Personalized vaccines may hold promise for ovarian cancer treatment

Ovarian cancer is one of the deadliest types of cancers because doctors lack effective early-diagnostic tools for the disease as well as treatment for the cancer once it progresses. But researchers at the University of Connecticut say the key to overcoming those hurdles may lie in personalized vaccines that rig an individual’s immune system to detect then destroy invading cancer cells.

Based on a previous animal study involving skin cancer, the vaccines may help the immune system identify dangerous changes in protein sequences that would compromise an individual’s immunity. These sequences, called epitopes, are what the immune system sees when it looks at a cell. But detecting cancer cells’ epitopes can be tricky, as those epitopes are similar to those of healthy cells.

“We want to break the immune system’s ignorance,” principal investigator Dr. Pramod Srivastava, director of the Carole and Ray Neag Comprehensive Cancer Center at UConn Health, said in a news release.

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Traditional vaccines for viruses work by helping immune cells bind to compromising epitopes, but that doesn’t work for cancers. By studying differences between mice’s cancer epitopes and their normal epitopes and inoculating the mice with vaccines made with the cancer epitopes that differed most from the healthy tissue, study authors observed that the mice were resistant to skin cancer. Researchers think the same rule could be applied to other cancers, like ovarian.

In the fall, pending approval by the Food and Drug Administration, researchers at UConn expect to begin a clinical trial that sequences DNA from the tumors of 15 to 20 women with ovarian cancer, and then using that data to create personalized vaccines for the women. According to the release, if the vaccines prove to be safe, researchers will then conduct a Phase II clinical trial to analyze whether they help prolong patients’ lives.

“This has the potential to dramatically change how we treat cancer,” Srivastava said in the newsrelease. “This research will serve as the basis for the first ever genomics-driven personalized medicine clinical trial in immunotherapy of ovarian cancer.”