Granzyme B PET Imaging as a Predictive Biomarker of Immunotherapy Response.

ABSTRACT: While cancer immunotherapy can produce dramatic responses, only a minority of patients respond to treatment. Reliable response biomarkers are needed to identify responders, and conventional imaging modalities have not proved adequate. Here, we provide a preclinical proof of concept for the use of granzyme B, a downstream effector of tumoral cytotoxic T cells, as an early biomarker for tumors responding to immunotherapy. We designed novel PET imaging probes for the murine and human granzyme B isoforms that specifically and quantitatively bind granzyme B. Immunotherapy-treated mice were imaged prior to therapy-induced tumor volume reduction. Imaging distinguished treated responders from nonresponders with excellent predictive ability. To assess the clinical value of a granzyme B imaging para

SUBMITTER: Larimer BM 

PROVIDER: S-EPMC5474226 | biostudies-literature | 2017 May

REPOSITORIES: biostudies-literature