Goggi, J.L., Hartimath, S.V., Hwang, Y. et al. Examining Immunotherapy Response Using Multiple Radiotracers. Mol Imaging Biol (2020). https://doi.org/10.1007/s11307-020-01477-w
Purpose: Cancer immunotherapy has shown huge potential in the fight against cancer, but only a small proportion of patients respond successfully to treatment. Non-invasive methods to stratify responders from non-responders are critically important as immune therapies are often associated with immune-related side effects. Currently, conventional clinical imaging modalities do not provide a useful measure of immune therapy efficacy. Sensitive imaging biomarkers that provide information about the tumoural microenvironment may provide useful insights allowing for improved patient management.
Procedures: We have assessed the ability of a number of radiopharmaceuticals to noninvasively
measure different aspects of the tumour microenvironment and correlated tumour uptake to immune therapy response in a syngeneic model of colon cancer, CT26-WT. Four radiopharmaceuticals, [18F]FDG (a glucose analogue), [18F]FEPPA (a marker for macrophage activation), [18F]FB-IL2 (a marker for CD25+ cells) and [68Ga] Ga-mNOTA-GZP (a marker for granzyme B, the serine protease downstream effector of cytotoxic T cells), were assessed as potential biomarkers to help stratify response to PD-1 monotherapy or combined anti-PD1 and CLTA4 therapy in vivo correlating tumour uptake with changes in tumour-associated immune cell populations.
This work was supported by Singapore’s Health and Biomedical Sciences (HBMS) Industry Alignment Fund Pre-Positioning (IAF-PP) grant H18/01/a0/018, administered by the Agency for Science,
Technology and Research (A*STAR).
This is a pre-print of an article published in Molecular Imaging And Biology. The final authenticated version is available online at: https://doi.org/10.1007/s11307-020-01477-w