What is Immunotherapy?

Immunotherapy is a type of cancer treatment that uses the body’s immune system to find and attack cancer cells. Learn more about the types of immunotherapy that make up the Cancer Center's immunology programs.

Immunotherapies use the body’s natural defense mechanisms to kill the tumor. Scientists have known for decades that while cancer cells are often detected by the immune system, most cancers evade an attack by the immune system. The revolution in immunotherapy arose from the discovery that most immune cells lie asleep next to the tumor, and that our goal is to re-awaken them from their slumber. The recent ‘checkpoint blockade’ therapies approved by the FDA, and now used in thousands of cancer patients, awaken the immune cells (called ‘T cells’) to attack and kill tumor cells.

Cellular Immunotherapy

CAR-T cell therapy is a form of cellular immunotherapy in which T cells that are normally produced by our bodies are engineered to eliminate tumors. To produce CAR-T cells, blood is collected from a patient; T cells are isolated and expanded in a specialized laboratory; and then a chimeric antigen receptor (CAR) is engineered into the T cells. The CAR is a homing device that guides the T cell to the patient’s tumor. The engineered T cells are then returned to the patient and the homing signal directs them to find and specifically kill cancer cells throughout the body, including the most dangerous metastases. In the past year, several clinical trials have demonstrated that CAR-T cells are extremely effective in eradicating certain cancers where standard treatments were ineffective, including acute lymphoblastic leukemia, chronic lymphocytic leukemia, and non-Hodgkin’s lymphoma. In principle, CAR-T cells can be engineered to target a wide variety of other blood cancers – such as multiple myeloma, acute myeloid leukemia – as well as solid tumors.

At Mass General Cancer Center, we are committed to make CAR-T cells work for many cancers. Learn more about our Cellular Immunotherapy Program.

Checkpoint Inhibitors

Immune checkpoint proteins reside on the surface of immune cells and put on the brakes that block immune cells from destroying cancer. Some tumor cells even learn to use these braking signals as a shield that blocks the incoming attack by the immune system. Checkpoint therapies are designed to block the checkpoint proteins, thereby removing the brakes from the immune response, and inducing the patient’s immune system to kill cancer cells. Recent clinical trials of checkpoint inhibitors show success in melanoma (where it is now the clear standard of care), lung cancer, kidney, colorectal, bladder and many other tumors.

Our question is: why are some patients responsive to this therapy while most others simply ignore the therapy? If we can answer this question, we will know who should be treated, and find new ways to make the therapy effective in as many patients as possible.

Cancer Vaccines

One of the central questions in all of cancer immunology is what targets are best recognized by the immune system on tumors. We have developed two new and exciting programs to identify the most potent and precise tumor-specific targets. In the first program, we have identified proteins that are modified in cancer cells (by a process called ‘phosphorylation’) and presented on the surface of cells to T cells of the immune system. In the second program, we found that mutations that are present in each tumor also generate mutated molecules presented by tumors to T cells.

We propose to use these two classes of targets – as well as additional tumor targets that we will identify using leading-edge technologies – to create both universal and personalized vaccines to protect our bodies against cancer.

Early Cancer Immunotherapy

How does the immune system control the early stages of cancer development? Can we use the power of the immune system to prevent cancer from progressing? Several cancers including skin, breast, colon and prostate cancers currently have screening procedures, which allow for early detection of the lesion. However, in the majority of the cases the surgical removal of the cancer does not prevent its recurrence. The immune system is an ideal agent for sustained inhibition of cancer recurrence.

We are focused on understanding the immune response against early cancers, and developing therapies that will lead to long-term cures in our cancer patients.