For ovarian cancer, immunotherapy on its own has not proven to be a very beneficial form of treatment.
Dr. Emese Zsiros, gynecologic oncologist of the Rosewell Park Comprehensive Cancer Center, says that we are behind in terms of immunotherapy as a treatment option for ovarian cancer compared to other cancer types. “Immunotherapy really started changing patient lives about five years ago,” she says.Read More
“We believe that we need to convert a patient’s tumor tissue to a different type of tumor tissue that has a lot more immune cells infiltrated thus having a better chance to respond to these medications,” says Zsiros.
Instead of using immunotherapy as a single agent treatment, to which ovarian cancer doesn’t respond well, the idea is to combine medications and the immune system to fight cancer by reducing blood flow to the tumors with drugs.
“We understand that the anti-angiogenic treatment or medications that help to normalize the tumor vessels could also lead to better immune cell infiltration,” says Zsiros.
She says scientists have engineered a clinical trial for combination therapy that puts together immunotherapy (pembrolizumab) and an anti-angiogenic agent (bevacizumab, also known as Avastin) and they also added an immunomodulator (cyclophosphamide). The regiment is inexpensive and non-toxic and has been shown to favorably modulate the system.
In the clinical trial, the results found that 40 percent of women with recurrent ovarian cancer included in the trial who were not responding to other treatment responded to the combination. They also found that 55 percent of the women included in the treatment saw their cancer become stable with the immunotherapy combination. So in total, of the women in the clinical trial who had no other treatment options, 95 percent were responsive to the therapies.
“We realized the sooner we treat patients with immunotherapy, the better they are doing with that,” Zsiros says.
The women in the trial were able to handle the treatment very well, according to Zsiros. They were active and traveling and maintaining a good quality of life during the clinical trial.
So with that trial, Zsiros says that two things were proven. The first being that women were responsive to the multi-agent immunotherapy and the second being that they maintained a good quality of life while undergoing the treatment.
In addition to Avastin, there are other immunotherapy options to treat ovarian cancer. They include targeted antibodies, adoptive cell therapy, cancer vaccines, immunomodulators and oncolytic virus therapy. These immunotherapy options work in different ways.
According to the Cancer Research Institute:
- Targeted antibodies are proteins that can be made to target markers on cancer cells to put a stop to cancerous activity such as growth.
- Adoptive cell therapy helps grow or alter a woman’s own immune cells and then reintroduces those cells to the woman.
- Cancer vaccines draw out an immune system response to specific tumor or tumor-associated antigens which causes the immune system to attack the cancer cells with those antigens.
- Immunomodulators take control the start and stop functions of the immune system, regulating how it responds with immune system responses to cancer.
- Oncolytic virus therapy uses “modified viruses” that infect the tumor cells and causes them to kill themselves.
The Cancer Research Institute offers resources for patients looking to get involved with immunotherapy clinical trials and other clinical trials on their website including an online search option, email address and phone line. To check out their page on clinical trials, click here.