Gene therapy is the introduction of genes into existing cells to prevent or cure a wide range of diseases. For example, suppose a brain tumor is forming by rapidly dividing cancer cells. The reason this tumor is forming is due to some defective or mutated gene.

Gene therapy has now become a relatively simple process. The basics of the process are the identification of the gene in question, duplication of that gene, and insertion of the gene into the human genome needing the gene (CIS) .

Gene therapy is the introduction, removal or change in genetic material—specifically DNA or RNA—into the cells of a patient to treat a specific disease. The transferred genetic material changes how a protein—or group of proteins—is produced by the cell.

There are two types of gene therapy treatment: Somatic cell gene therapy and germline therapy. Somatic cell gene therapy involves obtaining blood cells from a person with a genetic disease and then introducing a normal gene into the defective cell (Coutts, 1998).

For example, diseases such as cystic fibrosis, combined immunodeficiency syndromes, muscular dystrophy, hemophilia, and many cancers result from the presence of defective genes. Gene therapy can be used to correct or replace the defective genes responsible.

Gene therapy offers the possibility of a permanent cure for any of the more than 10,000 human diseases caused by a defect in a single gene. Among these diseases, the hemophilias represent an ideal target, and studies in both animals and humans have provided evidence that a permanent cure for hemophilia is within reach.

For example, the FDA and NIH revealed that 691 volunteers in gene-therapy experiments had either died or fallen ill in the seven years before Jesse’s death; only 39 of these incidents had been reported promptly as required.

Virus Vectors Retrovirus has been considered to be an ideal viral vector for gene therapy, because the viral genome is stably integrated into the chromosome. In fact, retroviral vectors have been the most extensively used gene therapy vectors in the early stages of clinical trials.

Possible Effects of Gene Therapy Such trials usually last 2 to 4 years and go through several phases of research. In the United States, the U.S. Food and Drug Administration (FDA) must then approve the new therapy for the marketplace, which can take another 2 years.

The main reason gene therapy is so expensive, however, may be the paradigm used in the price-setting strategy. The cost of production is weighed against the value of a life saved or the improved quality of life over a specified timeframe.

Although gene therapy is a promising treatment option for a number of diseases (including inherited disorders, some types of cancer, and certain viral infections), the technique remains risky and is still under study to make sure that it will be safe and effective.

French Anderson, MD, was “dubbed ‘the father of gene therapy’ after a team he led in 1990 cured a hereditary disease of the immune system in a 4-year-old girl.” That’s not quite the way it happened.

Cancer types, which have been targeted with gene therapy, include brain, lung, breast, pancreatic, liver, colorectal, prostate, bladder, head and neck, skin, ovarian, and renal cancer. Currently, two cancer gene therapy products have received market approval, both of which are in China.

RATIONALE: Gene therapy may improve the body’s ability to fight cancer or make the cancer more sensitive to chemotherapy. Drugs used in chemotherapy use different ways to stop tumor cells from dividing so they stop growing or die.