The Co-Expression of Programmed Death-Ligand 1 (PD-L1) in Untreated EGFR-Mutated Metastatic Lung Adenocarcinoma

Differential prognostic value of tumor and plasma T790M mutations in EGFR TKI-treated advanced NSCLC

Background

Substitution of methionine for threonine at codon 790 (T790M) of epidermal growth factor receptor (EGFR) represents the major mechanism of resistance to EGFR tyrosine kinase inhibitors (TKIs) in EGFR-mutant non-small-cell lung cancer. We determined the prognostic impact and association of secondary T790M mutations with the outcomes of osimertinib and chemotherapy.

Methods

Patients (n = 460) progressing from first-line EGFR-TKI treatment were assessed. Tissue and/or liquid biopsies were used to determine T790M status; post-progression overall survival (OS) was analyzed.

Results

Overall, 143 (31.1%) patients were T790M positive, 95 (20.7%) were T790M negative, and 222 (48.2%) had unknown T790M status. T790M status [T790M positive versus T790M negative: hazard ratio (HR) 0.48 (95% confidence interval (CI), 0.32-0.70); p < 0.001, T790M unknown versus T790M negative: HR 1.97 (95% CI, 1.47-2.64); p < 0.001] was significantly associated with post-progression OS. T790M positivity rates were similar for tissue (90/168, 53.6%) and liquid (53/90, 58.9%) biopsies (Fisher's exact test, p = 0.433). Tumor T790M-positive patients had significantly longer post-progression OS than tumor T790M-negative patients (34.1 versus 17.1 months; log-rank test, p = 8 × 10-5). Post-progression OS was similar between plasma T790M-positive and -negative patients (17.4 versus not reached; log-rank test, p = 0.600). In tumor T790M-positive patients, post-progression OS was similar after osimertinib and chemotherapy [34.1 versus 29.1 months; log-rank test, p = 0.900; HR 1.06 (95% CI, 0.44-2.57); p = 0.897].

Conclusion

T790M positivity predicts better post-progression OS than T790M negativity; tumor T790M positivity has a stronger prognostic impact than plasma T790M positivity. Osimertinib and chemotherapy provide similar OS benefits in patients with T790M-positive tumors.

Comprehensive characterization of MUC16 mutations in lung adenocarcinoma for immunotherapies and prognosis: An observational study

Lung adenocarcinoma (LUAD) is a non-small-cell lung cancer and is the leading cause of cancer-related deaths worldwide. Immunotherapy is a promising candidate for LUAD, and tumor mutation burden (TMB) could be a new biomarker to monitor the response of cancer patients to immunotherapy. It is known that the mucin 16 (MUC16) mutation is the most common and affects the progression and prognosis of several cancers. However, whether MUC16 mutations are associated with TMB and tumor-infiltrating immune cells in LUAD is not fully elucidated. All the data were obtained from the cancer genome atlas database to assess the prognostic value and potential mechanism of MUC16 in LUAD. An immune prognostic model (IPM) was developed based on immune-related genes that could be differentially expressed between MUC16MUT and MUC16WT LUAD patients. Later, the IPM effect on the prognosis and immunotherapy of LUAD was comprehensively evaluated. MUC16 was frequently mutated in LUAD, with a mutational frequency of 43.4%, significantly associated with higher TMB and better clinical prognosis. Based on 436 patients with LUAD, an IPM was established and validated to differentiate patients with a low or high risk of poor survival. The univariate and multivariate Cox regression analyses demonstrated that the IPM was an independent prognostic indicator for LUAD patients. Elevated expressions of PD-L1, LAG3, PDCD1, and SIGLEC15, and most of the T-effector and interferon-γ gene signatures, were depicted in the high-risk group. Moreover, the nomogram using the IPM and clinical prognostic factors also predicted the overall survival and clinical utility. Our project developed a robust risk signature depending on the MUC16 status and provided novel insights for individualized treatment options for LUAD patients.

Effect of BIM expression on the prognostic value of PD-L1 in advanced non-small cell lung cancer patients treated with EGFR-TKIs

The role of Programmed Cell Death Ligand 1 (PD-L1) expression in predicting epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKIs) efficacy remains controversial. Recent studies have highlighted that tumor-intrinsic PD-L1 signaling can be modulated by STAT3, AKT, MET oncogenic pathway, epithelial-mesenchymal transition, or BIM expression. This study aimed to investigate whether these underlying mechanisms affect the prognostic role of PD-L1. We retrospectively enrolled patients with EGFR mutant advanced stage NSCLC who received first-line EGFR-TKI between January 2017 and June 2019, the treatment efficacy of EGFR-TKI was assessed. Kaplan-Meier analysis of progression-free survival (PFS) revealed that patients with high BIM expression had shorter PFS, regardless of PD-L1 expression. This result was also supported by the COX proportional hazard regression analysis. In vitro, we further proved that the knockdown of BIM, instead of PDL1, induced more cell apoptosis following gefitinib treatment. Our data suggest that among the pathways affecting tumor-intrinsic PD-L1 signaling, BIM is potentially the underlying mechanism that affects the role of PD-L1 expression in predicting response to EGFR TKI and mediates cell apoptosis under treatment with gefitinib in EGFR-mutant NSCLC. Further prospective studies are required to validate these results.

Comparison of afatinib and erlotinib combined with bevacizumab in untreated stage IIIB/IV epidermal growth factor receptor-mutated lung adenocarcinoma patients: a multicenter clinical analysis study

Background:

Although bevacizumab in combination with afatinib or erlotinib is an effective and safe first-line therapy for advanced epidermal growth factor receptor (EGFR)-mutated non-small-cell lung cancer (NSCLC), there are very few clinical data comparing afatinib and erlotinib combined with bevacizumab. We performed a retrospective multicenter analysis for the comparison of two combination therapies.

Methods:

Between May 2015 and October 2020, data of 135 stage IIIB/IV EGFR-mutated NSCLC patients receiving first-line afatinib or erlotinib combined with bevacizumab combination therapy in Linkou, Keelung, Chiayi, and Kaohsiung Chang Gung Memorial Hospitals were retrieved and retrospectively analyzed.

Results:

In all, 67 patients received afatinib plus bevacizumab, and 68 patients received erlotinib plus bevacizumab. Afatinib combined with bevacizumab had an objective response rate (ORR) of 82.1% and a disease control rate (DCR) of 97.0%, and the ORR and DCR were 83.8 and 95.6%, respectively, in the erlotinib combined with bevacizumab group (p = 0.798 and p = 1.000). The median progression-free survival was 20.7 and 20.3 months for the afatinib plus bevacizumab group and the erlotinib plus bevacizumab group, respectively [hazard ratio (HR) = 1.02; 95% confidence interval (CI), 0.891–1.953; p = 0.167). The overall survival was 41.9 and 51.0 months for the afatinib plus bevacizumab group and erlotinib plus bevacizumab group, respectively (HR = 1.42; 95% CI, 0.829–2.436; p = 0.201). The secondary EGFR-T790M mutation rates after disease progression were 44% in the afatinib plus bevacizumab group and 58.8% in the erlotinib plus bevacizumab group (p = 0.165). Skin toxicity was the most frequent treatment-related adverse event (AE) in both treatment groups. Diarrhea, an AE, occurred significantly more frequently in the afatinib plus bevacizumab group than in the erlotinib plus bevacizumab group (p < 0.05).

Conclusion:

Afatinib combined with bevacizumab was equally as effective as erlotinib combined with bevacizumab for untreated advanced EGFR-mutated NSCLC. Prospective clinical studies that explore bevacizumab combined with afatinib or erlotinib for advanced EGFR-mutated NSCLC are warranted.

Efficacy and safety of immune checkpoint inhibitors in post-TKI NSCLC patients harboring EGFR mutations

OBJECTIVE

Immune checkpoint inhibitors (ICIs) have been validated in epidermal growth factor receptor (EGFR) wild-type advanced non-small cell lung cancer (NSCLC) patients. However, there exists no evidence regarding NSCLC patients harboring EGFR mutations, experiencing EGFR-TKI (tyrosine kinase inhibitor) treatment failure. We collected clinical information from real world and conducted a time series-based meta-analysis to determine the efficacy and safety of ICIs in patients harboring EGFR mutations and experienced EGFR-TKIs resistance.

METHODS

Twenty-two NSCLC patients with EGFR mutations after TKI resistance were included from two hospitals. PubMed, Embase and Cochrane Library were searched for relevant literature published until December 31, 2021. Endpoint outcomes included mortality and progression-free survival (PFS) at different times of follow-up.

RESULTS

In total, 22 patients showed that the median PFS was 5.6 months (range 2.0-9.0 months). According to treatment strategies, the median PFS was 2.4 months (range 2.0-5.3 months) in the ICI monotherapy group and 5.9 months (range 2.8-9.0 months) in the ICI combined Chemotherapy group. Additionally, sixteen studies, including 5 trials, 10 controlled cohorts and 1 real-world study, were assessed, involving a total of ICI-treated NSCLC patients with EGFR mutation after TKI failure. The 6-month survival and PFS rate were 0.82 (95% CI 0.36-0.97) and 0.55 (95% CI 0.34-0.74), respectively. ICI combined chemotherapy showed the best survival outcome among these groups, as demonstrated by the 12-month survival rate and PFS. No new safety signals were identified with the combination therapy. The frequency of treatment-related adverse events was similar to that in previously reported studies of chemotherapy combined with checkpoint inhibitors.

CONCLUSIONS

The addition of ICIs plus chemotherapy may significantly improve progression-free survival among patients with locally advanced or metastatic non-squamous NSCLC who EGFR-TKIs resistance.

Durvalumab as Consolidation Therapy in Post-Concurrent Chemoradiation (CCRT) in Unresectable Stage III Non-Small Cell Lung Cancer Patients: A Multicenter Observational Study

Background: The experience of using consolidation durvalumab in post-concurrent chemoradiation (CCRT) unresectable stage III non-small cell lung cancer (NSCLC) is rare in real-world clinical practice, and the factors associated with its efficacy are also unclear. We sought to analyze the efficacy of consolidation durvalumab and the factors associated with its efficacy using a multicenter observational study. Methods: The data for 61 patients with post-CCR unresectable stage III NSCLC receiving consolidation durvalumab at the Chang Gung Memorial Hospitals in Linkou, Keelung, Chiayi, and Kaohsiung from November 2017 to March 2020 were analyzed. (3) Results: The median post-CCRT progression-free survival (PFS) and time to metastatic disease or death (TMDD) for consolidation durvalumab were 14.0 months and 16.7 months, respectively. In multiple variant factors analysis, we found that an epidermal growth factor receptor (EGFR) mutation was an independently unfavorable predictive factor for consolidation durvalumab therapy regarding PFS. The median post-CCRT PFS was 6.50 months for EGFR-mutated patients and 33.63 months for EGFR wild-type and unknown patients (HR = 10.47; 95% CI, 4.55–24.07; p < 0.001). Conclusions: Consolidation durvalumab is effective and safe for post-CCRT unresectable stage III NSCLC in clinical practice, but EGFR mutation is an unfavorable factor for consolidation durvalumab. Thus, searching for a better consolidation therapy for EGFR-mutated patients is warranted.

Membrane-Associated RING-CH 8 Functions as a Novel PD-L1 E3 Ligase to Mediate PD-L1 Degradation Induced by EGFR Inhibitors

Expression of programmed death-ligand 1 (PD-L1) on cancer cells is a critical mechanism contributing to immunosuppression and immune escape. PD-L1 expression may also affect therapeutic outcomes of epidermal growth factor receptor (EGFR)-targeted therapy (e.g., with osimertinib/AZD9291) against EGFR-mutant non-small cell lung cancers (NSCLC) and can even be altered during the treatment albeit with largely undefined mechanisms. This study primarily focuses on elucidating the mechanism by which osimertinib induces PD-L1 degradation in addition to validating osimertinib's effect on decreasing PD-L1 expression in EGFR-mutant NSCLC cells and tumors. Osimertinib and other EGFR inhibitors effectively decreased PD-L1 levels primarily in EGFR-mutant NSCLCs and xenografted tumors. Osimertinib not only decreased PD-L1 mRNA expression, but also prompted proteasomal degradation of PD-L1 protein, indicating both transcriptional and posttranslational mechanisms accounting for osimertinib-induced reduction of PD-L1. Knockdown of β-TrCP or inhibition of GSK3 failed to prevent PD-L1 reduction induced by osimertinib. Rather, knockdown of membrane-associated RING-CH 8 (MARCH8) that encodes a membrane-bound E3 ubiquitin ligase rescued osimertinib-induced PD-L1 reduction. Furthermore, manipulation of MARCH8 expression accordingly altered PD-L1 degradation rate. Critically, MARCH8 interacted with PD-L1 through its N-terminal region and also ubiquitinated PD-L1 in cells. Collectively, these results strongly suggest that MARCH8 is a previously undiscovered E3 ubiquitin ligase responsible for PD-L1 degradation including osimertinib-induced PD-L1 degradation, establishing a novel connection between MARCH8 and PD-L1 regulation. IMPLICATIONS: This study has demonstrated a previously undiscovered function of MARCH8 in mediating PD-L1 degradation induced by EGFR inhibitors in EGFR-mutant NSCLC cells, establishing a novel connection between MARCH8 and PD-L1 regulation.

Immunotherapy and Vaccination in Surgically Resectable Non-Small Cell Lung Cancer (NSCLC)

Early-stage NSCLC (stages I and II, and some IIIA diseases) accounts for approximately 30% of non-small cell lung cancer (NSCLC) cases, with surgery being its main treatment modality. The risk of disease recurrence and cancer-related death, however, remains high among NSCLC patients after complete surgical resection. In previous studies on the long-term follow-up of post-operative NSCLC, the results showed that the five-year survival rate was about 65% for stage IB and about 35% for stage IIIA diseases. Platinum-based chemotherapy with or without radiation therapy has been used as a neoadjuvant therapy or post-operative adjuvant therapy in NSCLC, but the improvement of survival is limited. Immune checkpoint inhibitors (ICIs) have effectively improved the 5-year survival of advanced NSCLC patients. Cancer vaccination has also been explored and used in the prevention of cancer or reducing disease recurrence in resected NSCLC. Here, we review studies that have focused on the use of immunotherapies (i.e., ICIs and vaccination) in surgically resectable NSCLC. We present the results of completed clinical trials that have used ICIs as neoadjuvant therapies in pre-operative NSCLC. Ongoing clinical trials investigating ICIs as neoadjuvant and adjuvant therapies are also summarized.

Identifying the prognostic significance of B3GNT3 with PD-L1 expression in lung adenocarcinoma

Background

As a novel treatment, programmed cell death protein 1 (PD-1) inhibitor appears to be less effective in tumors of lung adenocarcinoma patients with epidermal growth factor receptor (EGFR) mutation. Beta-1,3-N-acetylglucosaminyltransferase 3 (B3GNT3) has reported to be associated with programmed death ligand 1 (PD-L1)/PD-1 interaction. However, the relationship between B3GNT3 and PD-L1 and its prognostic significance in

EGFR

mutant status are still unknown.

Methods

B3GNT3 was identified through transcriptome sequencing and The Cancer Genome Atlas Lung Adenocarcinoma (TCGA-LUAD) database. Flow cytometry and real-time polymerase chain reaction were performed to investigate the association between B3GNT3, PD-L1, and EGFR. Then, B3GNT3 and PD-L1 expression were evaluated by immunohistochemical analysis in 145 surgically resected primary lung adenocarcinomas. The relationships between survival and B3GNT3, PD-L1, and EGFR status were assessed, and the potential prognostic factors in patients with B3GNT3 expression were identified.

Results

We found that EGFR activation induced PD-L1 expression, and EGFR tyrosine kinase inhibitor (TKI) could reduce PD-L1 protein in EGFR-TKI-sensitive HCC827 and PC9 cell lines. Subsequent analysis showed that EGFR inhibitor could also lead to both decreased PD-L1 and B3GNT3 mRNA expression. A total of 145 lung adenocarcinoma patients were included. PD-L1 >1% and B3GNT3-positive expression in patients might contribute to worse prognosis in both overall survival (OS) [hazard ratio (HR), 2.63; 95% confidence interval (CI), 0.98–7.06; P=0.048] and disease-free survival (DFS) (HR, 3.04; 95% CI, 1.13–8.14; P=0.019), especially in the PD-L1 ≥50% group. However, when patients were negative for B3GNT3, PD-L1, and EGFR (or “triple negative”), there were significant decreases in OS (HR, 5.44; 95% CI, 0.99–29.83; P=0.029) and DFS (HR, 7.24; 95% CI, 1.32–39.73; P=0.008). Positive B3GNT3 expression was a significant risk factor associated with lower DFS (HR, 3.30; P=0.043).

Conclusions

Our results indicate that the B3GNT3 expression is tightly correlated with PD-L1 expression and EGFR mutation status. B3GNT3 is associated with poor prognosis in lung adenocarcinoma patients. Collectively, these findings may offer new insight into enhancing immune therapy efficacy for lung adenocarcinoma patients.

PD-L1 Immunohistochemistry Comparability and Their Correlation with Clinical Characteristics in NSCLC

Background

PD-L1 expression is an important predictive factor of response to therapy with immune checkpoint inhibitors (ICIs). This study was designed to retrospectively analyze the concordance of PD-L1 measurements using three different assays (Dako22C3, Dako28-8, and SP142) in NSCLC patients and to find possible predictors of high PD-L1 expression.

Materials and Methods

Data of 144 patients with histologically confirmed NSCLC and available PD-L1 measurements treated at the Taoyuan General Hospital from 2018 to 2019 were retrospectively reviewed in the study. Patients' characteristics, including age, sex, clinical stage (T, N, and M) of NSCLC (AJCC, 8^th edition), and EGFR/ALK alterations, were analyzed for association with PD-L1 expression.

Results

Measurements of PD-L1 expression levels with Dako22C3 and Dako28-8 were comparable while SP142 showed lower levels of PD-L1 expression. The overall agreement between Dako22C3 and Dako28-8 was 82.2% and 91.6% for both 1% and 50% TPS cut-offs, respectively. The above findings were confirmed by Cohen's kappa. In addition, we found that PD-L1 expression was significantly associated with advanced N stage but not with T and M stages.

Conclusion

Dako22C3 and Dako28-8 showed comparable results in assessing PD-L1 levels. Future prospective studies are needed to validate these findings. N stage may be a good predictor for PD-L1 expression.

The Combination of Afatinib and Bevacizumab in Untreated EGFR-Mutated Advanced Lung Adenocarcinoma: A Multicenter Observational Study

The efficacy of afatinib in combination with bevacizumab in untreated advanced epidermal growth factor receptor (EGFR)-mutated lung adenocarcinoma is currently unclear. We sought to investigate the efficacy of this combination through a multicenter observational analysis. Data for 57 patients with advanced EGFR-mutated lung adenocarcinoma who received afatinib combined with bevacizumab as first-line therapy at the Chang Gung Memorial Hospitals in Linkou and Kaohsiung and Taipei Tzu Chi Hospital from May 2015 to July 2019 were analyzed. The objective response rate and disease control rate of afatinib combined with bevacizumab therapy were 87.7% and 100%, respectively. In all patients, the median progression-free survival (PFS) and overall survival (OS) were 23.9 (95% confidence interval (CI) (17.56–29.17)) and 45.9 (95% CI (39.50–53.60)) months, respectively. No statistical significance between exon 19 deletion and L858R mutations was noted in PFS or OS. The most frequent adverse events (AEs) were diarrhea (98.2%) and dermatitis (96.5%), and most AEs were grade 2 or lower and manageable. The combination of afatinib and bevacizumab is an effective therapy for untreated advanced EGFR-mutated lung adenocarcinoma with acceptable safety. Future prospective studies focusing on this combination for untreated advanced EGFR-mutated lung adenocarcinoma are warranted.

Application of immune checkpoint inhibitors in EGFR-mutant non-small-cell lung cancer: from bed to bench

Targeted therapies are efficient in the context of oncogenic driver mutations. Epidermal growth factor receptor (EGFR)-mutant lung cancers represent a distinct subset of non-small-cell lung cancer (NSCLC) with marked sensitivity to EGFR tyrosine kinase inhibitors (TKIs). Despite the high response rate to EGFR TKIs in EGFR-mutant lung cancer, resistance and tumor recurrence are unavoidable. Therapeutic options are restricted in patients after exhaustion of targeted therapies. Immune checkpoint inhibitors (ICIs) represent a novel therapeutic option for advanced NSCLC with significant overall survival benefit in registration trials. No superiority in terms of long-term survival was observed in the EGFR mutation subgroup when ICIs were given as monotherapy in second-line treatment in earlier studies. Thus, the appropriate application of ICIs to patients harboring EGFR mutations remains an important field of ongoing research. Here, we discuss different immune checkpoint blockade strategies, including ICIs alone and in combination with TKIs, chemotherapy, radiation, and antiangiogenic agents in EGFR-mutant NSCLC as first-line and subsequent treatments. We also summarize the evidence concerning the heterogeneous molecular features and immune signatures of EGFR mutations and their associations with ICI therapy outcomes. This study was performed to improve our understanding of the optimal mode of immune-based treatment approaches in EGFR-mutant NSCLC.