A phase II pharmacodynamic study of erlotinib in patients with advanced non-small cell lung cancer previously treated with platinum-based chemotherapy

Novel EGFR inhibitors against resistant L858R/T790M/C797S mutant for intervention of non-small cell lung cancer

To overcome C797S mutation, the latest and most common resistance mechanism in the clinical treatment of third-generation EGFR inhibitor, a novel series of substituted 6-(2-aminopyrimidine)-indole derivatives were designed and synthesized. Through the structure-activity relationship (SAR) study, compound 11eg was identified as a novel and potent EGFR L858R/T790M/C797S inhibitor (IC50 = 0.053 μM) but had a weak effect on EGFRWT (IC50 = 1.05 μM). 11eg significantly inhibited the proliferation of the non-small cell lung cancer (NSCLC) cells harboring EGFRL858R/T790M/C797S with an IC50 of 0.052 μM. 11eg also showed potent inhibitory activity against other NSCLC cell lines harboring main EGFR mutants. Furthermore, 11eg exhibited much superior activity in arresting cell cycle and inducing apoptosis of NSCLC cells with mutant EGFRC797S. It blocked cellular EGFR signaling. Importantly, 11eg markedly suppressed the tumor growth in in vivo xenograft mouse model with good safety. Additionally, 11eg displayed good microsomal stability. These results demonstrated the potential of 11eg with novel scaffold as a promising lead compound targeting EGFRC797S to guide in-depth structural optimization.

An Expanded Role for IRBs in the Oversight of Research Biopsies

Research biopsies included in cancer clinical trials have the goal of advancing scientific understanding of the biological bases of cancer and its treatments, but may offer no prospect of direct benefit to participants and often pose more than minimal risk. The research community is examining the ethics of research biopsies increasingly often, especially when they are mandatory for study participation but do not support primary study objectives and thus are "nonintegral" to the study. Ethical concerns center on the limited scientific justification supporting some biopsies, risks to research participants, and the potential for coercion and therapeutic misconception during the informed consent process. There is also a lack of comprehensive oversight of research biopsies by regulatory agencies and institutions. This paper reviews these ethical concerns, discusses the scope of federal oversight, and suggests that institutional review boards (IRBs) should assume a larger role in ensuring the ethical conduct of research biopsies. It concludes with guidance to IRBs on how to weigh the risks, benefits, and acceptability of such biopsies in different contexts that is based on a framework the American Society of Clinical Oncology developed for the inclusion of research biopsies in oncology clinical trials.

Class III β-Tubulin Expression Is of Value in Selecting nab -Paclitaxel and Gemcitabine as First-Line Therapy in Unresectable Pancreatic Cancer

OBJECTIVES

Nab -paclitaxel and gemcitabine (GnP) or FOLFIRINOX (a combination of leucovorin, fluorouracil, irinotecan, and oxaliplatin [FFX]) is currently recognized as the standard first-line regimen for unresectable pancreatic ductal adenocarcinoma (PDAC). Class III β-tubulin (TUBB3) has the potential to predict resistance to taxane in various tumors; therefore, this study aimed to clarify whether TUBB3 is a predictive marker for GnP response.

METHODS

We retrospectively reviewed 113 patients with PDAC who received GnP or FFX as first-line chemotherapy and examined immunohistochemically the TUBB3 expression in specimens obtained by endoscopic ultrasound-guided fine-needle aspiration.

RESULTS

High TUBB3 expression was associated with a significantly lower disease control rate ( P = 0.017) and shorter progression-free survival (PFS) ( P = 0.019), and multivariate analysis revealed that TUBB3 expression was an independent variable for PFS in the GnP first-line group ( P = 0.045). In addition, in the FFX first-line group, TUBB3 expression was not correlated with PFS or overall survival (OS). In all 113 patients, TUBB3 expression was not also associated with OS.

CONCLUSIONS

Class III β-tubulin might be a predictive factor for the response of GnP, but not a prognostic factor for OS, helping the selection of an optimized first-line chemotherapy regimen for unresectable PDAC.

Eye, hepatobiliary, and renal disorders of erlotinib in patients with non-small-cell lung cancer: A meta-analysis

Background

Erlotinib is an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors used to treat EGFR mutation positive non-small-cell lung cancer (NSCLC). Skin rash and diarrhea are well-known and common adverse events in patients receiving erlotinib, whereas other adverse events, including eye, liver, or renal disorders have not been evaluated adequately. This meta-analysis aimed to evaluate the ocular, hepatobiliary, and renal toxicities of erlotinib in patients with NSCLC cancers.

Methods

In total, sixty studies were assessed, and the results of the included studies were quantitatively integrated using meta-analysis. The incidence of ocular, hepatobiliary (alanine aminotransferase [ALT] and bilirubin elevations; other hepatic adverse events), and renal adverse events were estimated. Additionally, the erlotinib-treated groups and the control groups (placebo or other treatment) were compared with respect to ocular disorders and ALT elevation. The study protocol has been registered in the International Prospective Register for Systematic Reviews (PROSPERO) CRD42018093758.

Results

The overall incidence of ocular disorders was 3.30% (95% confidence interval [CI] 2.20%–5.00%). The incidence of ALT elevation, bilirubin elevation, and other hepatobiliary disorders was 6.40% (95% CI 3.90%–10.4%), 3.80% (95% CI 2.30%–6.10%), and 1.00% (95% 0.60%–1.80%), respectively. The incidence of renal disorder was 3.10% (95% CI 1.90%–5.00%). The risk of ocular toxicity in the erlotinib treatment group was significantly increased (risk ratio = 2.91; 95% CI 1.70–4.98) compared to that in the control group. ALT elevation was not significantly different between the two groups.

Conclusion

Based on the results, careful monitoring of ocular toxicity in patients receiving erlotinib should be recommended and closer monitoring of hepatic toxicity should be also recommended in patients with liver-related risk factors.

Pneumonitis in advanced non-small-cell lung cancer patients treated with EGFR tyrosine kinase inhibitor: Meta-analysis of 153 cohorts with 15,713 patients: Meta-analysis of incidence and risk factors of EGFR-TKI pneumonitis in NSCLC

PURPOSE

Pneumonitis is a significant toxicity of EGFR tyrosine kinase inhibitors (EGFR-TKI) in non-small-cell lung cancer (NSCLC) patients. We studied the incidence of pneumonitis in clinical trials of EGFR-TKI published in 2003-2017, and performed subgroups analyses to identity predisposing factors.

METHODS

Ovid-MEDLINE and EMBASE search up to 4/17/17 using the keywords, "erlotinib", "gefitinib", "afatinib", "osimertinib", and "lung cancer", resulted in a total of 153 eligible trial cohorts with 15,713 advanced NSCLC patients treated with EGFR-TKI. The pooled incidence of all-grade, high-grade, and grade 5 pneumonitis was obtained. Subgroup analyses were performed with meta-regression using study-level covariates.

RESULTS

Among the patients without prior exposure to EGFR-TKI, the overall incidence was 1.12% (95% CI:0.79-1.58%) for all-grade, 0.61% (95% CI:0.40-0.93%) for high-grade, and 0.20% (95% CI:0.11-0.38%) for grade 5 pneumonitis. The incidence was significantly higher in Japanese studies compared to studies of non-Japan origin, for all-grade (4.77% vs. 0.55%, p < 0.001), high grade (2.49% vs. 0.37%, p < 0.001), and grade 5 pneumonitis (1.00% vs. 0.18%, p < 0.001). Multivariate analyses demonstrated higher odds of pneumonitis in Japanese studies for all-grade (odds ratio [OR]: 5.04; 95% CI:3.14-8.11, p < 0.001), high-grade (OR: 4.45; 95% CI:2.50-7.93, p < 0.001), and grade 5 pneumonitis (OR: 4.55; 95% CI:2.20-9.44, p < 0.001) compared to others, after adjusting for types of EGFR-TKI and lines of therapy. In patients with EGFR retreatment analyzed separately, the pooled incidence was 1.13% (95% CI:0.40-3.15%) for all-grade, 0.49% (95% CI:0.21-1.11%) for high-grade, and 0.16% (95% CI:0.04-0.65%) for grade 5 pneumonitis.

CONCLUSIONS

The overall incidence of EGFR-TKI pneumonitis was 1.12% in patients without prior exposure to EGFR-TKI, and 1.13% in EGFR-TKI retreatment group. The cohorts from Japan had significantly higher incidence of pneumonitis, providing insights for further mechanistic studies.

Burdensome Research Procedures in Trials: Why Less Is More

A large volume of trials involve invasive, nontherapeutic research procedures, like organ biopsy or sham surgeries, that can pose risks comparable with the experimental treatment itself but that have no direct benefit for volunteers. Though such procedures can enhance the value of clinical investigations, recent studies suggest that many studies involving invasive, nontherapeutic research procedures are not well planned and reported; some studies suggest that their results are often not utilized in the planning of new investigations. This commentary offers recommendations for how investigators, sponsors, and ethics committees might improve evaluation and implementation of studies involving invasive nontherapeutic procedures. We conclude by urging more demanding scientific standards for the rationale, design, and reporting of burdensome, nontherapeutic research procedures-particularly where they involve risk of serious complications.

EGFR gene copy number as a predictive/biomarker for patients with non-small-cell lung cancer receiving tyrosine kinase inhibitor treatment: a systematic review and meta-analysis

Epidermal growth factor receptor (EGFR) gene copy number has been proposed as a candidate biomarker for predicting treatment response to EGFR tyrosine kinase inhibitors (EGFR-TKIs) in patients with advanced non-small-cell lung cancer (NSCLC). MEDLINE, PubMed, Cochrane, and Google Scholar databases were searched until October 21, 2015 using the following search terms: lung neoplasms/lung cancer/non-small cell lung cancer/NSCLC, EGFR, gene amplification, copy number, erlotinib, gefitinib, tyrosine-kinase inhibitor/TKI, predictor. 17 studies were included in the analysis with a total of 2047 patients. The overall analysis found that increased EGFR gene copy number was associated with higher overall response rate (ORR), overall survival (OS) and progression-free survival (PFS; p values ≤0.008) compared with patients without a high EGFR gene copy number. Subgroup analysis found that in a population of patients who were primarily Caucasian, a higher EGFR gene copy number was also associated with increased ORR, OS, and PFS (p values ≤0.018). The results were similar in a population of Asian patients, except that a higher EGFR gene copy number was not associated with improved OS (p=0.248). Sensitivity analysis indicated that no one study overly influenced the results and that the findings are robust. The result of the analysis found that EGFR gene copy number was associated with increased OS and PFS, supporting the idea that EGFR gene copy number is a biomarker for response to EGFR-TKI therapy in patients with advanced NSCLC.

Mutation analysis of circulating plasma DNA to determine response to EGFR tyrosine kinase inhibitor therapy of lung adenocarcinoma patients

Long-lasting success in lung cancer therapy using tyrosine kinase inhibitors (TKIs) is rare since the tumors develop resistance due to the occurrence of molecularly altered subclones. The aim of this study was to monitor tumors over time based on the quantity of mutant plasma DNA and to identify early indications for therapy response and tumor progression. Serial plasma samples from lung adenocarcinoma patients treated with TKIs were used to quantify EGFR and KRAS mutations in circulating DNA by digital PCR. Mutant DNA levels were compared with the courses of responses to treatment with TKIs, conventional chemotherapy, radiotherapy, or combinations thereof. Variations in plasma DNA mutation levels over time were found in 15 patients. We categorize three major courses: First, signs of therapy response are associated with a fast clearing of plasma DNA mutations within a few days. Second, periods of stable disease are accompanied by either absence of mutations or fluctuation at low levels. Finally, dramatic increase of mutational load is followed by rapid tumor progression and poor patient survival. In summary, the serial assessment of EGFR mutations in the plasma of NSCLC patients allows conclusions about controlled disease and tumor progression earlier than currently available methods.

The prevalence and prognostic significance of KRAS mutation subtypes in lung adenocarcinomas from Chinese populations

BACKGROUND

We performed this retrospective study to identify the prevalence of KRAS mutation in Chinese populations and make a comprehensive investigation of the clinicopathological features of KRAS mutation in these patients.

PATIENTS AND METHODS

Patients from 2007 to 2013 diagnosed with primary lung adeno-carcinoma who received a radical resection were examined for KRAS, EGFR, HER2, BRAF mutations, and ALK, RET, and ROS1 fusions. Clinicopathological features, including sex, age, tumor-lymph node-metastasis stage, tumor differentiation, smoking status, histological subtypes, and survival information were analyzed.

RESULT

KRAS mutation was detected in 113 of 1,368 patients. Nine different subtypes of KRAS mutation were identified in codon 12, codon 13, and codon 61. KRAS mutation was more frequently found in male patients and former/current smoker patients. Tumors with KRAS mutation had poorer differentiation. Invasive mucinous adenocarcinoma predominant and solid predominant subtypes were more frequent in KRAS mutant patients. No statistical significance was found in relapse-free survival or overall survival between patients with KRAS mutation and patients with other mutations.

CONCLUSION

In Chinese populations, we identified KRAS mutation in 8.3% (113/1,368) of the patients with lung adenocarcinoma. KRAS mutation defines a molecular subset of lung adenocarcinoma with unique clinicopathological features.

Analysis of Impact of Post-Treatment Biopsies in Phase I Clinical Trials

PURPOSE

The use of biopsy-derived pharmacodynamic biomarkers is increasing in early-phase clinical trials. It remains unknown whether drug development is accelerated or enhanced by their use. We examined the impact of biopsy-derived pharmacodynamic biomarkers on subsequent drug development through a comprehensive analysis of phase I oncology studies from 2003 to 2010 and subsequent publications citing the original trials.

METHODS

We conducted a search to identify and examine publications of phase I oncology studies including the use of biopsy-derived pharmacodynamic biomarkers between 2003 and 2010. Characteristics of those studies were extracted and analyzed, along with outcomes from the biomarker data. We then compiled and reviewed publications of subsequent phase II and III trials citing the original phase I biomarker studies to determine the impact on drug development.

RESULTS

We identified 4,840 phase I oncology publications between 2003 and 2010. Seventy-two studies included a biopsy-derived pharmacodynamic biomarker. The proportion of biomarker studies including nondiagnostic biopsies increased over time (P = .002). A minimum of 1,873 tumor biopsies were documented in the 72 studies, 12 of which reported a statistically significant biomarker result. Thirty-three percent of studies (n = 24) were referenced by subsequent publications specifically with regard to the biomarkers. Only five positive biomarker studies were cited subsequently, and maximum tolerated dose was used for subsequent drug development in all cases.

CONCLUSION

Despite their increased use, the impact of biopsy-derived pharmacodynamic biomarkers in phase I oncology studies on subsequent drug development remains uncertain. No impact on subsequent dose or schedule was demonstrated. This issue requires further evaluation, given the risk and cost of such studies.

Predictive value of K-ras and PIK3CA in non-small cell lung cancer patients treated with EGFR-TKIs: a systemic review and meta-analysis

Objective

A meta-analysis was performed to augment the insufficient data on the impact of mutative EGFR downstream phosphatidylinositol-3-kinase (PI3K) and mitogen-activated protein kinase (MAPK) pathways on the clinical efficiency of epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) treatment of non-small cell lung cancer (NSCLC) patients.

Methods

Network databases were explored in April, 2015. Papers that investigated the clinical outcomes of NSCLC patients treated with EGFR-TKIs according to the status of K-ras and/or PIK3CA gene mutation were included. A quantitative meta-analysis was conducted using standard statistical methods. Odds ratios (ORs) for objective response rate (ORR) and hazard ratios (HRs) for progression-free survival (PFS) and overall survival (OS) were calculated.

Results

Mutation in K-ras significantly predicted poor ORR [OR =0.22; 95% confidence interval (CI), 0.13-0.35], shorter PFS (HR =1.56; 95% CI, 1.27-1.92), and shorter OS (HR =1.59; 95% CI, 1.33-1.91) in NSCLC patients treated with EGFR-TKIs. Mutant PIK3CA significantly predicted shorter OS (HR =1.83; 95% CI, 1.05-3.20), showed poor ORR (OR =0.70; 95% CI, 0.22-2.18), and shorter PFS (HR =1.79; 95% CI, 0.91-3.53) in NSCLC patients treated with EGFR-TKIs.

Conclusion

K-ras mutation adversely affected the clinical response and survival of NSCLC patients treated with EGFR-TKIs. PIK3CA mutation showed similar trends. In addition to EGFR, adding K-ras and PIK3CA as routine gene biomarkers in clinical genetic analysis is valuable to optimize the effectiveness of EGFR-TKI regimens and identify optimal patients who will benefit from EGFR-TKI treatment.

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.

Pharmacodynamic biomarkers: falling short of the mark?

In recent years, the clinical development of targeted therapies has been advanced by a greater understanding of tumor biology and genomics. Nonetheless, drug development remains a slow and costly process. An additional challenge is that targeted therapies may benefit only a subset of patients treated-typically those patients whose tumors are dependent on the target of interest. Thus, there is a growing need for the incorporation of both predictive and pharmacodynamic (PD) biomarkers in drug development. Predictive biomarkers are important to help guide patient selection, while PD biomarkers can provide information on the pharmacologic effects of a drug on its target. PD studies may provide insights into proof of mechanism (i.e., Does the agent hit its intended target?) and proof of concept (i.e., Does hitting the drug target result in the desired biologic effect?). PD studies may also provide information on the optimal biologic dosing or scheduling of a targeted agent. Herein, we review PD endpoints in the context of targeted drug development in non-small cell lung cancer, highlighting some of the key challenges encountered to date. In doing so, we discuss recent experiences with repeat tumor biopsies, surrogate tissue analysis, alternative clinical trial designs (e.g., window-of-opportunity trials), circulating biomarkers, and mechanism-based toxicity assessments. The application of such technologies and biomarkers in early clinical trials may facilitate rational drug development, while enhancing our understanding of why certain targeted therapies succeed or fail. See all articles in this CCR focus section, "Progress in pharmacodynamic endpoints."

Should KRAS mutation still be used as a routine predictor of response to EGFR-TKIs in advanced non-small-cell lung cancer? A revaluation based on meta-analysis

PURPOSE

Regarding the controversial investigations characterizing the role of KRAS status for predicting patients' response to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) in advanced non-small-cell lung cancer (NSCLC), we conducted a meta-analysis in unselected patients and a further subset analysis in EGFR wild-type advanced NSCLC to get a more accurate evaluation.

METHODS

We did systematically searches following the retrieval strategies. The end points were overall survival (OS), progression-free survival (PFS), and overall response rate (ORR).

RESULTS

Twelve prospective intervention trials comprised of 1,859 unselected advanced NSCLC patients were identified. KRAS mutation was associated with shorter OS and PFS [hazard ratio (HR) 2.09, 95 % confidence interval (CI) 1.56-2.80; HR 1.82, 95 % CI 1.50-2.20] and lower ORR (relative ratio 0.25, 95 % CI 0.11-0.59) in unselected advanced NSCLC. After subgroup analysis, the association with survival was strengthened in second- or later-line EGFR-TKIs treatment group, with an HR of 2.45 for OS (95 % CI 1.27-4.74) and 1.86 for PFS (95 % CI 1.51-2.29), while the association with response to EGFR-TKIs became nonsignificant (P = 0.153). Four retrospective studies on the role of KRAS status in EGFR wild-type advanced NSCLC were deemed eligible and presented that KRAS mutation was associated with none of the outcomes in EGFR wild-type patients treated with EGFR-TKIs.

CONCLUSIONS

In unselected advanced NSCLC patients, KRAS mutations could be used as a potential negative predictor of clinical benefit from EGFR-TKIs. However, KRAS testing is of limited value to identify patients for EGFR-TKIs when EGFR status is considered.

Predictive and Prognostic Biomarkers for Patients Treated with Anti-EGFR Agents in Lung Cancer: A Systemic Review and Meta-Analysis

BACKGROUND

Several studies have investigated predictive and prognostic biomarkers for patients treated with anti-epidermal growth factor receptor (EGFR) agents in lung cancer. However, the conclusion is controversial.

MATERIALS AND METHODS

A meta-analysis was conducted to evaluate the associations of mutant K-ras, PIK3CA and PTEN deficiency with the efficacy of anti-EGFR agents in lung cancer. The primary endpoint was objective response rate (ORR). The secondary endpoints were overall survival (OS) and progression-free survival (PFS).

RESULTS

A total of 61 studies were included in the final meta-analysis. The result showed that K-ras mutation was a good predictor for ORR (RR=0.42, 95%CI, 0.33-0.55, p=0.000) and an effective prognostic marker for OS (HR=1.37, 95%CI, 1.15-1.65, p=0.001) and PFS (HR=1.33, 95%CI, 1.05-1.69, p=0.019). However, PTEN deficiency or PIK3CA mutation did not show any significance predictive value for ORR (PTEN, RR=0.82, 95%CI, 0.56-1.19, p=0.286; PIK3CA, RR=1.08, 95%CI, 0.17-6.66, P=0.938). And PTEN deficiency or expression of PIK3CA did not show significance prognostic value for OS (PTEN, HR=0.88, 95%CI, 0.31-2.46,P=0.805; PIK3CA, HR=0.79, 95%CI: 0.23-2.68, P=0.706).

CONCLUSIONS

Our meta-analysis showed that K-ras mutation may be an effective predictor in lung cancer patients treated with anti-EGFR agents. Whereas, the predictive and prognostic value of PTEN deficiency and PIK3CA mutation need to be further investigated.

Developing biomarker-specific end points in lung cancer clinical trials

In cancer-drug development, a number of different end points have been used to establish efficacy and support regulatory approval, such as overall survival, progression-free survival (PFS), and radiographic response rate. However, these traditional end points have important limitations. For example, in lung cancer clinical trials, evaluating overall survival end points is a protracted process and these end points are most reliable when crossover to the investigational therapy is not permitted. Furthermore, although radiographic surrogate end points, such as PFS and response rate, generally correlate with clinical benefit in the setting of cytotoxic chemotherapy and molecular targeted therapies, novel immunotherapies might have atypical response kinetics, which confounds radiographic interpretation. In this Review, we discuss the need to develop alternative or surrogate end points for lung cancer clinical trials, and focus on several new biomarkers that could serve as surrogate end points, including functional imaging biomarkers, circulating factors (tumour proteins, DNA, and cells), and pharmacodynamic tumour markers. By enabling the size, duration, and complexity of cancer trials to be reduced, biomarker end points hold the promise to accelerate drug development and improve patient outcomes.

Management of diarrhea induced by epidermal growth factor receptor tyrosine kinase inhibitors

Treatment for non-small-cell lung cancer (nsclc) is moving away from traditional chemotherapy toward personalized medicine. The reversible tyrosine kinase inhibitors (tkis) erlotinib and gefitinib were developed to target the epidermal growth factor receptor (egfr). Afatinib, an irreversible ErbB family blocker, was developed to block egfr (ErbB1), human epidermal growth factor receptor 2 (ErbB2), and ErbB4 signalling, and transphosphorylation of ErbB3. All of the foregoing agents are efficacious in treating nsclc, and their adverse event profile is different from that of chemotherapy. Two of the most common adverse events with egfr tkis are rash and diarrhea. Here, we focus on diarrhea. The key to successful management of diarrhea is to treat early and aggressively using patient education, diet, and antidiarrheal medications such as loperamide. We also present strategies for the effective assessment and management of egfr tki-induced diarrhea.

KRAS mutations as prognostic and predictive markers in non-small cell lung cancer

A greater understanding of non-small-cell lung cancer at a molecular level has led to the identification of an increasing number of driver mutations. Extensive research of the KRAS gene as well as specific mutations has established its role in tumorigenesis. Nevertheless, the role of KRAS oncogene in non-small-cell lung cancer remains unclear. Recent studies indicated that mutant KRAS could be predictive of lack of response to chemotherapy, but large pooled analysis failed to confirm this result. The predictive value of KRAS mutation and EGFR-TKI treatment is more ambiguous with some recent evidence suggesting that it may be a negative predictive biomarker. This review provides an overview of RAS biology, assesses the utility of KRAS as a prognostic marker, and evaluates its role as a predictive marker for response to chemotherapy and EGFR-TKIs. In addition, we review some current studies that are targeting the KRAS pathway.

Changes in epidermal growth factor receptor expression during chemotherapy in non-small cell lung cancer

BACKGROUND

Antibodies targeting epidermal growth factor receptor (EGFR), such as cetuximab, may potentially improve outcome in non-small cell lung cancer (NSCLC) patients with high EGFR expression. The EGFR expression may be heterogeneously distributed within tumors, and small biopsies may thus not accurately reveal the EGFR expression. In addition, EGFR expression may also change during chemotherapy. The current study investigates the magnitude of these two issues.

MATERIALS AND METHODS

EGFR expression in diagnostic biopsies and resection specimen was compared in 53 NSCLC patients stage T1-4N0-1M0 treated with surgery without preceding chemotherapy (OP group), and 65 NSCLC patients stage T1-3N0-2M0 (NAC group) treated with preoperative carboplatin and paclitaxel in order to evaluate the discordance of EGFR expression between samples.

RESULTS

Discordance between tumors dichotomized according to EGFR expression (high: H-score ≥200; low: H-score <200) in diagnostic biopsies and immediate resection specimens was 25 % in the OP group and 33 % in the NAC group (p = 0.628). Five (9 %) of primary tumors in the OP group and 4 (13 %) in the NAC group had increased EGFR expression in the resection specimens as compared to the diagnostic biopsies (p = 0.583). A decrease in EGFR expression was observed in 6 (11 %) in the OP group and 7 (23 %) in the NAC group (p = 0.148).

CONCLUSION

EGFR expression in 25 % of diagnostic biopsies may potentially not be accurate compared to the prevailing pattern in the whole tumor based on the larger resection specimens. This may potentially be an obstacle for proper use of antibodies targeting the EGFR in NSCLC. EGFR expression does, however, not change significantly during paclitaxel and carboplatin and rebiopsies in order to decide on anti-EGFR antibody therapy following chemotherapy do not seem warranted.

Capillary isoelectric-focusing immunoassays to study dynamic oncoprotein phosphorylation and drug response to targeted therapies in non-small cell lung cancer

Developing proteomic biomarkers is valuable for evaluating therapeutic effects of drugs and generating better treatment strategies. However, conventional protein analysis is often challenging due to inadequate sample size of clinical specimens, lack of assay reproducibility, accuracy, and sensitivity. A novel capillary isoelectricfocusing (IEF) immunoassay system (NanoPro) was used to study the dynamic phosphorylation status of signaling molecules in non-small cell lung cancer (NSCLC) cells treated with EGFR tyrosine kinase and MEK inhibitors. NanoPro showed the same dynamic ERK phosphorylation as Western blotting with good assay reproducibility using 1,000 times less protein. The IEF separation in NanoPro system enables multiple protein phosphorylation isoforms to be resolved and detected simultaneously. With NanoPro, we identified a specific on-target mitogen-activated protein/extracellular signal-regulated kinase (MEK) response pattern to MEK inhibitor PD325901, which was not detectable by Western blot analysis. We also revealed a MEK2 signal that may be associated with NSCLC cell sensitivity to the EGF receptor inhibitor erlotinib, and distinguished erlotinib-sensitive cells from intrinsic as well as acquired resistant cells to erlotinib. Moreover, NanoPro could differentiate human ERK1 isoforms from the mouse isoforms based on their isoelectric point differences and showed that erlotinib effectively inhibited ERK phosphorylation in targeted human xenograft cancer cells but not in surrounding mouse stromal cells. With 8 μg of tumor aspirates, we precisely quantified the response of 18 signaling molecules to erlotinib and MEK1 inhibitor treatments in an NSCLC patient. NanoPro's higher sensitivity, better resolution of protein phosphorylation status, and reduced tissue requirement warrant NanoPro's investigation for future drug development and evaluation of drug effects of targeted therapies.

Synergistic effect of afatinib with su11274 in non-small cell lung cancer cells resistant to gefitinib or erlotinib

Epidermal growth factor receptor (EGFR) and c-MET receptors are expressed on many non-small cell lung cancer (NSCLC) cells. Current single agent therapeutic targeting of a mutant EGFR has a high efficacy in the clinic, but is not curative. Here, we investigated the combination of targeting EGFR and c-MET pathways in NSCLC cells resistant to receptor tyrosine kinase inhibitors (TKIs), using RNA interference and inhibition by TKIs. Different NSCLC cell lines with various genomic characteristics (H358, H1650 and H1975) were transfected with EGFR-specific-siRNA, T790M-specific-siRNA, c-MET siRNA or the combination. Subsequently EGFR TKIs (gefitinib, erlotinib or afatinib) or monoclonal antibody cetuximab were combined respectively with the c-MET-specific TKI su11274 in NSCLC cell lines. The cell proliferation, viability, caspase-3/7 activity and apoptotic morphology were monitored by spectrophotometry, fluorimetry and fluorescence microscopy. The combined effect of EGFR TKIs, or cetuximab and su11274, was evaluated using a combination index. The results showed that the cell lines that were relatively resistant to EGFR TKIs, especially the H1975 cell line containing the resistance T790M mutation, were found to be more sensitive to EGFR-specific-siRNA. The combination of EGFR siRNA plus c-MET siRNA enhanced cell growth inhibition, apoptosis induction and inhibition of downstream signaling in EGFR TKI resistant H358, H1650 and H1975 cells, despite the absence of activity of the c-MET siRNA alone. EGFR TKIs or cetuximab plus su11274 were also consistently superior to either agent alone. The strongest biological effect was observed when afatinib, an irreversible pan-HER blocker was combined with su11274, which achieved a synergistic effect in the T790M mutant H1975 cells. In a conclusion, our findings offer preclinical proof of principle for combined inhibition as a promising treatment strategy for NSCLC, especially for patients in whom current EGFR-targeted treatments fail due to the presence of the T790M-EGFR-mutation or high c-MET expression.

KRAS mutation: should we test for it, and does it matter?

Lung cancer is the leading cause of cancer mortality in the United States and worldwide. Previously, lung cancer was simplistically divided into non-small-cell lung cancer (NSCLC) and small-cell lung cancer. However, in the last decade, we have gone from a simplistic binary system of classifying lung cancer to defining NSCLC on the basis of molecular subsets. KRAS mutations represent the most common molecular change in NSCLC. The presence of KRAS mutation has been shown to be associated with a poor prognosis in NSCLC, but this is of little clinical utility. More important is determining the clinical utility of KRAS mutational analysis for predicting benefit of chemotherapy, epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs), anti-EGFR monoclonal antibodies, or other novel therapeutics. Current data does not support the routine use of KRAS mutational analysis for predicting chemotherapy benefit. Additionally, there was significant interest in using KRAS status to select patients for EGFR TKI and anti-EGFR monoclonal antibodies. However, the EGFR mutational status has demonstrated significant predictive value in the selection of patients for EGFR TKI therapy and is now the preferred test. An association between KRAS mutational status and benefit of anti-EGFR monoclonal antibodies has not been demonstrated in NSCLC. Here we review, in the context of NSCLC, the underlying biology of KRAS mutations, the predictive value of KRAS mutations for therapeutic intervention, and the integration of KRAS mutational testing into our current clinical paradigms.

Reproducibility of immunohistochemical scoring for epidermal growth factor receptor expression in non-small cell lung cancer: round robin test

CONTEXT

The addition of cetuximab to first-line chemotherapy substantially prolonged survival in patients with advanced non-small cell lung cancer whose tumors expressed high levels of epidermal growth factor receptor (EGFR; immunohistochemistry score of ≥200 on a scale of 0-300).

OBJECTIVE

To evaluate the interobserver reproducibility of this EGFR immunohistochemistry scoring system, based on both the tumor cell membrane staining intensity (graded 0-3+) and the percentage of cells staining at each intensity.

DESIGN

In parts 1 (initial feasibility study) and 2 of this 2-part round robin test, sections of different non-small cell lung cancer tissue microarrays were stained in a central reference laboratory. Following reference evaluation, EGFR expression in 30 selected tumor cores was characterized in serial sections by lung cancer pathology specialists. The reproducibility of scoring by different raters was assessed. Analysis of between-rater agreement was based on the allocation of EGFR immunohistochemistry scores into low- (<200) and high- (≥200) EGFR expression groups.

RESULTS

After discussion with raters of the issues impacting reproducibility identified in part 1 and following adjustment of processes, part 2 of the round robin test showed a high interobserver agreement in EGFR immunohistochemistry scoring, with an overall concordance rate of 90.9% and a mean κ coefficient of 0.812. Specimens with a reference EGFR immunohistochemistry score of lower than 200 and of 200 or higher showed mean concordance rates of 94.7% and 85.6%, respectively.

CONCLUSIONS

After appropriate training, assessing EGFR expression by this immunohistochemistry-based method allowed a highly reproducible allocation of non-small cell lung cancers into clinically relevant high- or low-EGFR expression groups.

Using pharmacokinetic and pharmacodynamic data in early decision making regarding drug development: a phase I clinical trial evaluating tyrosine kinase inhibitor, AEE788

PURPOSE

In this first-in-human study of AEE788, a tyrosine kinase inhibitor of epidermal growth factor receptor (EGFR), HER-2, and VEGFR-2, a comprehensive pharmacodynamic program was implemented in addition to the evaluation of safety, pharmacokinetics, and preliminary efficacy of AEE788 in cancer patients.

EXPERIMENTAL DESIGN

Patients with advanced, solid tumors received escalating doses of oral AEE788 once daily. Primary endpoints were to determine dose-limiting toxicities (DLTs) and maximum-tolerated dose (MTD). A nonlinear model (Emax model) was used to describe the relationship between AEE788 exposure and target-pathway modulation in skin and tumor tissues.

RESULTS

Overall, 111 patients were treated (25 to 550 mg/day). DLTs included rash and diarrhea; MTD was 450 mg/day. Effects on biomarkers correlated to serum AEE788 concentrations. The concentration at 50% inhibition (IC(50)) for EGFR in skin (0.033 μmol/L) and tumor (0.0125 μmol/L) were similar to IC(50) in vitro suggesting skin may be surrogate tissue for estimating tumor EGFR inhibition. No inhibition of p-MAPK and Ki67 was observed in skin vessels at ≤ MTD. Hence, AEE788 inhibited EGFR, but not VEGFR, at doses ≤ MTD. A total of 16 of 96 evaluable patients showed a >10% shrinkage of tumor size; one partial response was observed.

CONCLUSION

Our pharmacodynamic-based study showed effective inhibition of EGFR, but not of VEGFR at tolerable AEE788 doses. Emax modeling integrated with biomarker data effectively guided real-time decision making in the early development of AEE788. Despite clinical activity, target inhibition of only EGFR led to discontinuation of further AEE788 development.

Publication and reporting conduct for pharmacodynamic analyses of tumor tissue in early-phase oncology trials

PURPOSE

In principle, nondiagnostic biopsies for pharmacodynamic (PD) studies are carried out to inform decision-making in drug development. Because such procedures have no therapeutic value, their ethical justification requires that results be published. We aimed to assess the frequency of nonpublication of PD data in early phase cancer trials and to identify factors that prevent full publication of data.

METHODS

We identified a sample of early-phase cancer trials containing invasive nondiagnostic tissue procurement for PD analysis from American Society of Clinical Oncology and American Association for Cancer Research meeting abstracts published between 1995 and 2005. These trials were followed to publication to determine frequency of nonpublication of PD data. Corresponding authors on early-phase cancer trials using invasive nondiagnostic research procedures were also surveyed to identify factors preventing full publication of PD data.

RESULTS

In a sample of 90 trials, 22.2% (20 trials) resulted in no trial publication. Of published trials expected to contain PD reports, 16 (17.8%) did not include any PD data, and 21 (23.3%) reported incomplete PD data. We surveyed 92 authors; nonpublication was regarded as a frequent occurrence, and the most commonly cited barrier to full publication of PD data was strategic considerations in publication (58.8% of responding authors).

CONCLUSIONS

Our results suggest ways that investigators, study planners, and reviewers can improve the burden/knowledge value balance in PD studies.

EGFR and HER2-Akt-mTOR signaling pathways are activated in subgroups of salivary gland carcinomas

Salivary gland carcinomas encompass a wide spectrum of histological entities. To identify candidate therapeutic targets and innovative treatment options for these carcinomas, we examined epidermal growth factor receptor (EGFR), phosphorylated EGFR (p-EGFR), HER2, and phosphorylated forms of Akt (p-Akt) and mammalian target of rapamycin (p-mTOR) in 47 salivary gland tumors using immunohistochemistry. EGFR overexpression was found in 51 % of the tumors (24/47); in particular, EGFR overexpression occurred in mucoepidermoid (seven out of seven) and salivary duct carcinomas (9/12). Although EGFR amplification was not detected by fluorescence in situ hybridization analysis, increased copy number due to polysomy of chromosome 7, which houses EGFR, was observed in 4 of the 24 tumors with EGFR overexpression; this polysomy occurred most frequently in salivary duct carcinomas (three out of nine). HER2 overexpression was observed in 21 % (10/47) of all tumors; in these 10 tumors, HER2 gene amplification was found in seven cases. p-Akt was found in 51 % (24/47) of all tumors, most frequently in mucoepidermoid carcinomas (six out of seven). p-mTOR was found in 57 % of the latter (four out of seven). Consequently, different signaling cascades were found activated: (1) an EGFR/HER2(-Akt)-mTOR-dependent axis, with gene gains of HER2 and/or EGFR, activated in salivary duct carcinoma and carcinoma ex pleomorphic adenoma; (2) an EGFR(-Akt)-mTOR-dependent pathway activated in mucoepidermoid carcinoma or acinic cell carcinoma, without HER2 or EGFR gene alterations; and (3) an Akt-dependent pathway without EGFR/HER2 activation in other types. These findings indicate that phosphoprotein mapping of components in the EGFR/HER2-Akt-mTOR pathways may be a useful guide to select appropriate targeting regimens.

Impact of specific mutant KRAS on clinical outcome of EGFR-TKI-treated advanced non-small cell lung cancer patients with an EGFR wild type genotype

INTRODUCTION

This retrospective study was undertaken to investigate the impact of specific mutant KRAS on clinical outcome to either gefitinib or erlotinib (EGFR tyrosine kinase inhibitor, EGFR-TKI) in patients with EGFR wild type (WT) advanced non-small cell lung cancer (NSCLC).

METHODS

Patients with an EGFR WT genotype who were treated with an EGFR-TKI for advanced disease at our Institution were identified. Simultaneous availability of KRAS mutation status was required for study inclusion.

RESULTS

Sixty-seven patients were eligible. Median age was 60 years (39-84), and 10 patients (14.9%) had received an EGFR-TKI as upfront therapy. Overall, the median progression-free survival (PFS) and overall survival (OS) were 2.9 months and 18.0 months, respectively. KRAS mutant patients (n=18) experienced a significantly shorter PFS compared with those carrying a KRAS WT genotype (n=49) (1.6 months vs 3.0 months, respectively, P=0.04; HR=1.92). However, within the KRAS mutant group a great variability in terms of sensitivity to treatment was noted (PFS ranging from 0.7 months to 38.7 months). KRAS codon 13 mutant patients (n=4) experienced the worse outcome when compared with KRAS codon 12 mutants (n=14) and KRAS WT patients (P<0.0001 and P=0.01 for PFS and OS, respectively).

CONCLUSIONS

Though we found that EGFR WT/KRAS mutant advanced NSCLC patients are associated with an increased resistance to treatment, specific mutant KRAS may account for differential sensitivity to an EGFR-TKI. KRAS codon 13 mutants are those who seem to experience the worse clinical outcome.

Targeting the epidermal growth factor receptor in non-small cell lung cancer cells: the effect of combining RNA interference with tyrosine kinase inhibitors or cetuximab

BACKGROUND

The epidermal growth factor receptor (EGFR) is a validated therapeutic target in non-small cell lung cancer (NSCLC). However, current single agent receptor targeting does not achieve a maximal therapeutic effect, and some mutations confer resistance to current available agents. In the current study we have examined, in different NSCLC cell lines, the combined effect of RNA interference targeting the EGFR mRNA, and inactivation of EGFR signaling using different receptor tyrosine kinase inhibitors (TKIs) or a monoclonal antibody cetuximab.

METHODS

NSCLC cells (cell lines HCC827, H292, H358, H1650, and H1975) were transfected with EGFR siRNA and/or treated with the TKIs gefitinib, erlotinib, and afatinib, and/or with the monoclonal antibody cetuximab. The reduction of EGFR mRNA expression was measured by real-time quantitative RT-PCR. The down-regulation of EGFR protein expression was measured by western blot, and the proliferation, viability, caspase3/7 activity, and apoptotic morphology were monitored by spectrophotometry, fluorimetry, and fluorescence microscopy. The combined effect of EGFR siRNA and different drugs was evaluated using a combination index.

RESULTS

EGFR-specific siRNA strongly inhibited EGFR protein expression almost equally in all cell lines and inhibited cell growth and induced cell apoptosis in all NSCLC cell lines studied, albeit with a different magnitude. The effects on growth obtained with siRNA was strikingly different from the effects obtained with TKIs. The effects of siRNA probably correlate with the overall oncogenic significance of the receptor, which is only partly inhibited by the TKIs. The cells which showed weak response to TKIs, such as the H1975 cell line containing the T790M resistance mutation, were found to be responsive to siRNA knockdown of EGFR, as were cell lines with downstream TKI resistance mutations. The cell line HCC827, harboring an exon 19 deletion mutation, was more than 10-fold more sensitive to TKI proliferation inhibition and apoptosis induction than any of the other cell lines. Cetuximab alone had no relevant in vitro activity at concentrations obtainable in the clinic. The addition of EGFR siRNA to either TKIs or cetuximab additively enhanced growth inhibition and induction of apoptosis in all five cell lines, independent of the EGFR mutation status (wild-type or sensitizing mutation or resistant mutation). The strongest biological effect was observed when afatinib was combined with an EGFR-specific siRNA.

CONCLUSIONS

EGFR knockdown by siRNA further decreases the cell growth of lung cancer cells that are treated with TKIs or cetuximab alone, confirming that single agent drug targeting does not achieve a maximal biological effect. The siRNA inhibits EGFR oncogenic activity that bypasses downstream "resistance" mutations such as KRAS and PTEN. The combined treatment of siRNA and EGFR inhibitory agents is additive. The combination of a potent, irreversible kinase inhibitor such as afatinib, with EGFR-specific siRNAs should be further investigated as a new strategy in the treatment of lung cancer and other EGFR dependent cancers, including those with downstream resistance mutations.

The role of gene expression profiling in drug discovery

Monitoring gene expression through the dual approaches of transcriptomics (RNA profiling) and proteomics (protein profiling) has become a key component in our efforts to understand complex biological processes. From the molecular stratification of disease states and the selection of potential drug targets, to patient selection and the confirmation of engagement of pharmacology in clinical studies, we are seeing the impact of gene expression profiling across all phases of the drug discovery process. Ongoing technological advances have driven an expansion in the use of these techniques, demonstrated utility in preclinical and clinical settings and increased regulatory and clinical acceptance. As technologies continue to advance apace, gene expression profiling is likely to play an increasingly important role in the future development of drug discovery.

Intratumor heterogeneity and chemotherapy-induced changes in EGFR status in non-small cell lung cancer

INTRODUCTION

Biomarker expression is increasingly being used to customize treatment in non-small cell lung cancer (NSCLC). The choice of systemic treatment usually depends on biomarker expression in the initial diagnostic biopsy taken before initiation of first-line treatment. Chemotherapy induces DNA damages in the tumor cells, and thus, biomarker expression in the tumor after systemic treatment might not be identical to biomarker expression in the diagnostic biopsy. NSCLC is highly heterogeneous and biomarker expression may vary in different areas within the same tumor. This review explores the tumor heterogeneity and chemotherapy-induced changes in EGFR biomarker status in NSCLC.

METHODS

A literature search was performed in August 2011 using pubmed.

RESULTS

Fifteen trials explored EGFR status in primary tumor and subsequent resected primary tumor, lymph node metastases, or organ metastases. Four papers compared EGFR status in primary tumor or metastases before and after systemic treatment. All trials included relatively few patients and used different chemotherapy regimes, biopsy locations, or time intervals between biopsies.

CONCLUSIONS

Tumor heterogeneity and probably also previous systemic treatment may be an obstacle for correct interpretation of EGFR status in NSCLC. Heterogeneity regarding EGFR mutations is probably rare and previously reported intra and intertumor heterogeneity may be due to methodological issues. In the current and future clinical scenario with many different options for systemic treatment both as 2nd line and beyond, it is increasingly important to further elucidate the role extent of chemotherapy-induced changes in biomarker expression for proper use of biomarkers in order to customize treatment and thus improve prognosis.

EGFR expression as a predictor of survival for first-line chemotherapy plus cetuximab in patients with advanced non-small-cell lung cancer: analysis of data from the phase 3 FLEX study

BACKGROUND

Findings from the phase 3 First-Line ErbituX in lung cancer (FLEX) study showed that the addition of cetuximab to first-line chemotherapy significantly improved overall survival compared with chemotherapy alone (hazard ratio [HR] 0·871, 95% CI 0·762-0·996; p=0·044) in patients with advanced non-small-cell lung cancer (NSCLC). To define patients benefiting most from cetuximab, we studied the association of tumour EGFR expression level with clinical outcome in FLEX study patients.

METHODS

We used prospectively collected tumour EGFR expression data to generate an immunohistochemistry score for FLEX study patients on a continuous scale of 0-300. We used response data to select an outcome-based discriminatory threshold immunohistochemistry score for EGFR expression of 200. Treatment outcome was analysed in patients with low (immunohistochemistry score <200) and high (≥200) tumour EGFR expression. The primary endpoint in the FLEX study was overall survival. We analysed patients from the FLEX intention-to-treat (ITT) population. The FLEX study is registered with ClinicalTrials.gov, number NCT00148798.

FINDINGS

Tumour EGFR immunohistochemistry data were available for 1121 of 1125 (99·6%) patients from the FLEX study ITT population. High EGFR expression was scored for 345 (31%) evaluable patients and low for 776 (69%) patients. For patients in the high EGFR expression group, overall survival was longer in the chemotherapy plus cetuximab group than in the chemotherapy alone group (median 12·0 months [95% CI 10·2-15·2] vs 9·6 months [7·6-10·6]; HR 0·73, 0·58-0·93; p=0·011), with no meaningful increase in side-effects. We recorded no corresponding survival benefit for patients in the low EGFR expression group (median 9·8 months [8·9-12·2] vs 10·3 months [9·2-11·5]; HR 0·99, 0·84-1·16; p=0·88). A treatment interaction test assessing the difference in the HRs for overall survival between the EGFR expression groups suggested a predictive value for EGFR expression (p=0·044).

INTERPRETATION

High EGFR expression is a tumour biomarker that can predict survival benefit from the addition of cetuximab to first-line chemotherapy in patients with advanced NSCLC. Assessment of EGFR expression could offer a personalised treatment approach in this setting.

FUNDING

Merck KGaA.

The landscape of EGFR pathways and personalized management of non-small-cell lung cancer

Two classes of anti-EGF receptor (EGFR) agents, monoclonal anti-EGFR antibodies and small-molecule EGFR tyrosine kinase inhibitors, have been used for the treatment of non-small-cell lung cancer (NSCLC). However, only a subset of patients will benefit from EGFR-targeted therapy. The discovery of biomarkers that select the appropriate patients for the therapy and predict the responses to the therapy is urgently needed. Molecular genetic analyses provide new insights into EGFR pathway alterations and demonstrate promise for predicting the clinical outcome of patients with NSCLC. In this article, we summarize the latest available knowledge on the clinical impact of EGFR mutations, gene copy number, EGFR overexpression, phosphorylation expression and the alteration of the EGFR pathway downstream factors in predicting the response to EGFR-targeted therapy in NSCLC patients. The role of KRAS and BRAF mutations and ALK rearrangement in lung cancer-targeted therapy, are also reviewed.

Prospective molecular marker analyses of EGFR and KRAS from a randomized, placebo-controlled study of erlotinib maintenance therapy in advanced non-small-cell lung cancer

PURPOSE

The phase III, randomized, placebo-controlled Sequential Tarceva in Unresectable NSCLC (SATURN; BO18192) study found that erlotinib maintenance therapy extended progression-free survival (PFS) and overall survival in patients with advanced non-small-cell lung cancer (NSCLC) who had nonprogressive disease following first-line platinum-doublet chemotherapy. This study included prospective analysis of the prognostic and predictive value of several biomarkers.

PATIENTS AND METHODS

Mandatory diagnostic tumor specimens were collected before initiating first-line chemotherapy and were tested for epidermal growth factor receptor (EGFR) protein expression by using immunohistochemistry (IHC), EGFR gene copy number by using fluorescent in situ hybridization (FISH), and EGFR and KRAS mutations by using DNA sequencing. An EGFR CA simple sequence repeat in intron 1 (CA-SSR1) polymorphism was evaluated in blood.

RESULTS

All 889 randomly assigned patients provided tumor samples. EGFR IHC, EGFR FISH, KRAS mutation, and EGFR CA-SSR1 repeat length status were not predictive for erlotinib efficacy. A profound predictive effect on PFS of erlotinib relative to placebo was observed in the EGFR mutation-positive subgroup (hazard ratio [HR], 0.10; P < .001). Significant PFS benefits were also observed with erlotinib in the wild-type EGFR subgroup (HR, 0.78; P = .0185). KRAS mutation status was a significant negative prognostic factor for PFS.

CONCLUSION

This large prospective biomarker study found that patients with activating EGFR mutations derive the greatest PFS benefit from erlotinib maintenance therapy. No other biomarkers were predictive for outcomes with erlotinib, although the study was not powered for clinical outcomes in biomarker subgroups other than EGFR IHC-positive [corrected]. KRAS mutations were prognostic for reduced PFS. The study demonstrated the feasibility of prospective tissue collection for biomarker analyses in NSCLC.

Erlotinib 'dosing-to-rash': a phase II intrapatient dose escalation and pharmacologic study of erlotinib in previously treated advanced non-small cell lung cancer

BACKGROUND

To evaluate the anticancer activity of erlotinib in patients with previously treated, advanced non-small cell lung cancer (NSCLC) whose dose is increased to that associated with a maximal level of tolerable skin toxicity (i.e., target rash (TR)); to characterise the pharmacokinetics (PK) and pharmacodynamics (PD) of higher doses of erlotinib.

METHODS

Patients initially received erlotinib 150 mg per day. The dose was successively increased in each patient to that associated with a TR. Anticancer activity was evaluated. Plasma, skin, and hair were sampled for PK and PD studies.

RESULTS

Erlotinib dose escalation to 200-475 mg per day was feasible in 38 (90%) of 42 patients. Twenty-four (57%) patients developed a TR, but 19 (79%) did so at 150 mg per day. Five (12%) patients, all of whom developed a TR, had a partial response. Median progression-free survival (PFS) was 2.3 months (95% CI: 1.61, 4.14); median PFS was 3.5 months and 1.9 months, respectively, for patients who did and did not experience a TR (hazard ratio, 0.51; P=0.051). Neither rash severity nor response correlated with erlotinib exposure.

CONCLUSION

Intrapatient dose escalation of erlotinib does not appreciably increase the propensity to experience a maximal level of tolerable skin toxicity, or appear to increase the anticancer activity of erlotinib in NSCLC.

Downregulation of Mig-6 in nonsmall-cell lung cancer is associated with EGFR signaling

Downregulation of Mig-6 expression has been implicated in several human cancers and its loss can lead to prolonged activation of EGFR and carcinogenesis. The present study aimed to investigate the clinical significance of loss of Mig-6 expression in nonsmall-cell lung cancer (NSCLC) and the biological functions of Mig-6 in NSCLC cell lines. Mig-6 expression was downregulated in 47/91 (51.6%) cases of NSCLC that were examined. Mig-6 downregulation significantly correlated with poor differentiation (P = 0.0131), histological type (P = 0.0021), and EGFR expression (P = 0.003). In addition, knockdown of Mig-6 expression in H1299 and BE1 cells promoted EGF-induced tumor cell proliferation and migration. Furthermore, Mig-6 knockdown led to a significant increase in phospho-AKT, phospho-ERK, phospho-EGFR as well as MMP-2 and MMP-9 levels. These results indicate that downregulated Mig-6 in NSCLC tissues may serve as a new marker that can predict the activation of EGFR signaling pathway.

Managing treatment-related adverse events associated with egfr tyrosine kinase inhibitors in advanced non-small-cell lung cancer

Non-small-cell lung cancer (nsclc) has the highest prevalence of all types of lung cancer, which is the second most common cancer and the leading cause of cancer-related mortality in Canada. The need for more effective and less toxic treatment options for nsclc has led to the development of agents targeting the epidermal growth factor receptor (egfr)-mediated signalling pathway, such as egfr tyrosine kinase inhibitors (egfr-tkis). Although egfr-tkis are less toxic than traditional anti-neoplastic agents, they are commonly associated with acneiform-like rash and diarrhea. This review summarizes the clinical presentation and causes of egfr-tki-induced rash and diarrhea, and presents strategies for effective assessment, monitoring, and treatment of these adverse effects. Strategies to improve the management of egfr-tki-related adverse events should improve clinical outcomes, compliance, and quality of life in patients with advanced nsclc.

Cell death signaling and anticancer therapy

For a long time, it was commonly believed that efficient anticancer regimens would either trigger the apoptotic demise of tumor cells or induce a permanent arrest in the G₁ phase of the cell cycle, i.e., senescence. The recent discovery that necrosis can occur in a regulated fashion and the increasingly more precise characterization of the underlying molecular mechanisms have raised great interest, as non-apoptotic pathways might be instrumental to circumvent the resistance of cancer cells to conventional, pro-apoptotic therapeutic regimens. Moreover, it has been shown that some anticancer regimens engage lethal signaling cascades that can ignite multiple oncosuppressive mechanisms, including apoptosis, necrosis, and senescence. Among these signaling pathways is mitotic catastrophe, whose role as a bona fide cell death mechanism has recently been reconsidered. Thus, anticancer regimens get ever more sophisticated, and often distinct strategies are combined to maximize efficacy and minimize side effects. In this review, we will discuss the importance of apoptosis, necrosis, and mitotic catastrophe in the response of tumor cells to the most common clinically employed and experimental anticancer agents.

Erlotinib or gefitinib for the treatment of relapsed platinum pretreated non-small cell lung cancer and ovarian cancer: a systematic review

BACKGROUND

Platinum-based chemotherapy is the standard of care for ovarian cancer and non-small cell lung cancer (NSCLC). However, resistance to platinum agents invariably develops. Targeted therapies, such as tyrosine kinase inhibitors (TKIs), have great potential here as they exert their anti-tumour effect via alternative mechanisms to platinum-based drugs and as such may remain unaffected by emergent resistance to platinum.

METHODS

A systematic review was conducted to investigate whether two EGFR-TKIs, erlotinib and gefitinib, have efficacy in the platinum-resistance setting. Preclinical studies of platinum-resistant cancer cell lines, which had been subsequently treated with EGFR-TKIs, were sought to establish proof-of-concept. Clinical trials reporting administration of EGFR-TKIs to ovarian cancer and NSCLC patients relapsed after therapy with platinum drugs were investigated to determine sensitivity of these cohorts to EGFR-TKI treatment. The role of EGFR mutation, copy number and protein expression on response to EGFR-TKIs after failure of platinum chemotherapy were also investigated.

RESULTS

Preclinical models of platinum-resistant cancer were found which display a spectrum of cross-resistance profiles to EGFR-TKIs. Sensitivity to EGFR-TKIs is dependent on the activation of the EGFR pathway or EGFR interacting proteins such as HER-2. EGFR-TKIs show favourable response rates in platinum-pretreated NSCLC, 11.14% and 15.25% for 150mg/day erlotinib and 250mg/day gefitinib, respectively. These response rates significantly improve in patients of Asian descent (28.3% and 29.17%, respectively) and patients with EGFR activation mutations (41.6% and 63.89%, respectively) or increased copy number (33.3% and 45.45%, respectively). Gefitinib significantly outperformed erlotinib and should therefore be the EGFR-TKI of choice in platinum-pretreated relapsed NSCLC. In contrast, response rates are very poor to both erlotinib and gefitinib in platinum pretreated ovarian cancer, 0-5.9% and they should not be used in this cohort of patients. Preclinical models demonstrate that, while cross resistance can occur between platinums and EGFR-TKIs, there is not a generalised cross-resistance phenotype. Erlotinib and gefitinib are suitable for the treatment of platinum-pretreated NSCLC, particularly in patients with EGFR mutations or increases in copy number. Unfortunately, the high rates of EGFR protein overexpression in ovarian cancer are not translating to a clinically useful therapeutic target for EGFR-TKIs; EGFR mutations are rare in ovarian cancer. Newer TKIs may improve response rates in these cohorts and future clinical trials need to collect tumour biopsies from all patients to ensure the success of personalised chemotherapy.

Clinical benefits as endpoints in advanced non-small cell lung cancer treated with integrative medicine

"Living with cancer" and symptom control are the features and advantages of integrative medicine in advanced non-small cell lung cancer (NSCLC) treatment. However, with the current concept of response evaluation criteria by the WHO and RECIST, it is difficult to exhibit the above characteristics. Clinical benefit (CB) is designed as an endpoint recently widely understood and accepted in oncology clinical trials. With the review of its definition and development, we suggest CB to be used as an endpoint in advanced NSCLC treatment with integrative medicine. CB should encompass two connotations: one is improved quality of life and symptom control and the other is disease control rate (DCR), including complete response (CR), partial response (PR), and stable disease (SD). We need to design randomized controlled trials (RCT) to investigate the interrelationship of CB rate and survival to provide high-grade evidence proving that advanced lung cancer patients could really benefit from integrative medicine treatment.

Malignant pleural effusion from lung adenocarcinoma treated by gefitinib

Small molecule inhibitors targeting epidermal growth factor receptor (EGFR) are known to be active against non-small cell lung cancer (NSCLC) although the pharmacodynamics of these agents on malignant pleural effusion (MPE) remains unclear. Here we describe a case of lung adenocarcinoma with massive MPE treated successfully by gefitinib and chest drainage. Using sequential MPE samples before and during gefitinib therapy, the morphological changes and apoptosis of cancer cells were analyzed. Apoptosis of cancer cells was detected as early as 4 hours on, but not before, gefitinib therapy, suggesting that the pharmacodynamic assessment of such molecular targeting agents might be feasible for MPE.