certain items be omitted from the name such as the indication, the viral subtypes/plasmid backbone (if there is no significant difference in the tropism/action), and the promoter used to drive expression of the transgene. These items can be included in the package insert. It is FDA’s opinion that in terms of a nomenclature system for gene transfer medicinal products, the simpler the better, although this position is still under review.

The important aspects of gene transfer medicinal products are (i) the distinction between in-vivo gene transfer or clinical transfer of ex-vivo genetically modified cells, (ii) the nature of the gene often termed expression vector or expression construct used to modify the cells in vivo or ex vivo and (iii) the exact nature of the gene transfer reagent (non-viral vector or naked nucleic acid) or the viral particle used for the genetic modification.

Issues relating to nomenclature for gene transfer medicinal products using International Nonproprietary Names (INN) will be discussed at the next meeting of the WHO Clinical Gene Transfer Monitoring Group.

References

1. Gene therapy of human severe combined immunodeficiency (SCID)-XI diseases. Science, 288: 669-672 (2000).

2. Food and Drug Administration. Biologicals Response Modifiers Advisory Committee. Retroviral gene therapies for the treatment of patients with severe combined immunodeficiency - Safety Issues. 10 October 2002. http://www.fda.gov/PHRMS/DOCKETS/ac/02/briefing/ 3897B1_01.htm

3. FDA places temporary halt on gene therapy trials using retroviral vectors in blood stem cells. FDA Talk Paper, T03-04, 14 January 2003. http://www.fda.gov/

4. European Agency for the Evaluation of Medicines (EMEA). Note for Guidance on the Quality, Preclinical and Clinical Aspects of Gene Transfer Medicinal Products. CPMP/BWP/3088/99.

5. World Health Organization. Guidelines for assuring the quality of DNA vaccines. Technical Report Series, No. 878, 1998.

6. Food and Drug Administration. Guidance for Human Somatic Cell Therapy and Gene Therapy. CBER 3/30/ 1998.

7. Food and Drug Administration. Supplemental Guidance on Testing for Replication Competent Retrovirus in Retroviral Vector Based Gene Therapy Products and During Follow-up of Patients in Clinical Trials Using Retroviral Vectors.. CBER, October 2000. http://www.fda.gov/cber/guidelines.htm