Vaccine may double survival in patients with aggressive brain tumour
A small early-stage US trial has produced promising results for a new cancer vaccine, which may double survival in patients with the aggressive brain tumour glioblastoma multiforme (GBM).
The vaccine targets a protein found on the tumours of around half of all people with GBM, called epithelial growth factor receptor variant III (EGFRvIII).
The new vaccine works by enhancing the body's immune response against cells covered with this protein, so preventing re-growth of the tumour following treatment.
The trial involved just 23 patients who had undergone standard anti-cancer-therapy, and who then received monthly doses of the vaccine as well as a chemotherapy drug called temozolomide.
Temozolomide was developed in the late 90s by Cancer Research UK scientists and has provided substantial benefits for people with GBM.
Researchers found that patients survived without re-growth of their tumours for a median of 16.6 months - more than double the usual progression-free survival for GBM patients.
Patients in the trial also lived for an average of 33.1 months, which is significantly longer than the typical 14.3-month survival in GBM patients.
Dr John Sampson, the Duke University neurosurgeon who presented the findings at an American Society of Clinical Oncology meeting in Chicago, commented: "This vaccine represents a very promising therapy for a cancer that comes out of the blue and robs people of something most of us take for granted - time.
"We're more than doubling survival time in this group, and we have some patients who are four, five or six years out from diagnosis, which is virtually unheard of," he continued.
"The possibility of doubling expected survival - with few if any side-effects - would represent a big step and a lot of hope for this group of patients."
Dr Sampson noted that the effectiveness of the combination of temozolomide - which works by suppressing the immune system - and the vaccine - which works by boosting the immune system - was something of a surprise.
"It stands to reason that chemotherapy, which suppresses the body's immune system, would make the vaccine less effective," he explained. "What we found was that the opposite is true. While the body is recovering from chemotherapy, immune response is actually stronger as the immune system overcompensates in order to right itself. It's the perfect time to introduce a vaccine."
Following the promising results from the phase II trial, a larger phase III trial is now underway in the US.
Henry Scowcroft, Cancer Research UK information manager, said: "Although this trial only involved 23 patients, the initial results appear very encouraging.
"Since temozolomide - a drug developed by Cancer Research UK - was licensed in 1999, it has provided huge benefits for many people with glioblastoma. So developing a way to extend these survival times further would be even better news.
"But these findings need to be confirmed, and built upon, in the next phase of development. We're eagerly awaiting the results of the US-based trials that the team plan to carry out."