Glossary

Many diseases are caused directly or indirectly by abnormal genes or abnormal function of genes. Gene therapy is a new way of treating such diseases by giving a gene to the patients as a drug. The first human gene therapy was conducted in the United States in 1990 to a patient of the hereditary disease, Adenosine Deaminase deficiency (ADA). Since then approximately 4,000 cases of gene therapy have been reported in the world, targeting disorders such as hereditary diseases, cancer, and AIDS. Today target disorders have been expanded to include chronic disorders such as rheumatoid arthritis and ischemic heart disease. In Japan, gene therapy has been performed since 1995.

Vector means a “Carrier” or “Conveyer.” A vector transports a therapeutic gene(s) to target tissues or organs and introduces the gene (s) into the target cells. Therefore, the level of technology behind a vector is a major factor that determines the success or failure of a gene therapy. Therapeutic genes vary from disease to disease but a vector can carry and introduce all these genes to the cells. Therefore, it is often said, “Vector technology is the foundation of gene therapy.”

A number of vectors have been used in clinical studies, including modified viruses such as retrovirus, adenovirus, and adeno-associated virus, as well as artificial, non-virus vectors such as liposome. Although many vectors have been tried in basic studies, only a handful of vectors have reached the stage of practical use, and yet many of them were found ineffective and/or raised serious safety concerns.

Efforts are continuously being made around the world to improve these vectors and their usage. However, DNAVEC Corporation’s Sendai virus vector has already been shown to excel other vectors greatly in both efficacy and safety by animal studies. This finding is the basis of our conviction that Sendai virus vector may have potential to become a global standard of gene therapy vectors.