Osimertinib in untreated epidermal growth factor receptor (EGFR)-mutated advanced non-small cell lung cancer

Activity and resistance to KRASG12C inhibitors in non-small cell lung cancer and colorectal cancer

Non-small cell lung cancer (NSCLC) and colorectal cancer (CRC) are associated with a high mortality rate. Mutations in the V-Ki-ras2 Kirsten Rat Sarcoma Viral Oncogene Homolog (KRAS) proto-oncogene GTPase (KRAS) are frequently observed in these cancers. Owing to its structural attributes, KRAS has traditionally been regarded as an "undruggable" target. However, recent advances have identified a novel mutational regulatory site, KRASG12C switch II, leading to the development of two KRASG12C inhibitors (adagrasib and sotorasib) that are FDA-approved. This groundbreaking discovery has revolutionized our understanding of the KRAS locus and offers treatment options for patients with NSCLC harboring KRAS mutations. Due to the presence of alternative resistance pathways, the use of KRASG12C inhibitors as a standalone treatment for patients with CRC is not considered optimal. However, the combination of KRASG12C inhibitors with other targeted drugs has demonstrated greater efficacy in CRC patients harboring KRAS mutations. Furthermore, NSCLC and CRC patients harboring KRASG12C mutations inevitably develop primary or acquired resistance to drug therapy. By gaining a comprehensive understanding of resistance mechanisms, such as secondary mutations of KRAS, mutations of downstream intermediates, co-mutations with KRAS, receptor tyrosine kinase (RTK) activation, Epithelial-Mesenchymal Transitions (EMTs), and tumor remodeling, the implementation of KRASG12C inhibitor-based combination therapy holds promise as a viable solution. Furthermore, the emergence of protein hydrolysis-targeted chimeras and molecular glue technologies has been facilitated by collaborative efforts in structural science and pharmacology. This paper aims to provide a comprehensive review of the recent advancements in various aspects related to the KRAS gene, including the KRAS signaling pathway, tumor immunity, and immune microenvironment crosstalk, as well as the latest developments in KRASG12C inhibitors and mechanisms of resistance. In addition, this study discusses the strategies used to address drug resistance in light of the crosstalk between these factors. In the coming years, there will likely be advancements in the development of more efficacious pharmaceuticals and targeted therapeutic approaches for treating NSCLC and CRC. Consequently, individuals with KRAS-mutant NSCLC may experience a prolonged response duration and improved treatment outcomes.

The impact of EGFR T790M mutation status following the development of Osimertinib resistance on the efficacy of Osimertinib in non-small cell lung cancer: A meta-analysis

BACKGROUND

Previous studies have suggested that loss of the EGFR T790M gene mutation may contribute to the development of resistance to Osimertinib in non-small cell lung cancer (NSCLC).

AIMS

This study aims to assess the relationship between the clinical effectiveness of Osimertinib in NSCLC patients and the T790M mutation status following resistance to Osimertinib and examine differences between plasma and tissue tests and between Asian and non-Asian groups.

METHODS

The PubMed, Web of Science, Cochrane, and EMBASE databases were comprehensively searched for studies on the association between T790M mutation status and the efficacy of Osimertinib between January 2014 and November 2023. Meta-analysis was carried out using Review Manager 5.4 software.

RESULTS

After evaluating 2727 articles, a total of 14 studies were included in the final analysis. Positive correlations between EGFR T790M mutation status after Osimertinib resistance and longer PFS (HR: 0.44, 95% CI: 0.30-0.66), longer OS (HR: 0.3, 95% CI: 0.10-0.86), longer TTD (HR: 0.69, 95% CI: 0.45-1.07), and improved clinical outcomes including PFS and TTD subgroups (HR: 0.58, 95% CI: 0.47-0.73) were observed. Subgroup analysis revealed that, compared with the blood tests, the results of the T790M mutation tests by the tissue are more significant (HR: 0.24, 95% CI: 0.11-0.52 for tissue tests; HR: 0.47, 95% CI: 0.22-1.00 for plasma tests), and the PFS of Osimertinib were similar for Asian and non-Asian patients (HR: 0.46, 95% CI: 0.31-0.68 for Asians; HR: 0.12, 95% CI: 0.01-1.27 for non-Asians).

CONCLUSIONS

Persistence of the T790M gene mutation after the development of Osimertinib resistance is associated with higher therapeutic benefits of Osimertinib in NSCLC patients. The results of tissue detection are more significant than those of plasma detection.

Trastuzumab deruxtecan (DS8201) for advanced non-small cell lung cancer with HER2 exon 20 insertion mutation: a case report

An antibody-drug conjugate (ADC) of human epidermal growth factor receptor-2 (HER2) provides effective treatment for patients with HER2-positive non-small cell lung cancer (NSCLC). Exon 20 insertion mutations are the most common among HER2 mutations. This mutant subtype is highly drug-resistant, and patients receiving conventional treatment often have a poor prognosis. Trastuzumab deruxtecan (T-DXd), a novel anti-HER2 ADC, has emerged as a novel treatment option for HER2-positive (mutated, expressed, amplified, alternated) NSCLC, based on several studies and reported results. Herein, we report a case of stage IV NSCLC with HER2 exon 20 mutation in a 52-year-old male patient whose tumor recurred after radical resection of pulmonary carcinoma, who could not tolerate chemotherapy, and presented with bone metastasis. After treatment with T-DXd, the tumor significantly regressed and bone metastasis improved, maintaining a state of no progression for 21 months. This case report evidences the use of T-DXd in the treatment of NSCLC with HER2 exon 20 insertion mutation.

Receptor tyrosine kinase inhibitors in cancer

Targeted therapy is a new cancer treatment approach, involving drugs that particularly target specific proteins in cancer cells, such as receptor tyrosine kinases (RTKs) which are involved in promoting growth and proliferation, Therefore inhibiting these proteins could impede cancer progression. An understanding of RTKs and the relevant signaling cascades, has enabled the development of many targeted drug therapies employing RTK inhibitors (RTKIs) some of which have entered clinical application. Here we discuss RTK structures, activation mechanisms and functions. Moreover, we cover the potential effects of combination drug therapy (including chemotherapy or immunotherapy agents with one RTKI or multiple RTKIs) especially for drug resistant cancers.

High dose osimertinib in patients with advanced stage EGFR exon 20 mutation-positive NSCLC: Results from the phase 2 multicenter POSITION20 trial

INTRODUCTION

Patients with life-threatening advanced non-small cell lung cancer (NSCLC) who harbor an exon 20 deletion and/or insertion mutation (EGFRex20 + ) have limited effective treatment options. The high dose 3rd generation tyrosine kinase inhibitor (TKI) osimertinib shows promising in vitro activity in EGFRex20 + NSCLC tumors.

METHODS

The POSITION20 is a single arm phase II, multicenter study investigating 160 mg osimertinib in patients with EGFRex20+, T790M negative NSCLC. We allowed patients to be treatment naïve and to have asymptomatic brain metastases. The primary endpoint was overall response rate (ORR). Secondary outcomes were duration of response (DoR), progression free survival (PFS), overall survival (OS), and treatment related adverse events (trAEs).

RESULTS

From June 2018 to October 2021, 25 patients were enrolled across five centers in the Netherlands. The median age was 70 years (range, 47-87), 20 patients (80%) were women, and the median number of previous lines of therapy was 1 (range, 0-3). The exon 20 mutations were clustered between A763 and L777. The most common exon 20 mutations were p.(N771_H773dup) (n = 3) and p.(A767_V769dup) (n = 3). The ORR was 28% (95% CI, 12-49%), including seven partial responses, with a median DoR of 5.3 months (range, 2.7-27.6). The median PFS was 6.8 months (95% CI, 4.6-9.1) and the median OS was 15.2 months (95% CI, 14.3-16.0). The most common trAEs were diarrhea (72%), dry skin (44%), and fatigue (44%). The primary reason for discontinuation was progressive disease in 14 patients (56%).

CONCLUSION

The POSITION20 study showed modest antitumor activity in patients with EGFRex20 + NSCLC treated with 160 mg osimertinib, with a confirmed ORR of 28% and acceptable toxicity.

Targeting S100A9-ALDH1A1-retinoic acid signaling to suppress brain relapse in EGFR-mutant lung cancer

The epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) osimertinib has significantly prolonged progression-free survival (PFS) in EGFR-mutant lung cancer patients, including those with brain metastases. However, despite striking initial responses, osimertinib-treated patients eventually develop lethal metastatic relapse, often to the brain. Although osimertinib-refractory brain relapse is a major clinical challenge, its underlying mechanisms remain poorly understood. Using metastatic models of EGFR-mutant lung cancer, we show that cancer cells expressing high intracellular S100A9 escape osimertinib and initiate brain relapses. Mechanistically, S100A9 upregulates ALDH1A1 expression and activates the retinoic acid (RA) signaling pathway in osimertinib-refractory cancer cells. We demonstrate that the genetic repression of S100A9, ALDH1A1, or RA receptors (RAR) in cancer cells, or treatment with a pan-RAR antagonist, dramatically reduces brain metastasis. Importantly, S100A9 expression in cancer cells correlates with poor PFS in osimertinib-treated patients. Our study therefore identifies a novel, therapeutically targetable S100A9-ALDH1A1-RA axis that drives brain relapse.

Exploration of the Tumor-Suppressive Immune Microenvironment by Integrated Analysis in EGFR-Mutant Lung Adenocarcinoma

Background

Clinical evidence has shown that few non-small cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR) mutations can benefit from immunotherapy. The tumor immune microenvironment (TIME) is a significant factor affecting the efficacy of immunotherapy. However, the TIME transformational process in EGFR-mutation patients is unknown.

Methods

The mRNA expression and mutation data and lung adenocarcinoma (LUAD) clinical data were obtained from The Cancer Genome Atlas (TCGA) database. Profiles describing the immune landscape of patients with EGFR mutations were characterized by differences in tumor mutation burden (TMB), ESTIMATE, CIBERSORT, and microenvironment cell populations-counter (MCP-counter).

Results

In total, the TCGA data for 585 patients were analyzed. Among these patients, 98 had EGFR mutations. The TMB was lower in the EGFR group (3.94 mut/Mb) than in the KRAS mutation group (6.09 mut/Mb, P < 0.001) and the entire LUAD (6.58 mut/Mb, P < 0.001). The EGFR group had a lower population of activated immune cells and an even higher score of immunosuppressive cells. A further inter-group comparison showed that differences in the TMB and tumor-infiltrating lymphocytes were only found between patients with oncogenic mutations and unknown mutation. Meanwhile, there were more myeloid dendritic cells (DCs) in EGFR 19del than in L858R-mutation patients and in common mutation patents than in uncommon mutation patients (P < 0.05). Additionally, we established a D score, where D = MCP-counter score for cytotoxic T lymphocytes (CTLs)/MCP-counter score for myeloid DCs. Further analysis revealed that lower D scores indicated immune suppression and were negatively related to several immunotherapy biomarkers.

Conclusions

The TIME of EGFR mutant NSCLC was immunosuppressive. Myeloid DCs gradually increased in EGFR 19del, L858R, and uncommon mutations. The potential role of CTLs and DCs in the TIME of patients requires further investigation.

Role of receptor tyrosine kinases mediated signal transduction pathways in tumor growth and angiogenesis-New insight and futuristic vision

In the past two decades, significant progress has been made in the past two decades towards the understanding of the basic mechanisms underlying cancer growth and angiogenesis. In this context, receptor tyrosine kinases (RTKs) play a pivotal role in cell proliferation, differentiation, growth, motility, invasion, and angiogenesis, all of which contribute to tumor growth and progression. Mutations in RTKs lead to abnormal signal transductions in several pathways such as Ras-Raf, MEK-MAPK, PI3K-AKT and mTOR pathways, affecting a wide range of biological functions including cell proliferation, survival, migration and vascular permeability. Increasing evidence demonstrates that multiple kinases are involved in angiogenesis including RTKs such as vascular endothelial growth factor, platelet derived growth factor, epidermal growth factor, insulin-like growth factor-1, macrophage colony-stimulating factor, nerve growth factor, fibroblast growth factor, Hepatocyte Growth factor, Tie 1 & 2, Tek, Flt-3, Flt-4 and Eph receptors. Overactivation of RTKs and its downstream regulation is implicated in tumor initiation and angiogenesis, representing one of the hallmarks of cancer. This review discusses the role of RTKs, PI3K, and mTOR, their involvement, and their implication in pro-oncogenic cellular processes and angiogenesis with effective approaches and newly approved drugs to inhibit their unrestrained action.

Complete response of radioresistant brain metastases from non-small cell lung cancer with temozolomide: A case report and literature review

RATIONALE

Non-small cell lung cancer (NSCLC) patients with brain metastases (BMs) have been found as subjects of poor prognosis. Whole-brain radiotherapy (WBRT), surgery, and stereotactic radiosurgery, epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI), or some combinations are the most commonly employed strategies for the treatment of treatments BMs. However, some patients are resistant to all these treatments.

PATIENT CONCERNS

We present an NSCLC patient with progression of BMs after treatment with WBRT and EGFR-TKIs. The patient was diagnosed with multiple metastases on July 9, 2014, and treated with docetaxel plus cisplatin chemotherapy followed with gefitinib as the maintenance therapy. The patient showed recurrence of BMs after 8-months of chemotherapy. WBRT with 30 Gy was administrated in 10 fractions. Tumor progression of the brain was diagnosed with an magnetic resonance imaging scan after 2-months of WBRT.

DIAGNOSES

The patient was diagnosed as pulmonary adenocarcinoma with diffuse metastases in both lungs and multiple metastases in bone and brain. Progression of BMs was confirmed through magnetic resonance imaging.

INTERVENTIONS

This patient was administered temozolomide (150 mg/m2/d for 5 days every 28-day cycle). As a whole, 6 cycles were performed after the progression of BMs from August 2015.

OUTCOMES

The patient got complete brain remission and lived without discomfort. The intracranial lesion did not progress until the progression of the lung lesion and led to death on February 20, 2019. The intracranial progression-free survival was 42 months, whereas the overall survival was 55 months.

LESSONS

For patients with NSCLC and BMs, temozolomide can be used as a treatment option, especially in patients with EGFR-TKIs resistance or without driver mutations.

Molecular profiling of afatinib-resistant non-small cell lung cancer cells in vivo derived from mice

Non-small-cell lung cancer (NSCLC) is a leading cause of cancer-related death worldwide. NSCLC patients with overexpressed or mutated epidermal growth factor receptor (EGFR) related to disease progression are treated with EGFR-tyrosine kinase inhibitors (EGFR-TKIs). Acquired drug resistance after TKI treatments has been a major focus for development of NSCLC therapies. This study aimed to establish afatinib-resistant cell lines from which afatinib resistance-associated genes are identified and the underlying mechanisms of multiple-TKI resistance in NSCLC can be further investigated. Nude mice bearing subcutaneous NSCLC HCC827 tumors were administered with afatinib at different dose intensities (5-100 mg/kg). We established three HCC827 sublines resistant to afatinib (IC₅₀ > 1 μM) with cross-resistance to gefitinib (IC₅₀ > 5 μM). cDNA microarray revealed several of these sublines shared 27 up- and 13 down-regulated genes. The mRNA expression of selective novel genes - such as transmembrane 4 L six family member 19 (TM4SF19), suppressor of cytokine signaling 2 (SOCS2), and quinolinate phosphoribosyltransferase (QPRT) - are responsive to afatinib treatments only at high concentrations. Furthermore, c-MET amplification and activations of a subset of tyrosine kinase receptors were observed in all three resistant cells. PHA665752, a c-MET inhibitor, remarkably increased the sensitivity of these resistant cells to afatinib (IC₅₀ = 12-123 nM). We established afatinib-resistant lung cancer cell lines and here report genes associated with afatinib resistance in human NSCLC. These cell lines and the identified genes serve as useful investigational tools, prognostic biomarkers of TKI therapies, and promising molecule targets for development of human NSCLC therapeutics.

A multicenter real-world study of tumor-derived DNA from pleural effusion supernatant in genomic profiling of advanced lung cancer

Background

Pleural effusion (PE) is commonly observed in advanced lung cancer. Research has suggested that molecular profiling of PE could be used to detect tumor driver mutations, thus informing clinical decision-making. However, the performance of PE samples in a real-world setting has yet to be examined.

Methods

A total of 678 metastatic lung cancer patients with pleural effusion were enrolled in this study. Cohort 1 included 22 patients whose PE and matched plasma samples were simultaneously collected as a pilot study. Cohort 2 comprised 656 patients, from whom 734 samples were collected in a real world setting. These samples were subjected to targeted next-generation sequencing (NGS) of 1,021 cancer-related genes.

Results

PE supernatant was the preferred choice for genetic profiling. While the maximal somatic allele frequency (MSAF) of plasma in patients with M1a stage was significantly lower than that in patients with M1b/c stages (4.4%±9.6% vs. 9.0%±14.1%, P<0.01), the MSAF of PE supernatant was similar between M1a and M1b/c stages. PE supernatant demonstrated higher sensitivity than plasma in detecting actionable mutations in cohort 1 (81.8% vs. 45.5%, P=0.01) as well as in M1a disease (84.7% vs. 42.1%, P<0.01), but not in M1b/c disease, in cohort 2. Known resistant mutations were identified in 72 of the 117 patients who were resistant to first- or second-generation EGFR-TKIs, 22 of the 42 patients who were resistant to osimertinib, and 9 of the 13 patients who were resistant to crizotinib. Remarkably, PE supernatant outperformed plasma in identifying mutations that confer resistance to first- and second-generation EGFR-TKIs (75.4% vs. 29.8%, P<0.001).

Conclusions

This real-world large cohort study verified that PE supernatant had higher sensitivity than plasma for identifying actionable mutations, including resistance mutations. PE supernatant would be preferred by physicians for assessing tumor genomics in advanced lung cancer when tumor tissue is not available.

Mechanisms of resistance to osimertinib

The introduction of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) has significantly improved the prognosis of advanced non-small cell lung cancer (NSCLC) patients with EGFR mutations. The most common mechanism of acquired resistance to first- and second-generation EGFR TKIs is represented by the secondary T790M mutation. Osimertinib, a third-generation TKI designed to target both EGFR sensitizing mutations and T790M, was first approved for the treatment of EGFR T790M mutation-positive NSCLC patients in progression after EGFR TKI therapy. The FLAURA study demonstrated that first-line treatment of EGFR mutant patients with osimertinib significantly improved progression free survival (PFS) over first-generation EGFR-TKIs, thus leading to its approval also in this setting. Moreover, osimertinib has shown significant central nervous system (CNS) activity and a favorable safety profile. The current review focuses on the clinical development of osimertinib, the mechanisms of acquired resistance identified in patients receiving osimertinib and the strategies currently under evaluation to overcome resistance.

Combination therapy of brain radiotherapy and EGFR-TKIs is more effective than TKIs alone for EGFR-mutant lung adenocarcinoma patients with asymptomatic brain metastasis

Background

The treatment strategy for brain metastasis (BM) in patients with epidermal growth factor receptor (EGFR) -mutant lung adenocarcinoma (LAC) remains controversial. In the present study, we compared the efficacy of brain radiotherapy (RT) in combination with tyrosine kinase inhibitors (TKIs) and TKIs alone for advanced LAC patients with EGFR mutations and BM.

Methods

We retrospectively studied 78 patients diagnosed with EGFR-mutant LAC who developed BM. These patients were divided into two groups: 49 patients in the combination treatment group who received brain RT in combination with EGFR-TKIs (including 23 patients with asymptomatic BM before RT); 29 patients in the TKI group who received EGFR-TKI targeted therapy alone (including 22 patients with asymptomatic BM before TKI treatment).

Results

The median intracranial progression-free survival (iPFS) of the combination treatment group was longer than that of the TKI alone group (21.5 vs. 15 months; P = 0.036). However, there were no significant differences in median progression-free survival (PFS, 12 vs. 13 months; P = 0.242) and median overall survival (mOS, 36 vs. 23 months; P = 0.363) between the two groups. Further analysis of asymptomatic BM showed that both the median iPFS and the mOS of the combination treatment group were significantly longer than for the TKI alone group (iPFS, 21.5 vs. 14.8 months, P = 0.026; mOS, 36 vs. 23 months, P = 0.041). Cox multivariate regression analysis found no independent adverse predictors of iPFS in all patients.

Conclusions

The synchronous combination of brain RT and TKIs was superior to EGFR-TKIs alone for EGFR-mutant LAC patients with BM. The combination treatment group exhibited longer iPFS, while the PFS and OS were not significantly different between the two groups. In addition, the combination treatment could result in better iPFS and OS in those with asymptomatic BM. Therefore, addition of brain RT was useful for intracranial metastatic lesions.

Dacomitinib for the first-line treatment of patients with EGFR-mutated metastatic non-small cell lung cancer

Introduction: Different EGFR tyrosine kinase inhibitors (TKIs) are currently approved for the first-line treatment of NSCLC patients with EGFR mutations. Dacomitinib is an orally administered, second-generation pan-HER inhibitor that has shown to improve PFS and OS compared to the first-generation TKI gefitinib and is the most recent inhibitor to be approved in this setting. Areas covered: This article will review relevant literature regarding preclinical findings and clinical data from phase I-III trials of dacomitinib. We particularly discuss the mechanism of action of dacomitinib and its clinical efficacy and toxicity as a novel, first-line therapeutic option for EGFR-mutated NSCLC. Expert commentary: The therapeutic landscape for EGFR-mutated NSCLC has been greatly expanded. In the first-line setting, we have currently first-, second- and third-generation EGFR TKIs available and some combination strategies, including EGFR TKIs with anti-angiogenic drugs or chemotherapy, have also shown to be effective. However, more data are needed to define the optimal therapeutic sequencing of all these targeted agents and combinations. In this view, molecular profiling of tumor tissues and liquid biopsies may provide novel insights on mechanisms of resistance to different drugs and guide treatment decisions.