Cancer immunotherapy holds great promise for the treatment of cancer and has generated tremendous enthusiasm.  However, these treatments still fail in the majority of patients, are associated with severe side effects, and are costly.  We are developing novel PET imaging agents to rapidly distinguish between responding and non-responding patients with the goal of improving treatment decisions and enabling research into mechanisms of immune-therapeutic success or failure.

 

Granzyme B PET Imaging. Granzyme B is a serine protease released by active CD8 T cells that is one of the primary mediators of the tumoricidal immune response.  We have developed a specific peptide-based imaging agent (GZP) for use in immunocompetent cancer models and have demonstrated that GZP PET imaging can predict response to checkpoint inhibitors prior to changes in tumor size.  We continue to aggressively work in this area to better define the clinical and research value of GZP PET imaging.

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  • 68Ga-GZP PET imaging in CT-26 syngeneic tumor model treated with anti-PD-1 and anti-CTLA4 checkpoint inhibitors distinguishes between responders and non-responders prior to size changes

 

CD3 Imaging. CD3 is a universal marker of T cells.  CD3 PET imaging serves a complimentary role to GZP PET imaging to dynamically track T-cell infiltration into tumors

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  • 89Zr-DFO-anti-CD3 imaging of CT-26 syngeneic mouse tumor xenografts treated with CTLA-4 monotherapy demonstrates increased uptake in responding tumors relative to non-responding tumors, which could be used for therapeutic guidance