Combination immunotherapy shows promising preclinical results in glioblastoma

Researchers have demonstrated that an immunotherapy combination consisting of a dendritic cell vaccine and PD-1 blockade generates a more effective immune response against glioblastomas than the use of either therapy alone.

The study, published recently in JCI Insight, was carried out by Robert Prins and colleagues at the University of California Los Angeles (UCLA) Jonsson Comprehensive Cancer Center (CA, USA).  The team demonstrated that combining a dendritic cell vaccine with a PD-1 blockade increased long-term survival in glioma-tumor bearing mice.

Lead author Prins commented: “These findings are the first that specifically outline the mechanism by which an effective immune response can be seen in tumors located in the brain. We discovered that effective antitumor immunity to glioblastoma must have a significant infiltration of killer T cells and a blockade of the important checkpoint axes that make these killer T cells dysfunctional within the tumor.”

The increased efficacy of this combination therapy can be attributed to both the dendritic cells, which  allow for the infiltration of T cells into the glioblastoma,  and the PD-1 antibody blockade, which modulates the tumor’s immune resistance; overall promoting an antitumoral immune response.

It is hoped that this preliminary study will help further the understanding of the mechanisms by which dendritic cell vaccines induce tumo-r specific immune responses and, therefore, aid researchers in their bid to translate their findings into a clinical setting for advanced glioblastomas patients.

Source: Antonios JP, Soto H, Prins RM et al. PD-1 blockade enhances the vaccination-induced immune response in glioma. JCI Insight. DOI: 10.1172/jci.insight.87059 (2016); Jonsson Comprehensive Cancer Center press release