Despite promising results in a phase I trial, the vaccine ICT-107 failed to significantly prolong overall survival in patients with glioblastoma multiforme in a follow-up phase II trial.
Glioblastoma multiforme (GBM) is an aggressive type of type of brain tumor that occurs mainly in adults. Treatment often involves surgery followed by radiation and chemotherapy. With standard care, the median length of survival is 15 months after diagnosis and only 10 percent of patients survive more than five years. Because survival tends to be poor even with aggressive treatment, researchers continue to evaluate new ways of treating this disease.
ICT-107 is a vaccine designed to alert the immune system to the existence of cancer cells and activate a tumor-killing response. It targets six antigens involved in the development of glioblastoma cells.
The vaccine is based on dendritic cells, which are antigen-presenting cells that are responsible for helping the immune system recognize “invaders.” They are derived from white blood cells taken from each participating patient in a routine blood draw. In the laboratory, the cells are cultured with synthetic peptides of the six antigens. This process “trains” the dendritic cells to recognize the tumor antigens as targets. When the “new” dendritic cells in the vaccine are injected under the patient’s skin, they are intended to seek and destroy lingering tumor cells. The vaccine is administered three times at two-week intervals after standard radiation and chemotherapy.
The current phase 2 trial is a randomized, double-blind, placebo-controlled study that included 124 patients with newly diagnosed GBM who were randomly assigned to receive the vaccine or placebo. The study was designed to evaluate the safety and efficacy of ICT-107 in newly diagnosed patients. All patients had undergone surgical resection and chemo-radiation. All patients in the study received Temodar® (temozolamide), the current standard of care, and 81 patients received ICT-107.
The regimen consisted of 4 induction doses of ICT-107 after chemo-radiation and then maintenance doses until disease progression. The primary endpoint of trial was overall survival, and secondary endpoints included progression-free survival and safety and immune response.
The results indicated that patients who received ICT-107 survived only about 2 to 3 months longer than those who received placebo—and the difference was not considered statistically significant. In contrast, progression-free survival was improved with the vaccine. Patients receiving the vaccine had a median progression-free survival time that was 2 months longer than those in the placebo group.
These results come after a phase I trial indicated that the vaccine may be able to dramatically extend survival. Although the current trial missed its primary endpoint, the researchers note that the improvements in progression-free survival are promising. Patients who have not yet progressed will continue until an appropriate termination point can be determined and the company will continue to analyze the data from the study.
 ImmunoCellular Therapeutics Phase II Study Demonstrates That Glioblastoma Patients Live Longer Without Disease Progression When Treated With ICT-107:
Study Achieves Progression-free Survival Endpoint with Statistical Significance; Primary Endpoint of Overall Survival Not Statistically Significant. ImmunoCellular News Release. Available at: http://investors.imuc.com/releasedetail.cfm?ReleaseID=813442
 Phuphanich S, Wheeler C, Rudnick J, et al. Long-term remission over 5 years in patients with newly diagnosed glioblastoma (GBM) treated with ICT-107 vaccine: A follow-up study. Abstracts from the 4th Quadrennial Meeting of the World Federation of Neuro-Oncology held in conjunction with the 18th Annual Meeting of the Society for Neuro-Oncology, November 21-24, 2013, San Francisco, California. Neuro Oncol (2013) 15 (suppl 3): iii68-iii74. Abstract#: IT-015