Dynamic change of PD-L1 expression on circulating tumor cells in advanced solid tumor patients undergoing PD-1 blockade therapy.

ABSTRACT: Background: Tumor PD-L1 levels have predictive value in PD-1/PD-L1 checkpoint blockade therapies, yet biopsies can only provide baseline information. Whether PD-L1 expression on circulating tumor cells (CTCs) could serve as an alternative biomarker is of great interest. Design: We established an immunofluorescence assay for semi-quantitative assessment of the PD-L1 expression levels on CTCs with four categories (PD-L1^negative, PD-L1^low, PD-L1^medium and PD-L1^high). 35 patients with different advanced gastrointestinal tumors were enrolled in a phase 1 trial of a PD-1 inhibitor, IBI308. The CTC numeration and the PD-L1 expression levels were analyzed. Results: Prior the treatment of IBI308, 97% (34/35) patients had CTCs, ranging

SUBMITTER: Yue C 

PROVIDER: S-EPMC5993493 | biostudies-literature | 2018

REPOSITORIES: biostudies-literature