Epidermal Growth Factor Receptor-tyrosine Kinase Inhibitors Failure Research Articles

Immunotherapy strategies for EGFR-mutated advanced NSCLC after EGFR tyrosine-kinase inhibitors failure.

This study aimed to investigate the efficacy of immunotherapy, as monotherapy or in combination, comparing to chemotherapy with or without anti-angiogenesis for advanced non-small cell lung cancer (NSCLC) patients progressing to epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs). We retrospectively analyzed patients with advanced NSCLC harboring EGFR mutations who received immune checkpoint inhibitors (ICI) and/or chemotherapy after EGFR-TKIs failure at Shanghai Chest Hospital between Aug 2016 and Oct 2022. According to the subsequent immunotherapy regimen, the patients were assigned to ICI monotherapy (IM), IO plus anti-angiogenesis (IA), ICI plus chemotherapy (IC), ICI plus chemotherapy plus anti-angiogenesis (ICA). Eligible patients undergoing standard chemotherapy were assigned to chemotherapy plus anti-angiogenesis (CA) and chemotherapy alone (CM). Efficacy was evaluated according to the RECIST 1.1version, and calculated the objective response rate (ORR) and disease control rate (DCR). Survival curves were plotted using the Kaplan-Meier method, and the median progression-free survival (PFS) was calculated. Differences among survival curves of the six groups were assessed using the log-rank test. A total of 237 advanced NSCLC patients with EGFR mutations were included in this study. Of the 160 patients who received immunotherapy, 57 received ICI monotherapy, 27 received ICI plus anti-angiogenesis therapy, 43 received ICI plus chemotherapy, and 33 received ICI plus anti-angiogenesis plus chemotherapy. 77 patients received standard chemotherapy, of which 30 received chemotherapy plus anti-angiogenesis and 47 received chemotherapy alone. Patients in ICA group showed significant longer PFS than IM (7.2 vs 1.9 months, P=0.011), IA (7.2 vs 4.8 months, P=0.009) and CM group (7.2 vs 4.4 months, P=0.005). There was no significant difference in PFS between the ICA and IC (7.2 vs 5.6 months, P=0.104) or CA (7.2 vs 6.7 months, P=0.959) group. Meanwhile, the ICA group showed the highest ORR and DCR (36.4% and 90.9%) compared to the other five groups. The IC group had a higher ORR than the IA and CA group (32.6% vs 7.4% vs 10.0%, respectively), but the DCR was comparable (79.1% vs 74.1% vs 76.7%, respectively). The ORR of the CM group was 6.4% and the DCR was 66.0%. IM group showed the lowest ORR and DCR (1.8% and 36.8%). Treatment-related adverse events (TRAEs) of grade 3 or worse occurred in 9 (27.3%) patients in the ICA group, 6 (20.0%) in the CA group, 7 (14.9%) in the CM group, 5 (11.6%) in the IC group, 5 (8.8%) in the IM group, and 2 (7.4%) in the IA group. NSCLC patients with positive EGFR mutations after EGFR-TKIs failure received subsequent immunotherapy plus anti-angiogenesis and chemotherapy are likely to have more benefits in ORR, DCR and mPFS.

Tislelizumab plus chemotherapy for patients with EGFR-mutated non-squamous non-small cell lung cancer who progressed on EGFR tyrosine kinase inhibitor therapy

BackgroundTreatment options are limited for epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer (NSCLC) after treatment failure with EGFR tyrosine kinase inhibitors (TKIs). This multicenter open-label, phase II study...

Cost-effectiveness analysis of different sequences of osimertinib administration for epidermal growth factor receptor-mutated non-small-cell lung cancer.

Osimertinib is a third-generation epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) that is clinically effective in patients with EGFR-mutated non-small-cell lung cancer (NSCLC). However, the use of this treatment is limited by its high cost. A cost-effectiveness analysis of different sequences of osimertinib administration in China and the United States was conducted in the present study. Markov models were established based on data from the FLAURA and AURA3 trials. First-line osimertinib was compared with both first-generation EGFR-TKIs and second-line osimertinib after the failure of first-generation EGFR-TKIs. The analysis also considered different payment modalities available in China. Additionally, one-way and probability sensitivity analyses, with a willingness-to-pay threshold (WTP) of three times the per capita gross domestic product [$27,783/quality-adjusted life year (QALY) for China and $100,000/QALY for the United States], were performed. The first-line osimertinib group displayed higher QALYs and costs than those of the first-generation EGFR-TKI group. The first generation EGFR-TKI group displayed an incremental cost-effectiveness ratio (ICER) of $212,252/QALY in China and $151,922/QALY in the United States. In addition, the ICERs were negative in the second-line osimertinib group, with higher QALYs and lower costs compared with those in the first-line osimertinib group. Furthermore, osimertinib company donation was of benefit in China, with an average cost-effectiveness of $836/QALY. The one-way sensitivity analysis highlighted the influence of utilities in different states. First-line osimertinib could be cost-effective either with higher WTP or a price reduction of 68% in China and 9% in the United States. Although first-line osimertinib therapy could have health benefits, it was not cost-effective compared with first-line first-generation EGFR-TKIs and second-line osimertinib therapy. However, paying via company donation may be a good choice in China.

Post-Progression Survival in Secondary EGFR T790M-Mutated Non-Small-Cell Lung Cancer Patients With and Without Osimertinib After Failure of a Previous EGFR TKI.

Osimertinib is effective in non-small-cell lung cancer (NSCLC) with an acquired epidermal growth factor receptor (EGFR) T790M mutation, the most common resistance mechanism to first- and second-generation EGFR tyrosine kinase inhibitors (TKIs). We aimed to evaluate survival outcome of patients with EGFR-mutant NSCLC who have progressed on previous EGFR TKI therapy. Advanced NSCLC patients with EGFR mutation after acquired resistance to first- or second-generation EGFR TKI who received tumor rebiopsy after EGFR TKI failure from 1 January 2012 to 31 December 2017 were reviewed. Patient clinical characteristics, T790M mutation status, and post-progression survival (PPS) were recorded by chart review. We included 240 patients and the percentage of secondary T790M mutations in first time tissue rebiopsy was 52.9%. 38 of the initial T790M-negative patients received second rebiopsies and 14 (36.8%) of these were T790M positive. The duration between first and second rebiopsy tended to be longer in patients who had T790M mutation in the second biopsy (11.5 vs. 6.9months, p = 0.043). After EGFR TKI failure, the median PPS of patients who had the T790M mutation and history of osimertinib use was 42.6months (95% CI 34.6-50.5), compared to 18.0 (95% CI 9.6-26.4) months in T790M-positive patients without a history of osimertinib use, and 18.8 (95% CI 9.3-28.4) months in patients with no T790M mutation (p < 0.0001). Multivariate analysis showed that history of osimertinib use was correlated with improved survival. These data further emphasize that osimertinib should be a standard of care in patients with pretreated EGFR T790M-positive NSCLC.

Correlation between the qualification for bevacizumab use and the survival of patients with non-small cell lung cancer harboring the epidermal growth factor receptor mutation: a retrospective analysis

Previously, the combination of epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) and bevacizumab (BEV) was investigated. A subgroup analysis of the IMpower150 trial, which investigated the combination of atezolizumab, carboplatin, paclitaxel, and bevacizumab (ABCP), demonstrated the benefit of ABCP in patients harboring EGFR mutations. This study aims to assess the prognostic significance of the qualification for BEV use and the proportion of patients who potentially benefit from BEV-containing combination therapy before and after initial EGFR-TKI treatment. We retrospectively analyzed the data of 297 patients with advanced or recurrent non-squamous non-small cell lung cancer (NSCLC) harboring EGFR mutations who had received EGFR-TKIs. We performed statistical analyses using the Kaplan-Meier method and the Cox regression adjusted for risk factors. Of the 297 patients, 203 (68%) were eligible to receive BEV ("BEV fit") at the time of EGFR-TKI initiation. Among the "BEV unfit" patients at baseline (n = 70), 14 (20%) became eligible to receive ABCP ("ABCP fit") at the time of EGFR-TKI failure. The median overall survival (OS) of the "BEV fit" and "BEV unfit" patients was 26.2 [95% confidence interval (CI) 23.7-31.2] and 19.1 (95% CI 15.0-25.1) months, respectively (P < 0.001). The multivariate analysis revealed a marked correlation between survival and the qualification for BEV use. The qualification for BEV use at baseline is independently related to the OS. Some patients harboring EGFR mutations, including those who were "BEV unfit" at baseline, could be eligible for the ABCP regimen after EGFR-TKI treatment.

Negative impact of malignant effusion on osimertinib treatment for non-small cell lung cancer harboring EGFR mutation

Summary3rd-generation epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs), including osimertinib, have reasonable efficacy in non–small-cell lung cancers (NSCLC) with EGFR mutations. However, the efficacy of osimertinib in NSCLC patients with fluids, such as pleural, pericardial and abdominal effusions, is unclear. We evaluated the efficacy of osimertinib in this specific setting. NSCLC patients harboring EGFR T790 M mutations who experienced progressive disease after first EGFR-TKI treatment and started osimertinib treatment between April 2016 and August 2018 were retrospectively screened. In particular, we assessed the efficacy of osimertinib for NSCLC with EGFR T790 M mutations in patients who were diagnosed with EGFR T790 M mutation by malignant effusion. Among 90 patients with EGFR T790 M mutation who started osimertinib treatment after EGFR-TKI failure, 21 were diagnosed from malignant effusions excluding cerebrospinal fluid (F group) and 69 using other methods including tissue biopsies (NF group). Patient characteristics were well-balanced between the two groups. Overall response was 50%, and significantly worse in the F group (29%) than the NF group (57%; P = 0.025). Median progression-free survival with osimertinib treatment in the F group (7.1 months, 95% confidence interval [CI]: 2.3–14.0) was significantly shorter than that in the NF group (11.9 months, 95% CI: 9.5–16.0; P = 0.046)). Median drainage-free time was 10.9 months (95% CI: 1.4 months– not reached). The present study showed that the efficacy of osimertinib for NSCLC in which EGFR T790 M mutation is detected by malignant effusion may be less than in EGFR T790 M-mutated NSCLC detected by other methods.

Development, validation, and comparison of gene analysis methods for detecting EGFR mutation from non-small cell lung cancer patients-derived circulating free DNA.

The feasibility and required sensitivity of circulating free DNA (cfDNA)-based detection methods in second-line epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) treatment are not well elucidated. We examined T790M and other activating mutations of EGFR by cfDNA to assess the clinical usability. In 45 non-small cell lung cancer (NSCLC) patients harboring activating EGFR mutations, cfDNAs were prepared from the plasma samples. EGFR mutations in cfDNA were detected using highly sensitive methods and originally developed assays and these results were compared to tissue-based definitive diagnoses. The specificity of each cfDNA-based method ranged 96–100% whereas the sensitivity ranged 56–67%, indicating its low pseudo-positive rate. In EGFR-TKI failure cohort, 41–46% samples were positive for T790M by each cfDNA-based method, which was comparable to re-biopsy tissue-based T790M positive rates in literature. The concordance of the results for each EGFR mutation ranged from 83–95%. In eight patients, the results of the cfDNA-based assays and re-biopsy-derived tissue-based test were compared. The observed overall agreement ranged in 50–63% in T790M, and in 63–100% in activating EGFR mutations. In this study, we have newly developed three types of assay which have enough sensitivity to detect cfDNA. We also detected T790M in 44% of patients who failed prior EGFR-TKI treatment, indicating that cfDNA-based assay has clinical relevance for detecting acquired mutations of EGFR.

Clinical Management of Non-Small Cell Lung Cancer with Concomitant EGFR Mutations and ALK Rearrangements: Efficacy of EGFR Tyrosine Kinase Inhibitors and Crizotinib.

Patients harboring concomitant epidermal growth factor receptor (EGFR) mutations and anaplastic lymphoma kinase (ALK) arrangements constitute a small subgroup of non-small-cell lung cancer (NSCLC) patients. The efficacy of EGFR tyrosine kinase inhibitors (TKIs) and the ALK-specific TKI crizotinib in these patients has not been well-established. This study investigated the efficacy of targeted therapies in these patients compared with patients with EGFR or ALK alterations alone. Patients were screened for EGFR mutation and ALK rearrangement at the Shanghai Chest Hospital (2011-2017). Progression-free survival (PFS), objective response rate (ORR), and overall survival (OS) were retrospectively analyzed. A total of 5816 patients were screened, and 26 patients were identified as having concomitant EGFR mutations and ALK rearrangements; 22 patients were eligible for survival analysis. Additionally, 95 EGFR-mutant patients and 60 ALK-rearranged patients were randomly selected for analysis. The ORR to EGFR TKIs was 63.2% (12/19) for EGFR/ALK co-altered patients and 62.1% (59/95) for EGFR-mutant patients (p = 0.93) with a median PFS of 10.3 and 11.4months, respectively (hazard ratio [HR] 0.96; 95% confidence interval [CI] 0.59-1.57; p = 0.87). The ORR to crizotinib was 66.7% (8/12) for double-positive patients and 65.0% (39/60) for ALK-rearranged patients (p = 1.00), with a median PFS of 11.1 and 12.5months, respectively (HR 1.39; 95% CI 0.69-2.80; p = 0.28). OS was 27.1, 36.2, and 36.8months for EGFR-mutant, ALK-rearranged, and EGFR/ALK co-altered patients, respectively, and the EGFR/ALK co-existing subgroup tended to have a longer survival period than EGFR-mutant cohorts, though no statistical difference was found (p = 0.12). The median PFS of crizotinib as a sequential therapy after failure of EGFR TKIs was 15.0months, which exhibited no statistically significant difference compared with the median PFS of ALK-altered patients who received crizotinib (p = 0.80). Both first-generation EGFRTKIs and the ALK TKI crizotinib were effective in these patients. Sequential treatment with EGFR TKIs and crizotinib should be considered as a management option.

Newer-Generation EGFR Inhibitors in Lung Cancer: How Are They Best Used?

The FLAURA trial established osimertinib, a third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI), as a viable first-line therapy in non-small cell lung cancer (NSCLC) with sensitizing EGFR mutations, namely exon 19 deletion and L858R. In this phase 3 randomized, controlled, double-blind trial of treatment-naïve patients with EGFR mutant NSCLC, osimertinib was compared to standard-of-care EGFR TKIs (i.e., erlotinib or gefinitib) in the first-line setting. Osimertinib demonstrated improvement in median progression-free survival (18.9 months vs. 10.2 months; hazard ratio 0.46; 95% CI, 0.37 to 0.57; p < 0.001) and a more favorable toxicity profile due to its lower affinity for wild-type EGFR. Furthermore, similar to later-generation anaplastic lymphoma kinase (ALK) inhibitors, osimertinib has improved efficacy against brain metastases. Despite this impressive effect, the optimal sequencing of osimertinib, whether in the first line or as subsequent therapy after the failure of earlier-generation EGFR TKIs, is not clear. Because up-front use of later-generation TKIs may result in the inability to use earlier-generation TKIs, this treatment paradigm must be evaluated carefully. For EGFR mutant NSCLC, considerations include the incidence of T790M resistance mutations, quality of life, whether there is a potential role for earlier-generation TKIs after osimertinib failure, and overall survival. This review explores these issues for EGFR inhibitors and other molecularly targeted therapies.

Making progress in epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer by surpassing resistance: third-generation EGFR tyrosine kinase inhibitors (EGFR-TKIs).

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) represent the standard of care for advanced non-small cell lung cancer (NSCLC) patients whose tumours harbor an activating EGFR mutation. Unfortunately, resistance to first- and second-generation EGFR-TKIs inevitably occurs in all patients with EGFR-mutant disease approximately within a year of treatment. At least half of these cases are attributed to the emergence of a secondary mutation in exon 20 of the EGFR gene, namely the T790M mutation. Third-generation EGFR-TKIs, including osimertinib and rociletinib, target this epigenic mutation, thus re-sensitizing cancer cells to EGFR-TKI inhibition. Osimertinib to date represents the standard of care in EGFR-mutant tumors after failure of first-line EGFR-TKIs by over-performing platinum-based chemotherapy in the recently reported AURA-3 randomized phase III clinical trial. The aim of this review is to describe the different treatment strategies that have been developed to reverse resistance to first- and second-line EGFR-TKIs, the corresponding mechanisms of resistance and the development of novel-generation EGFR-TKIs. We also discuss the challenge posed by the implementation of third-generation EGFR-TKIs earlier in the course of the disease in first-line treatment of EGFR-mutant NSCLC.

Standard-dose osimertinib for refractory leptomeningeal metastases in T790M-positive EGFR-mutant non-small cell lung cancer

Background:Osimertinib demonstrated promising efficacy for refractory leptomeningeal metastases (LM) in preclinical data and a clinical study at 160 mg, but there is limited data for the standard 80 mg dose.Methods:T790M-positive patients with suspected LM after classical epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) failure were enroled.Results:We investigated 13 patients (5 definitive and 8 possible LM cases). In two of the five definitive cases with T790M in and outside the central nervous system (CNS), osimertinib was effective for both lesions, with cerebrospinal fluid (CSF) clearance of cancer cells and sensitive/T790M mutations. In three definitive cases with extra-CNS T790M without CSF T790M, cancer cells and sensitive mutations in the CSF persisted after osimertinib initiation. The median progression-free survival of all 13 patients was 7.2 months. Osimertinib was generally well-tolerated despite poor performance status, but interstitial lung disease (grade 2) was confirmed in one patient. Based on 25 samples from 13 patients, the osimertinib CSF penetration rate was 2.5±0.3%.Conclusions:Osimertinib 80 mg is a useful therapeutic option for refractory LM after classical EGFR-TKI failure. It appears more effective in CSF T790M-positive cases.

ID3021 Acquired resistance to with EGFR tyrosine kinase inhibitors by the EGFR T790M mutation in non-small cell lung cancer

Mutations in the tyrosine kinase (TK) domain of the epidermal growth factor receptor (EGFR) gene respond well to treatment with EGFR tyrosine kinase inhibitors (EGFR-TKIs) including gefitinib and erlotinib in non-small cell lung cancer (NSCLC). Detection of these mutations has an important role for therapeutic decision-making in NSCLC treatment. However, all patients who experienced marked improvements with these drugs eventually developed disease progression after 10-20 months of treatment due to the acquisition of drug resistance. Approximately half of the cases with acquired resistance to EGFR-TKIs can be accounted for by a second-site mutation in exon 20 of the EGFR kinase domain T790M. In this study, 40 patients with advanced NSCLC who developed acquired resistance to EGFR-TKIs were selected. The diagnosis was defined based on the Jackman criteria for acquired resistance to EGFR-TKIs in lung cancers. Re-biopsy were performed at National cancer hospital and Oncology hospitals at Ha Noi and Ho Chi Minh City. Scorpion ARMS method was used to detect EGFR mutation status. In all, 40% (16/40) of the patients carried T790M mutation after the failure of EGFR-TKIs. The study demonstrated a critical role of molecular diagnostics for TKI acquired resistance through re-biopsies at the time of disease progression.

The efficacy and toxicity of afatinib in advanced EGFR-positive non-small-cell lung cancer patients after failure of first-generation tyrosine kinase inhibitors: a systematic review and meta-analysis.

The first generation epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs), gefitinib and erlotinib, have become the standard first-line treatment for non-small-cell lung cancer (NSCLC) patients with EGFR mutation. However, there was no pooled analysis focused on the usage of the second-generation TKI, afatinib, in advanced EGFR-positive NSCLC patients after failure of first generation TKIs. Therefore, a meta-analysis was conducted to solve the above question. Electronic databases were searched for eligible literatures. ORR (objective response rate), DCR (disease controlled rate), PFS (progression-free survival), OS (overall survival) and primary grade 3/4 adverse events were pooled with the corresponding 95% confidence interval using R software. Sensitivity analyses and heterogeneity were quantitatively evaluated. A total of 545 EGFR-positive patients were available for analysis from five studies after detailed screening from 909 relevant studies. The pooled ORR and DCR of afatinib in EGFR-positive patients after failure of the first generation EGFR-TKIs were 0.12 (0.08-0.19) and 0.60 (0.53-0.68), respectively. Besides, the 6 m-PFS rate, 1 y-PFS rate and 6 m-OS rate were 0.26 (0.22-0.30), 0.08 (0.06-0.10) and 0.74 (0.56-0.86). The grade 3/4 rate of diarrhea and that of skin deformity were 0.23 (0.10-0.46) and 0.14 (0.05-0.33), respectively. Sensitivity analyses revealed similar results with lower heterogeneity. Considering the efficacy, toxicity and current availability, afatinib could be a therapeutic option for advanced EGFR mutated NSCLC patients after the failure of 1st-generation TKIs.

Association Between EGFR T790M Status and Progression Patterns During Initial EGFR-TKI Treatment in Patients Harboring EGFR Mutation

BackgroundEmergence of the T790M point mutation in exon 20 of the epidermal growth factor receptor (EGFR) is the most common mechanism of resistance to EGFR tyrosine kinase inhibitors (EGFR-TKIs). The aim of this study was to investigate the association between T790M mutation status and the progression patterns during EGFR-TKI treatment. MethodsWe reviewed 181 patients with advanced non–small-cell lung cancer harboring EGFR mutation, who were evaluated for T790M mutation status after initial EGFR-TKI failure (gefitinib, erlotinib, or afatinib). We retrospectively investigated the patient characteristics, initial EGFR-TKI response, T790M mutation status, subsequent treatment after initial EGFR-TKIs, timing of re-biopsy, and progression patterns during the EGFR-TKI treatment. ResultsAfter the resistance to the EGFR-TKIs, the T790M mutation was identified in 87 (48%) of 181 patients. Seventy-three (40%) patients had solitary lesion progression, and 108 (60%) had multiple lesion progression during the initial EGFR-TKI treatment. The prevalence of the T790M mutation was significantly greater in patients with solitary lesion progression than those with multiple lesion progression (58% vs. 24%; P < .0001). The overall response rate and progression-free survival on initial EGFR-TKIs were significantly better in patients who acquired T790M after failure of EGFR-TKIs than those without T790M (overall response rate, 80% vs. 60%; P = .0033 and progression-free survival, 11.4 vs. 9.3 months; P = .0050). The multivariate analysis showed that gender, initial EGFR-TKI response, and progression patterns were significantly associated with T790M mutation status. DiscussionThe progression patterns during initial EGFR-TKIs and initial EGFR-TKI response are associated with the T790M mutation.

Clinical outcomes of platinum-based chemotherapy according to T790M mutation status in EGFR-positive non-small cell lung cancer patients after initial EGFR-TKI failure

BackgroundEmergence of the T790M point mutation in exon 20 of epidermal growth factor receptor (EGFR) is the most common mechanism of resistance to EGFR tyrosine kinase inhibitors (EGFR-TKIs). It remains unclear whether the efficacy of platinum-doublet chemotherapy is impacted by the presence of the T790M mutation. The aim of this study is to evaluate the efficacy of platinum-doublet chemotherapy after initial EGFR-TKI failure according to the EGFR T790M in patients with advanced EGFR-mutation-positive non-small cell lung cancer (NSCLC). Patients and methodsWe retrospectively reviewed 50 patients with advanced NSCLC harboring EGFR mutations who underwent rebiopsy to evaluate their T790M mutation status after development of resistance to first-line EGFR-TKIs (gefitinib, erlotinib, or afatinib) and were subsequently treated with second-line platinum-based chemotherapy. ResultsThe median age of patients was 63 years (range, 35–77 years), and 15 (30%) patients were male. Histological examination revealed that all patients had adenocarcinoma, 39 (78%) had stage IV disease, and 11 (22%) patients had postoperative recurrence. Of all, 17 patients (34%) had the T790M mutation by rebiopsy after initial EGFR-TKI failure. The overall response rate (ORR) of platinum-doublet chemotherapy was 24% for both T790M-positive and T790M-negative patients. There was no significant difference in the progression-free survival (PFS) in T790M-positive and T790M-negative patients (median PFS, 6.0 months vs. 5.1 months; 95% confidence interval [CI], 0.1–11.9 vs. 4.4–5.8; hazard ratio [HR], 0.90 [95%CI, 0.49–1.66]; P=0.7210). None of the factors were predictive of platinum-doublet chemotherapy efficacy by the multivariate analysis. ConclusionThere were no differences in clinical outcomes of platinum-based chemotherapy according to the T790M status of NSCLC patients.

Precision treatment after resistance to first-generation EGFR-TKI in patients with non-small cell lung cancer

Recently, with the research progress in molecular classification, the treatment of advanced non-small cell lung cancer (NSCLC) has been established as a model of anti-tumor treatment of precision medicine. The discovery of epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKI) has transformed the treatment of NSCLC from platinum based doublet chemotherapy into era of target therapy. EGFR-TKI, such as erlotinib and gefitinib, have been recommended as standard first-line treatment of patients with EGFR mutation. However, acquired resistance, defined as tumor progression after initial response, seems to be an inevitable consequence of this treatment approach. Clinical modes of EGFR-TKI failure are classified into three types: dramatic progression, gradual progression and local progression. A threonine-to-methionine substitution (T790M) in exon 20 of the EGFR gene is the most common mechanism of resistance. Other mechanisms of resistance include MET amplification, epithelial to mesenchymal transition, small cell transformation, and PIK3CA mutation. This brief comment will provide an overview of the complex and heterogeneous problem of acquired resistance to EGFR-TKI therapy in NSCLC, and the clinical treatment options and new targeted drugs overcoming EGFR-TKI acquired resistance.

Estimation of cell-free circulating EGFR mutation concentration predicts outcomes in NSCLC patients treated with EGFR-TKIs.

Detection of circulating tumor DNA using droplet digital polymerase chain reaction (ddPCR) is a highly-sensitive, minimally invasive alternative to serial biopsies for assessment and management of cancer. We used ddPCR to assess the utility of measuring plasma concentrations of common epidermal growth factor receptor (EGFR) mutations (L858R, exon 19 deletion, and T790M) in 57 non-small cell lung cancer (NSCLC) patients treated with EGFR tyrosine kinase inhibitors (EGFR-TKIs). High baseline plasma EGFR mutation (pEGFRmut) concentrations were associated with shorter progression-free survival (8.43 months) than low baseline pEGFRmut (16.23 months; p = 0.0019). By contrast, there were no differences in tumor shrinkage or overall survival between groups. During EGFR-TKI treatment, pEGFRmut levels decreased to zero in 89.58% of patients. Twenty-five of the 27 patients who progressed had basal pEGFRmut, and 18 also had circulating T790M. All 20 patients with dramatic progression (according to a categorization system for EGFR-TKIs failure) had basal pEGFRmut, and 13 had T790M mutation at progression. These results support the use of ddPCR for analysis of plasma EGFR mutations for prediction of PFS and to monitor clinical responses to EGFR-TKIs in NSCLC patients.

Standardized uptake value on 18F-FDG-PET/CT is a predictor of EGFR T790M mutation status in patients with acquired resistance to EGFR-TKIs

BackgroundThe development of epidermal growth factor receptor (EGFR) T790M point mutation in exon 20 (T790M) is the most common mechanism of resistance to EGFR tyrosine kinase inhibitors (EGFR-TKIs). The purpose of this study was to determine the association of 18F-2-fluoro-2-deoxyglucose-positron emission tomography/computed tomography (FDG–PET/CT) metrics with T790M status after acquiring resitance to EGFR-TKI resistance. MethodsWe retrospectively reviewed 34 advanced non-small cell lung cancer (NSCLC) patients harboring EGFR mutation who underwent rebiopsy and FDG–PET/CT before rebiopsy. These patients were evaluated for baseline characteristics, initial response to EGFR–TKIs, site of rebiopsy, overall survival, and FDG–PET/CT metrics, such as standardized uptake value (SUV), metabolic tumor volume, and total lesion glycolysis of the rebiopsy site. ResultsThe median age was 67 years (range, 37–86 years); 19 of the patients (56%) were men. Histologic examination revealed adenocarcinoma in all but one patient, with 20 patients (59%) having stage IIIB and IV disease. Upon initial mutational analyses, the types of EGFR mutation included 17 (50%) deletions in exon 19 and 17 (50%) L858R point mutations in exon 21. At the time of acquired resistance to EGFR-TKIs, T790M mutation was identified in 20 (59%) patients. T790M-positive patients had significantly lower levels of median SUVmean and median SUVmax of the rebiopsy site on FDG–PET/CT, compared with T790M-negative patients (SUVmean: 4.57 vs. 9.91, P=0.0069; SUVmax: 7.26 vs. 16.06, P=0.0054). The survival in patients who acquired T790M after failure of EGFR-TKIs was significantly longer than those without T790M (10.2 mos. vs. 18.6 mos., P<0.05). ConclusionT790M status was associated with lower levels of SUVmean and SUVmax on FDG–PET/CT and significantly longer survival.

Pretreatment albumin-to-globulin ratio as a predictive marker for tyrosine kinase inhibitor in non-small cell lung cancer.

A low albumin-to-globulin ratio (AGR) has been known as a prognostic factor for cancer-related mortality. However, no study has elucidated its usefulness as a predictive factor in the era of targeted therapy, and so, we evaluated this in the present study. We retrospectively analyzed 2012 non-small cell lung cancer (NSCLC) patients treated with epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs). Among these patients, 645 patients who had EGFR mutation and suitable pretreatment laboratory values were included. AGR was calculated 2 months before treatment and 4 months after treatment in each patient. The optimal cutoff value of AGR, and progression free survival (PFS) were also determined. The optimal cutoff value of AGR was 1.17, which yielded a highest HR of 1.89 (P< 0.001) for poor PFS. The median PFS was 9.5 months (95% confidential interval [CI] 7.0-10.4) in patients with pretreatment AGR < 1.17 and 13.5 months (95% CI 11.9-14.7) in those with pretreatment AGR ≥ 1.17. Pretreatment AGR showed an independent predictive value (adjusted HR 1.80, P < 0.001) when age, performance status, and pre-TKI systemic treatment was adjusted for. We suggest that patients with NSCLC with EGFR mutations who have AGR values lower than 1.17 at the beginning of EGFR TKI treatment should be considered to have a high risk of early EGFR TKI failure.

High-dose erlotinib for refractory leptomeningeal metastases after failure of standard-dose EGFR-TKIs.

After initial response to epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs), approximately one-third of patients develop central nervous system (CNS) metastases, including leptomeningeal metastases (LM). To achieve longer survival, control of CNS metastases is important, but therapeutic options are limited for LM after failure of standard-dose EGFR-TKIs. We retrospectively evaluated the efficacy and safety of high-dose erlotinib in EGFR-mutant non-small cell lung cancer (NSCLC) patients with refractory LM after failure of standard-dose EGFR-TKIs. Survivals from diagnosis of LM to death were compared in patients with or without high-dose erlotinib. Between January 2007 and April 2013, we identified 35 patients with EGFR-mutant NSCLC, complicated with LM, and 12 underwent high-dose erlotinib, while the other 23 received only standard-dose EGFR-TKIs. In patients receiving high-dose erlotinib, magnetic resonance imaging response was confirmed in 3 (30%) of 10 evaluable patients. Median time to CNS progression was 2.3months (95% confidence interval [CI] 1.8-5.5months). Performance status and neurological symptoms improved in 4 (33%) of 12 and 6 (50%) of 12 patients, respectively. No severe adverse events (≥grade 3) associated with high-dose erlotinib were observed. Median survival time from diagnosis of LM in patients with high-dose erlotinib was 6.2months (95% CI 2.5-8.5months), and in those without 5.9months (95% CI 1.3-7.8months) (p=0.94). High-dose erlotinib suggested its efficacy and safety in some patients with refractory LM. It represents a potential therapeutic option against LM after failure of standard-dose EGFR-TKIs, especially to palliate LM-related neurological symptoms.