What is the Difference Between Gene Therapy and Immunotherapy?

Gene therapy and immunotherapy are both types of treatment for cancer and other diseases. They represent different approaches to disease therapy, though there is some overlap. 

What is gene therapy? 

Gene therapy is a way of treating or preventing disease by altering the genetic instructions within an individual’s cells. Most diseases aren’t caused by a single mutant gene — an alteration in the DNA sequence — but some mainly rare, inherited disorders, may be due to mutation in a single gene.  

Gene therapy that works inside the body uses a virus or gene editing tool such as CRISPR to replace or disable faulty genes that are responsible for the disorder. For example, scientists might deliver copies of normal genes to the body to replace mutated genes that are causing cells to make an ineffective or dangerous protein.  

What are some examples of gene therapy? 

Dana-Farber Cancer Institute offers U.S. Food and Drug Administration approved gene therapies for certain patients over 12 years old with sickle cell disease or beta thalassemia. These diseases affect blood-forming cells and are life-long inherited blood diseases. 

These treatments are given as a one-time therapy, however patients may require intensive treatment prior to receiving the therapy and will be monitored closely afterwards. 

Learn more about gene therapy at Dana-Farber. 

Gene therapies are also approved for hemophilia, spinal muscular atrophy, Duchenne muscular dystrophy, and an inherited retinal disorder. 

What is immunotherapy? 

Immunotherapy is a strategy aimed at improving the ability of the body’s natural defenses — the immune system —- to recognize and attack cancer cells. Some immunotherapies help train the immune system to recognize and attack cancer cells, such as cancer vaccines and T-cell therapies.  

Another type of immunotherapy aims to disarm the mechanisms cancer cells use to shield themselves from the immune system. These therapies are called immune checkpoint inhibitors. They target immune checkpoints, which are proteins on the surface of cancer cells that can be thought of as shields or masks that help the cancer hide from the immune system.  

What are some examples of immunotherapy? 

Immune checkpoint inhibitors are used widely to treat cancer and have made a significant different for many patients with melanoma, lung cancer, breast cancer and more.   

These drugs were made possible by key discoveries in the 1990s, when scientists learned how cancer cells can exploit naturally occurring molecules that turn off the body’s immune response to tumors. This led to insights about how to use drugs that can turn the immune response on again, harnessing its power to fight cancer. Immune checkpoint inhibitor drugs are typically monoclonal antibodies that are designed to find and inhibit specific immune checkpoint proteins. 

Learn more about immune checkpoint inhibitors. 

Bispecific antibodies are another form of immunotherapy. A bispecific antibody attaches to two proteins that appear on different cells – one on a cancer cell and one on an immune cell. The idea is to bring the two cells closer to one another to activate the immune cell and prime it to attack the cancer cell. 

Learn more about approved bispecific antibodies for multiple myeloma and for non-Hodgkin lymphoma.  

CAR T-cell therapy is also considered immunotherapy and is used widely to treat multiple forms of blood cancer: 

• B-cell acute lymphoblastic leukemia (ALL) 

• B-cell non-Hodgkin lymphoma including 

• Multiple myeloma 

Learn more about CAR T-Cell therapy at Dana-Farber. 

Dana-Farber researchers are also investigating the use of CAR T-cell therapy and other forms of cellular therapies, such as cancer vaccines, NK cell therapy and CAR NK-cell therapy in clinical trials for patients with blood cancers and solid tumors.   

Learn more about cellular therapy clinical trials. 

Learn more about cancer vaccine clinical trials. 

How are gene therapy and immunotherapy similar? 

The two approaches overlap in therapies that use gene therapy to perform immunotherapy. For instance, CAR-T cell therapy uses a patient’s own T cells, which are genetically modified in a laboratory to make a protein called a chimeric antigen receptor (CAR). When the modified T cells are returned to the patient, the CAR enables the T cells to seek out and destroy the cancer cells wherever they are found in the body. 

Learn more about how these therapies are used to treat cancer.

About the Medical Reviewer

Dr. Antin received his MD from Cornell University in 1978, and postgraduate training in hematology and medical oncology at DFCI and Brigham and Women's Hospital. He subsequently served as director of the Bone Marrow Transplantation Service at BWH from 1987 to 1997. He now heads the Stem Cell Transplant Program of the Department of Medical Oncology at DFCI and BWH. He is a founding member and past president of the American Society of Blood and Marrow Transplantation and a past Chairman of the Steering Committee of the BMT Clinical Trial Network.