Common virus may serve as target for deadly brain tumour vaccine

Washington, May 18 : Researchers at the Duke's Preston Robert Tisch Brain Tumor Center have found that by targeting a common virus, doctors may be able to prolong the lives of patients suffering from the most prevalent and deadly type of brain tumour.

The virus is a type of commonly found herpes virus called human cytomegalovirus (CMV), which is normally dormant showing very few clinical symptoms and usually remains undetected in most people.

But, over 80 percent of patients newly diagnosed with the brain cancer glioblastoma multiforme (GBM) showed detectable CMV in their blood as well as in their tumors, which made the Duke team to look for ways to target brain tumors by going after this particular virus.

"Previous work has demonstrated the activation of this virus in patients with GBMs, so we took it one step further and tested a vaccine, in a small group of patients, that seems to show some efficacy in stalling the recurrence of these deadly tumors. We knew there was a connection between this virus and the brain cancer, and we were hoping to take advantage of that connection to treat one by treating the other," said Duane Mitchell, M.D., Ph.D., a Duke researcher and lead investigator on the study.

The scientists enrolled 21 patients for the trial, and found that the vaccine had delayed the re-growth of tumors from a usual six to seven months after surgery to more than 12 months. In fact, previous results also displayed a lengthened overall survival among GBM patients, from about 14 months with standard treatment to greater than 20 months.

"These results are preliminary and we're comparing survival data to what we know about average survival with standard treatment for this patient population. But we are encouraged that we may have found a very plausible target for a new and complementary treatment for this deadly disease," said Mitchell.

The vaccine was administered to patients in conjunction with the chemotherapy drug temozolomide.

"We believe that use of temozolomide can further stimulate immune response to the vaccine because it initially depletes the infection-fighting immune cells. We find that their function is re-invigorated as they build back up during recovery. It's the perfect time to introduce a vaccine, which works by stimulating an immune response," said Mitchell.

The researchers presented their findings in a poster session at the annual American Society of Clinical Oncology meeting in Chicago.

ANI