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

Autor: Chunyan Yue, Yubo Jiang, Ping Li, Yuehua Wang, Jian Xue, Nannan Li, Da Li, Ruina Wang, Yongjun Dang, Zhiyuan Hu, Yanlian Yang, Jianming Xu
Jazyk: angličtina
Rok vydání: 2018
Předmět:
Zdroj: OncoImmunology, Vol 7, Iss 7 (2018)
Druh dokumentu: article
ISSN: 2162-402X
2162402X
DOI: 10.1080/2162402X.2018.1438111
Popis: 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-L1negative, PD-L1low, PD-L1medium and PD-L1high). 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 from1 to 70 (median 7). 74% (26/35) had PD-L1positive CTCs, and 60% (21/35) had at least one PD-L1high CTCs. The disease control (DC) rate in PD-L1high patients (48%) is much higher than the others (14%). The group with at least 20% abundance of PD-L1high CTCs had even higher DC rate of 64% (9/14), with only 14% DC rate for the rest (3/21). We also observed that the count changes of total CTC, PD-L1postive CTC and PD-L1high CTC correlate quite well with disease outcome (P
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