Afatinib versus cisplatin plus gemcitabine for first-line treatment of Asian patients with advanced non-small-cell lung cancer harbouring EGFR mutations (LUX-Lung 6): an open-label, randomised phase 3 trial

Classification of Epidermal Growth Factor Receptor Gene Mutation Status Using Serum Proteomic Profiling Predicts Tumor Response in Patients with Stage IIIB or IV Non-Small-Cell Lung Cancer

Objectives

Epidermal growth factor receptor (EGFR) gene mutations in tumors predict tumor response to EGFR tyrosine kinase inhibitors (EGFR-TKIs) in non-small-cell lung cancer (NSCLC). However, obtaining tumor tissue for mutation analysis is challenging. Here, we aimed to detect serum peptides/proteins associated with EGFR gene mutation status, and test whether a classification algorithm based on serum proteomic profiling could be developed to analyze EGFR gene mutation status to aid therapeutic decision-making.

Patients and Methods

Serum collected from 223 stage IIIB or IV NSCLC patients with known EGFR gene mutation status in their tumors prior to therapy was analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and ClinProTools software. Differences in serum peptides/proteins between patients with EGFR gene TKI-sensitive mutations and wild-type EGFR genes were detected in a training group of 100 patients; based on this analysis, a serum proteomic classification algorithm was developed to classify EGFR gene mutation status and tested in an independent validation group of 123 patients. The correlation between EGFR gene mutation status, as identified with the serum proteomic classifier and response to EGFR-TKIs was analyzed.

Results

Nine peptide/protein peaks were significantly different between NSCLC patients with EGFR gene TKI-sensitive mutations and wild-type EGFR genes in the training group. A genetic algorithm model consisting of five peptides/proteins (m/z 4092.4, 4585.05, 1365.1, 4643.49 and 4438.43) was developed from the training group to separate patients with EGFR gene TKI-sensitive mutations and wild-type EGFR genes. The classifier exhibited a sensitivity of 84.6% and a specificity of 77.5% in the validation group. In the 81 patients from the validation group treated with EGFR-TKIs, 28 (59.6%) of 47 patients whose matched samples were labeled as “mutant” by the classifier and 3 (8.8%) of 34 patients whose matched samples were labeled as “wild” achieved an objective response (p<0.0001). Patients whose matched samples were labeled as “mutant” by the classifier had a significantly longer progression-free survival (PFS) than patients whose matched samples were labeled as “wild” (p=0.001).

Conclusion

Peptides/proteins related to EGFR gene mutation status were found in the serum. Classification of EGFR gene mutation status using the serum proteomic classifier established in the present study in patients with stage IIIB or IV NSCLC is feasible and may predict tumor response to EGFR-TKIs.

Clinical activity of afatinib in patients with advanced non-small-cell lung cancer harbouring uncommon EGFR mutations: a combined post-hoc analysis of LUX-Lung 2, LUX-Lung 3, and LUX-Lung 6

BACKGROUND

Most patients with non-small-cell lung cancer tumours that have EGFR mutations have deletion mutations in exon 19 or the Leu858Arg point mutation in exon 21, or both (ie, common mutations). However, a subset of patients (10%) with mutations in EGFR have tumours that harbour uncommon mutations. There is a paucity of data regarding the sensitivity of these tumours to EGFR inhibitors. Here we present data for the activity of afatinib in patients with advanced non-small-cell lung cancer that have tumours harbouring uncommon EGFR mutations.

METHODS

In this post-hoc analysis, we used prospectively collected data from tyrosine kinase inhibitor-naive patients with EGFR mutation-positive advanced (stage IIIb-IV) lung adenocarcinomas who were given afatinib in a single group phase 2 trial (LUX-Lung 2), and randomised phase 3 trials (LUX-Lung 3 and LUX-Lung 6). Analyses were done in the intention-to-treat population, including all randomly assigned patients with uncommon EGFR mutations. The type of EGFR mutation (exon 19 deletion [del19], Leu858Arg point mutation in exon 21, or other) and ethnic origin (LUX-Lung 3 only; Asian vs non-Asian) were pre-specified stratification factors in the randomised trials. We categorised all uncommon mutations as: point mutations or duplications in exons 18-21 (group 1); de-novo Thr790Met mutations in exon 20 alone or in combination with other mutations (group 2); or exon 20 insertions (group 3). We also assessed outcomes in patients with the most frequent uncommon mutations, Gly719Xaa, Leu861Gln, and Ser768Ile, alone or in combination with other mutations. Response was established by independent radiological review. These trials are registered with ClinicalTrials.gov, numbers NCT00525148, NCT00949650, and NCT01121393.

FINDINGS

Of 600 patients given afatinib across the three trials, 75 (12%) patients had uncommon EGFR mutations (38 in group 1, 14 in group 2, 23 in group 3). 27 (71·1%, 95% CI 54·1-84·6) patients in group 1 had objective responses, as did two (14·3%, 1·8-42·8) in group 2 and two (8·7%, 1·1-28·0) in group 3. Median progression-free survival was 10·7 months (95% CI 5·6-14·7) in group 1, 2·9 months (1·2-8·3) in group 2; and 2·7 months (1·8-4·2) in group 3. Median overall survival was 19·4 months (95% CI 16·4-26·9) in group 1, 14·9 months (8·1-24·9) in group 2, and 9·2 months (4·1-14·2) in group 3. For the most frequent uncommon mutations, 14 (77·8%, 95% CI 52·4-93·6) patients with Gly719Xaa had an objective response, as did nine (56·3%, 29·9-80·2) with Leu861Gln, and eight (100·0%, 63·1-100·0) with Ser768Ile.

INTERPRETATION

Afatinib was active in non-small-cell lung cancer tumours that harboured certain types of uncommon EGFR mutations, especially Gly719Xaa, Leu861Gln, and Ser768Ile, but less active in other mutations types. Clinical benefit was lower in patients with de-novo Thr790Met and exon 20 insertion mutations. These data could help inform clinical decisions for patients with non-small-cell lung cancer harbouring uncommon EGFR mutations.

FUNDING

Boehringer Ingelheim.

Exon 19 deletion was associated with better survival outcomes in advanced lung adenocarcinoma with mutant EGFR treated with EGFR-TKIs as second-line therapy after first-line chemotherapy: a retrospective analysis of 128 patients

OBJECTIVE

To determine whether the specific genotype of exon 19 deletion has a better survival outcome than that of exon 21 substitution in advanced lung adenocarcinoma with EGFR mutant patients that were treated with EGFR-TKIs as second-line therapy after first-line chemotherapy.

METHODS

Between April 1, 2010 and December 31, 2012, the detailed clinical information of 128 patients was screened from the hospital information database of the First Affiliated Hospital and the Third Affiliated Hospital of Kunming Medical University by inclusion/exclusion criteria. Then, a telephone follow-up and a review of all patients' image data were done to obtain the survival information of all patients. After that, all patients' data were processed by IBM(®) SPSS(®) version 19.0.

RESULTS

There were correlations between EGFR mutation status, gross tumor type and PFS or OS according to the Kaplan-Meier survival analyses and log-rank tests. The exon 19 deletions had significantly better survival outcomes in comparison to exon 21 substitutions (median PFS: 8.1 vs. 6.8 months, P = 0.002; median OS: 17.6 vs. 12.5 months, P = 0.000). Stratification analyses of PFS and OS revealed that exon 19 deletions had a survival superior to exon 21 substitutions.

CONCLUSION

Compared with L858R mutation, the genotype of exon 19 deletion had a better survival outcome in terms of PFS and OS in patients with advanced lung adenocarcinoma treated with EGFR-TKIs as second-line therapy after first-line chemotherapy.

Use of the epidermal growth factor receptor inhibitors gefitinib, erlotinib, afatinib, dacomitinib, and icotinib in the treatment of non-small-cell lung cancer: a systematic review

INTRODUCTION

This systematic review addresses the use of epidermal growth factor receptor (egfr) inhibitors in three populations of advanced non-small-cell lung cancer (nsclc) patients-unselected, selected, and molecularly selected-in three treatment settings: first line, second line, and maintenance.

METHODS

Ninety-six randomized controlled trials found using the medline and embase databases form the basis of this review.

RESULTS

In the first-line setting, data about the efficacy of egfr tyrosine kinase inhibitors (tkis) compared with platinum-based chemotherapy are inconsistent. Results from studies that selected patients based on clinical characteristics are also mixed. There is high-quality evidence that an egfrtki is preferred over a platinum doublet as initial therapy for patients with an activating mutation of the EGFR gene. The egfrtkis are associated with a higher likelihood of response, longer progression-free survival, and improved quality of life. Multiple trials of second-line therapy have compared an egfrtki with chemotherapy. Meta-analysis of those data demonstrates similar progression-free and overall survival. There is consequently no preferred sequence for second-line egfrtki or second-line chemotherapy. The egfrtkis have also been evaluated as switch-maintenance therapy. No molecular marker could identify patients in whom a survival benefit was not observed; however, the magnitude of the benefit was modest.

CONCLUSIONS

Determination of EGFR mutation status is essential to making appropriate treatment decisions in patients with nsclc. Patients who are EGFR mutation-positive should be treated with an egfrtki as first-line therapy. An egfrtki is still appropriate therapy in patients who are EGFR wild-type, but the selected agent should be administered as second- or third-line therapy.

Next-Generation Covalent Irreversible Kinase Inhibitors in NSCLC: Focus on Afatinib

First-generation, reversible epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs), erlotinib and gefitinib, represented an important addition to the treatment armamentarium for non-small-cell lung cancer (NSCLC) patients with activating EGFR mutations. However, all patients inevitably develop acquired resistance to these agents, primarily due to secondary EGFR mutations, molecular aberrations affecting other signaling pathways, or transformation to small-cell histology. It was hypothesized that development of second-generation TKIs with broader inhibitory profiles could confer longer-lasting clinical activity and overcome acquired resistance to first-generation inhibitors. Here, we review the development of afatinib, an irreversible ErbB family blocker that potently inhibits signaling of all homodimers and heterodimers formed by the EGFR, human epidermal growth factor receptor (HER)-2, HER3, and HER4 receptors. In two phase III trials in patients with EGFR mutation-positive NSCLC, first-line afatinib significantly improved progression-free survival (PFS) and health-related quality of life versus standard-of-care chemotherapy. Moreover, in preplanned sub-analyses, afatinib significantly improved overall survival in patients harboring EGFR Del19 mutations. Afatinib has also demonstrated clinical activity in NSCLC patients who had progressed on erlotinib/gefitinib, particularly when combined with cetuximab, and offers 'treatment beyond progression' benefit when combined with paclitaxel versus chemotherapy alone. Furthermore, a recent phase III study demonstrated that PFS was significantly improved with afatinib versus erlotinib for the second-line treatment of patients with squamous cell carcinoma of the lung. The activity of afatinib in both first-line and relapsed/refractory settings may reflect its ability to irreversibly inhibit all ErbB family members. Afatinib has a well-defined safety profile with characteristic gastrointestinal (diarrhea, stomatitis) and cutaneous (rash/acne) adverse events.

Randomized, open-label trial evaluating the preventive effect of tetracycline on afatinib induced-skin toxicities in non-small cell lung cancer patients

BACKGROUND

Afatinib has shown long progression free survival and improvement in quality of life in advanced Non-Small Cell Lung Cancer (NSCLC) patients. Although afatinib causes acneiform rash, it can be manageable. Tetracyclines are usually used to treat it; nonetheless, there is no trial that evaluates their prophylactic efficacy on afatinib induced-skin toxicities (AIST).

PATIENTS AND METHODS

This open-label, randomized, controlled trial assessed the preventive effect of tetracycline for reducing afatinib-skin toxicities in NSCLC patients receiving afatinib 40 mg/day. Patients were randomly assigned to receive pre-emptive treatment with tetracycline 250 mg every 12h for 4 weeks or not. Reactive treatment in both groups included general dermatological recommendations such as use of skin moisturizers, sunscreen and topical steroids, according to toxicity severity. All patients were blindly monitored for skin toxicities by an expert dermatologist at the start of treatment with afatinib (day 0), weeks 2 and 4 of treatment. The protocol is registered on clinicaltrials.gov (NCT01880515).

RESULTS

We included 90 patients, no differences were found in clinical and dermatological baseline characteristics. Rash incidence of any grade, and grade ≥2 was less frequent in the pre-emptive arm vs. the control arm (44.5 vs. 75.6%, RR 0.4 [95% CI 0.17-0.99], p=0.046 and 15.6 vs. 35.6%, RR 0.35 [95% CI, 0.12-0.91], p=0.030, respectively). No difference was found in paronychia, xerosis, mucositis, folliculitis, and skin fissure. No adverse event was associated with tetracycline. Neither rash nor pre-emptive tetracycline impacted on response rate, progression-free or overall survivals.

CONCLUSION

Pre-emptive tetracycline was well tolerated and reduced the rash incidence and severity associated with afatinib in more than 60%.

Clinical approaches to treat patients with non-small cell lung cancer and epidermal growth factor receptor tyrosine kinase inhibitor acquired resistance

The discovery of epidermal growth factor receptor activating mutations (EGFR Mut+) has determined a paradigm shift in the treatment of non-small cell lung cancer (NSCLC). In several phase III studies, patients with NSCLC EGFR Mut+ achieved a significantly better progression-free survival when treated with a first- (gefitinib, erlotinib) or second-generation (afatinib) EGFR tyrosine kinase inhibitor (TKI) compared with standard chemotherapy. However, despite these impressive results, most patients with NSCLC EGFR Mut+ develop acquired resistance to TKIs. This review will discuss both the mechanisms of resistance to TKIs and the therapeutic strategies to overcome resistance, including emerging data on third-generation TKIs.

Targeting EGFR in lung cancer: Lessons learned and future perspectives

The development of individualized therapies has become the focus of current oncology research. Precision medicine has demonstrated great potential for bringing safe and effective drugs to those patients stricken with cancer, and is becoming a reality as more oncogenic drivers of malignancy are discovered. The discovery of Epidermal Growth Factor Receptor (EGFR) mutations as a driving mutation in non-small cell lung cancer (NSCLC) and the subsequent success of the tyrosine kinase inhibitors (TKI) have led the way for NSCLC to be at the forefront of biomarker-based drug development. However, this direction was not always so clear, and this article describes the lessons learned in targeted therapy development from EGFR in NSCLC.

Ultra High Performance Liquid Chromatography Method for the Determination of Two Recently FDA Approved TKIs in Human Plasma Using Diode Array Detection

Generally, tyrosine kinase inhibitors have narrow therapeutic window and large interpatient variability compared to intrapatient variability. In order to support its therapeutic drug monitoring, two fast and accurate methods were developed for the determination of recently FDA approved anticancer tyrosine kinase inhibitors, afatinib and ibrutinib, in human plasma using ultra high performance liquid chromatography coupled to PDA detection. Diclofenac sodium was used as internal standard. The chromatographic separation was achieved on an Acquity UPLC BEH C18 analytical column using a mobile phase combining ammonium formate buffer and acetonitrile at a constant flow rate of 0.4 mL/min using gradient elution mode. A µSPE (solid phase extraction) procedure, using Oasis MCX µElution plates, was processed and it gave satisfying and reproducible results in terms of extraction yields. Additionally, the methods were successfully validated using the accuracy profiles approach (β = 95% and acceptance limits = ±15%) over the ranges 5-250 ng/mL for afatinib and from 5 to 400 ng/mL for ibrutinib in human plasma.

Rationale for targeting the ErbB family of receptors in patients with advanced squamous cell carcinoma of the lung

Squamous cell carcinoma (SCC) of the lung represents around 30% of all non-small-cell lung cancers. Treatment options for nonsquamous histology have increased in recent years following the development of pemetrexed chemotherapy and the identification of activating EGFR mutations and ALK rearrangements as targets for effective noncytotoxic agents. By contrast, until recently the development of new therapies for SCC has lagged behind. However, the identification of important genetic events driving SCC, including a greater understanding of the role of the ErbB receptor family in SCC pathogenesis, as well as recent immunotherapy advances, have led to new treatment options for SCC.

Phase II study of biomarker-guided neoadjuvant treatment strategy for IIIA-N2 non-small cell lung cancer based on epidermal growth factor receptor mutation status

Background

Neoadjuvant erlotinib and customized adjuvant therapy are appealing but controversial. The purpose of this study was to evaluate the role of biomarker-guided neoadjuvant treatment strategy in patients with IIIA-N2 non-small cell lung cancer (NSCLC) stratified by epidermal growth factor receptor (EGFR) mutation status.

Findings

Patients with resectable histologically documented stage IIIA-N2 NSCLC were assigned to a neoadjuvant erlotinib arm or a gemcitabine/carboplatin (GC) arm based on EGFR mutation status. The primary endpoint was response rate (RR). Secondary endpoints were progression-free survival (PFS) and overall survival (OS).

Twenty-four patients with IIIA-N2 NSCLC were enrolled in the trial from January 2008 until May 2011. The overall response rate was 41.7 % and the PFS and OS were 7.9 and 23.2 months, respectively, in overall population. The RR was 58.3 % (7/12) for the erlotinib arm with mutant EGFR and 25.0 % (3/12) for the GC arm with wild type EGFR (P = 0.18). Median PFS was 6.9 months versus 9.0 months, respectively (P = 0.071). Median OS was 14.5 months for the erlotinib arm and 28.1 months for the GC arm (P = 0.201). No unexpected toxicities were observed.

Conclusions

The primary endpoint was met and biomarker-guided neoadjuvant treatment strategy in patients with IIIA-N2 NSCLC is feasible. Erlotinib alone in neoadjuvant setting of EGFR mutant population showed an improved response but without survival benefits.

Trial registration

ClinicalTrials.gov NCT00600587 https://www.clinicaltrials.gov/ct2/show/NCT00600587?term=NCT00600587&rank=1

Electronic supplementary material

The online version of this article (doi:10.1186/s13045-015-0151-3) contains supplementary material, which is available to authorized users.

EGFR Mutations and Resistance to Irreversible Pyrimidine-Based EGFR Inhibitors

PURPOSE

Mutant selective irreversible pyrimidine-based EGFR kinase inhibitors, including WZ4002, CO-1686, and AZD9291, are effective in preclinical models and in lung cancer patients harboring the EGFR T790M gefitinib/erlotinib resistance mutation. However, little is known about how cancers develop acquired resistance to this class of EGFR inhibitors. We sought to identify and study EGFR mutations that confer resistance to this class of agents.

EXPERIMENTAL DESIGN

We performed an N-ethyl-N-nitrosourea (ENU) mutagenesis screen in EGFR-mutant (sensitizing alone or with concurrent EGFR T790M) Ba/F3 cells and selected drug-resistant clones. We evaluated the sensitivity of EGFR inhibitors in models harboring drug-resistant EGFR mutations.

RESULTS

We identified 3 major drug resistance mutations. EGFR L718Q, L844V, and C797S cause resistance to both WZ4002 and CO-1686 while, in contrast, only EGFR C797S leads to AZD9291 resistance. Cells containing an EGFR-sensitizing mutation, Del 19 or L858R, in conjunction with L718Q, L844V, or C797S retain sensitivity to quinazoline-based EGFR inhibitors, gefitinib and afatinib. The C797S mutation, in the presence of Del 19 or L858R and T790M, causes resistance to all current EGFR inhibitors, but L858R/T790M/C797S remains partially sensitive to cetuximab which leads to disruption of EGFR dimerization.

CONCLUSIONS

Our findings provide insights into resistance mechanisms to irreversible pyrimidine-based EGFR inhibitors and identify specific genomic contexts in which sensitivity is retained to existing clinical EGFR inhibitors. These findings will guide the development of new strategies to inhibit EGFR.

The latest therapeutic strategies after resistance to first generation epidermal growth factor receptor tyrosine kinase inhibitors (EGFR TKIs) in patients with non-small cell lung cancer (NSCLC)

First-generation epidermal growth factor receptor tyrosine kinase inhibitors (EGFR TKIs), gefitinib and erlotinib, produce reliable responses and survival benefits in selected patients with advanced non-small cell lung cancer (NSCLC). Unfortunately, most patients who initially respond to first-line therapy with EGFR TKIs will experience disease progression in 1-2 years. To overcome the resistance of EGFR TKIs, the potent resistance mechanisms and novel therapeutic strategies have been developed. T790M mutation and activation of bypass signaling pathway are identified the predominant mechanisms of acquired resistance to TKIs. Several approaches have shown promise, such as next-generation EGFR TKIs, immunotherapy, and combinational therapies. And the limited clinical data suggest that all drugs are acceptable safe. Additionally, this review will also focus on the increasingly importance of re-biopsy at the time of disease progression, and the matching effective therapies is related to the identification of specific molecular types of tumors.

Long progression-free survival with afatinib in a patient with EGFR-unknown lung adenocarcinoma after erlotinib failure: a case report

Important therapeutic advances for patients with advanced non-small cell lung cancer (NSCLC) have recently occurred, and the development of targeted therapy has revolutionized the treatment of these patients. We report the case of an NSCLC patient with unknown EGFR mutation status who developed resistance to erlotinib and was treated with afatinib. After 19 months of therapy with afatinib, the patient is still in treatment and maintains stable disease. Emerging resistance to reversible TKIs is a significant problem. Oral irreversible TKIs such as afatinib may offer an effective treatment option after failure with reversible TKIs.

Management of egfr tki-induced dermatologic adverse events

Targeting the epidermal growth factor receptor (egfr) pathway has become standard practice for the treatment of advanced non-small-cell lung cancer. Compared with chemotherapy, egfr tyrosine kinase inhibitors (tkis) have been associated with improved efficacy in patients with an EGFR mutation. Together with the increase in efficacy comes an adverse event (ae) profile different from that of chemotherapy. That profile includes three of the most commonly occurring dermatologic aes: acneiform rash, stomatitis, and paronychia. Currently, no randomized clinical trials have evaluated the treatments for the dermatologic aes that patients experience when taking egfr tkis. Based on the expert opinion of the authors, some basic strategies have been developed to manage those key dermatologic aes. Those strategies have the potential to improve patient quality of life and compliance and to prevent inappropriate dose reductions.

Precision Therapy for Lung Cancer: Tyrosine Kinase Inhibitors and Beyond

For patients with advanced cancers there has been a concerted effort to transition from a generic treatment paradigm to one based on tumor-specific biologic, and patient-specific clinical characteristics. This approach, known as precision therapy has been made possible owing to widespread availability and a reduction in the cost of cutting-edge technologies that are used to study the genomic, proteomic, and metabolic attributes of individual tumors. This review traces the evolution of precision therapy for lung cancer from the identification of molecular subsets of the disease to the development and approval of tyrosine kinase, as well as immune checkpoint inhibitors for lung cancer therapy. Challenges of the precision therapy era including the emergence of acquired resistance, identification of untargetable mutations, and the effect on clinical trial design are discussed. We conclude by highlighting newer applications for the concept of precision therapy.

Tyrosine kinase inhibitors for epidermal growth factor receptor gene mutation-positive non-small cell lung cancers: an update for recent advances in therapeutics

The presence of activating gene mutations in the epidermal growth factor receptor of non-small cell lung cancer patients is predictive (improved progression-free survival and improved response rate) when treated with small molecule tyrosine kinase inhibitors such as gefitinib, erlotinib and afatinib. The two most common mutations that account for greater than 85% of all EGFR gene mutations are in-frame deletions in exon 19 (LREA deletions) and substitution in exon 21 (L858R). Exon 18 mutations occur much less frequently at about 4% of all EGFR gene mutations. Together, exon 19 deletion and exon 21 L858R gene substitution are present in about 10% of Caucasian patients and 20-40% of Asian patients with non-small cell lung cancer. T790M gene mutation at exon 20 is associated with acquired resistance to epidermal growth factor receptor tyrosine kinase inhibitors. Early studies showed that activating EGFR gene mutations are most common in patients with adenocarcinoma histology, women, never smokers and those of Asian ethnicity. A recent multi-center phase III trial suggested that frontline epidermal growth factor receptor tyrosine kinase inhibitor therapy with afatinib is associated with improved progression-free survival compared to chemotherapy regardless of race. Moreover, guidelines now suggest EGFR gene mutation testing should be conducted in all patients with lung adenocarcinoma or mixed lung cancers with an adenocarcinoma component, regardless of characteristics such as smoking status, gender or race. The success of targeted therapies in non-small cell lung cancer patients has changed the treatment paradigm in metastatic non-small cell lung cancer. However, despite a durable response of greater than a year, resistance to epidermal growth factor receptor tyrosine kinase inhibitors inevitably occurs. This mini-review describes the clinically relevant EGFR gene mutations and the efficacy/toxicity of small molecule epidermal growth factor receptor tyrosine kinase inhibitors as targeted therapies for these gene mutations. Therapeutic strategies to overcome resistance, including emerging and novel therapies, are discussed.

Molecular histology of lung cancer: from targets to treatments

Lung cancer is the leading cause of cancer-related death worldwide with a 5-year survival rate of less than 15%, despite significant advances in both diagnostic and therapeutic approaches. Combined genomic and transcriptomic sequencing studies have identified numerous genetic driver mutations that are responsible for the development of lung cancer. In addition, molecular profiling studies identify gene products and their mutations which predict tumour responses to targeted therapies such as protein tyrosine kinase inhibitors and also can offer explanation for drug resistance mechanisms. The profiling of circulating micro-RNAs has also provided an ability to discriminate patients in terms of prognosis/diagnosis and high-throughput DNA sequencing strategies are beginning to elucidate cell signalling pathway mutations associated with oncogenesis, including potential stem cell associated pathways, offering the promise that future therapies may target this sub-population, preventing disease relapse post treatment and improving patient survival. This review provides an assessment of molecular profiling within lung cancer concerning molecular mechanisms, treatment options and disease-progression. Current areas of development within lung cancer profiling are discussed (i.e. profiling of circulating tumour cells) and future challenges for lung cancer treatment addressed such as detection of micro-metastases and cancer stem cells.

Role of mesenchymal-epithelial transition amplification in resistance to anti-epidermal growth factor receptor agents

All patients with epidermal growth factor receptor (EGFR) mutant advanced non-small cell lung cancer (NSCLC) treated with an EGFR-tyrosine kinase inhibitor (EGFR-TKI) such as gefitinib, erlotinib or afatinib will progress after a median of 9-12 months. So far, development of a secondary T790M mutation represents the most common (approximately 60%) mechanism of resistance to these drugs. The relative rarity of mesenchymal-epithelial transition (MET) amplification in NSCLC suggests that this event plays a limited role in primary resistance to EGFR-TKI. In contrast, MET gene amplification has been detected as a secondary event representing one of the most relevant mechanisms involved in the acquired resistance to EGFR-TKIs both in preclinical and clinical studies. The aim of this review is to discuss the role of MET amplification as a mechanism of resistance to anti-EGFR therapies and to review strategies which aim at overcoming this mechanism of resistance, including studies assessing drug combinations targeting both EGFR and MET pathways.

[TKI Resistance for T790M Mutation]

BACKGROUND AND OBJECTIVE

Epidermal growth factor receptor (EGFR) the development of orally activesmall molecule inhibitors for non-small cell lung cancer (NSCLC) provides anew treatment plan. EGFR gene mutation in patients with activation EGFR tyrosine kinase inhibitor (EGFR-TKIs) therapy for the treatment of sensitive, so that a large number of clinical benefit. The first generation of reversible ATP-competitive EGFR-TKIs, gefitinib and erlotinib as first-line, second-line or has the effect of maintenance therapy. Although the initial effect of these drugs have, but most patients will produce drug resistance. Within a year, 50%-60% patients had T790M housekeeping gene mutation associated with. Irreversible EGFR-TKIs recent background: afatinib and dac-omitinib covalent binding and inhibition of multiple ErbB family receptors (EGFR, HER2 and HER4). People evaluate these drugs as first-line treatment of significance, and acquired drug resistance situation significance on the first generation EGFR-TKIs. Afatinib is the first ErbB family approved blocking agent, used to treat with EGFR activating mutations in patients with non small cell lung cancer; dacomitinib are in the later stages of clinical development. EGFR inhibitors specifically targeting T790M resistance mutations (AZD9291, CO-1686, HM61713) are in the early stages of development. As discussed in this paper, the scope of the EGFR-TKIs kinase to target different, EGFR receptor binding was reversible and drug interaction potential is also different. For clinicians, these differences of the multi drug treatment of patients with non-small cell lung cancer with meaning, from the innovative anticancer drug combination therapy strategy point of view, these differences are also of great significance.

Pooled safety analysis of EGFR-TKI treatment for EGFR mutation-positive non-small cell lung cancer

OBJECTIVES

Three epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) - afatinib, erlotinib, and gefitinib - are available for the treatment of patients with EGFR mutation-positive non-small cell lung cancer (NSCLC). Given the long-term exposure of such patients to EGFR-TKIs, the toxicological properties of these agents in these individuals may differ from those observed in unselected patients. We compared the frequencies of severe adverse events (AEs) among EGFR mutation-positive NSCLC patients treated with these three EGFR-TKIs.

MATERIALS AND METHODS

We performed a pooled analysis of severe AEs according to the type of EGFR-TKI administered with the use of data extracted from prospective clinical trials that evaluated the clinical efficacy of gefitinib, erlotinib, or afatinib in NSCLC patients with EGFR mutations.

RESULTS

Twenty-one trials published between 2006 and 2014 and including 1468 patients were eligible for analysis. Patients in 13 trials (n=457) received gefitinib, those in 5 trials (n=513) received erlotinib, and those in 3 trials (n=498) received afatinib. Rash and diarrhea of grade ≥3 were significantly more frequent with afatinib therapy than with erlotinib or gefitinib therapy. The frequency of interstitial lung disease (ILD) of grade ≥3 was low (0.6-2.2%) with all three EGFR-TKIs and did not differ significantly among them. Gefitinib was associated with a significantly higher frequency of hepatotoxicity of grade ≥3 compared with erlotinib or afatinib. The overall frequency of AEs leading to treatment withdrawal was 6.1% (83 of 1354 evaluable patients), with such AEs occurring significantly more often with afatinib or gefitinib than with erlotinib. The most common withdrawal AEs were skin toxicity, ILD, and hepatotoxicity.

CONCLUSION

Such information on AEs should facilitate selection of the most appropriate EGFR-TKI for EGFR mutation-positive NSCLC patients with regard to mitigation of the risk for certain types of toxicity.

Detection and Dynamic Changes of EGFR Mutations from Circulating Tumor DNA as a Predictor of Survival Outcomes in NSCLC Patients Treated with First-line Intercalated Erlotinib and Chemotherapy

PURPOSE

Blood-based circulating-free (cf) tumor DNA may be an alternative to tissue-based EGFR mutation testing in NSCLC. This exploratory analysis compares matched tumor and blood samples from the FASTACT-2 study.

EXPERIMENTAL DESIGN

Patients were randomized to receive six cycles of gemcitabine/platinum plus sequential erlotinib or placebo. EGFR mutation testing was performed using the cobas tissue test and the cobas blood test (in development). Blood samples at baseline, cycle 3, and progression were assessed for blood test detection rate, sensitivity, and specificity; concordance with matched tumor analysis (n = 238), and correlation with progression-free survival (PFS) and overall survival (OS).

RESULTS

Concordance between tissue and blood tests was 88%, with blood test sensitivity of 75% and a specificity of 96%. Median PFS was 13.1 versus 6.0 months for erlotinib and placebo, respectively, for those with baseline EGFR mut(+) cfDNA [HR, 0.22; 95% confidence intervals (CI), 0.14-0.33, P < 0.0001] and 6.2 versus 6.1 months, respectively, for the EGFR mut(-) cfDNA subgroup (HR, 0.83; 95% CI, 0.65-1.04, P = 0.1076). For patients with EGFR mut(+) cfDNA at baseline, median PFS was 7.2 versus 12.0 months for cycle 3 EGFR mut(+) cfDNA versus cycle 3 EGFR mut(-) patients, respectively (HR, 0.32; 95% CI, 0.21-0.48, P < 0.0001); median OS by cycle 3 status was 18.2 and 31.9 months, respectively (HR, 0.51; 95% CI, 0.31-0.84, P = 0.0066).

CONCLUSIONS

Blood-based EGFR mutation analysis is relatively sensitive and highly specific. Dynamic changes in cfDNA EGFR mutation status relative to baseline may predict clinical outcomes.

Known and putative mechanisms of resistance to EGFR targeted therapies in NSCLC patients with EGFR mutations-a review

Lung cancer is the leading cause of cancer related deaths in Canada with non-small cell lung cancer (NSCLC) being the predominant form of the disease. Tumor characterization can identify cancer-driving mutations as treatment targets. One of the most successful examples of cancer targeted therapy is inhibition of mutated epidermal growth factor receptor (EGFR), which occurs in ~10-30% of NSCLC patients. While this treatment has benefited many patients with activating EGFR mutations, almost all who initially benefited will eventually acquire resistance. Approximately 50% of cases of acquired resistance (AR) are due to a secondary T790M mutation in exon 20 of the EGFR gene; however, many of the remaining mechanisms of resistance are still unknown. Much work has been done to elucidate the remaining mechanisms of resistance. This review aims to highlight both the mechanisms of resistance that have already been identified in patients and potential novel mechanisms identified in preclinical models which have yet to be validated in the patient settings.

Neoadjuvant and adjuvant epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) therapy for lung cancer

The Lung Adjuvant Cisplatin Evaluation (LACE) meta-analysis and the meta-analysis of individual participant data reported by non-small cell lung cancer (NSCLC) Meta-analysis Collaborative Group in neo-adjuvant setting validated respectively that adjuvant and neoadjuvant chemotherapy would significantly improve overall survival (OS) and recurrence-free survival for resectable NSCLC. However, chemotherapy has reached a therapeutic plateau. It has been confirmed that epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) targeting therapy provides a dramatic response to patients with advanced EGFR-mutation positive NSCLC. Researchers have paid more attention to exploring applications of TKIs to early resectable NSCLCs. Several studies on adjuvant TKI treatment concluded its safety and feasibility. But there existed certain limitations of these studies as inference factors to interpret data accurately: the BR19 study recruited patients among which almost 52% had stage IB and only 15 (3.0%, 15/503) had been confirmed with EGFR-mutant type; retrospective studies performed at Memorial Sloan Kettering Cancer Center (MSKCC) selected EGFR mutant-type NSCLC patients but couldn't avoid inherent defects inside retrospective researches; the RADIANT study revised endpoints from targeting at EGFR immunohistochemistry (IHC)+ and/or fluorescence in situ hybridization (FISH)+ mutation to only EGFR IHC+ mutation, leading to selective bias; despite that the SELECT study validated efficacy of adjuvant TKI and second round of TKI after resistance occurred, a single-arm clinical trial is not that persuasive in the absence of comparison with chemotherapy. Taking all these limitations into account, CTONG1104 in China and IMPACT in Japan have been conducted and recruiting patients to offer higher level of evidences to explore efficacy of preoperative TKI therapy for early resectable EGFR mutation positive NSCLC patients (confirmed by pathological results of tumor tissue or lymph node biopsy). On the other hand, case reports and several phase II clinical trials with small sample size tried to elbow their way on respect of preoperative TKI treatment and advised that TKI tended to improve response rate. However, no data on survival rate was present. The first phase II study of biomarker-guided neoadjuvant therapy for stage IIIA-N2 NSCLC patients stratified by EGFR mutation status, sponsored by CSLC0702, showed erlotinib tended to improve response rate, but failed to show benefits of disease-free survival (DFS) or OS. Subsequently, CTONG1103 was designed to investigate efficacy of erlotinib vs. combination of gemcitabine/cisplatin (GC) as neoadjuvant treatment in stage IIIA-N2 NSCLC with sensitizing EGFR mutation in exon 19 or 21. All these ongoing trials should be worthy of our expect to provide convincing evidences for customized therapy for patients with resectable NSCLC.

Clinical activity of the mutant-selective EGFR inhibitor AZD9291 in patients with EGFR inhibitor-resistant non-small cell lung cancer

The first generation epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) are effective in advanced non-small cell lung cancer (NSCLC) with EGFR mutations. Unfortunately, disease progression generally occurs after 9 to 14 months of targeted therapy. The substitution of threonine with methionine at amino acid position 790 (T790M), as the second mutation in EGFR, is the most common resistance mechanism and is detected in tumor cells from more than 50-60% of patients after disease progression. However, current targeted therapeutic strategies for patients with acquired resistance are limited. This has led to the development of "third generation" EGFR-TKIs that are designed to target T790M and EGFR-TKI sensitizing mutations more selectively than wild-type. AZD9291, as a mono-anilino-pyrimidine compound, is a novel, irreversible EGFR-TKI, has proved to be more effective against both EGFR-TKI sensitizing and resistance T790M mutations in preclinical models. This phase I clinical study showed that AZD9291 has robust efficacy and is well tolerated in EGFR mutant NSCLC patients with acquired resistance to EGFR-TKIs.

Clinical trials for lung cancer in China

Lots of international multi-center clinical trials have been conducted in China over the past 10 years. We also have more and more clinical trials designed and launched by qualified Chinese investigators in recent years, especially after the establishment of the Chinese Thoracic Oncology Group (CTONG) in 2007. These trials are mainly about targeted drugs. The finished ones provided more evidence for the use of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) in the first-line/maintenance/second-line settings in Chinese patients. The ongoing ones will diversify the use of EGFR-TKIs in 1(st)/2(nd)/3(rd) line settings and help to answer the questions whether patients will benefit from (neo)adjuvant EGFR-TKIs and chemotherapy intercalating and maintenance use of EGFR-TKIs. Here, we introduce far-reaching clinical trials conducted, ongoing and will be launched soon in China.

Gefitinib and erlotinib in metastatic non-small cell lung cancer: a meta-analysis of toxicity and efficacy of randomized clinical trials

BACKGROUND

Tyrosine kinase inhibitors (TKIs) targeting the epidermal growth factor receptor (EGFR) have been evaluated in patients with metastatic and advanced non-small cell lung cancer (NSCLC). The U.S. Food and Drug Administration initially granted accelerated approval to gefitinib but subsequently rescinded the authorization. Erlotinib and afatinib are similar compounds approved for the treatment of metastatic NSCLC. The objective of this study was to compare the efficacy and toxicity of erlotinib, gefitinib, and afatinib in NSCLC.

METHODS

We tabulated efficacy variables including overall response rate (ORR), progression-free survival (PFS), and overall survival (OS) and quantitated toxicities and rates of dose reductions and discontinuation. Summary odds ratios were calculated using random and fixed-effects models. An odds ratio was the summary measure used for pooling of studies.

RESULTS

We examined 28 studies including three randomized trials with afatinib. Clinical toxicities, including pruritus, rash, anorexia, diarrhea, nausea, fatigue, mucositis, paronychia, and anemia, were similar between erlotinib and gefitinib, although some statistical differences were observed. Afatinib treatment resulted in more diarrhea, rash, and paronychia compared with erlotinib and gefitinib. Regarding efficacy, similar outcomes were recorded for ORR, PFS, or OS in the total population and in specific subgroups of patients between erlotinib and gefitinib. All three TKIs demonstrated higher ORRs in first line in tumors harboring EGFR mutations.

CONCLUSION

Gefitinib has similar activity and toxicity compared with erlotinib and offers a valuable alternative to patients with NSCLC. Afatinib has similar efficacy compared with erlotinib and gefitinib in first-line treatment of tumors harboring EGFR mutations but may be associated with more toxicity, although further studies are needed. Gefitinib deserves consideration for U.S. marketing as a primary treatment for EGFR-mutant NSCLC.

Organoid development in cancer genome discovery

The tumor response to most therapeutic agents in cancer is highly unpredictable. Cancer models which can adequately represent tumor heterogeneity and predict in vivo drug sensitivity are intense areas of investigation. Cancer cell lines and patient-derived xenograft models are the most frequently used models in cancer research and anticancer drug screening. Recently, cancer 'organoid' culture conditions have been developed to establish in vitro growth of patient-derived samples at higher efficiency and they are very promising for large scale drug screening and fundamental cancer biology research. Here, we leverage our experience in prostate cancer to discuss the advantages and limitations of these cancer models and summarize the development of cancer organoid culture--a development which may provide a new path towards personalized medicine in the future.

Magnitude of the benefit of progression-free survival as a potential surrogate marker in phase 3 trials assessing targeted agents in molecularly selected patients with advanced non-small cell lung cancer: systematic review

Background

In evaluation of the clinical benefit of a new targeted agent in a phase 3 trial enrolling molecularly selected patients with advanced non-small cell lung cancer (NSCLC), overall survival (OS) as an endpoint seems to be of limited use because of a high level of treatment crossover for ethical reasons. A more efficient and useful indicator for assessing efficacy is needed.

Methods and Findings

We identified 18 phase 3 trials in the literature investigating EGFR-tyrosine kinase inhibitor (TKIs) or ALK-TKIs, now approved for use to treat NSCLC, compared with standard cytotoxic chemotherapy (eight trials were performed in molecularly selected patients and ten using an “all-comer” design). Receiver operating characteristic analysis was used to identify the best threshold by which to divide the groups. Although trials enrolling molecularly selected patients and all-comer trials had similar OS-hazard ratios (OS-HRs) (0.99 vs. 1.04), the former exhibited greater progression-free survival-hazard ratios (PFS-HR) (mean, 0.40 vs. 1.01; P<0.01). A PFS-HR of 0.60 successfully distinguished between the two types of trials (sensitivity 100%, specificity 100%). The odds ratio for overall response was higher in trials with molecularly selected patients than in all-comer trials (mean: 6.10 vs. 1.64; P<0.01). An odds ratio of 3.40 for response afforded a sensitivity of 88% and a specificity of 90%.

Conclusion

The notably enhanced PFS benefit was quite specific to trials with molecularly selected patients. A PFS-HR cutoff of ∼0.6 may help detect clinical benefit of molecular targeted agents in which OS is of limited use, although desired threshold might differ in an individual trial.

The epidermal growth factor receptor (EGRF) in lung cancer

In the last decade, important advances have been made in understanding of cancer biology, particularly non-small-cell lung cancer (NSCLC) with the discovery of oncogenic drivers of the disease. The epidermal growth factor receptor (EGFR) gene and its pathways was the first oncogenic driver discovered to be mutated and treatable in lung cancer. Treatment with EGFR tyrosine kinase inhibitors (TKIs) is the standard of care for molecularly selected EGFR-mutant patients, while its role in unselected lung cancer patients is nowadays controversial. This review will provide an overview of the EGFR pathway and options for its treatment of lung cancer.

Afatinib for the treatment of metastatic non-small cell lung cancer

Targeting the epidermal growth factor receptor (EGFR) in patients with non-small cell lung cancer (NSCLC) harboring sensitizing mutations in the tyrosine kinase (TKI) domain has led to a significant change in the management of this disease. The classic or sensitizing mutations are G719X mutation in exon 18, in-frame deletions or insertion of exon 19, L858R or L861Q mutation in exon 21. Approximately 90% of these mutations are exon 19 deletion or exon 21 L858R point mutation. Gefitinib and erlotinib are reversible first-generation inhibitors of mutant EGFR, and treatment with these agents in the first-line setting has demonstrated a progression-free survival of 9.5-13.7 months. However, the majority of these patients ultimately develop resistance to these drugs. Afatinib is an irreversible pan-ErbB inhibitor that was developed to circumvent the problem of resistance to first-generation TKIs. The LUX-Lung studies have evaluated the efficacy and toxicities of afatinib in treatment-naïve and refractory NSCLC patients. The promising results of some of these trials led to approval of afatinib by the US Food and Drug Administration for patients with advanced NSCLC and EGFR exon 19 deletions or exon 21 (L858R) substitution mutations. Afatinib causes toxicities similar to those of the first-generation EGFR TKIs, such as diarrhea, rash, acne, and stomatitis, and overall is well tolerated. This article focuses on the clinical studies of afatinib in patients with NSCLC.

Management of EGFR mutated nonsmall cell lung carcinoma patients

Tyrosine kinase inhibitors (TKIs) targeting the epidermal growth factor receptor (EGFR) are common in the therapeutic armentarium of lung cancer today. Initially tested in an unselected population, they have been of limited usefulness until the identification EGFR gene mutations. Activating mutations generate conformational changes that result in a shift toward an active state of the catalytic domain and are associated with sensitivity to first generation EGFR TKI. Other mutations have been associated with resistance to these drugs, but for rare mutations there is limited data concerning their role in predicting response to EGFR TKI. To date, four molecules have been approved for the treatment of EGFR mutated lung cancer. Gefitinib and/or erlotinib are available in almost all countries. Afatinib has been approved by the US Food and Drug Administration and by the European Medicines Agency, and icotinib has been approved only in China. Other, more active, third generation agents with a higher binding affinity for the receptor, or that are directed against specific mutations, are under development. EGFR TKIs have a favourable impact on progression-free survival when given as first line treatment in mutated patients, but may also have a moderate effect as a salvage therapy and in maintenance in an unselected population.

Molecular targeted therapy in the treatment of advanced stage non-small cell lung cancer (NSCLC)

Historically, patients with advanced stage non-small cell lung cancer (NSCLC) were treated with chemotherapy alone, but a therapeutic plateau has been reached. Advances in the understanding of molecular genetics have led to the recognition of multiple molecularly distinct subsets of NSCLC. This in turn has led to the development of rationally directed molecular targeted therapy, leading to improved clinical outcomes. Tumour genotyping for EGFR mutations and ALK rearrangement has meant chemotherapy is no longer given automatically as first-line treatment but reserved for when patients do not have a 'druggable' driver oncogene. In this review, we will address the current status of clinically relevant driver mutations and emerging new molecular subsets in lung adenocarcinoma and squamous cell carcinoma, and the role of targeted therapy and mechanisms of acquired resistance to targeted therapy.

[Nimotuzumab significantly enhances chemosensitivity of PC9 human lung adenocarcinoma cells to paclitaxel in vitro]

BACKGROUND

Nimotuzumab is a humanized IgG1 type monoclonal antibody targeting epidermal growth factor receptor, and can enhance chemosensitivity and radiosensitivity of certain cancers. The aim of this study is to investigate the effects of nimotuzumab on the chemosensitivities of PC9 human lung adenocarcinoma cells to common chemtherapeutic drugs including ciaplatin, gemcitabine, paclitaxel, pemetrexed and vinorelbine, and to elucidate possible mechanisms.

METHODS

PC9 human lung adenocarcinoma cell line was used in the study. Cell proliferation was determined by WST-1 assay and cell apoptosis was detected by TUNEL assay. Cell cycle distribution was analyzed by DNA analysis with FACS. Tublin and microfilaments were observed by immunofluorescence staining.

RESULTS

Nimotuzumab significantly enhanced the chemosensitivity of PC9 cells to paclitaxel. Cell proliferation was inhibited significantly (P<0.05) and cell apoptosis rate was higher in nimotuzumab combined with low dose paclitaxel (0.05 μg/mL) group (P=0.013). G2/M arrest was increased significantly by nimotuzumab combined with paclitaxel group (P<0.05). Nimotuzumab caused aggregation of tublin and microfilaments into well organized microtubules.

CONCLUSIONS

Nimotuzumab enhanced the chemosensitivity of PC9 cell to paclitaxel by enhancing G2/M arrest and aggregation of tublin and microfilaments. Therefore, Nimotuzumab combined with taxane drugs could be a potential effective regimen in non-small cell lung cancer.

Oncogene addiction: pathways of therapeutic response, resistance, and road maps toward a cure

A key goal of cancer therapeutics is to selectively target the genetic lesions that initiate and maintain cancer cell proliferation and survival. While most cancers harbor multiple oncogenic mutations, a wealth of preclinical and clinical data supports that many cancers are sensitive to inhibition of single oncogenes, a concept referred to as 'oncogene addiction'. Herein, we describe the clinical evidence supporting oncogene addiction and discuss common mechanistic themes emerging from the response and acquired resistance to oncogene-targeted therapies. Finally, we suggest several opportunities toward exploiting oncogene addiction to achieve curative cancer therapies.