Heterogeneity in PD-L1 expression between primary and metastatic lymph nodes: a predictor of EGFR-TKI therapy response in non-small cell lung cancer.

There is inconclusive evidence to suggest that the expression of programmed cell death ligand 1 (PD-L1) is a putative predictor of response to EGFR-TKI therapy in advanced EGFR-mutant non-small cell lung cancer (NSCLC). We evaluated the heterogeneity in PD-L1 expression in the primary lung site and metastatic lymph nodes to analyze the association between PD-L1 expression and response for patients treated with EGFR-TKI. This study reviewed 184 advanced NSCLC patients with EGFR mutations who received first-generation EGFR-TKI as first-line treatment from 2020 to 2021 at Shanghai Chest Hospital. The patients were divided into the primary lung site group (n = 100) and the metastatic lymph nodes group (n = 84) according to the biopsy site. The patients in each group were divided into TPS < 1%, TPS 1-49%, and TPS ≥ 50% groups according to PD-L1 expression. The median PFS was 7 (95% CI: 5.7-8.3) months, and the median OS was 26 (95% CI: 23.5-28.5) months for all patients. No correlation existed between PFS or OS and PD-L1 expression. The median PFS in the primary lung site group was 11 months (95% CI: 9.6-12.4) in the TPS < 1% group, 8 months (95% CI: 6.6-9.4) in TPS 1-49% group, and 4 months (95% CI: 3.2-4.8) in TPS ≥ 50% group, with statistically significant differences (p = 0.000). The median OS of the TPS < 1% group and TPS ≥ 50% group showed a statistically significant difference (p = 0.008) in the primary lung site group. In contrast, PD-L1 expression in the lymph nodes of EGFR-mutant patients was unrelated to PFS or OS after EGFR-TKI therapy. PD-L1 expression from the primary lung site might predict clinical benefit from EGFR-TKI, whereas PD-L1 from metastatic lymph nodes did not. This retrospective study was approved by the Ethics Committee of Shanghai Chest Hospital (ID: IS23060) and performed following the Helsinki Declaration of 1964 (revised 2008).

Hu Y ，Zhang Y ，Lu Y ，Xu Y ，Xu J ，Zhong H ，Cheng L ，Zhong R ... -  《RESPIRATORY RESEARCH》

Efficacy of ICI-based treatment in advanced NSCLC patients with PD-L1≥50% who developed EGFR-TKI resistance.

Platinum-based chemotherapy is still the standard of care for Epidermal growth factor receptor (EGFR) mutated non-small cell lung cancer (NSCLC) patients after developing EGFR-TKI resistance. However, no study focusing on the role of immuno checkpoint inhibitor (ICI) based treatments for EGFR mutated NSCLC patients who carried programmed death ligand 1 (PD-L1) tumor proportion score (TPS) greater than 50% progressed after EGFR-TKI therapy. In this study, we retrospectively investigated the outcomes of ICI-based treatments for EGFR mutated NSCLC patients carried PD-L1 TPS≥50% after developing EGFR-TKI resistance and to explore the population that may benefited from ICI-based treatment. We retrospectively collected data of advanced NSCLC patients with EGFR mutations and PD-L1 TPS≥50% who have failed prior EGFR-TKI therapies without T790M mutation at Shanghai Chest Hospital between January 2018 and June 2021. Progression-free survival (PFS) and overall survival (OS) were utilized to evaluate the outcomes of this study. A total of 146 patients were included. Up to June 20th, 2022, median follow-up was 36.7 months (IQR, 12.5-44.2 months). Among the population, 66 patients (45.2%) received chemotherapy, the remaning (54.8%) received ICI-based treatment, including 56 patients(70.0%) received ICI combined with chemotherapy (IC) and 24 patients (30.0%) received ICI monotherapy (IM). In IC group,31 patients received ICI combined with chemotherapy,19 patients received ICI combined with antiangiogenic therapy and remaing received ICI combined with chemotherapy and antiangiogenic therapy. Survival analysis shown that patients who received ICI-based treatment had better progress-free survival (PFS) and overall survival (OS) compared with those treated with other therapy (median PFS, 10.0 vs. 4.0 months, P<0.001; median OS, 39.5 vs. 24.2 months, P<0.001). What's more, patients who treated with IC treatment had a superior survival time than those received IM treatment (median PFS, 10.3 vs. 7.0 months, P<0.001; median OS, 41.6 vs. 32.4 months, P<0.001). Subgroup analysis found that the PFS and OS benefit of IC was evident in all subgroups. For advanced NSCLC patients with EGFR mutations and PD-L1 TPS≥50% who have failed prior EGFR-TKI therapies without T790M mutation, ICI-based treatment could provide a more favorable survival than classical chemotherapy. What' s more, compared with ICI monotherapy, ICI combined with chemotherapy seems to be the preferred treatment.

Li Y ，Jiang H ，Qian F ，Chen Y ，Zhou W ，Zhang Y ，Lu J ，Lou Y ，Han B ，Zhang W ... -  《Frontiers in Immunology》

Impact of EGFR-TKI Treatment on the Tumor Immune Microenvironment in EGFR Mutation-Positive Non-Small Cell Lung Cancer.

The impact of EGFR tyrosine kinase inhibitors (TKI) on the tumor immune microenvironment (TME) in non-small cell lung cancer (NSCLC) is unclear. We retrospectively identified 138 patients with EGFR-mutated NSCLC who underwent rebiopsy after progression during EGFR-TKI treatment. PD-L1 and CD73 expression in tumor cells and tumor-infiltrating lymphocyte (TIL) density at baseline and after progression were determined by IHC. Tumor mutation burden (TMB) was determined by next-generation sequencing. The proportion of patients with a PD-L1 expression level of ≥50% (high) increased from 14% before to 28% after EGFR-TKI (P = 0.0010). Whereas CD8+ and FOXP3+ TIL densities were significantly lower after EGFR-TKI treatment than before, CD8+ TIL density was maintained in tumors with a high PD-L1 expression level. Expression of CD73 in tumor cells after EGFR-TKI treatment was higher than that before in patients with a high PD-L1 expression level. TMB tended to be higher after EGFR-TKI treatment than before (3.3→4.1 mutations/Mbp, P = 0.0508). Median progression-free survival for subsequent treatment with antibodies to PD-1 was longer for patients with a high than for those with a low PD-L1 expression after EGFR-TKI (7.1 vs. 1.7 months, P = 0.0033), and two of five patients whose PD-L1 expression level changed from low to high after EGFR-TKI treatment achieved a PFS of >6 months. EGFR-TKI treatment was associated with changes in the TME of EGFR-mutated NSCLC, and such changes may provide clues for optimization of subsequent PD-1 inhibitor treatment.

Isomoto K ，Haratani K ，Hayashi H ，Shimizu S ，Tomida S ，Niwa T ，Yokoyama T ，Fukuda Y ，Chiba Y ，Kato R ，Tanizaki J ，Tanaka K ，Takeda M ，Ogura T ，Ishida T ，Ito A ，Nakagawa K ... -  《-》

Association of PD-L1 tumor proportion score ≥20% with early resistance to osimertinib in patients with EGFR-mutated NSCLC.

Hamakawa Y ，Agemi Y ，Shiba A ，Ikeda T ，Higashi Y ，Aga M ，Miyazaki K ，Taniguchi Y ，Misumi Y ，Nakamura Y ，Shimokawa T ，Saigusa Y ，Kobayashi N ，Okamoto H ，Kaneko T ... -  《Cancer Medicine》

Tumor immune microenvironment and nivolumab efficacy in EGFR mutation-positive non-small-cell lung cancer based on T790M status after disease progression during EGFR-TKI treatment.

The efficacy of programmed death-1 blockade in epidermal growth factor receptor gene (EGFR) mutation-positive non-small-cell lung cancer (NSCLC) patients with different mechanisms of acquired resistance to EGFR tyrosine kinase inhibitors (TKIs) is unknown. We retrospectively evaluated nivolumab efficacy and immune-related factors in such patients according to their status for the T790M resistance mutation of EGFR. We identified 25 patients with EGFR mutation-positive NSCLC who were treated with nivolumab after disease progression during EGFR-TKI treatment (cohort A). Programmed death-ligand 1 (PD-L1) expression and tumor-infiltrating lymphocyte (TIL) density in tumor specimens obtained after acquisition of EGFR-TKI resistance were determined by immunohistochemistry. Whole-exome sequencing of tumor DNA was carried out to identify gene alterations. The relation of T790M status to PD-L1 expression or TIL density was also examined in an independent cohort of 60 patients (cohort B). In cohort A, median progression-free survival (PFS) was 2.1 and 1.3 months for T790M-negative and T790M-positive patients, respectively (P = 0.099; hazard ratio of 0.48 with a 95% confidence interval of 0.20-1.24). Median PFS was 2.1 and 1.3 months for patients with a PD-L1 expression level of ≥1% or <1%, respectively (P = 0.084; hazard ratio of 0.37, 95% confidence interval of 0.10-1.21). PFS tended to increase as the PD-L1 expression level increased with cutoff values of ≥10% and ≥50%. The proportion of tumors with a PD-L1 level of ≥10% or ≥50% was higher among T790M-negative patients than among T790M-positive patients of both cohorts A and B. Nivolumab responders had a significantly higher CD8+ TIL density and nonsynonymous mutation burden. T790M-negative patients with EGFR mutation-positive NSCLC are more likely to benefit from nivolumab after EGFR-TKI treatment, possibly as a result of a higher PD-L1 expression level, than are T790M-positive patients.

Haratani K ，Hayashi H ，Tanaka T ，Kaneda H ，Togashi Y ，Sakai K ，Hayashi K ，Tomida S ，Chiba Y ，Yonesaka K ，Nonagase Y ，Takahama T ，Tanizaki J ，Tanaka K ，Yoshida T ，Tanimura K ，Takeda M ，Yoshioka H ，Ishida T ，Mitsudomi T ，Nishio K ，Nakagawa K ... -  《-》