In a small, preliminary trial, a personalized vaccine halted the spread of aggressive group of cancers among more than half of patients who received it.
HER2-positive cancers have too much of the HER2 protein on their surface, such that a cancer can grow rapidly and be more likely to spread to other areas of the body. Areas of the body known to have HER2-positive cancers are bladder, stomach, breasts, pancreas, and ovaries.
Researchers at the U.S. National Cancer Institute, used the patients’ own blood cells and reformed immune cells to fashion personalized vaccines to target HER2-positive cancers all over the body.
Study author Dr. Jay Berzofsky, chief of the vaccine branch at the Center for Cancer Research at the National Cancer Institute, said the “benefit was seen in people with cancer in the ovaries, colon, and stomach.”
The vaccine was safe in humans without any acute or delayed side effects, and clinical benefit was observed in six of 11 patients whose data were available for analysis,” he said.
According to Dr. Otis Brawley, chief medical officer of the American Cancer Society, “it’s a good sign to see an apparent benefit in a phase 1 trial.”
However, Brawley warned that the research is extremely early and too early to start celebrating, adding that more research is needed.
Berzofsky said the researchers are not really certain of the exact mechanism behind the success, but are continuing research to understand how the vaccine works.
One patient with ovarian cancer had a complete response that lasted 89 weeks, meaning the cancer can’t be found anymore with blood or imaging tests, Brawley stated.
Another patient with gastroesophageal cancer had a partial response that lasted for months, the researchers said. Partial response means that the cancer has been reduced by 50 percent or more, Brawley stated.
The researchers plan on combining the current vaccine with a drug that can help overcome a cancer’s ability to suppress the immune system in the next phase of research. The drugs are called checkpoint inhibitors.