Ovarian cancer begins in the ovaries, the female reproductive organs that produce eggs and estrogen. According to the American Cancer Society (ACS), it’s the fifth-leading cause of cancer death in women. But it can impact anyone with ovaries.

Ovarian cancer is usually treated with surgery and chemotherapy. If you have advanced ovarian cancer, your doctors may recommend immunotherapy.

In this article, you will learn more about immunotherapy for ovarian cancers, whether it is effective, and how it may be used as part of your cancer treatment plan.

What is immunotherapy?

Your immune system protects you from viruses, bacteria, and other infections.

“Your immune system would be able to protect you from cancer. Cancer cells are still a part of you, unlike a virus, which your immune system recognizes as a foreign invader. The immune system doesn’t respond to cancer because of this.”

Cancer treatment that helps your immune system learn how to identify and respond to cancer cells is called immunotherapy.

There are several types of immunotherapy.

  • Immune checkpoint inhibitors: These are drugs that help the immune system better detect cancer cells.
  • Monoclonal antibodies: These are manufactured antibodies that can target specific aspects of cancer cells.
  • Chimeric antigen receptor T-cell therapy: CAR T-cell therapy trains certain immune cells, called T cells, to find and destroy cancer cells.
  • Cytokines: These are proteins that can stimulate the immune system.
  • Immunomodulators: These are drugs that help boost the immune system.
  • Cancer vaccines: These are vaccines that trigger the immune system to respond to cancer.
  • Oncolytic viruses: These are modified viruses that are designed to infect and kill cancer cells.

Immunotherapy for ovarian cancer

Immunotherapy isn’t a common treatment for ovarian cancer. In fact, a 2020 review of studies found that, when it comes to treating ovarian cancer, most types of immunotherapy are still being tested in clinical trials.

If you have advanced ovarian cancers, immunotherapy could be an option. Your doctor may have to help you enroll in a trial.

Additionally, according to the ACS, the immune checkpoint inhibitor pembrolizumab (Keytruda) may be used for ovarian cancer in specific situations. Examples of such situations include:

  • When the cancer is advanced.
  • When the cancer has certain levels of genetic changes.
  • When the cancer has started growing again after treatment with other drugs.

Pembrolizumab is given as an intravenous (IV) infusion. According to the drug label, you may receive it every 3 weeks or every 6 weeks.

What are immune checkpoint inhibitors?

Immune checkpoints are part of your immune system. Their function is to help prevent your immune system from responding too strongly, which would damage healthy cells.

T cells are important in the immune system. T cells have an immune checkpoint. The signal to turn off the T cell is sent when thisProtein is binding to a correspondingProtein on certain cancer cells.

T cells can no longer attack cancer cells.

Immune checkpoint inhibitors work by disrupting the process. The T cell is free to attack the cancer cell if the signal that switches off the T cells is prevented.

Several clinical trials in recent years have explored the use of ICIs for ovarian cancers. The results of been promising, but mixed. ICIs are rarely used as the sole treatment for ovarian cancer.

The ICIs are used in the treatment of many different types of cancer.

Is immunotherapy effective for ovarian cancer?

Immune checkpoint inhibitors are sometimes used for ovarian cancer. These drugs are used together.

A 2021 review analyzed 15 clinical trials of ICIs for ovarian cancer. When these drugs were used alone, the overall response rate was only 9%. A higher response rate (36%) was seen when they were combined with chemotherapy.

When caught early, before it spreads, the outlook for ovarian cancers is actually quite good. But the outlook for advanced ovarian cancer is not as favorable, with a 5-year relative survival rate of 30.8%.

According to the SEER program of the National Cancer Institute, around 80% of people with ovarian cancer aren’t diagnosed until their cancer has already spread beyond the ovaries.

Combination therapy

“Clinical trials are focusing on using ICIs in combination with other types of cancer drugs since treatment with ICIs alone doesn’t appear to be effective. Some of the results are promising.”

For example, a 2020 clinical trial involving 40 people with recurrent ovarian cancer looked at treatment with pembrolizumab in combination with a targeted therapy drug and a chemotherapy drug.

The therapy was beneficial to 95 percent of participants. 25% of participants had a treatment response that lasted longer than a year.

Using different combinations of ICIs may also be helpful. A 2020 clinical trial found that using nivolumab (Opdivo) plus ipilimumab (Yervoy) led to a better treatment response rate. It also slightly increased progression-free survival rates.

Side effects of immunotherapy for ovarian cancer

There are some side effects of immunotherapy for ovarian cancer. These may include:

More serious side effects are rare. These can include a type of allergic reaction, called an infusion reaction, while receiving your treatment infusion. Autoimmune reactions, when your immune system mistakenly attacks healthy cells, can also occur.

Your care team will inform you of the types of side effects that you may experience before you start your treatment. If you begin to experience any side effects from your treatment, be sure to reach out to them.

Immunotherapy clinical trials

Ovarian cancer is still being treated with immunotherapy. Doctors and scientists are working hard to find newer, more effective ways to use immunotherapy.

This is accomplished through clinical trials. If you have ovarian cancer and are interested in immunotherapy, talk with your care team to see if there are any trials that you’d qualify for.

You can look through the list of ovarian cancer clinical trials supported by the National Cancer Institute, many of which involve immunotherapy. Also, ClinicalTrials.gov is a searchable database of privately and publicly funded clinical trials worldwide.

Other ovarian cancer treatments

As we mentioned earlier, there are other more common treatments for ovarian cancer. These include:

  • Surgery: This involves a surgical procedure to remove the cancer from the body.
  • Chemotherapy: Chemotherapy uses drugs that can kill cancer cells or slow down their growth.
  • Targeted therapy: This treatment uses drugs that target specific aspects of cancer cells.

There are many factors that affect the type of treatment recommended for ovarian cancer. Some of these include.

  • the specific type of ovarian cancer that you have
  • the extent (stage) of the cancer
  • The characteristics of the cancer are determined by factors such as genes and biomarkers.
  • Which other types of treatments have been used.
  • Your age and health.
  • Your choice.


A type of cancer treatment called immunotherapy helps your immune system fight the disease. It is not a common treatment for ovarian cancer.

In some cases, your doctor may suggest immunotherapy as a part of your treatment. This will be done in a clinical trial, either alone or in combination with other cancer drugs.

If you are interested in immunotherapy for ovarian cancer, you should talk to your care team. You may be eligible for a trial that is currently underway.