Afatinib versus placebo for patients with advanced, metastatic non-small-cell lung cancer after failure of erlotinib, gefitinib, or both, and one or two lines of chemotherapy (LUX-Lung 1): a phase 2b/3 randomised trial

Progress in Research on Tumor Metastasis Inhibitors

Tumor metastasis is a significant cause of malignant cancer-related death. Therefore, inhibiting tumor metastasis is an effective means of treating malignant tumors. Increasing our understanding of the molecular mechanisms that govern tumor metastasis can reveal new anti-cancer targets. This article will discuss the breakthroughs in this area and the corresponding recent developments in anti-cancer drug discovery.

A randomized, multi-center, open-label study to compare the safety and efficacy between afatinib monotherapy and combination therapy of afatinib and HAD-B1 for the locally advanced or metastatic NSCLC patients with EGFR mutations

BACKGROUND

Afatinib is an epidermal growth factor receptor - tyrosine kinase inhibitor (EGFR-TKI) with proven efficacy for treating patients with advanced or metastatic non-small cell lung cancer (NSCLC). Unfortunately, responses are limited by acquired resistance. Because traditional Korean medicine may have synergistic effects when combined with chemotherapy or radiotherapy, the aim of our study is to elucidate the efficacy and safety of afatinib plus HangAmDan-B1 (HAD-B1) combination therapy in the treatment of patients with NSCLC, as well as EGFR mutations, who need afatinib therapy.

METHODS/DESIGN

This study is a randomized, multi-center, open clinical trial. A total of 178 eligible subjects, recruited at 8 centers, are randomly assigned to take Afatinib (20-40 mg) ± HAD-B1 (0.972 g/day) for 48 weeks. In the test group, HAD-B1 and afatinib will be used in combination. The primary outcome is a comparison of progression-free survival (PFS) between afatinib monotherapy and afatinib plus HAD-B1 combination therapy in patients with local advanced or metastatic (Stage IIIA, B, C/IV) NSCLC. Secondary outcomes are the overall survival rates, clinical responses, tumor size reductions, health-related qualities of life, and safety.

DISCUSSION

The result of this clinical trial will provide evidence for the efficacy and safety of using HAD-B1 in the treatment of EGFR-positive patients with locally advanced or metastatic NSCLC who require afatinib therapy.

TRIAL REGISTRATION

Clinical Research Information Service (CRIS), Republic of Korea (ID: KCT0005414), on September 23, 2020.

Estimated direct costs of non-small cell lung cancer by stage at diagnosis and disease management phase: A whole-disease model

Background

Non‐small cell lung cancer (NSCLC) is the first cause of cancer‐related death among men and the second among women worldwide. It also poses an economic threat to the sustainability of healthcare services. This study estimated the direct costs of care for patients with NSCLC by stage at diagnosis, and management phase of pathway recommended in local and international guidelines.

Methods

Based on the most up‐to‐date guidelines, we developed a very detailed “whole‐disease” model listing the probabilities of all potentially necessary diagnostic and therapeutic actions involved in the management of each stage of NSCLC. We assigned a cost to each procedure, and obtained an estimate of the total and average per‐patient costs of each stage of the disease and phase of its management.

Results

The mean expected cost of a patient with NSCLC is 21,328 € (95% C.I. −20 897−22 322). This cost is 16 291 € in stage I, 19530 € in stage II, 21938 € in stage III, 22175 € in stage IV, and 28 711 € for a Pancoast tumor. In the early stages of the disease, the main cost is incurred by surgery, whereas in the more advanced stages radiotherapy, medical therapy, treatment for progressions, and supportive care become variously more important.

Conclusions

An estimation of the direct costs of care for NSCLC is fundamental in order to predict the burden of new oncological therapies and treatments on healthcare services, and thus orient the decisions of policy‐makers regarding the allocation of resources.

Key points

Significant findings of the study

The high costs of surgery make the early stages of the disease no less expensive than the advanced stages.

What this study adds

An estimation of the direct costs of care is fundamental in order to orient the decisions of policy‐makers regarding the allocation of resources.

In Vitro and in Vivo Efficacy of NBDHEX on Gefitinib-resistant Human Non-small Cell Lung Cancer

Gefitinib, a first-generation EGFR tyrosine kinase inhibitor (EGFR-TKI), is recommended for treatment of non-small cell lung cancer (NSCLC) patients who harbor activating EGFR mutations. However, the tumors of most patients initially sensitive to gefitinib will develop resistance within several months of therapy. Drug resistance is a major obstacle to NSCLC treatment. The novel glutathione transferase P1 (GSTPi) inhibitor 6-(7-nitro-2, 1, 3-benzoxadiazol-4-ylthio) hexanol (NBDHEX) has recently been shown to be active against tumors. In this study, we investigated the in vitro and in vivo efficacy of NBDHEX against NSCLC. Treatment with NBDHEX inhibited GSTpi enzymatic activity and promoted apoptosis of gefinitb-resistant NSCLC cells. Moreover, NBDHEX reduced tumor growth in mice. These findings indicated that NBDHEX is a good candidate for treatment of NSCLC patients, and that NBDHEX offers a new approach to cancer therapy.

Loss of PLK2 induces acquired resistance to temozolomide in GBM via activation of notch signaling

Background

Glioblastoma (GBM) is a lethal type of primary brain tumor with a median survival less than 15 months. Despite the recent improvements of comprehensive strategies, the outcomes for GBM patients remain dismal. Accumulating evidence indicates that rapid acquired chemoresistance is the major cause of GBM recurrence thus leads to worse clinical outcomes. Therefore, developing novel biomarkers and therapeutic targets for chemoresistant GBM is crucial for long-term cures.

Methods

Transcriptomic profiles of glioblastoma were downloaded from gene expression omnibus (GEO) and TCGA database. Differentially expressed genes were analyzed and candidate gene PLK2 was selected for subsequent validation. Clinical samples and corresponding data were collected from our center and measured using immunohistochemistry analysis. Lentiviral transduction and in vivo xenograft transplantation were used to validate the bioinformatic findings. GSEA analyses were conducted to identify potential signaling pathways related to PLK2 expression and further confirmed by in vitro mechanistic assays.

Results

In this study, we identified PLK2 as an extremely suppressed kinase-encoding gene in GBM samples, particularly in therapy resistant GBM. Additionally, reduced PLK2 expression implied poor prognosis and TMZ resistance in GBM patients. Functionally, up-regulated PLK2 attenuated cell proliferation, migration, invasion, and tumorigenesis of GBM cells. Besides, exogenous overexpression of PLK2 reduced acquired TMZ resistance of GBM cells. Furthermore, bioinformatics analysis indicated that PLK2 was negatively correlated with Notch signaling pathway in GBM. Mechanically, loss of PLK2 activated Notch pathway through negative transcriptional regulation of HES1 and degradation of Notch1.

Conclusion

Loss of PLK2 enhances aggressive biological behavior of GBM through activation of Notch signaling, indicating that PLK2 could be a prognostic biomarker and potential therapeutic target for chemoresistant GBM.

SHOC2 Is a Critical Modulator of Sensitivity to EGFR-TKIs in Non-Small Cell Lung Cancer Cells

EGFR mutation-positive patients with non-small cell lung cancer (NSCLC) respond well to treatment with EGFR-tyrosine kinase inhibitors (EGFR-TKI); however, treatment with EGFR-TKIs is not curative, owing to the presence of residual cancer cells with intrinsic or acquired resistance to this class of drugs. Additional treatment targets that may enhance the efficacy of EGFR-TKIs remain elusive. Using a CRISPR/Cas9-based screen, we identified the leucine-rich repeat scaffold protein SHOC2 as a key modulator of sensitivity to EGFR-TKI treatment. On the basis of in vitro assays, we demonstrated that SHOC2 expression levels strongly correlate with the sensitivity to EGFR-TKIs and that SHOC2 affects the sensitivity to EGFR-TKIs in NSCLC cells via SHOC2/MRAS/PP1c and SHOC2/SCRIB signaling. The potential SHOC2 inhibitor celastrol phenocopied SHOC2 depletion. In addition, we confirmed that SHOC2 expression levels were important for the sensitivity to EGFR-TKIs in vivo. Furthermore, IHC showed the accumulation of cancer cells that express high levels of SHOC2 in lung cancer tissues obtained from patients with NSCLC who experienced acquired resistance to EGFR-TKIs. These data indicate that SHOC2 may be a therapeutic target for patients with NSCLC or a biomarker to predict sensitivity to EGFR-TKI therapy in EGFR mutation-positive patients with NSCLC. Our findings may help improve treatment strategies for patients with NSCLC harboring EGFR mutations. IMPLICATIONS: This study showed that SHOC2 works as a modulator of sensitivity to EGFR-TKIs and the expression levels of SHOC2 can be used as a biomarker for sensitivity to EGFR-TKIs.

Hepatotoxicity with epidermal growth factor receptor tyrosine kinase inhibitors in non-small-cell lung cancer patients: A network meta-analysis

WHAT IS KNOWN AND OBJECTIVE

The efficacy of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) in patients diagnosed with non-small-cell lung cancer (NSCLC) has been confirmed by a large number of studies. However, hepatotoxicity caused by EGFR-TKIs has not been widely investigated. This review compares the hepatotoxicity of different EGFR-TKIs through a network meta-analysis.

METHODS

PubMed, EMBASE, Cochrane Library and ClinicalTrials.gov were systematically searched from their individual inceptions to 20 May 2020 with the goal of identifying randomized controlled trials (RCTs) reporting hepatotoxicity in NSCLC patients receiving EGFR-TKIs. A random-effects pairwise meta-analysis and network meta-analysis were performed within a frequentist framework. Risk ratios (RRs) and 95% confidence intervals (CIs) were calculated.

RESULTS

Twelve eligible RCTs, including data from 6,280 patients diagnosed with NSCLC, were analysed. In our network meta-analysis, gefitinib was associated with a higher risk for hepatotoxicity compared to placebo (RR, 2.55; 95% CI, 1.32-4.89) and dacomitinib (RR, 2.60; 95% CI, 1.30-5.20) in terms of all-grades alanine transaminase (ALT) elevation. As for all-grades aspartate transaminase (AST) elevation, gefitinib and erlotinib showed a significantly increased risk for hepatotoxicity compared to afatinib, dacomitinib and placebo (erlotinib vs. afatinib: RR, 1.85; 95% CI, 1.05-3.24; erlotinib vs. dacomitinib: RR, 1.68; 95% CI, 1.19-2.36; erlotinib vs. placebo: RR, 3.38; 95% CI, 1.69-6.73; gefitinib vs. afatinib: RR, 2.23; 95% CI, 1.32-3.79; gefitinib vs. dacomitinib: RR, 2.03; 95% CI, 1.51-2.73; gefitinib vs. placebo: RR, 4.08; 95% CI, 2.11-7.91). There was a high risk of high-grade ALT elevation in patients treated with gefitinib compared to patients treated with erlotinib (RR, 4.31; 95% CI, 2.15-8.66), dacomitinib (RR, 6.95; 95% CI, 1.85-26.05) or placebo (RR, 8.38; 95% CI, 1.56-45.01). No statistically significant differences were identified among the five agents analysed in terms of all-grades TB elevation and high-grade AST elevation. The surface under the cumulative ranking curve (SUCRA) revealed that gefitinib showed a potentially higher risk for ALT and AST elevation compared to other EGFR-TKIs regardless of grade.

WHAT IS NEW AND CONCLUSION

Current evidence indicates that the association between afatinib or dacomitinib and risk of liver enzyme elevation remains uncertain in patients diagnosed with NSCLC. Some evidence suggests that gefitinib and erlotinib may be associated with a significantly increased risk for hepatotoxicity in patients with NSCLC. However, given that the elevation of liver enzymes was not definitely associated with EGFR-TKIs and publication bias, further studies are required to confirm these results.

Structural and biophysical insights into the mode of covalent binding of rationally designed potent BMX inhibitors

The bone marrow tyrosine kinase in chromosome X (BMX) is pursued as a drug target because of its role in various pathophysiological processes. We designed BMX covalent inhibitors with single-digit nanomolar potency with unexploited topological pharmacophore patterns. Importantly, we reveal the first X-ray crystal structure of covalently inhibited BMX at Cys496, which displays key interactions with Lys445, responsible for hampering ATP catalysis and the DFG-out-like motif, typical of an inactive conformation. Molecular dynamic simulations also showed this interaction for two ligand/BMX complexes. Kinome selectivity profiling showed that the most potent compound is the strongest binder, displays intracellular target engagement in BMX-transfected cells with two-digit nanomolar inhibitory potency, and leads to BMX degradation PC3 in cells. The new inhibitors displayed anti-proliferative effects in androgen-receptor positive prostate cancer cells that where further increased when combined with known inhibitors of related signaling pathways, such as PI3K, AKT and Androgen Receptor. We expect these findings to guide development of new selective BMX therapeutic approaches.

Epidermal Growth Factor Receptor (EGFR)-Mutated Non-Small-Cell Lung Cancer (NSCLC)

Epidermal growth factor receptor (EGFR) mutations are the most common oncogenic drivers in non-small-cell lung cancer (NSCLC). Significant developments have taken place which highlight the differences in tumor biology that exist between the mutant and wild-type subtypes of NSCLC. Patients with advanced EGFR-mutant NSCLC have a variety of EGFR-targeting agents available proven to treat their disease. This has led to superior patient outcomes when used as a monotherapy over traditional cytotoxic systemic therapy. Attempts at combining EGFR agents with other anticancer systemic treatment options, such as chemotherapy, antiangiogenic agents, and immunotherapy, have shown varied outcomes. Currently, no specific combination stands out to cause a shift away from the use of single-agent EGFR inhibitors in the first-line setting. Similarly, adjuvant EGFR inhibitors, are yet to significantly add to patient overall survival if used at earlier timepoints in the disease course. Liquid biopsy is an evolving technology with potential promise of being incorporated into the management paradigm of this disease. Data are emerging to suggest that this technique may be capable of identifying early resistance mechanisms and consequential disease progression on the basis of the analysis of blood-based circulating tumor cells.

An electrophilic warhead library for mapping the reactivity and accessibility of tractable cysteines in protein kinases

Targeted covalent inhibitors represent a viable strategy to block protein kinases involved in different disease pathologies. Although a number of computational protocols have been published for identifying druggable cysteines, experimental approaches are limited for mapping the reactivity and accessibility of these residues. Here, we present a ligand based approach using a toolbox of fragment-sized molecules with identical scaffold but equipped with diverse covalent warheads. Our library represents a unique opportunity for the efficient integration of warhead-optimization and target-validation into the covalent drug development process. Screening this probe kit against multiple kinases could experimentally characterize the accessibility and reactivity of the targeted cysteines and helped to identify suitable warheads for designed covalent inhibitors. The usefulness of this approach has been confirmed retrospectively on Janus kinase 3 (JAK3). Furthermore, representing a prospective validation, we identified Maternal embryonic leucine zipper kinase (MELK), as a tractable covalent target. Covalently labelling and biochemical inhibition of MELK would suggest an alternative covalent strategy for MELK inhibitor programs.

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.

Impact of Sex and Smoking on the Efficacy of EGFR-TKIs in Terms of Overall Survival in Non-small-Cell Lung Cancer: A Meta-Analysis

Background: To comprehensively understand the impact of sex and smoking on the efficacy of epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) therapy in terms of overall survival (OS) in non-small-cell lung cancer (NSCLC).

Methods: PubMed, Cochrane Library, Embase, and Scopus were searched from inception to March 17, 2019. OS was analyzed based on hazard ratios (HRs) and 95% confidence intervals (CIs) and estimated using the random effects model.

Results: Our meta-analysis included 22 studies involving 11,874 patients. In the primary analysis, we found no statistically significant efficacy difference for EGFR-TKI intervention between females and males (pooled HR 0.95, 95% CI 0.87–1.04, P = 0.30) and no obvious efficacy difference between never smokers and ever smokers (pooled HR 0.91, 95% CI 0.76–1.09, P = 0.31). In the subgroup analysis of placebo control treatment, we found that female NSCLC patients who received EGFR-TKI therapy had a longer OS than male patients (pooled HR 0.86, 95% CI 0.75–1.00, P = 0.04), while smoking status showed no significant effect on the efficacy of EGFR-TKI treatment in terms of the OS of NSCLC patients in all subgroup analyses.

Conclusion: The efficacy of EGFR-TKI therapy for NSCLC patients is independent of smoking status but dependent on sex, and females have a longer OS than males.

Fatal toxic effects related to EGFR tyrosine kinase inhibitors based on 53 cohorts with 9,569 participants

Background

To estimate the incidence and susceptible factors of fatal toxic effects related to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs).

Methods

PubMed and Embase were thoroughly searched for clinical trials based on the following terms and corresponding Medical Subject Heading ones: “erlotinib”, “gefitinib”, “afatinib”, “dacomitinib”, “osimertinib”, and “non-small-cell lung cancer (NSCLC)”. A total of 53 eligible cohorts with 9,569 participants were collected.

Results

A total of 105 cases of fatal toxic effects related to EGFR-TKIs occurred in 53 cohorts. The overall incidence was 1.33% [95% confidence interval (CI): 1.08–1.63%]. The odds and incidence were apparently higher in Japanese group (compared with non-East Asian group) [2.72 vs. 1.30, P=0.015; odds ratio (OR): 2.26, 95% CI: 1.17–4.37, P=0.015], in first-line treatment group (compared with EGFR-TKI retreatment group) (1.54 vs. 0.69, P=0.028; OR: 2.41, 95% CI: 1.10–5.26, P=0.028), and in the trial phase II (compared with trial phase III) (1.82% vs. 1.11%, P=0.009; OR: 1.73, 95% CI: 1.15–2.62, P=0.009). Notably, the Japanese group was higher than non-East Asian group after controlling for the treatment-line and trial phase (OR: 2.16, 95% CI: 1.12–4.16, P=0.022). Interstitial lung disease (ILD) was predominant in 29 fatal causes followed by pneumonia, respiratory failure and diarrhea.

Conclusions

The overall incidence of fatal toxic effects related to EGFR-TKIs was 1.33%, and the major fatal cause was ILD, followed by pneumonia, respiratory failure and diarrhea. The susceptible factor of fatal toxic effects related to EGFR-TKIs was the Japanese group. This study provided a capability for clinicians to predict and detect high-risk populations of fatal toxic effects.

Efficacy of Next-Generation EGFR-TKIs in Patients With Non-Small Cell Lung Cancer: A Meta-Analysis of Randomized Controlled Trials

Background:

The efficacy of next-generation epidermal growth factor receptor-tyrosine kinase inhibitors in patients with advanced non-small cell lung cancer who have failed first-generation epidermal growth factor receptor-tyrosine kinase inhibitors still remains under investigation.

Objective:

The aim of this meta-analysis was to systematically assess the efficacy and safety profiles of next-generation epidermal growth factor receptor-tyrosine kinase inhibitors in patients with advanced non-small cell lung cancer who failed first-generation epidermal growth factor receptor-tyrosine kinase inhibitors.

Methods:

We performed a comprehensive search of several electronic databases up to September 2018 to identify clinical trials. The primary end point was overall survival, progression-free survival, disease controlled rate, objective response rate, and adverse events. Epidermal growth factor receptor-tyrosine kinase inhibitor emergent severe adverse events (grade ≥ 3) were analyzed. Odds ratio along with 95% confidence interval were utilized for main outcome analysis.

Results:

In total, we had 3 randomized controlled trials in this analysis. The group of next-generation epidermal growth factor receptor-tyrosine kinase inhibitors had significantly improved progression-free survival (odds ratio = 0.34, 95% confidence interval = 0.29-0.40, P < .00001), as well as objective response rate (odds ratio = 10.48, 95% confidence interval = 3.87-28.34, P < .00001) and disease controlled rate (odds ratio = 6.03, 95% confidence interval = 4.41-8.25, P < .00001). However, there was no significant difference in overall survival with next-generation epidermal growth factor receptor-tyrosine kinase inhibitors (odds ratio = 1.05, 95% confidence interval = 0.85-1.31, P = .66). Meanwhile, the odds ratio for treatment-emergent severe adverse events (diarrhea, rash/acne, nausea, vomiting, anemia) between patients who received next-generation epidermal growth factor receptor-tyrosine kinase inhibitors and those who received first-generation epidermal growth factor receptor-tyrosine kinase inhibitors did not show safety benefit (P > .05).

Conclusions:

Next-generation epidermal growth factor receptor-tyrosine kinase inhibitors were shown to be the better agent to achieve higher response rate and longer progression-free survival in patients with non-small cell lung cancer as the later-line therapy for previously treated patients with first-generation epidermal growth factor receptor-tyrosine kinase inhibitors. Meanwhile, they did not achieve benefit in overall survival and safety compared with the chemotherapy group. Further research is needed to develop a database of all EGFR mutations and their individual impacts on the various treatments.

Challenges and Opportunities in Cancer Drug Resistance

There has been huge progress in the discovery of targeted cancer therapies in recent years. However, even for the most successful and impactful cancer drugs which have been approved, both innate and acquired mechanisms of resistance are commonplace. These emerging mechanisms of resistance have been studied intensively, which has enabled drug discovery scientists to learn how it may be possible to overcome such resistance in subsequent generations of treatments. In some cases, novel drug candidates have been able to supersede previously approved agents; in other cases they have been used sequentially or in combinations with existing treatments. This review summarizes the current field in terms of the challenges and opportunities that cancer resistance presents to drug discovery scientists, with a focus on small molecule therapeutics. As part of this review, common themes and approaches have been identified which have been utilized to successfully target emerging mechanisms of resistance. This includes the increase in target potency and selectivity, alternative chemical scaffolds, change of mechanism of action (covalents, PROTACs), increases in blood-brain barrier permeability (BBBP), and the targeting of allosteric pockets. Finally, wider approaches are covered such as monoclonal antibodies (mAbs), bispecific antibodies, antibody drug conjugates (ADCs), and combination therapies.

Mechanistic Study of Potent Fluorinated EGFR Kinase Inhibitors with a Quinazoline Scaffold against L858R/T790M/C797S Resistance Mutation: Unveiling the Fluorine Substituent Cooperativity Effect on the Inhibitory Activity

Fluorination has considerable potential with regard to the design of kinase inhibitors for anticarcinoma therapy. It was recently reported that fluorination increases the potency of inhibitors of the epidermal growth factor receptor (EGFR), mutations of which have been linked specifically to nonsmall-cell lung cancer. For the L858R/T790M/C797S triplet mutant (EGFR^TM), a difluorinated inhibitor, 25g, was found to have 4.23 times greater potency against the EGFR^TM than an unfluorinated inhibitor, 25a. This discovery necessitates a rational explanation for the underlying inhibitory mechanisms. Here, we apply multiple computational approaches to explore, validate, and differentiate the binding modes of 25a and 25g in the EGFR^TM and investigate the cooperativity effect of fluorine substituents on the inhibitory activity. Our results showed that the EGFR^TM in the presence of 25g undergoes a series of conformational changes that favor inhibitor binding to both the active and allosteric sites. Further, the cooperativity effect of fluorine substituents is positive: the complex stability is increased by each additional fluorine substituent. Estimated binding free energies show good correlation with the experimental biological activity. Subsequently, the decomposition energy analysis revealed that the van der Waals interaction is the principal force contributing to variations in the binding affinities of 25a and 25g to the EGFR^TM. Per-residue energy-based hierarchical clustering analysis suggests that three hot-spot residues, L718, K745, and D855, are the key in achieving optimal binding modes for 25g with higher affinity in the EGFR^TM compared to 25a. This study provides a rationale for the superior EGFR^TM-inhibitory potency exhibited by 25g over 25a, which is expected to be useful for the future rational structure-based design of novel EGFR^TM inhibitors with improved potency and selectivity.

High expression levels of pyrimidine metabolic rate-limiting enzymes are adverse prognostic factors in lung adenocarcinoma: a study based on The Cancer Genome Atlas and Gene Expression Omnibus datasets

Reprogramming of metabolism is described in many types of cancer and is associated with the clinical outcomes. However, the prognostic significance of pyrimidine metabolism signaling pathway in lung adenocarcinoma (LUAD) is unclear. Using the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) datasets, we found that the pyrimidine metabolism signaling pathway was significantly enriched in LUAD. Compared with normal lung tissues, the pyrimidine metabolic rate–limiting enzymes were highly expressed in lung tumor tissues. The high expression levels of pyrimidine metabolic–rate limiting enzymes were associated with unfavorable prognosis. However, purinergic receptors P2RX1, P2RX7, P2RY12, P2RY13, and P2RY14 were relatively downregulated in lung cancer tissues and were associated with favorable prognosis. Moreover, we found that hypo-DNA methylation, DNA amplification, and TP53 mutation were contributing to the high expression levels of pyrimidine metabolic rate–limiting enzymes in lung cancer cells. Furthermore, combined pyrimidine metabolic rate–limiting enzymes had significant prognostic effects in LUAD. Comprehensively, the pyrimidine metabolic rate–limiting enzymes were highly expressed in bladder cancer, breast cancer, colon cancer, liver cancer, and stomach cancer. And the high expression levels of pyrimidine metabolic rate–limiting enzymes were associated with unfavorable prognosis in liver cancer. Overall, our results suggested the mRNA levels of pyrimidine metabolic rate–limiting enzymes CAD, DTYMK, RRM1, RRM2, TK1, TYMS, UCK2, NR5C2, and TK2 were predictive of lung cancer as well as other cancers.

Pyrotinib in HER2-Mutant Advanced Lung Adenocarcinoma After Platinum-Based Chemotherapy: A Multicenter, Open-Label, Single-Arm, Phase II Study

PURPOSE

Targeted therapies against non-small-cell lung cancer (NSCLC) harboring HER2 mutations remain an unmet need. In this study, we assessed the efficacy and safety of pyrotinib in patients with HER2-mutant advanced NSCLC in a prospective, multicenter, open-label, single-arm, phase II study.

PATIENTS AND METHODS

Patients with stage IIIB or IV HER2-mutant lung adenocarcinoma who were previously treated with platinum-based chemotherapy were enrolled to receive pyrotinib at a dose of 400 mg/d for 21-day cycles. The primary end point was objective response rate per independent review committee (IRC).

RESULTS

Between October 20, 2016, and December 10, 2018, 60 patients received pyrotinib monotherapy. At baseline, 58 (96.7%) were stage IV, and 25 (41.7%) received at least 2 lines of prior chemotherapy. As of data cutoff on June 20, 2019, IRC-assessed objective response rate was 30.0% (95% CI, 18.8% to 43.2%). All subgroups of patients with different HER2 mutation types showed a favorable objective response rate. The objective response rates were similar between patients with and without brain metastases (25.0% v 31.3%). The median duration of response was 6.9 months (95% CI, 4.9 to 11.1 months). The median progression-free survival was 6.9 months (95% CI, 5.5 to 8.3 months) per IRC. The median overall survival was 14.4 months (95% CI, 12.3 to 21.3 months). Treatment-related adverse events of grade 3 or 4 occurred in 28.3% of patients, with the most common being diarrhea (20.0%; all grade 3). No treatment-related deaths were reported.

CONCLUSION

Pyrotinib showed promising antitumor activity and an acceptable safety profile in chemotherapy-treated patients with HER2-mutant NSCLC.

New therapeutic approaches to overcoming resistant EGFR exon 20 alterations

EGFR exon 20 alterations are rare events seen mainly in non-small cell lung cancer (NSCLC). They include EGFR T790 and C797S mutations (associated with secondary resistance to classic EGFR tyrosine kinase inhibitors (TKIs)), and EGFR exon 20 in-frame insertions (associated with resistance to first- and second-generation EGFR TKIs). In silico modeling of structural changes in aberrant proteins has informed selection of compounds with potential clinical activity: poziotinib (whose smaller size permits access to the restricted kinase pocket created by EGFR and ERBB2 exon 20 insertions); cetuximab (an antibody that attenuates dimerization caused by EGFR exon 20 insertions), and TAK-788 (another EGFR/ERBB2 TKI). Other alterations, such as EGFR T790 M, are responsive to osimertinib, while the EGFR C797S alteration seen in osimertinib resistance demonstrates preclinical sensitivity to combined brigatinib and cetuximab. These observations indicate that clinical resistance can be overcome by utilizing advanced genomic interrogation coupled with computer modeling.

Recent updates on the resistance mechanisms to epidermal growth factor receptor tyrosine kinase inhibitors and resistance reversion strategies in lung cancer

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) have led to a substantial improvement in the prognosis of lung cancer patients by explicitly targeting the activating mutations within the EGFR. Initially, patients harboring tumors with EGFR mutations show progression-free survival and improvement in the response rates toward all-generation EGFR-TKIs; however, these agents fail to deliver the intended results in the long-term due to drug resistance. Therefore, it is necessary to recognize specific cardinal mechanisms that regulate the resistance phenomenon. Understanding the intricate mechanisms underlying EGFR-TKIs resistance in lung cancer could provide cognizance for more advanced targeted therapeutics. The present review features insights into current updates on the discrete mechanisms, including secondary or tertiary mutations, parallel and downstream signaling pathways, acquiring an epithelial-to-mesenchymal transition (EMT) signature, microRNAs (miRNAs), and epigenetic alterations, which lead to intrinsic and acquired resistance against EGFR-TKIs in lung cancer. In addition, this paper also reviews current possible strategies to overcome this issue using combination treatment of recently developed MET inhibitors, allosteric inhibitors or immunotherapies, transformation of EMT, targeting miRNAs, and epigenetic alterations in intrinsic and acquired EGFR-TKIs resistant lung cancer. In conclusion, multiple factors are responsible for intrinsic and acquired resistance to EGFR-TKIs and understanding of the detailed molecular mechanisms, and recent advancements in pharmacological studies are needed to develop new strategies to overcome intrinsic and acquired EGFR-TKIs resistance in lung cancer.

Efficacy and safety of afatinib for non-small-cell lung cancer: state-of-the-art and future perspectives

INTRODUCTION

Afatinib is a second-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, acting as an irreversible and multitarget blocker of ErbB family members. Afatinib is currently approved for advanced non-small-cell lung cancer (NSCLC) harboring common and uncommon sensitizing EGFR mutations and for squamous NSCLC patients progressing after first-line platinum-based chemotherapy.

AREAS COVERED

This review summarizes the efficacy and safety profile of afatinib compared with chemotherapy and other EGFR TKIs, in order to evaluate its characteristics and potential role in the increasingly complex treatment landscape of EGFR-mutant lung cancer. Future perspectives and innovative drug combinations are also discussed.

EXPERT OPINION

Afatinib has been demonstrated to improve efficacy and quality of life compared with chemotherapy with a managed toxicity profile. However, in recent years, the increasing availability of different treatment options for advanced EGFR-mutant NSCLC has made the current treatment scenario more complicated, with an increasing need of new and deeper scientific data. In this light, the identification and validation of potential clinicopathological and/or molecular predictors of benefit, as well as the clarification of resistance mechanisms, may help to clarify the most appropriate treatment strategies and sequences for EGFR-mutant patients.

QT interval prolongation related to afatinib treatment in a patient with metastatic non-small-cell lung cancer

Afatinib improves survival in metastatic non-small-cell lung cancer driven by activating epidermal growth factor receptor mutations. QT interval prolongation is a possible side effect of targeted anticancer drugs, but this has not been reported before with afatinib. We report a case of metastatic pulmonary adenocarcinoma with epidermal growth factor receptor exon 19 deletion who was treated with first-line afatinib. The patient was started on afatinib with a total dose of 40 mg/day and experienced grade 3 (>500 ms) QT interval prolongation in the seventh week. Dose was interrupted and then reduced to 30 mg/day after the event repeated. QT prolongation occurred only once with the reduced dose and radiologic oligoprogression was detected. Local therapy was performed and afatinib was continued as 30 mg/day. To the best of our knowledge, this case marks the first QT interval prolongation associated with afatinib. It is prudent to perform a baseline cardiologic evaluation and electrocardiogram monitoring in non-small cell lung cancer patients treated with this drug.

Advances in targeting acquired resistance mechanisms to epidermal growth factor receptor tyrosine kinase inhibitors

Next-generation sequencing (NGS) of tumor samples and circulating tumor DNA has revolutionized diagnostic and therapeutic strategies in lung cancer. The identification of the epidermal growth factor receptor (EGFR) oncogenic driver has translated into successful therapy of advanced lung cancer using EGFR tyrosine kinase inhibitors (TKI). Unfortunately, responses are limited by acquired mechanisms of resistance. We review herein the current landscape of acquired resistance mechanisms to EGFR-TKI therapy and recent advances in therapeutic strategies to overcome acquired resistance.

Therapeutic options for advanced epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer: a Bayesian network secondary analysis

The most favorable treatments for advanced EGFR-mutant NSCLC are less indicated. Forty-one studies were eligible for this Bayesian network secondary analysis. For PFS, erlotinib (Erlo)+bevacizumab (Bev) (HR 0.26, 95% CrI: 0.08-0.75 vs placebo), osimertinib (Osi) (HR 0.29, 0.11-0.70 vs placebo), and afatinib (Afa) were top-ranking individual treatments, while immunotherapy (IT)+anti-VEGFR (aVEGFR)+platinum-based therapy (Plat) (HR 0.42, 0.06-2.63 vs placebo), EGFR-TKI (ET)+aVEGFR (HR 0.35, 0.14-0.85 vs placebo), and ET+aVEGFR+Plat were top-ranking medication classes. For OS, Osi (HR 0.52, 0.10-2.00 vs placebo), cetuximab (Cet)+Bev+Plat (HR 0.51, 0.06-3.38 vs placebo), and cilengitide (Cil)+Cet+Plat were top-ranking individual treatments, while ET+aVEGFR+Plat, ET+Plat, and third-generation EGFR-TKI (3^rd ET) were top-ranking medication classes. For PFS regarding the EGFR genomic aberration status, Erlo+Bev, Osi, and Afa were superior for exon 19 deletion status, whereas ET+Bev, Osi, and gefitinib (Gef)+pemetrexed (Peme) were excellent for exon 21 L858Arg mutation status. The results were consistent in terms of the ORR and DoR and remained robust across sensitivity analyses. However, Erlo + Bev had the most grade 3 or higher adverse events. Osi, Erlo+Bev, and Erlo+Bev+Plat are reasonably recommended to balance PFS and OS, but adverse events should be considered. IT+aVEGFR+Plat shows potential superiority, but more clinical evidence is needed.

Secondary Resistant Mutations to Small Molecule Inhibitors in Cancer Cells

Secondary resistant mutations in cancer cells arise in response to certain small molecule inhibitors. These mutations inevitably cause recurrence and often progression to a more aggressive form. Resistant mutations may manifest in various forms. For example, some mutations decrease or abrogate the affinity of the drug for the protein. Others restore the function of the enzyme even in the presence of the inhibitor. In some cases, resistance is acquired through activation of a parallel pathway which bypasses the function of the drug targeted pathway. The Catalogue of Somatic Mutations in Cancer (COSMIC) produced a compendium of resistant mutations to small molecule inhibitors reported in the literature. Here, we build on these data and provide a comprehensive review of resistant mutations in cancers. We also discuss mechanistic parallels of resistance.

Rare epidermal growth factor receptor (EGFR) mutations in non-small cell lung cancer

Epidermal growth factor receptor (EGFR) mutations are the second most common oncogenic driver event in non-small cell lung cancer (NSCLC). Classical activating mutations (exon 19 deletions and the L858R point mutation) comprise the vast majority of EGFR mutations and are well defined as strong predictors for good clinical response to EGFR tyrosine kinase inhibitors (EGFRi). However, low frequency mutations including point mutations, deletions, insertions and duplications occur within exons 18-25 of the EGFR gene in NSCLC and are associated with poorer responses to EGFRi. Despite an increased uptake of more sensitive detection methods to identify rare EGFR mutations in patients, our understanding of the biology of these rare EGFR mutations is poor compared to classical mutations. In particular, clinical data focused on these mutations is lacking due to their rarity and challenges in trial recruitment, resulting in an absence of effective treatment strategies for many low frequency EGFR mutations. In this review, we describe the structural and mechanistic features of rare EGFR mutations in NSCLC and discuss the preclinical and clinical evidence for EGFRi response for individual rare EGFR mutations. We also discuss EGFRi sensitivity for complex EGFR mutations, and conclude by offering a perspective on the outstanding questions and future steps required to make advances in the treatment of NSCLC patients that harbour rare EGFR mutations.

Targeting human epidermal growth factor receptor 2 enhances radiosensitivity and reduces the metastatic potential of Lewis lung carcinoma cells

BACKGROUND

Sublethal radiation induces matrix metalloproteinase 9 (MMP-9)-mediated radioresistance in Lewis lung carcinoma (LLC) cells and their metastatic dissemination. We aim to determine if EGFR/HER2 activation associates with MMP-9-mediated radioresistance and invasiveness in irradiated LLC cells.

METHODS

LLC cells were treated with erlotinib or afatinib followed by sublethal radiation. After irradiation, we examined the phosphorylation of EGFR/HER2 and MMP-9 expression. Colony formation assay determined if the kinase inhibitors sensitize LLC cells to radiation. Matrigel-coated Boyden chamber assay assessed cellular invasiveness. Resulting tumors of wild-type LLC cells or HER2 knock-down mutant cells were irradiated to induce pulmonary metastases.

RESULTS

Afatinib more effectively sensitized LLC cells to radiation and decreased invasiveness by inhibiting phosphorylation of EGFR, HER2, Akt, ERK, and p38, and down-regulating MMP-9 when compared to erlotinib. Afatinib abolished radiation-induced lung metastases in vivo. Furthermore, LLC HER2 knock-down cells treated with radiation had growth inhibition.

CONCLUSION

Dual inhibition of radiation-activated EGFR and HER2 signaling by afatinib suppressed the proliferation and invasion of irradiated LLC cells. Increased radiosensitivity and decreased metastatic dissemination were observed by pharmacological or genetic HER2 inhibition in vivo. These findings indicate that HER2 plays a pivotal role in enhancing radioresistance and reducing metastatic potential of LLC cells.

IGF2 Autocrine-Mediated IGF1R Activation Is a Clinically Relevant Mechanism of Osimertinib Resistance in Lung Cancer

EGFR-mutated lung cancer accounts for a significant proportion of lung cancer cases worldwide. For these cases, osimertinib, a third-generation EGFR tyrosine kinase inhibitor, is extensively used as a first-line or second-line treatment. However, lung cancer cells acquire resistance to osimertinib in 1 to 2 years. Thus, a thorough clarification of resistance mechanisms to osimertinib is highly anticipated. Recent next-generation sequencing (NGS) of lung cancer samples identified several genetically defined resistance mechanisms to osimertinib, such as EGFR C797S or MET amplification. However, nongenetically defined mechanisms are not well evaluated. For a thorough clarification of osimertinib resistance, both genetic and nongenetic mechanisms are essential. By using our comprehensive protein phosphorylation array, we detected IGF1R bypass pathway activation after EGFR abolishment. Both of our established lung cancer cells and patient-derived lung cancer cells demonstrated IGF2 autocrine-mediated IGF1R pathway activation as a mechanism of osimertinib resistance. Notably, this resistance mechanism was not detected by a previously performed NGS, highlighting the essential roles of living cancer cells for a thorough clarification of resistance mechanisms. Interestingly, the immunohistochemical analysis confirmed the increased IGF2 expression in lung cancer patients who were treated with osimertinib and met the established clinical definition of acquired resistance. The findings highlight the crucial roles of cell-autonomous ligand expression in osimertinib resistance. Here, we report for the first time the IGF2 autocrine-mediated IGF1R activation as a nongenetic mechanism of osimertinib resistance in lung cancer at a clinically relevant level. IMPLICATIONS: Using comprehensive protein phosphorylation array and patient-derived lung cancer cells, we found that IGF2 autocrine-mediated IGF1R pathway activation is a clinically relevant and common mechanism of acquired resistance to osimertinib.

Afatinib for the Treatment of NSCLC Harboring Uncommon EGFR Mutations: A Database of 693 Cases

INTRODUCTION

Limited clinical data are available regarding the efficacy of EGFR tyrosine kinase inhibitors (EGFR TKIs) in patients with NSCLC harboring uncommon EGFR mutations. This pooled analysis assessed the activity of afatinib in 693 patients with tumors harboring uncommon EGFR mutations treated in randomized clinical trials, compassionate-use and expanded-access programs, phase IIIb trials, noninterventional trials, and case series or studies.

METHODS

Patients had uncommon EGFR mutations, which were categorized as follows: (1) T790M; (2) exon 20 insertions; (3) "major" uncommon mutations (G719X, L861Q, and S768I, with or without any other mutation except T790M or an exon 20 insertion); (4) compound mutations; and (5) other uncommon mutations. Key end points were overall response rate (ORR), duration of response, and time to treatment failure (TTF).

RESULTS

In EGFR TKI-naive patients (n = 315), afatinib demonstrated activity against major uncommon mutations (median TTF = 10.8 mo; 95% confidence interval [CI]: 8.1-16.6; ORR = 60.0%), compound mutations (median TTF = 14.7 mo; 95% CI: 6.8-18.5; ORR = 77.1%), other uncommon mutations (median TTF = 4.5 mo; 95% CI: 2.9-9.7; ORR = 65.2%), and some exon 20 insertions (median TTF = 4.2 mo; 95% CI: 2.8-5.3; ORR = 24.3%). The median duration of response for major uncommon mutations, compound mutations, other uncommon mutations, and some exon 20 insertions was 17.1, 16.6, 9.0, and 11.9 months, respectively. Activity of afatinib was also observed in EGFR TKI-pretreated patients (n = 378). A searchable database of these outcomes by individual genotype was generated.

CONCLUSIONS

Afatinib has clinical activity in NSCLC against major uncommon and compound EGFR mutations. It also has broad activity against other uncommon EGFR mutations and some exon 20 insertions. The data support the use of afatinib in these settings.

Overall Survival with Osimertinib in Untreated, EGFR-Mutated Advanced NSCLC

BACKGROUND

Osimertinib is a third-generation, irreversible tyrosine kinase inhibitor of the epidermal growth factor receptor (EGFR-TKI) that selectively inhibits both EGFR-TKI-sensitizing and EGFR T790M resistance mutations. A phase 3 trial compared first-line osimertinib with other EGFR-TKIs in patients with EGFR mutation-positive advanced non-small-cell lung cancer (NSCLC). The trial showed longer progression-free survival with osimertinib than with the comparator EGFR-TKIs (hazard ratio for disease progression or death, 0.46). Data from the final analysis of overall survival have not been reported.

METHODS

In this trial, we randomly assigned 556 patients with previously untreated advanced NSCLC with an EGFR mutation (exon 19 deletion or L858R allele) in a 1:1 ratio to receive either osimertinib (80 mg once daily) or one of two other EGFR-TKIs (gefitinib at a dose of 250 mg once daily or erlotinib at a dose of 150 mg once daily, with patients receiving these drugs combined in a single comparator group). Overall survival was a secondary end point.

RESULTS

The median overall survival was 38.6 months (95% confidence interval [CI], 34.5 to 41.8) in the osimertinib group and 31.8 months (95% CI, 26.6 to 36.0) in the comparator group (hazard ratio for death, 0.80; 95.05% CI, 0.64 to 1.00; P = 0.046). At 3 years, 79 of 279 patients (28%) in the osimertinib group and 26 of 277 (9%) in the comparator group were continuing to receive a trial regimen; the median exposure was 20.7 months and 11.5 months, respectively. Adverse events of grade 3 or higher were reported in 42% of the patients in the osimertinib group and in 47% of those in the comparator group.

CONCLUSIONS

Among patients with previously untreated advanced NSCLC with an EGFR mutation, those who received osimertinib had longer overall survival than those who received a comparator EGFR-TKI. The safety profile for osimertinib was similar to that of the comparator EGFR-TKIs, despite a longer duration of exposure in the osimertinib group. (Funded by AstraZeneca; FLAURA ClinicalTrials.gov number, NCT02296125.).

Treatment of Non-small Cell Lung Cancer with EGFR-mutations

The discovery of activating mutations in the epidermal growth factor receptor (EGFR) gene and development of tyrosine kinase inhibitors (TKIs) of EGFR have achieved a paradigm shift in treatment strategy of non-small cell lung cancer (NSCLC). For advanced NSCLC harboring activating EGFR mutations, an EGFR-TKI is preferably prescribed as it provides a superior survival benefit over platinum-based chemotherapy. To further improve the therapeutic outcomes, more potent EGFR-TKIs through irreversible inhibition of tyrosine kinase have been developed. In a recent clinical trial, an irreversible EGFR-TKI (osimertinib) showed a superior survival benefit with lower toxicity profile. In addition, combination treatments such as an EGFR-TKI plus platinum-based chemotherapy may achieve a long-term survival. For earlier-stage resectable NSCLC with EGFR-mutations, several clinical trials to assess the efficacy of EGFR-TKIs in pre-operative induction setting and in postoperative adjuvant setting are now ongoing. Here we review and discuss the current status and future perspectives of treatment for EGFR-mutated NSCLC.

The emerging treatment landscape of targeted therapy in non-small-cell lung cancer

Lung cancer is one of the most common cancer in the world. In 2018, there were over 2 million new cases of lung cancer and over 1.7 million deaths were attributed to lung cancer. Targeted therapy has emerged as an important mean of the disease management for patients with non-small-cell lung cancer (NSCLC). Herein, we review and analyze recent literature, discuss the targeting pathways and ongoing clinical trials in lung cancer. Chemotherapy is no longer the best available treatment for all patients. Therapeutic decisions should be guided by an understanding of the molecular features of patient's tumor tissues. The future gains will likely emerge from finding optimal ways of combining targeted therapy, immunotherapy, and chemotherapy.

Identification of a novel glycolysis-related gene signature for predicting metastasis and survival in patients with lung adenocarcinoma

Background

Lung cancer (LC) is one of the most lethal and most prevalent malignant tumors, and its incidence and mortality are increasing annually. Lung adenocarcinoma (LUAD) is the most common pathological type of lung cancer. Several biomarkers have been confirmed by data excavation to be related to metastasis, prognosis and survival. However, the moderate predictive effect of a single gene biomarker is not sufficient. Thus, we aimed to identify new gene signatures to better predict the possibility of LUAD.

Methods

Using an mRNA-mining approach, we performed mRNA expression profiling in large LUAD cohorts (n = 522) from The Cancer Genome Atlas (TCGA) database. Gene Set Enrichment Analysis (GSEA) was performed, and connections between genes and glycolysis were found in the Cox proportional regression model.

Results

We confirmed a set of nine genes (HMMR, B4GALT1, SLC16A3, ANGPTL4, EXT1, GPC1, RBCK1, SOD1, and AGRN) that were significantly associated with metastasis and overall survival (OS) in the test series. Based on this nine-gene signature, the patients in the test series could be divided into high-risk and low-risk groups. Additionally, multivariate Cox regression analysis revealed that the prognostic power of the nine-gene signature is independent of clinical factors.

Conclusion

Our study reveals a connection between the nine-gene signature and glycolysis. This research also provides novel insights into the mechanisms underlying glycolysis and offers a novel biomarker of a poor prognosis and metastasis for LUAD patients.

Overview of Current Immunotherapies Targeting Mutated KRAS Cancers

The occurrence of somatic substitution mutations of the KRAS proto-oncogene is highly prevalent in certain cancer types, which often leads to constant activation of proliferative pathways and subsequent neoplastic transformation. It is often seen as a gateway mutation in carcinogenesis and has been commonly deemed as a predictive biomarker for poor prognosis and relapse when conventional chemotherapeutics are employed. Additionally, its mutational status also renders EGFR targeted therapies ineffective owing to its downstream location. Efforts to discover new approaches targeting this menacing culprit have been ongoing for years without much success, and with incidences of KRAS positive cancer patients being on the rise, researchers are now turning towards immunotherapies as the way forward. In this scoping review, recent immunotherapeutic developments and advances in both preclinical and clinical studies targeting K-ras directly or indirectly via its downstream signal transduction machinery will be discussed. Additionally, some of the challenges and limitations of various K-ras targeting immunotherapeutic approaches such as vaccines, adoptive T cell therapies, and checkpoint inhibitors against KRAS positive cancers will be deliberated.

Cx32 mediates norepinephrine-promoted EGFR-TKI resistance in a gap junction-independent manner in non-small-cell lung cancer

The second-generation EGFR-TKI Afatinib is an irreversible ErbB family blocker used to treat patients with non-small-cell lung cancer (NSCLC). Unfortunately, resistance to this drug develops over time, and patients are always under great psychological pressure. A previous study showed that chronic stress hormones participate in EGFR-TKI resistance via β2 -AR signaling via an IL-6 dependent mechanism. Our study further explores a novel potential underlying mechanism. In the present study, we show that the stress hormone norepinephrine (NE) promotes Afatinib resistance by upregulating Cx32 expression. Furthermore, we, for the first time, find that Cx32 is a target gene for transcription factor CREB and NE enhances Cx32 mRNA expression by activation of CREB. We also demonstrate that Cx32 promotes Afatinib resistance by decreasing the degradation of EGFR-TKI resistance-associated proteins (MET, IGF-1R) and by increasing their transcription levels. Together, these results reveal that the stress hormone NE accelerates Afatinib resistance by increasing the expression of Cx32, which augments MET and IGF-1R levels in cancer cells and provides a promising therapeutic strategy against EGFR-TKI Afatinib resistance in NSCLC.

Nanoformulations of small molecule protein tyrosine kinases inhibitors potentiate targeted cancer therapy

Protein tyrosine kinases (PTKs) are closely related to tumor development and usually participate in apoptosis, DNA repair, and cell proliferation by activating signaling pathways. Therefore, PTKs have become the most promising targets for cancer therapy. In recent years, a large number of studies on the mechanism of tyrosine kinase activation have indicated that tyrosine kinase inhibitors (TKIs) have important clinical significance and application prospects as targeted anticancer drugs because they can effectively block certain cellular signaling pathways, inhibit tumor metastases and reduce tumor proliferation. Although the increasing emergence of anticancer drug resistance limits the clinical application of TKIs, emerging nanotechnology has made it possible to solve this problem. In this work, the state-of-art of small molecule protein tyrosine kinase inhibitors and the applications of drug delivery systems for TKIs are reviewed, and the potentials and challenges for future research of small molecule TKIs are addressed.

Real-World Data Of Osimertinib In Patients With Pretreated Non-Small Cell Lung Cancer: A Retrospective Study

Purpose

Osimertinib is an oral, irreversible epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) targeted for both EGFR sensitizing mutations and T790M resistance mutation in patients with non-small-cell lung cancer (NSCLC). We assessed efficacy and safety of osimertinib in patients with pretreated NSCLC in a real-world setting.

Patients and methods

Ninety-four patients with advanced NSCLC who received osimertinib after progression of prior EGFR-TKIs or chemotherapy treatments were retrospectively collected.

Results

In patients evaluable for response analysis (n = 91), overall objective response rate (ORR) was 47.3%, and disease control rate (DCR) was 90.1%. Median duration of response (DoR) in responding patients was 12.5 months (95% confidence interval [CI], 10.7 to 14.3). Median progression-free survival (PFS) was 8.5 months (95% CI, 7.4 to 9.6) in 2nd line group, 9.1 months (95% CI, 6.6 to 11.6) in ≥3rd line group, and 8.6 months (95% CI, 7.2 to 10.0) in overall population. For subgroup analysis, DCR and median PFS were 91.9% and 8.6 months (95% CI, 7.2 to 10.0) in patients with detectable T790M mutation, respectively, while 80.0% and 3.2 months (95% CI, 0.5 to 5.9) for those without. Median PFS was significantly longer for T790M-positive patients co-occurring with exon19del than with L858R (17.9 months vs 7.3 months; P<0.001). Among 45 patients with metastases to the central nervous system (CNS), median systemic PFS was 8.8 months (95% CI, 6.9 to 10.7), while intracranial time to progression (iTTP) was not reached. Safety profile was acceptable, no adverse events (AEs) related deaths was observed.

Conclusion

Osimertinib was highly active in patients with pretreated advanced NSCLC who harbored EGFR T790M mutation, with manageable side-effects.

FDA- and EMA-Approved Tyrosine Kinase Inhibitors in Advanced EGFR-Mutated Non-Small Cell Lung Cancer: Safety, Tolerability, Plasma Concentration Monitoring, and Management

Non-small-cell lung cancer (NSCLC) is the most common form of primary lung cancer. The discovery of several oncogenic driver mutations in patients with NSCLC has allowed the development of personalized treatments based on these specific molecular alterations, in particular in the tyrosine kinase (TK) domain of the epidermal growth factor receptor (EGFR) gene. Gefitinib, erlotinib, afatinib, and osimertinib are TK inhibitors (TKIs) that specifically target EGFR and are currently approved by the Food and Drug Administration (FDA) and the European Medicines Agency (EMA) as first line treatment for sensitive EGFR-mutant patients. However, these four drugs are associated with severe adverse events (AEs) that can significantly impact patient health-related quality of life and patient monitoring. EGFR-TKIs are commonly used together with other types of medication that can substantially interact. Here, we review approaches used for the management of TKI-AEs in patients with advanced NSCLC to promote the benefits of treatments and minimize the risk of TKI treatment discontinuation. We also consider potential TKI–drug interactions and discuss the usefulness of plasma concentration monitoring TKIs based on chromatographic and mass spectrometry approaches to guide clinical decision-making. Adjusting the most appropriate therapeutic strategies and drug doses may improve the performance therapy and prognosis of patients with advanced EGFR-mutated NSCLC.

Overview of current systemic management of EGFR-mutant NSCLC

Front-line epidermal growth factor receptor tyrosine kinase inhibitor (EGFR TKI) therapy is the standard of care for lung cancer patients with sensitising EGFR mutations (exon 19 deletion or L858R mutation). Several phase III studies have demonstrated the superiority of gefitinib, erlotinib (first generation of TKIs) or afatinib (second generation) to chemotherapy in progression-free survival and response rates. Drug-related toxicities, such as diarrhoea, acneiform skin rash, mucositis, and paronychia, are frequently encountered in patients who receive EGFR TKIs. Other rare side-effects, such as hepatic impairment and interstitial lung disease, should be identified early and managed carefully. Patients with uncommon EGFR mutations, such as G719X, S768I, and L861Q, may require special selection of EGFR TKIs. The combination of erlotinib plus bevacizumab has been accepted in certain parts of the world as an alternative front-line treatment. This review article summarizes the studies leading to the establishment of EGFR TKIs in EGFR-mutant lung cancer patients. The side-effect profiles of the current EGFR TKIs in these large trials are listed, and the management of uncommon EGFR mutations is discussed. Finally, the potential role of combination front-line treatment is discussed.

Inhibition of osimertinib-resistant epidermal growth factor receptor EGFR-T790M/C797S

We present inhibitors of drug resistant mutants of EGFR including T790M and C797S. In addition, we present the first X-ray crystal structures of covalent inhibitors in complex with C797S-mutated EGFR to gain insight into their binding mode.

Precision medicine has revolutionized the treatment of patients in EGFR driven non-small cell lung cancer (NSCLC). Targeted drugs show high response rates in genetically defined subsets of cancer patients and markedly increase their progression-free survival as compared to conventional chemotherapy. However, recurrent acquired drug resistance limits the success of targeted drugs in long-term treatment and requires the constant development of novel efficient inhibitors of drug resistant cancer subtypes. Herein, we present covalent inhibitors of the drug resistant gatekeeper mutant EGFR-L858R/T790M based on the pyrrolopyrimidine scaffold. Biochemical and cellular characterization, as well as kinase selectivity profiling and western blot analysis, substantiate our approach. Moreover, the developed compounds possess high activity against multi drug resistant EGFR-L858R/T790M/C797S in biochemical assays due to their highly reversible binding character, that was revealed by characterization of the binding kinetics. In addition, we present the first X-ray crystal structures of covalent inhibitors in complex with C797S-mutated EGFR which provide detailed insight into their binding mode.

Vol-PACT: A Foundation for the NIH Public-Private Partnership That Supports Sharing of Clinical Trial Data for the Development of Improved Imaging Biomarkers in Oncology

PURPOSE

To develop a public-private partnership to study the feasibility of a new approach in collecting and analyzing clinically annotated imaging data from landmark phase III trials in advanced solid tumors.

PATIENTS AND METHODS

The collection of clinical trials fulfilled the following inclusion criteria: completed randomized trials of > 300 patients, highly measurable solid tumors (non-small-cell lung cancer, colorectal cancer, renal cell cancer, and melanoma), and required sponsor and institutional review board sign-offs. The new approach in analyzing computed tomography scans was to transfer to an academic image analysis laboratory, draw contours semi-automatically by using in-house-developed algorithms integrated into the open source imaging platform Weasis, and perform serial volumetric measurement.

RESULTS

The median duration of contracting with five sponsors was 12 months. Ten trials in 7,085 patients that covered 12 treatment regimens across 20 trial arms were collected. To date, four trials in 3,954 patients were analyzed. Source imaging data were transferred to the academic core from 97% of trial patients (n = 3,837). Tumor imaging measurements were extracted from 82% of transferred computed tomography scans (n = 3,162). Causes of extraction failure were nonmeasurable disease (n = 392), single imaging time point (n = 224), and secondary captured images (n = 59). Overall, clinically annotated imaging data were extracted in 79% of patients (n = 3,055), and the primary trial end point analysis in each trial remained representative of each original trial end point.

CONCLUSION

The sharing and analysis of source imaging data from large randomized trials is feasible and offer a rich and reusable, but largely untapped, resource for future research on novel trial-level response and progression imaging metrics.

Optimizing the sequencing of tyrosine kinase inhibitors (TKIs) in epidermal growth factor receptor (EGFR) mutation-positive non-small cell lung cancer (NSCLC)

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer, accounting for 80-85% of cases. Epidermal growth factor receptor (EGFR) mutations are observed in approximately 40% and 20% of patients with NSCLC in Asian and non-Asian populations, respectively. First-generation (gefitinib, erlotinib) and second-generation (afatinib, dacomitinib) EGFR-tyrosine kinase inhibitors (TKIs) have been standard-of-care (SoC) first-line treatment for patients with sensitizing EGFR mutation positive advanced NSCLC following Phase III trials versus platinum-based doublet chemotherapy. However, most patients treated with first-line first- or second-generation EGFR-TKIs develop resistance. Osimertinib, a third-generation, central nervous system active EGFR-TKI which potently and selectively inhibits both EGFR-TKI sensitizing (EGFRm) and the most common EGFR T790 M resistance mutations, has shown superior efficacy versus first-generation EGFR-TKIs (gefitinib / erlotinib). Osimertinib is now a treatment option for patients with advanced NSCLC harboring EGFRm in the first-line setting, and treatment of choice for patients with T790 M positive NSCLC following disease progression on first-line EGFR-TKIs. The second-generation EGFR-TKI dacomitinib has also recently been approved for the first-line treatment of EGFRm positive metastatic NSCLC. There remains a need to determine appropriate sequencing of EGFR-TKIs in this setting, including EGFR-TKIs as monotherapy or in combination with other TKIs / signaling pathway inhibitors. This review considers the evolving role of sequencing treatments to maximize benefits for patients with EGFRm positive advanced NSCLC.

Role of the dynamic tumor microenvironment in controversies regarding immune checkpoint inhibitors for the treatment of non-small cell lung cancer (NSCLC) with EGFR mutations

Immunotherapy has been incorporated into the first- and second-line treatment strategies for non-small cell lung cancer (NSCLC), profoundly ushering in a new treatment landscape. However, both adaptive signaling and oncogenic (epidermal growth factor receptor (EGFR)-driven) signaling may induce PD-L1 upregulation in NSCLC. Nevertheless, the superiority of immune checkpoint inhibitors (ICIs) in advanced EGFR-mutant NSCLC is only moderate. ICIs appear to be well tolerated, but clinical activity for some advanced EGFR-mutant NSCLC patients has only been observed in a small proportion of trials. Hence, there are still several open questions about PD-L1 axis inhibitors in patients with NSCLC whose tumors harbor EGFR mutations, such as the effect of EGFR tyrosine kinase inhibitors (TKIs) or EGFR mutations in the tumor microenvironment (TME). Finding the answers to these questions requires ongoing trials and preclinical studies to identify the mechanisms explaining this possible increased susceptibility and to identify prognostic molecular and clinical markers that may predict benefits with PD-1 axis inhibition in this specific NSCLC subpopulation. The presence of multiple mechanisms, including dynamic immune TME profiles, changes in PD-L1 expression and low tumor mutational burdens, may explain the conflicting data regarding the correlation between PD-L1 axis inhibitors and EGFR mutation status. We conducted a review of this currently controversial topic in an attempt to aid in the decision-making process.

Afatinib in locally advanced/metastatic NSCLC harboring common EGFR mutations, after chemotherapy: a Phase IV study

Aim

The current study evaluated the efficacy and tolerability of second-line afatinib in patients with EGFR mutation-positive (EGFRm+) non-small-cell lung cancer (NSCLC) following chemotherapy.

Patients & methods

In this open-label, single-arm Phase IV study, patients with EGFRm+ (Del19/L858R) NSCLC who had progressed following platinum-based chemotherapy received afatinib (starting dose 40 mg/day). The primary end point was confirmed objective response.

Results

60 patients received afatinib for a median duration of 11.5 months. 50% of patients had a confirmed objective response, of median duration 13.8 months. Median progression-free survival was 10.9 months. The most common treatment-related adverse events were diarrhea (72%), rash (28%) and paronychia (23%).

Conclusion

Our data support the use of afatinib (40 mg/day) as an effective and well-tolerated second-line treatment in EGFRm+ NSCLC.