Treatment of solid
cancers with
chimeric antigen receptor (CAR) T cells is plagued by the lack of ideal target
antigens that are both absolutely
tumor specific and homogeneously expressed. We show that multi-
antigen prime-and-kill recognition circuits provide flexibility and precision to overcome these challenges in the context of
glioblastoma. A synNotch receptor that recognizes a specific priming
antigen, such as the heterogeneous but
tumor-specific
glioblastoma neoantigen
epidermal growth factor receptor splice variant III (
EGFRvIII) or the central nervous system (CNS) tissue-specific
antigen myelin oligodendrocyte glycoprotein (MOG), can be used to locally induce expression of a CAR. This enables thorough but controlled
tumor cell killing by targeting
antigens that are homogeneous but not absolutely
tumor specific. Moreover, synNotch-regulated CAR expression averts tonic signaling and exhaustion, maintaining a higher fraction of the T cells in a naïve/stem cell memory state. In immunodeficient mice bearing intracerebral patient-derived xenografts (PDXs) with heterogeneous expression of
EGFRvIII, a single
intravenous infusion of
EGFRvIII synNotch-CAR T cells demonstrated higher antitumor efficacy and T cell durability than conventional constitutively expressed CAR T cells, without off-
tumor killing. T cells transduced with a synNotch-CAR circuit primed by the CNS-specific
antigen MOG also exhibited precise and potent control of intracerebral PDX without evidence of priming outside of the brain. In summary, by using circuits that integrate recognition of multiple imperfect but complementary
antigens, we improve the specificity, completeness, and persistence of T cells directed against
glioblastoma, providing a general recognition strategy applicable to other solid
tumors.