At the CRI Virtual Immunotherapy Patient Summit in October, patients and caregivers were eager to further their understanding of immunotherapy for ovarian cancer.
Kunle Odunsi, M.D., Ph.D., Chair of the Department of Gynecologic Oncology and the Executive Director of the Center for Immunotherapy at Roswell Park Comprehensive Cancer Center, led the ovarian cancer and immunotherapy breakout session.
We followed up with Dr. Odunsi after the event to discuss several more questions from attendees.
Why is ovarian cancer so difficult to treat with immunotherapy?
Dr. Odunsi: Ovarian cancer has developed several mechanisms by which it escapes from immune attack. The presence of immune cells that will fight off the cancer is not sufficient for immunotherapy to be effective in ovarian cancer. We also need to combat many of those mechanisms by which ovarian cancer suppresses anti-tumor immune response.
Given ovarian cancer is quite rare, what immunotherapy treatments are proving effective? When are they most used?
Dr. Odunsi: At the present time, there are no FDA-approved immunotherapy treatments for ovarian cancer. However, there are several ongoing clinical trials that are beginning to show that combinations of different immunotherapies, or immunotherapy with standard therapies, could be beneficial in ovarian cancer patients. Our real challenge is to identify biomarkers that will allow us to identify those patients that are mostly likely to derive benefits. This is an active area of investigation in ovarian cancer because it is clear to us that some patients can definitely derive benefit.
All the protocols for immunotherapy I have read exclude autoimmune disease. Does this mean that I will be excluded? Is there a way around this?
Dr. Odunsi: The reason for excluding autoimmune disease is that immunotherapy is turning the immune system against cancer cells and sometimes there could be collateral effect on normal tissues that could lead to autoimmune disease. For example, immune checkpoint inhibitors have been shown to cause some forms of autoimmune disease affecting the thyroid gland, the liver, the pancreas, the adrenal gland, and so on. This is why most protocols exclude autoimmune disease and to be put on to the protocol to discuss the nature and severity of your pre-existing autoimmune disease before going on any immunotherapy clinical trial.
How effective is the screening to determine whether a trial is expected to be effective to my particular type of ovarian cancer?
Dr. Odunsi: This is the whole area of biomarker development in order to identify patients who are more likely to derive benefit. There is ongoing work in this area but if I can illustrate with an example, patients whose tumors have evidence of microsatellite instability tend to benefit more from immune checkpoint inhibitors. Because the evidence for this was very strong, the FDA approved the use of immune checkpoint inhibitors for any cancer type where there is evidence of microsatellite instability. It is my hope that in the very near future we will be able to identify effective biomarkers for all types of ovarian cancers.
Is immunotherapy ever recommended as maintenance for "cured" ovarian cancer after chemotherapy?
Dr. Odunsi: As I explained during my presentation, there are different types of immunotherapies. At the present time, there is no approved type of immunotherapy for maintenance after remission in ovarian cancer. However, there are ongoing clinical trials testing whether the use of cancer vaccines can help extend remission rates in patients who have responded very well to their therapies. Any approach for maintenance has to be associated with minimal side effects and cancer vaccines could be a potential approach that leads to benefit but with reduced risk of side effects. There are also ongoing clinical trials testing whether immune checkpoint inhibitors can be used in the maintenance setting. The results of all of these approaches are still being awaited with great interest.
learn more about immunotherapy for ovarian cancer