RT Journal Article SR Electronic T1 Enhancement of anti-PD-L1 antibody plus anlotinib efficacy due to downregulation of PD-L1 in the micro-conduit endothelium within the tumor: a randomized double-blind trial JF Cancer Biology & Medicine JO Cancer Biology & Medicine FD China Anti-Cancer Association SP 20230423 DO 10.20892/j.issn.2095-3941.2023.0423 A1 Zhang, Cuicui A1 Chu, Tianqing A1 Wang, Qiming A1 Cheng, Ying A1 Zhang, Yongxiang A1 Wang, Ruili A1 Ma, Leilei A1 Qian, Chaonan A1 Han, Baohui A1 Li, Kai YR 2024 UL http://www.cancerbiomed.org/content/early/2024/05/29/j.issn.2095-3941.2023.0423.abstract AB Objective: The possible enhancing effect of anlotinib on programmed death receptor ligand (PD-L1) antibody and the efficacy-predicting power of PD-L1 in micro-conduit endothelium, including lymphatic endothelial cells (LECs) and blood endothelial cells (BECs), were determined to identify patients who would benefit from this treatment.Methods: PD-L1 positivity in LECs, BECs, and tumor cells (TCs) was assessed using paraffin sections with multicolor immunofluorescence in an investigator’s brochure clinical trial of TQB2450 (PD-L1 antibody) alone or in combination with anlotinib in patients with non-small cell lung cancer. Progression-free survival (PFS) with different levels of PD-L1 expression was compared between the two groups.Results: Among 75 patients, the median PFS (mPFS) was longer in patients who received TQB2450 with anlotinib [10 and 12 mg (161 and 194 days, respectively)] than patients receiving TQB2450 alone (61 days) [hazard ratio (HR)10 mg = 0.390 (95% confidence interval {CI}, 0.201–0.756), P = 0.005; HR12 mg = 0.397 (0.208–0.756), P = 0.005]. The results were similar among 58 patients with high PD-L1 expression in LECs and TCs [159 and 209 vs. 82 days, HR10 mg = 0.445 (0.210–0.939), P = 0.034; HR12 mg = 0.369 (0.174–0.784), P = 0.009], and 53 patients with high PD-L1 expression in BECs and TCs [161 and 209 vs. 41 days, HR10 mg = 0.340 (0.156–0.742), P = 0.007; HR12 mg = 0.340 (0.159–0.727), P = 0.005]. No differences were detected in the mPFS between the TQB2450 and combination therapy groups in 13 low/no LEC-expressing and 18 low/no BEC-expressing PD-L1 cases.Conclusions: Mono-immunotherapy is not effective in patients with high PD-L1 expression in LECs and/or BECs. Anlotinib may increase efficacy by downregulating PD-L1 expression in LECs and/or BECs, which is presumed to be a feasible marker for screening the optimal immune patient population undergoing anti-angiogenic therapy.The authors confirm that data supporting the findings of this study are available in the article.