Overcoming Hurdles in Immunotherapy for Ovarian Cancer

Right now, there are some hurdles blocking the success of immunotherapy treatments for ovarian cancer. That’s why the best way to explore the prospect of immunotherapy when investigating treatment options for ovarian cancer is to do so carefully and thoroughly.

“Ask questions, do your research and really ask about the options available and importantly try and get a second opinion,” says Dr. Kunle Odunsi, a gynecologic oncologist  and director of the University of Chicago Medicine Comprehensive Cancer Center.

To start, it is important to understand exactly what immunotherapy is.

According to Dr. Odunsi, “immunotherapy is the ability to use the immune system to find and destroy cancer.”

While immunotherapy only has one approved treatment for ovarian cancer, as opposed to some other types of cancers, it has been shown that the body’s immune system can identify ovarian cancer.

“In the case of ovarian cancer, it became very clear that the immune system can recognize ovarian cancer,” says Dr. Odunsi. “In fact, some work that was done by our group and others more than 15 years ago, clearly showed that.”

In spite of the immune system’s ability to recognize ovarian cancer though, the success rate of immunotherapy in treating ovarian cancer has been modest.

“There are a number of factors that separate ovarian cancer from other cancer types,” explains Dr. Odunsi. “Ovarian cancer is a disease that occurs in the abdominal cavity. So, first of all, by the time we find it, it’s spread, to different areas of the abdomen, sometimes in the bowel, on the diaphragm.”

The environment of ovarian cancer makes it more difficult for the immune system to fight the cancer than another environment would.

“It turns out that the ovarian cancer environment is what we call an immunosuppressant environment,” says Dr. Odunsi. “In other words, if good immune cells arrive at the ovarian environment trying to do their job, there are many barriers they need to overcome.

Ovaries have unique characteristics that make it difficult for the body’s immune system to fight the cancer.”

According to Dr. Odunsi, some of those barriers have actually been identified already by researchers and that now, because we know what the barriers are, the question becomes how to manipulate the environment itself to make that environment more conducive to immunotherapy.

Researchers are also focused on the driver behind the immune response to cancer, Dr. Odunsi says.

“The most important driver in having an immune response to cancer is a group of cells called killer cells or T cells,” says Dr. Odunsi. “They have the ability to kill cancer cells. If they are handicapped they are unable to function.”

Because T cells are so important to help the body fight cancer, researchers are focused on figuring out how to make sure those cells are able to complete their job.

“One question that researchers are focused on right now is discovering how to drive enough T cells into the ovarian environment and once they get to the environment, how do you ensure that those cells survive and are capable of doing their job—killing cancer,” says Dr. Odunsi.

These are some of the questions, Dr. Odunsi says that he and other doctors are currently researching to help advance immunotherapy for ovarian cancer.

Currently, according to the Cancer Research Institute, the only approved immunotherapy treatment for ovarian cancer is bevacizumab—also known as Avastin, which is a drug that blocks blood vessel growth on tumors.

There is hope for immunotherapy options for ovarian cancer to expand, with organizations like the Cancer Research Institute dedicating their resources to help discover and develop immunotherapy treatments for ovarian cancer, which they have been doing since 1985.