Optimizing outcomes and treatment sequences in EGFR mutation-positive non-small-cell lung cancer: recent updates

Development of Stable Amino-Pyrimidine-Curcumin Analogs: Synthesis, Equilibria in Solution, and Potential Anti-Proliferative Activity

With the clear need for better cancer treatment, naturally occurring molecules represent a powerful inspiration. Recently, curcumin has attracted attention for its pleiotropic anticancer activity in vitro, especially against colorectal and prostate cancer cells. Unfortunately, these encouraging results were disappointing in vivo due to curcumin's low stability and poor bioavailability. To overcome these issues, herein, the synthesis of eight new pyrimidine-curcumin derivatives is reported. The compounds were fully characterized (1H/13C NMR (Nuclear Magnetic Resonance), LC-MS (Liquid Chromatography-Mass Spectrometri), UV-Vis spectroscopy), particularly their acid/base behavior; overall protonation constants were estimated, and species distribution, as a function of pH, was predicted, suggesting that all the compounds are in their neutral form at pH 7.4. All the compounds were extremely stable in simulated physiological media (phosphate-buffered saline and simulated plasma). The compounds were tested in vitro (48 h incubation treatment) to assess their effect on cell viability in prostate cancer (LNCaP and PC3) and colorectal cancer (HT29 and HCT116) cell lines. Two compounds showed the same anti-proliferative activity as curcumin against HCT116 cells and improved cytotoxicity against PC3 cells.

An outlook of docking analysis and structure-activity relationship of pyrimidine-based analogues as EGFR inhibitors against non-small cell lung cancer (NSCLC)

Almost 80% of lung cancer diagnoses each year correspond to non-small cell lung cancer (NSCLC). The percentage of NSCLC with EGFR overexpression ranges from 40% to 89%, with squamous tumors showing the greatest rates (89%) and adenocarcinomas showing the lowest rates (41%). Therefore, in NSCLC therapy, blocking the EGFR-driven pathway by inhibiting the intracellular tyrosine kinase domain of EGFR has exhibited significant improvement. In this view, several small molecules particularly pyrimidine/fused pyrimidine scaffolds were intended for molecular hybridization to develop EGFR-TK inhibitors. However, the associated limitation such as resistance and genetic mutation along with adverse effects, constrained the long-term treatment and effectiveness of such medication. Therefore, in recent years, pyrimidine derivatives were uncovered as potential EGFR TKIs. The present review summarised the research progress of EGFR TKIs to dazed structure-activity relationship, biological evaluation, and comparative docking studies of pyrimidine compounds. We have added the comparative docking analysis followed by the molecular simulation study against the four different PDBs of EGFR to strengthen the already existing research. Docking analysis unfolded that compound 14 resulted as noticeable with all different PDB and managed to interact with some of the crucial amino acid residues. From a future perspective, researchers must develop a more selective inhibitor, that can selectively target the mutation. Our review will support medicinal chemists in the direction of the development of novel pyrimidine-based EGFR TKIs.Communicated by Ramaswamy H. Sarma.

Insights into fourth generation selective inhibitors of (C797S) EGFR mutation combating non-small cell lung cancer resistance: a critical review

Lung cancer is the second most common cause of morbidity and mortality among cancer types worldwide, with non-small cell lung cancer (NSCLC) representing the majority of most cases. Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR TKIs) are among the most commonly used targeted therapy to treat NSCLC. Recent years have seen the evaluation of many synthetic EGFR TKIs, most of which showed therapeutic activity in pertinent models and were classified as first, second, and third-generation. The latest studies have concluded that their efficacy was also compromised by additional acquired mutations, including C797S. Because second- and third-generation EGFR TKIs are irreversible inhibitors, they are ineffective against C797S containing EGFR triple mutations (Del19/T790M/C797S and L858R/T790M/C797S). Therefore, there is an urgent unmet medical need to develop next-generation EGFR TKIs that selectively inhibit EGFR triple mutations via a non-irreversible mechanism. This review covers the fourth-generation EGFR-TKIs' most recent design with their essential binding interactions, the clinical difficulties, and the potential outcomes of treating patients with EGFR mutation C797S resistant to third-generation EGFR-TKIs was also discussed. Moreover, the utilization of various therapeutic strategies, including multi-targeting drugs and combination therapies, has also been reviewed.

Imidazo[1,2-a]quinazolines as novel, potent EGFR-TK inhibitors: Design, synthesis, bioactivity evaluation, and in silico studies

Tyrosine protein kinases (TKs) have been proved to play substantial roles on many cellular processes and their overexpression tend to be found in various types of cancers. Therefore, over recent decades, numerous tyrosine protein kinase inhibitors particularly epidermal growth factor receptor (EGFR) inhibitors have been introduced to treat cancer. Present study describes a novel series of imidazo[1,2-a]quinazolines 18 as potential -inhibitors. These imidazoquinazolines (18a and 18o, in particular) had great anti-proliferative activities with IC₅₀ values in the micromolar (µM) range against PC3, HepG2, HeLa, and MDA-MB-231 comparing with Erlotinib as reference marketed drug. Further evaluations on some derivatives revealed their potential to induce apoptotic cell death and cell growth arrest at G0 phase of the cell cycle. Afterwards, the kinase assay on the most potent compounds 18a and 18o demonstrated their inhibitory potencies and selectivity toward EGFR (with EGFR-IC₅₀ values of 82.0 µM and 12.3 µM, respectively). Additionally, western blot analysis on these compounds 18a and 18o exhibited that they inhibited the phosphorylation of EGFR and its downstream molecule extracellular signal-regulated kinase (ERK1/2). However, the level of B-Actin phosphorylation was not changed. Finally, density functional theory calculations, docking study, and independent gradient model (IGM) were performed to illustrate the structure-activity relationship (SAR) and to assess the interactions between proteins and ligands. The results of molecular docking studies had great agreement with the obtained EGFR inhibitory results through in vitro evaluations.

Treatment Strategies for Non-Small Cell Lung Cancer with Common EGFR Mutations: A Review of the History of EGFR TKIs Approval and Emerging Data

The development of targeted therapies over the past two decades has led to a dramatic change in the management of EGFR-mutant non-small cell lung cancer (NSCLC). While there are currently five approved EGFR tyrosine kinase inhibitors (TKIs) for treating EGFR-mutant NSCLC in the first-line setting, therapy selection after progression on EGFR TKIs remains complex. Multiple groups are investigating novel therapies and drug combinations to determine the optimal therapy and treatment sequence for these patients. In this review, we summarize the landmark trials and history of the approval of EGFR TKIs, their efficacy and tolerability, and the role of these therapies in patients with central nervous system metastasis. We also briefly discuss the mechanisms of resistance to EGFR TKIs, ongoing attempts to overcome resistance and improve outcomes, and finalize by offering treatment sequencing recommendations.

RELAY, Ramucirumab Plus Erlotinib Versus Placebo Plus Erlotinib in Patients with Untreated, Epidermal Growth Factor Receptor Mutation-Positive, Metastatic Non-Small-Cell Lung Cancer: Safety Profile and Manageability

INTRODUCTION

RELAY was a global, double-blind, placebo-controlled phase III study that demonstrated superior progression-free survival (PFS) for ramucirumab plus erlotinib (RAM + ERL) versus placebo plus erlotinib (PBO + ERL) in the first-line treatment of patients with epidermal growth factor receptor (EGFR) exon 19 deletion or exon 21 (L858R) mutation-positive, metastatic non-small-cell lung cancer (NSCLC).

OBJECTIVE

This article provides an in-depth analysis of the safety profile of RAM + ERL versus PBO + ERL observed in RELAY.

METHODS

Eligible patients met these criteria: stage IV NSCLC; EGFR exon 19 deletion or exon 21 substitution (L858R) mutation; Eastern Cooperative Oncology Group performance status 0 or 1; and no central nervous system metastases. Patients were randomized (1:1) to receive erlotinib 150 mg/day orally plus either ramucirumab 10 mg/kg intravenously or matching placebo once every 2 weeks, until disease progression or unacceptable toxicity. The primary endpoint was PFS. Safety was evaluated based on reported treatment-emergent adverse events (AEs) and clinical laboratory assessments.

RESULTS

The safety population comprised 446 patients (221 in RAM+ERL arm; 225 in PBO + ERL arm) who received at least one dose of study drug between January 2016 and February 2018. The overall incidence of grade ≥ 3 AEs was higher with RAM + ERL than with PBO + ERL, primarily driven by grade 3 hypertension. Grade ≥ 3 dermatitis acneiform and diarrhea were also reported more frequently in the RAM + ERL arm. The increased incidence of AEs with RAM + ERL was easily detected through routine monitoring and managed through dose adjustments and appropriate supportive care.

CONCLUSION

This in-depth safety analysis from RELAY supports that RAM + ERL, irrespective of the increased incidence of AEs, does not affect a patient's ability to benefit from treatment.

CLINICAL TRIAL REGISTRATION NUMBER

NCT02411448.

Study of patient characteristics, treatment patterns, EGFR testing patterns and outcomes in real-world patients with EGFRm+ non-small cell lung cancer

OBJECTIVE

This retrospective, observational study examined patient characteristics, treatment patterns, testing patterns, and outcomes of US patients receiving first-/second- or third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs).

METHODS

This study used an electronic health record-derived de-identified database. Eligible patients had advanced EGFRm⁺ non-small cell lung cancer. Descriptive statistics were used to describe demographic, clinical, and treatment characteristics. Logistic regression models were used to identify patient characteristics that were associated with the use of osimertinib vs. a first-/second-generation EGFR TKI. Kaplan-Meier methods were used for survival analysis.

RESULTS

Of the 782 patients who received first-line (1L) therapy with first-/second-generation EGFR TKIs in cohort A, erlotinib was the most common (58%), and osimertinib was the most widely prescribed second-line (2L) therapy (52%). Of the patients who received 1L therapy with osimertinib, a greater range of treatments were prescribed in 2L. A third of patients treated with first-/second-generation EGFR TKIs underwent EGFR testing near the end of 1L, and 44% of these patients had T790M positive disease. The median time on targeted therapy (TTT) of the cohort was 11.1 months (95% confidence interval [CI] 9.7, 12.3), and the median overall survival from the start of 1L therapy was 23.5 months (95% CI 20.7, 24.8).

CONCLUSIONS

The majority of patients treated with first-/second-generation EGFR TKIs went on to receive osimertinib in the 2L setting, but overall, only a third of patients had received molecular testing at progression. Improved testing frequency is vital to inform treatment decisions.

Post-chemotherapy and targeted therapy imaging of the chest in lung cancer

Non-small-cell lung cancer (NSCLC) is frequently diagnosed when it is not amenable to local therapies; therefore, systemic agents are the mainstay of therapy for many patients. In recent years, treatment of advanced NSCLC has evolved from a general approach primarily involving chemotherapy to a more personalised strategy in which biomarkers such as the presence of genomic tumour aberrations and the expression of immune proteins such as programmed death-ligand 1 (PD-L1), in combination with other elements of clinical information such as histology and clinical stage, guide management. For instance, pathways resulting in uncontrolled growth and proliferation of tumour cells due to epidermal growth factor receptor (EGFR) mutations and anaplastic lymphoma kinase (ALK) rearrangements may be targeted by tyrosine kinase inhibitors (TKIs). In this article, we review the current state of medical oncology, imaging characteristics of mutations, pitfalls in response assessments and the imaging of complications.

Afatinib in EGFR TKI-Naïve Patients with Locally Advanced or Metastatic EGFR Mutation-Positive Non-Small Cell Lung Cancer: A Pooled Analysis of Three Phase IIIb Studies

Background

Afatinib is approved for first-line treatment of patients with epidermal growth factor receptor mutation-positive (EGFRm+) non-small-cell lung cancer (NSCLC). Here, we report findings from a combined analysis of three phase IIIb studies of afatinib in EGFR tyrosine kinase inhibitor (TKI)-naïve patients.

Methods

EGFR-TKI-naïve patients with EGFRm+ NSCLC received afatinib 40 mg/day. Dose reductions were permitted for adverse events (AEs). Efficacy endpoints included progression-free survival (PFS), time to symptomatic progression (TTSP), and tumor response. Subgroup analyses were performed by Eastern Cooperative Oncology Group performance status (ECOG PS), presence of brain metastasis, age and common/uncommon EGFR mutations (plus other factors).

Results

1108 patients were treated. Median age was 61 years (range, 25-89); 19.2% had baseline brain metastases, 4.4% had ECOG PS ≥2, and 17.9% had tumors harboring uncommon mutations. Treatment-related AEs (TRAEs) were reported in 97.2%, most commonly diarrhea and rash. 41.6% had AEs leading to dose reduction. Median PFS was 13.0 months [95% confidence interval (CI): 12.0-13.8]; median TTSP was 14.8 months (95% CI: 13.9-16.1). Objective response rate (ORR) was 55.0%. Age, presence of baseline brain metastases, major (G719X, L861Q, S768I) or compound uncommon mutations had little/no effect on PFS, TTSP, or ORR, while outcomes were poorer in patients with ECOG PS 2 or exon 20 insertion/T790M mutations.

Conclusions

Afatinib was tolerable with no new safety signals. Afatinib demonstrated encouraging efficacy in a broad patient population, including those with brain metastases or uncommon EGFR mutations.

Pyrimidine-based EGFR TK inhibitors in targeted cancer therapy

Despite significant improvements of new treatment options, cancer continues to represent as one of the most common and fatal disease. The EGFR signaling pathway is considered as a significant approach in targeted therapy of cancers. Blocking the EGFR-driven pathway by inhibiting the intracellular tyrosine kinase domain of EGFR have shown considerable improvement in cancer therapy. In an effort to identify EGFR tyrosine kinase inhibitors (TKI), several small molecules especially pyrimidine containing derivatives have been designed by applying molecular simulation and evaluated the emergence of epigenetic mutation and resistance problems restricted the long-term effectiveness of such medication and explained the need for further investigations in this field. In recent years, the studies have been focused on genetic alterations on EGFR tyrosine kinase domain, which led to the design and synthesis of more selective and effective inhibitors. Herein, we give an overview of the importance and status of EGFR inhibitors in cancer therapy. In addition, we provide an update of the recent advances in design, discovery and development of novel pyrimidine containing compounds as promising selective EGFR TK inhibitors.

Afatinib as First-Line Treatment in Asian Patients with EGFR Mutation-Positive NSCLC: A Narrative Review of Real-World Evidence

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR TKIs) are a standard of care in the first-line treatment of patients with EGFR mutation-positive metastatic non-small-cell lung cancer (NSCLC). EGFR mutations are relatively common in Asian patients with NSCLC, and there is an increasing number of studies supporting the effectiveness of the second-generation TKI afatinib in routine clinical practice in Asia. This article reviews these real-world studies investigating afatinib as first-line treatment for EGFR mutation-positive NSCLC in Asian patients. Evidence from real-world studies with afatinib in this patient population supports findings from randomized controlled trials (RCTs) showing that afatinib is associated with more favorable outcomes compared with the first-generation EGFR TKIs. The effectiveness of afatinib has also been shown in real-world studies in Asian patients with poor prognostic factors, who are often under-represented or excluded from RCTs, such as those with uncommon EGFR mutations, brain metastases, or poor performance status, and elderly patients. The tolerability profile of afatinib in the real-world setting reflects that seen in RCTs, with no new safety signals reported in real-world studies in Asian patients with EGFR mutation-positive NSCLC. Dose-modification strategies also seem to be effective in the real world, with results of the RealGido study, which included 44% Asian patients, confirming findings from prospective clinical trials showing that tolerability-guided afatinib dose modifications can reduce the incidence of adverse events without adversely affecting clinical outcomes. While further research, including clinical trial data, is needed, real-world data have also demonstrated the feasibility of sequential afatinib followed by the third-generation TKI osimertinib in T790M-positive EGFR mutation-positive patients, which showed longer overall survival. Together, these real-world results demonstrate the real-world clinical effectiveness of afatinib as first-line treatment for patients with EGFR mutation-positive NSCLC.

Cost-Effectiveness Analysis of Afatinib, Erlotinib, and Gefitinib as First-Line Treatments for EGFR Mutation-Positive Non-Small-Cell Lung Cancer in Ontario, Canada

OBJECTIVE

The objective of this study was to compare the cost effectiveness of first-line epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) for the treatment of non-small-cell lung cancer.

METHODS

This study used Ontario Cancer Registry-linked administrative data to identify patients with a primary diagnosis of lung cancer who received EGFR-TKIs as first-line treatment between 1 January, 2014 and 31 August, 2019. A net benefit regression approach accounting for baseline covariates and propensity scores was used to estimate incremental net benefits and incremental cost-effectiveness ratios. Outcome measures were calculated over a 68-month period and were discounted with an annual rate of 1.5%. Sensitivity analyses were conducted to assess and characterize the uncertainties.

RESULTS

A total of 547 patients were included in the study, of whom 20.1%, 23.6%, and 56.3% received afatinib, erlotinib, and gefitinib, respectively. Erlotinib was dominated by afatinib and gefitinib. Compared to gefitinib, afatinib was associated with higher effectiveness (adjusted incremental quality-adjusted life-year: 0.21), higher total costs (adjusted incremental costs: $9745), and an incremental cost-effectiveness ratio of $46,506 per quality-adjusted life-year gained. Results from the sensitivity analyses indicated the findings of the base-case analysis were robust.

CONCLUSIONS

Contrary to previously published studies, our study established head-to-head comparisons of effectiveness and treatment-related costs of first-line EGFR-TKIs. Our findings suggest afatinib was the most cost-effective option among the three EGFR-TKIs.

Cost-effectiveness analysis of first-line treatments for advanced epidermal growth factor receptor-mutant non-small cell lung cancer patients

Objectives

Recent studies showed prolonged survival for advanced epidermal growth factor receptor (EGFR)‐mutant non‐small cell lung cancer (NSCLC) patients treated with both monotherapies and combined therapies. However, high costs limit clinical applications. Thus, we conducted this cost‐effectiveness analysis to explore an optimal first‐line treatment for advanced EGFR‐mutant NSCLC patients.

Materials and Methods

Survival data were extracted from six clinical trials, including ARCHER1050 (dacomitinib vs. gefitinib); FLAURA (osimertinib vs. gefitinib/erlotinib); JO25567 and NEJ026 (bevacizumab +erlotinib vs. erlotinib); NEJ009 (gefitinib +chemotherapy vs. gefitinib); and NCT02148380 (gefitinib +chemotherapy vs. gefitinib vs. chemotherapy) trials. Cost‐related data were obtained from hospitals and published literature. The effect parameter (quality‐adjusted life year [QALY]) was the reflection of both survival and utility. Incremental cost‐effectiveness ratio (ICER), average cost‐effectiveness ratio (ACER), and net benefit were calculated, and the willingness‐to‐pay (WTP) threshold was set at $30828/QALY from the perspective of the Chinese healthcare system. Sensitivity analysis was performed to explore the stability of results.

Results

We compared treatment groups with control groups in each trial. ICERs were $1897750.74/QALY (ARCHER1050), $416560.02/QALY (FLAURA), ‐$477607.48/QALY (JO25567), ‐$464326.66/QALY (NEJ026), ‐$277121.22/QALY (NEJ009), ‐$399360.94/QALY (gefitinib as comparison, NCT02148380), and ‐$170733.05/QALY (chemotherapy as comparison, NCT02148380). Moreover, ACER and net benefit showed that the combination of EGFR‐TKI with chemotherapy and osimertinib was of more economic benefit following first‐generation EGFR‐TKIs. Sensitivity analyses showed that the impact of utilities and monotherapy could be cost‐effective with a 50% cost reduction.

Conclusion

First‐generation EGFR‐TKI therapy remained the most cost‐effective treatment option for advanced EGFR‐mutant NSCLC patients. Our results could serve as both a reference for both clinical practice and the formulation of medical insurance reimbursement.

Factors affecting treatment selection and overall survival for first-line EGFR-tyrosine kinase inhibitor therapy in non-small-cell lung cancer

Aim: To investigate the factors associated with treatment selection and overall survival for first-line EGFR-tyrosine kinase inhibitors (EGFR-TKIs) therapy among patients with non-small-cell lung cancer. Materials & methods: We conducted a retrospective cohort study of linked administrative health databases in Ontario, Canada. Results: A total of 1011 patients received an EGFR-TKI as first-line therapy. Treatment selection and overall survival associated with these treatments were affected by age, sex, geographical residency, comorbidities and different sites of metastasis. Conclusion: Though recent approval of osimertinib offers a potential new standard of care in the first-line setting, earlier generation TKIs remain pillars in treatment of non-small-cell lung cancer therapeutic armamentarium. Our findings may contribute to optimizing treatment sequencing of EGFR-TKIs to maximize clinical benefits.

Licochalcone A inhibits EGFR signalling and translationally suppresses survivin expression in human cancer cells

Dysfunction of epidermal growth factor receptor (EGFR) signalling plays a critical role in the oncogenesis of non–small‐cell lung cancer (NSCLC). Here, we reported the natural product, licochalcone A, exhibited a profound anti‐tumour efficacy through directly targeting EGFR signalling. Licochalcone A inhibited in vitro cell growth, colony formation and in vivo tumour growth of either wild‐type (WT) or activating mutation EGFR‐expressed NSCLC cells. Licochalcone A bound with L858R single‐site mutation, exon 19 deletion, L858R/T790M mutation and WT EGFR ex vivo, and impaired EGFR kinase activity both in vitro and in NSCLC cells. The in silico docking study further indicated that licochalcone A interacted with both WT and mutant EGFRs. Moreover, licochalcone A induced apoptosis and decreased survivin protein robustly in NSCLC cells. Mechanistically, we found that treatment with licochalcone A translationally suppressed survivin through inhibiting EGFR downstream kinases ERK1/2 and Akt. Depletion of the translation initiation complex by eIF4E knockdown effectively inhibited survivin expression. In contrast, knockdown of 4E‐BP1 showed the opposite effect and dramatically enhanced survivin protein level. Overall, our data indicate that targeting survivin might be an alternative strategy to sensitize EGFR‐targeted therapy.

A review of Osimertinib in NSCLC and pharmacist role in NSCLC patient care

Lung cancer is a complex, genetically heterogeneous disease. It is the most common cause of cancer-related deaths worldwide. Non-small cell lung cancer (NSCLC) represents the majority of the diagnosed lung cancer cases. Osimertinib is a new treatment option that demonstrated a superior efficacy over standard epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) or platinum-based chemotherapy. The safety and efficacy of osimertinib (a third generation EGFR-TKIs) were confirmed by well-designed clinical trials. Consequently, osimertinib was considered a first-line treatment option, particularly in patients with EGFR mutant NSCLC. It has been approved by FDA for the treatment of advance or metastatic NSCLC patients with specific EGFR-mutant NSCLC. As an active member of the multidisciplinary team, pharmacist has a promising role in assuring safe, effective and cost-effective treatment in patient with NSCLC. This review article aims to highlight the latest evidence about osimertinib use as a new treatment option in the clinical practice and to review the potential pharmacist key roles in NSCLC patient care.

Treatment sequence of first and second generation tyrosine kinase inhibitor followed by osimertinib in EGFR-mutated non-small-cell lung cancer: a real life study

Background: We aimed to assess the effectiveness and cost of patients with first line tyrosine kinase inhibitors (TKIs) sequence of first (1G) and second generation (2G) followed by osimertinib. Materials & methods: Using the French nationwide claims and hospitalization database, we analyzed non-small-cell lung cancer patients who had been treated with osimertinib between April 2015 and December 2017, after a first line treatment with a TKI-1G/2G. Results: The median time on treatment for sequential TKI-1G/2G followed by osimertinib was 34 months (95% CI: 31-46); 13 and 12months, respectively for TKI 1G or 2G and TKI 3G, respectively. The median overall survival for sequential TKI 1G or 2G followed by osimertinib was 37 months (95% CI: 34-42). The mean monthly costs per patient was €5162. Conclusion: These results, in line with those observed during clinical trials, confirm the effectiveness of the sequence TKI-1G/2G followed by osimertinib in EGFR-mutated non-small-cell lung cancer.

A review on progression of epidermal growth factor receptor (EGFR) inhibitors as an efficient approach in cancer targeted therapy

The identification of molecular agents inhibiting specific functions in cancer cells progression is considered as one of the most successful plans in cancer treatment. The epidermal growth factor receptor (EGFR) over-activation is observed in a vast number of cancers, so, targeting EGFR and its downstream signaling cascades are regarded as a rational and valuable approach in cancer therapy. Several synthetic EGFR tyrosine kinase inhibitors (TKIs) have been evaluated in recent years, mostly exhibited clinical efficacy in relevant models and categorized into first, second, third and fourth-generation. However, studies are still ongoing to find more efficient EGFR inhibitors in light of the resistance to the current inhibitors. In this review, the importance of targeting EGFR signaling pathway in cancer therapy and related epigenetic mutations are highlighted. The recent advances on the discovery and development of different EGFR inhibitors and the use of various therapeutic strategies such as multi-targeting agents and combination therapies have also been reviewed.

Switching from first or second generation EGFR-TKI to osimertinib in EGFR mutation-positive NSCLC

Aim:

We evaluated the efficacy of a novel switch protocol for EGFR-TKIs for EGFR mutation-positive NSCLC.

Materials & methods:

Clinical records were collected from the patients who had received one of two sequential combination strategies of EGFR-TKIs: Salvage use of osimertinib for T790M-mediated acquired resistance to an prior EGFR-TKI or switch use of osimertinib where an EGFR-TKI was switched to osimertinib before disease progression.

Results:

Progression-free survival of osimertinib and time from the start of treatment until progression to osimertinib was comparable between the salvage use and switch use of osimertinib.

Conclusion:

Switch use of osimertinib seemed to produce improved efficacy for patients with activating EGFR mutations, because of the lack of patient selection via T790M.

Non-small cell lung cancer-small cell lung cancer transformation as mechanism of resistance to tyrosine kinase inhibitors in lung cancer

Mutated or rearranged driver kinases in non-small cell lung cancer (NSCLC) cells are clinically amenable to treatment with tyrosine kinase inhibitors (TKIs) resulting in prolonged survival and significant benefit compared to cytotoxic chemotherapy. The most frequent genomic alterations are observed for epidermal growth factor receptor and anaplastic lymphoma kinase, which can be blocked by a range of specific TKIs in sequence. In clinics, resistance to TKIs emerges after approximately one year and comprises secondary mutations of the kinases (on-target) or alternative pathways circumventing the original kinase (off-target) alterations. A special feature of NSCLC is the occurrence of histological transformation to small cell lung cancer (SCLC) in up to 14% of cases, which, in general, is accompanied by resistance to the original TKIs. SCLC transformed tumors may be treated with the classical platinum/etoposide regimen but thus far there are no definitive guidelines. Four transformed pleural SCLC lines in our lab indicate the presence of a gradual NSCLC-SCLC shift with overlapping drug sensitivities. In conclusion, the treatment of NSCLC-SCLC transformed cancer cells would need a better chemosensitivity assessment using functional genomics to guide further therapy.

Deguelin suppresses non-small cell lung cancer by inhibiting EGFR signaling and promoting GSK3β/FBW7-mediated Mcl-1 destabilization

Activating mutations of epidermal growth factor receptor (EGFR) play crucial roles in the oncogenesis of human non-small cell lung cancer (NSCLC). By screening 79 commercially available natural products, we found that the natural compound deguelin exhibited a profound anti-tumor effect on NSCLC via directly down-regulating of EGFR-signaling pathway. Deguelin potently inhibited in vitro EGFR kinase activity of wild type (WT), exon 19 deletion, and L858R/T790M-mutated EGFR. The in silico docking study indicated that deguelin was docked into the ATP-binding pocket of EGFRs. By suppression of EGFR signaling, deguelin inhibited anchorage-dependent, and independent growth of NSCLC cell lines, and significantly delayed tumorigenesis in vivo. Further study showed that deguelin inhibited EGFR and downstream kinase Akt, which resulted in the activation of GSK3β and eventually enhanced Mcl-1 phosphorylation at S159. Moreover, deguelin promoted the interaction between Mcl-1 and E3 ligase SCF^FBW7, which enhanced FBW7-mediated Mcl-1 ubiquitination and degradation. Additionally, phosphorylation of Mcl-1 by GSK3β is a prerequisite for FBW7-mediated Mcl-1 destruction. Depletion or pharmacological inactivation of GSK3β compromised deguelin-induced Mcl-1 ubiquitination and reduction. Taken together, our data indicate that enhancement of ubiquitination-dependent Mcl-1 turnover might be a promising approach for cancer treatment.