A multifunctional role for adjuvant anti-4-1BB therapy in augmenting antitumor response by chimeric antigen receptor T cells

Abstract

Adoptive immunotherapy utilizing chimeric antigen receptor (CAR) T cells has demonstrated high success rates in hematologic cancers, but results against solidmalignancies have been limited to date, due in part to the immunosuppressive tumor microenvironment. Activation of the 4-1BB (CD137) pathway using an agonistic α-4-1BB antibody is known to provide strong costimulatory signals for augmenting and diversifying T-cell responses.Wetherefore hypothesized that a combination of α-4-1BB and CAR T-cell therapy would result in improved antitumor responses. Using a human-Her2 self-antigen mouse model, we report here that α-4- 1BB significantly enhanced CAR T-cell efficacy directed against the Her2 ..