GSE115594
ML29755 RNA-seq data
Programmed death-ligand 1 (PD-L1) expression has been associated with response to PD-1/PD-L1 inhibition, but responses are also seen in patients with PD-L1 negative tumors when assessed immunohistochemically (IHC) with various antibodies. To help elucidate these findings, we performed a positron emission tomography (PET) imaging study in human with the anti-PD-L1 antibody atezolizumab labeled with Zirconium-89 (89Zr) prior to treatment with atezolizumab to assess normal tissue distribution and evaluate tumor tracer uptake. Additionally, to help explain why some patients respond to checkpoint inhibitors despite low or absent PD-L1 expression, we compared PD-L1 expression and immune phenotypes based on both CD8 IHC and RNA sequencing of post-tracer biopsies to tumor tracer uptake (SUVmax). Overall design: In this trial, 22 patients completed the full imaging series of up to 4 PET scans and were subsequently treated with atezolizumab monotherapy until progressive disease (PD) from which 11 post-tracer tumor biopsies were available for RNA sequencing, which are available here.