Abstract IA16: Whole-body PD-L1 and PD-1 PET: First-in-human experience

Interaction between PD-L1 and PD-1 is central to the mechanism of action of, as well as prognostic and predictive to, PD-(L)1 immune checkpoint inhibition (ICI) therapy in non-small cell lung cancer (NSCLC). PD-L1 expression determined by immunohistochemistry (IHC), however, correlates moderately with patient survival and response to anti PD-(L)1 ICI. This discrepancy may be because of sampling errors from the spatial heterogeneity of tumor PD-L1 expression. Here we show that PD-L1 and PD-1 PET imaging can (1) visualize whole-body PD-(L)1 expression in patients with NSCLC, (2) specifically, revealing expression heterogeneity within tumors as well as among tumors within the same patient, and (3) demonstrate in vivo interactions between PD-L1 expression and anti PD-1 ICI, thus enhancing our understanding of tumor biology toward ICI. Citation Format: David Leung. Whole-body PD-L1 and PD-1 PET: First-in-human experience [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2019 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(3 Suppl):Abstract nr IA16.