EGFR mutation status in non-small cell lung cancer receiving PD-1/PD-L1 inhibitors and its correlation with PD-L1 expression: a meta-analysis

Efficacy of immunotherapy in patients with oncogene-driven non-small-cell lung cancer: a systematic review and meta-analysis

Background

Immunotherapy is an emerging antitumor therapy that can improve the survival of patients with advanced non-small-cell lung cancer (NSCLC). However, only about 20% of NSCLC patients can benefit from this treatment. At present, whether patients with driving gene-positive NSCLC can benefit from immunotherapy is one of the hot issues. Therefore, we conducted a meta-analysis to evaluate the efficacy of immunotherapy in patients with oncogene-driven NSCLC and concluded the efficacy of altered subtypes.

Methods

A literature search was performed using PubMed, Web of Science, and Cochrane databases. The primary endpoints included the objective response rate (ORR), median progression-free survival (mPFS), and median overall survival (mOS) in patients with oncogene-driven NSCLC.

Results

In all, 86 studies involving 4524 patients with oncogene-driven NSCLC were included in this meta-analysis. The pooled ORRs in clinical trials treated with monoimmunotherapy of EGFR, ALK, and KRAS alteration were 6%, 0%, and 23%, respectively. In retrospective studies, the pooled ORRs of EGFR, ALK, KRAS, BRAF, MET, HER2, RET, and ROS1 alteration were 8%, 3%, 28%, 24%, 23%, 14%, 7%, and 8%, respectively. Among them, the pooled ORRs of KRAS non-G12C mutation, KRAS G12C mutation, BRAF V600E mutation, BRAF non-V600E mutation, MET-exon 14 skipping, and MET-amplification were 33% 40%, 20%, 34%, 17%, and 60%, respectively. In addition, the pooled mPFS rates of EGFR, KRAS, MET, HER2, and RET alteration were 2.77, 3.24, 2.48, 2.31, and 2.68 months, while the pooled mOS rates of EGFR and KRAS alteration were 9.98 and 12.29 months, respectively. In prospective data concerning EGFR mutation, the pooled ORR and mPFS treated with chemo-immunotherapy (IC) reached 38% and 6.20 months, while 58% and 8.48 months with chemo-immunotherapy plus anti-angiogenesis therapy (ICA). Moreover, the pooled mPFS and mOS of monoimmunotherapy was 2.33 months and 12.43 months.

Conclusions

EGFR-, ALK-, HER2-, RET-, and ROS1-altered NSCLC patients have poor reactivity to monoimmunotherapy but the efficacy of immune-based combined therapy is significantly improved. KRAS G12C mutation, BRAF non-V600E mutation, and MET amplification have better responses to immunotherapy, and more prospective studies are needed for further research.

PDL1-status predicts primary resistance of metastatic, EGFR-mutated non small cell lung cancers to EGFR tyrosine-kinase inhibitors

BACKGROUND

EGFR tyrosine-kinase inhibitors (TKIs) are the reference treatment for metastatic, EGFR-mutated, non-small-cell lung cancers (EGFRm NSCLCs). However, 16-20% of those tumors progress early (3-6 months) and factors predicting that resistance are unknown. This study was undertaken to examine PDL1 status as such a factor.

METHODS

This retrospective analysis included metastatic, EGFRm-NSCLC patients who received first-line 1st-, 2nd- or 3rd-generation EGFR TKIs with PDL1 expression determined in pretreatment biopsies. Kaplan-Meier estimations of probabilities of progression-free survival (PFS) and overall survival (OS) were compared with log-rank test, and logistic-regression analyses.

RESULTS

PDL1 status of the 145 included patients was ≥1% (47%), 1-49% (33%) or ≥50% (14%). For PDL1-positive vs PDL1-negative patients, respectively, median PFS lasted 8 (95% CI: 6-12) vs 12 (95% CI: 11-17) months (p = 0.008), with 18% vs. 8% (NS) of NSCLCs progressing at 3 months, and 47% vs. 18% (HR 0.25 [95% CI 0.10-0.566], p<0.001) at 6 months. Multivariate analysis retained 1st- or 2nd-generation EGFR TKI, brain metastases and albuminemia <35 g/L at diagnosis as significantly associated with shorter PFS, but not PDL1 status, which was independently associated with progression at 6 months (HR 3.76 [1.23-12.63], p = 0.02). PDL1-negative and PDL1-positive patients' OS lasted 27 (95% CI 24-39) and 22 (95% CI 19-41) months, respectively (NS). Multivariate analysis retained only brain metastases or albuminemia <35 g/L at diagnosis as being independently associated with OS.

CONCLUSION

PDL1 expression ≥1% seems to be associated with early progression during the first 6 months of first-line EGFR-TKI treatment of metastatic EGFRm NSCLCs, without impacting OS.

Hope and Challenges: Immunotherapy in EGFR-Mutant NSCLC Patients

EGFR tyrosine kinase inhibitors (TKIs) are the preferred initial treatment for non-small cell lung cancer (NSCLC) patients harboring sensitive EGFR mutations. Sadly, remission is transient, and no approved effective treatment options are available for EGFR-TKI-advanced EGFR-mutant NSCLCs. Although immunotherapy with immune checkpoint inhibitors (ICIs) induces sustained cancer remission in a subset of NSCLCs, ICI therapy exhibits limited activity in most EGFR-mutant NSCLCs. Mechanistically, the strong oncogenic EGFR signaling in EGFR-mutant NSCLCs contributes to a non-inflamed tumor immune microenvironment (TIME), characterized by a limited number of CD8+ T cell infiltration, a high number of regulatory CD4+ T cells, and an increased number of inactivated infiltrated T cells. Additionally, EGFR-mutant NSCLC patients are generally non-smokers with low levels of PD-L1 expression and tumor mutation burden. Promisingly, a small population of EGFR-mutant NSCLCs still durably respond to ICI therapy. The hope of ICI therapy from pre-clinical studies and clinical trials is reviewed in EGFR-mutant NSCLCs. The challenges of application ICI therapy in EGFR-mutant NSCLCs are also reviewed.

Significance of programmed death-ligand 1 expression in resected lung cancer and its relationship with EGFR mutation

BACKGROUND

Several studies have reported that the high expression of programmed death-ligand 1 (PD-L1) within tumor cells predicts a poor prognosis. However, the relationship between the PD-L1 expression and lymph node metastasis or driver mutations in lung cancer remains poorly understood.

METHODS

A total of 356 consecutive patients who underwent surgical resection for primary lung cancer were included in the study. There were 268 adenocarcinomas including 100 EGFR mutations, 67 squamous cell carcinomas (Sq), and 21 other histologies. The high expression of PD-L1 was defined as a tumor proportion score (TPS) of ≥50. The relationship between the PD-L1 expression and clinicopathological factors and recurrence-free survival (RFS) was analyzed.

RESULTS

The PD-L1 expression was high in 75 patients. It was significantly related to smoking history, Sq histology, driver mutation negative, elevated serum carcinoembryonic antigen levels, and lymph node metastasis. Among patients with driver mutations, a high PD-L1 TPS was found in patients with EGFR G719X mutation. A significant difference in RFS was observed in adenocarcinoma patients. A multivariate analysis of adenocarcinoma cases revealed that tumor size and lymph node metastasis were independent prognostic factors for poor RFS, while the PD-L1 expression was not. A logistic regression analysis revealed that the absence of driver mutations, lymph node metastasis, and a history of smoking were significantly associated with the high expression of PD-L1.

CONCLUSION

Lymph node metastasis was positively related with the high expression of PD-L1, resulting in poor RFS. A high PD-L1 TPS was observed in patients with the EGFR G719X mutation.

Immune Checkpoint Inhibitors Combined with Targeted Therapy: The Recent Advances and Future Potentials

Immune checkpoint inhibitors (ICIs) have revolutionized the therapeutic landscape of cancer and have been widely approved for use in the treatment of diverse solid tumors. Targeted therapy has been an essential part of cancer treatment for decades, and in most cases, a special drug target is required. Numerous studies have confirmed the synergistic effect of combining ICIs with targeted therapy. For example, triple therapy of PD-L1 inhibitor atezolizumab plus BRAF inhibitor vemurafenib and MEK inhibitor cobimetinib has been approved as the first-line treatment in advanced melanoma patients with BRAF^V600 mutations. However, not all combinations of ICIs and targeted therapy work. Combining ICIs with EGFR inhibitors in non-small-cell lung cancer (NSCLC) with EGFR mutations only triggered toxicities and did not improve efficacy. Therefore, the efficacies of combinations of ICIs and different targeted agents are distinct. This review firstly and comprehensively covered the current status of studies on the combination of ICIs mainly referring to PD-1 and PD-L1 inhibitors and targeted drugs, including angiogenesis inhibitors, EGFR/HER2 inhibitors, PARP inhibitors and MAPK/ERK signaling pathway inhibitors, in the treatment of solid tumors. We discussed the underlying mechanisms, clinical efficacies, side effects, and potential predictive biomarkers to give an integrated view of the combination strategy and provide perspectives for future directions in solid tumors.

Breaking the Invisible Barriers: Unleashing the Full Potential of Immune Checkpoint Inhibitors in Oncogene-Driven Lung Adenocarcinoma

The rapid development of targeted therapy paved the way toward personalized medicine for advanced non-small cell lung cancer (NSCLC). Lung adenocarcinoma (ADC) harboring actionable genetic alternations including epidermal growth factor receptor (EGFR), anaplastic lymphoma kinase (ALK), Kirsten rat sarcoma virus (ALK) and c-ros oncogene 1 (ROS1) treated with tyrosine kinase inhibitors (TKIs) incurred lesser treatment toxicity but better therapeutic responses compared with systemic chemotherapy. Angiogenesis inhibitors targeting vascular endothelial growth factor (VEGF) have also shown an increase in overall survival (OS) for NSCLC patients. However, acquired resistance to these targeted therapies remains a major obstacle to long-term maintenance treatment for lung ADC patients. The emergence of immune checkpoint inhibitors (ICIs) against programmed cell death protein 1 (PD-1) or programmed cell death-ligand 1 (PD-L1) has changed the treatment paradigm for NSCLC tumors without actionable genetic alternations. Clinical studies have suggested, however, that there are no survival benefits with the combination of targeted therapy and ICIs. In this review, we will summarize and discuss the current knowledge on the tumor immune microenvironment and the dynamics of immune phenotypes, which could be crucial in extending the applicability of ICIs for this subpopulation of lung ADC patients.

Modifying factors of PD-L1 expression on tumor cells in advanced non-small-cell lung cancer

BACKGROUND

Programmed death ligand-1 (PD-L1) expression predicts immunotherapy utility in nononcogenic addictive lung adenocarcinoma (ADC). However, its reproducibility and reliability may be compromised outside clinical trials. This study aimed to evaluate factors associated with PD-L1 expression in lung ADC.

METHODS

This observational study assessed 547 tumor samples with advanced lung ADC from January 2016 to December 2020 in a single cancer institution. Tumor samples were stained by at least one approved PD-L1 clone, SP263 (Ventana) or 22C3 (Dako), and stratified in tumor proportion score (TPS) <1%, 1-49%, or ≥50%.

RESULTS

Of all the tumor samples, positive PD-L1 staining was higher in poorly differentiated tumors (67.3% vs. 32.7%, p < 0.001). Analytical factors associated with a PD-L1 high expression (TPS ≥ 50%) were the SP263 clone (19.6% vs. 8.2%, p < 0.001), time of archival tumor tissue <12 months (15.3% vs. 3.8%, p = 0.024), whenever the analysis was performed in the most recent years (2019-2020) (19.0% vs. 8.3%, p < 0.001), and whenever the analysis was performed by pathologists in the academic setting (Instituto Nacional de Cancerologia, INCan) (19.9% vs. 11.9%, p = 0.001). In the molecular analysis, EGFR wild-type tumors had an increased proportion of PD-L1 positive and PD-L1 high cases (60.2% vs. 47.9%, p = 0.006 and 17.4% vs.8.5%, p = 0.004). A moderate correlation (r = 0.69) in the PD-L1 TPS% was observed between the two different settings (INCan vs. external laboratories).

CONCLUSION

Clinicopathological factors were associated with an increased PD-L1 positivity rate. These differences were significant in the PD-L1 high group and associated with the academic setting, the SPS263 clone, time of archival tumor tissue <12 months, and a more recent period in the PD-L1 analysis.

Safety of Surgery after Neoadjuvant Targeted Therapies in Non-Small Cell Lung Cancer: A Narrative Review

New drugs, including immune checkpoint inhibitors and targeted therapy, have changed the prognosis in a subset of patients with advanced lung cancer, and are now actively investigated in a number of trials with neoadjuvant and adjuvant regimens. However, no phase III randomized studies were published yet. The current narrative review proves that targeted therapies are safe in neoadjuvant approach. Unsurprisingly, administration of therapy is related to an acceptable toxicity profile. Severe adverse events’ rate that rarely compromises outcomes of patients with advanced lung cancer is not that commonly accepted in early lung cancer as it may lead to missing the chance of curative surgery. Among those complications, the most important factors that may limit the use of targeted therapies are severe respiratory adverse events precluding the resection occurring after treatment with some anaplastic lymphoma kinase and rarely after epidermal growth factor receptor tyrosine kinase inhibitors. At this point, in the presented literature assessing the feasibility of neoadjuvant therapies with anaplastic lymphoma kinase and epidermal growth factor receptor tyrosine kinase inhibitors, we did not find any unexpected intraoperative events that would be of special interest to a thoracic surgeon. Moreover, the postoperative course was associated with typical rate of complications.