What is Gene Therapy?
Basics of Gene Therapy


What is gene therapy?
Gene therapy is a type of treatment that uses genetic material with the goal of changing the course of a disease. It is a therapeutic approach that is being investigated for the treatment of multiple diseases.1 Though many gene therapies are currently in early research or clinical trials, some have already been approved by the US Food and Drug Administration (FDA).
See glossary for more terms > is a type of treatment that uses genetic material with the goal of changing the course of a disease. It is a therapeutic approach that is being investigated for the treatment of multiple diseases.1 Though many gene therapies are currently in early research or clinical trials, some have already been approved by the US Food and Drug Administration (FDA).2
What is the goal of gene therapy?
The goal of gene therapy is to treat diseases at the genetic level (the source). Gene therapy is a promising treatment option that is being studied for a number of diseases including inherited diseases and cancers.
The goal of gene therapy is to treat diseases at the genetic level (the source). Gene therapy is a promising treatment option that is being studied for a number of diseases including inherited diseases and cancers.1
For over 100 years, scientists have studied the human body and the building blocks of DNA.3 With each mark of progress comes a better understanding of how our bodies work and how we may be able to keep them healthy and free from disease.
Today, gene therapy continues to build on that strong foundation of DNA research. The technology of gene therapy targets disease at the genetic level by one or more of the following approaches1:
- Adding new genes (Gene additionadds functioning genetic material to do the work of a faulty gene
See glossary for more terms >) - Editing existing genes using these techniques
- Disruption or inactivation
- Correction or insertion
What are the potential risks of gene therapy?
As with any treatment, there are risks associated with gene therapy. Risk depends on the type of gene therapy, type of Vectora delivery system used to introduce genetic material into the nucleus
See glossary for more terms >, and administration method. Some risks can be serious.4
Potential risks of gene therapy include:4
- A harmful immune reaction
- Complications from the inserted genetic material (eg, insertional oncogenesis, a known risk where DNA mutations can occur)
- Adverse events related to the effects off-target editing
- Unexpected gene activation or inactivation
Additionally, there may be risks associated with the administration process. There are different risks depending on whether gene therapy is directly administered to the cells in the body (in vivo) or if cells are genetically altered outside the body and transplanted back into the body (ex vivo). Some of these risks may be managed through supportive care.
Gene therapy techniques are continually being researched. Patients, caregivers, and physicians should always discuss the risks and benefits of a specific gene therapy treatment.

Gene-ius Questions
To help understand gene therapy, here is a general example of a gene therapy and how it moves from research to a potential reality:
- Scientists discover the genetic basis of a disease, which might be a mutation in a single gene.5
- Scientists target their research on ways to modify the specific mutation.5
- Different gene therapy techniques are explored in a laboratory in order to figure out which are most effective and show the most promise in treating a genetic disease.6
- Once scientists find a technique that they believe has the potential to work, the gene therapy goes through preclinical research and rigorous clinical trials to evaluate the safety and Efficacythe ability for a medication to achieve its desired effect
See glossary for more terms > of the treatment.6 - Successful completion of clinical trials may result in approval by the European Medicines Agency (EMA) and/or the US Food and Drug Administration (FDA) and a specific gene therapy becoming available for people with the disease.7,8
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References
1. National Institutes of Health. Genetics Home Reference. Help me understand genetics. Accessed March 4, 2020. https://ghr.nlm.nih.gov/primer 2. Food and Drug Administration. FDA continues strong support of innovation in development of gene therapy products. Press release. Accessed March 4, 2020. https://www.fda.gov/news-events/pressannouncements/fda-continues-strong-support-innovation-development-gene-therapyproducts 3. Wirth T, Parker N, Ylä-Hertuala. History of gene therapy. Gene. 2013;525(2):162-169. 4. Anguela XM, High KA. Entering the Modern Era of Gene Therapy. Annu Rev Med. 2019;70:273-288. 5. Amberger JS, Bocchini CA, Scott AF, Hamosh A. OMIM.org: leveraging knowledge across phenotype-gene relationships. Nucleic Acids Res. 2019;47(D1):D1038–D1043. 6. Food and Drug Administration. Human gene therapy for rare diseases: guidance for industry. January 2020. Accessed March 4, 2020. https://www.fda.gov/media/113807/download 7. Food and Drug Administration. Development & approval process: drugs. Accessed March 4, 2020. https://www.fda.gov/drugs/development-approval-process-drugs 8. European Medicines Agency. From laboratory to patient: the journey of a medicine assessed by EMA. Accessed March 4, 2020. https://www.ema.europa.eu/en/documents/other/laboratory-patientjourney-centrally-authorised-medicine_en.pdf