Vaccine Doubles Life Expectancy for Brain Tumor Patients

Researchers at Duke University’s Preston Robert Tisch Brain Tumor Center chose the annual meeting of the American Society of Clinical Oncology to present the exciting results of a Phase II study involving a vaccine that induces immunity to glioblastoma multiforme (GBM) brain tumors. There is speculation that the tumor Senator Edward M. Kennedy is currently fighting is a GBM.

The vaccine works by targeting a specific protein associated with about one-half of all GBM cases. The protein, epithelial growth factor receptor variant III (EGFRvIII), is prevalent in GBMs but not in healthy tissue. Because the protein is associated only with tumors, it has been considered a likely vaccine target.

According to the findings of the Duke study, the vaccine not only kills the cancerous cells by targeting the protein, it also enhances the immune system’s response to it, preventing recurrence in patients who have already undergone the standard regimen of treatment.

Of the 23 patients in the study, all had GBMs and had been treated with standard measures at Duke University or at MD Anderson Cancer Center. Patients were given monthly injections of the vaccine along with temozolomide, a chemotherapeutic agent thought to boost immune response to the EGFRvIII protein.

Speaking as lead investigator for the study, John Sampson, MD, PhD, and Duke neurosurgeon, describes a “surprising conclusion” to the study. Since chemotherapy suppresses the body’s natural immunity, the research team expected the response to the vaccine would be less effective than it proved to be. Instead, the research proved the opposite. The immune system reacts vigorously to chemotherapy in a natural struggle to correct itself and Sampson says this is the optimum phase of treatment in which to introduce the vaccine.

Using standard treatment, patients typically see 6.4 months of survival without recurrence of GBM tumors but study participants receiving the vaccine more than doubled that time, with regrowth occurring at a median of 16.6 months.

Lifetime survival after standard treatment for GBMs averages 14.3 months but the vaccinated patients in the study survived 33.1 months, on average, with few if any side effects. Researchers report the most common complaint voiced is swelling at the site of vaccine injection.

More than 20 sites across the US are now involved with Phase III trials of the vaccine licensed by Celldex Therapeutics, which also provided the vaccine for the study. Celldex, a part of Avant Immunotherapeutics, and the National Institutes of Health funded the study, the complete details of which were presented on June 2 in Chicago.

Source: Duke University Medical Center

Filed under: Brain cancer, Cancer, Medical Research, Prevention