Brain cancer vaccine nearly doubled patients survival in mid-stage trial
A team of researchers from Duke University Medical Center and the University of Texas M.D. Anderson Cancer Center has achieved very impressive results in a mid-stage clinical study for an experimental therapeutic vaccine developed by Celldex Therapeutics for glioblastoma, the brain cancer.
The group of scientists reported that the glioblastoma patients who received the vaccine, named CDX-110, survived nearly twice as long as patients who received standard therapies. This study involved 35 patients who were newly diagnosed with the brain cancer and received surgery, radiation and the chemotherapy drug temozolomide. One arm of 18 patients were also treated with injections of the new vaccine one month after completing radiation and continued to receive the vaccine as long as it appeared to be effective.
The results showed the median survival time for those in the vaccine group was 26 months, compared with 15 months for the control group. Progression-free survival was 14.2 months in the vaccine group, compared to 6.3 months in the control group. Impressively, some of the patients in the vaccine group were still alive after five years of treatment.
Dr. John Sampson from Duke University Medical Center said “It does appear to help patients live much longer than we could have expected,” he added, the survivors were “pretty unusual” given the lethal cancer they are fighting.
The vaccine appeared to stimulate an immune response in approximately half of the patients who received it, suggesting such responses were linked to increased survival time, “but the numbers are so small that we cannot conclude this with any degree of certainty,” Dr. Amy Heimberger, co-lead investigator from M.D. Anderson, said in a news release from Duke.
The vaccine targets the EGFRvIII variant, which allows cancer cells to multiply out of control, seeding new tumors throughout the brain, “Our study showed that the vaccine eliminated all of the cancer cells carrying this marker in all but one of our study participants,” said Darell D. Bigner, director of the Preston Robert Tisch Brain Tumor Center.
Glioblastoma is the most common and most aggressive type of primary brain tumor in humans. The worst form of brain cancer typically kills half its victims within a year and patients rarely survive more than three years. About 10,000 new cases of glioblastoma appear in the United States every year.
Celldex Therapeutics developed the vaccine CDX-110, and collaborated with Pfizer previously for the vaccine development. However Pfizer pulled out of the strategic partnership because the “program is no longer a strategic priority of Pfizer”. Celldex said it plans to develop the brain cancer vaccine on its own.
ImmunoCellular Therapeutic also developed an experimental dendritic cell based brain cancer vaccine, which showed some promising results in an early-stage brain cancer trial.