Prospective phase II study of gefitinib for chemotherapy-naive patients with advanced non-small-cell lung cancer with epidermal growth factor receptor gene mutations

EGFR mutant lung cancer

Thoracic oncologists traditionally have made treatment decisions based upon tumor histology, distinguishing non-small cell lung cancer (NSCLC) from small cell lung cancer (SCLC). However, recent data has revealed that at least one histological subtype of NSCLC, lung adenocarcinoma comprises multiple molecularly distinct diseases. Lung adenocarcinoma subsets now can be defined by specific 'driver' mutations in genes encoding components of the EGFR signaling pathway. Importantly, these mutations have implications regarding targeted therapy. Here, we focus on EGFR mutant NSCLC-a prime example of a clinically relevant molecular subset of lung cancer, with defined mechanisms of drug sensitivity, primary drug resistance, and acquired resistance to EGFR tyrosine kinase inhibitors. Efforts are now being made to overcome mechanisms of acquired resistance. These findings illustrate how knowledge about the genetic drivers of tumors can lead to rational targeted therapy for individual patients.

Current status and future potential of somatic mutation testing from circulating free DNA in patients with solid tumours

Genetic alterations can determine the natural history of cancer and its treatment response. With further advances in DNA sequencing technology, multiple novel genetic alterations will be discovered which could be exploited as prognostic, predictive and pharmacodynamic biomarkers in the development and use of cancer therapeutics. As such, the importance in clinical practice of efficient and robust somatic mutation testing in solid tumours cannot be overemphasized in the current era of personalized medicine. However, significant challenges remain regarding the testing of genetic biomarkers in clinical practice. Reliance on archived formalin fixed, paraffin embedded tumour, obtained from diagnostic biopsies, for testing somatic genetic alterations could restrict the scientific community in asking relevant questions about a patient's cancer biology. Problems inherent with using formalin fixed, archival tissue are well recognized and difficult to resolve. It could be argued that to achieve rapid and efficient incorporation of genetic biomarkers into clinical practice, somatic mutation testing in cancer patients should be simpler, less invasive using a readily available clinical sample, whilst maintaining robustness and reproducibility. In this regard, use of circulating free DNA (cfDNA) from plasma or serum as an alternative and/or additional source of DNA to test cancer specific genetic alterations is an attractive proposition. In light of encouraging results from recent studies, this mini review will discuss the current role and future potential of somatic mutation testing from circulating or cell free DNA derived from the blood of patients with solid tumours.

Soluble epidermal growth factor receptor (sEGFR) and carcinoembryonic antigen (CEA) concentration in patients with non-small cell lung cancer: correlation with survival after erlotinib and gefitinib treatment

BACKGROUND

In patients with non-small cell lung cancer (NSCLC), a higher response rate can be achieved with epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) when selection for therapy is guided by mutation analysis or gene amplification. However, both tests are complex and require tumour tissue. Simple methods to identify responders prior to EGFR-TKI treatment are urgently needed. This study aimed to define the relation between serum sEGFR levels, carcinoembryonic antigen (CEA) and survival in NSCLC patients treated with EGFR-TKIs.

METHODS

Patients with stage III/IV NSCLC treated with gefitinib or erlotinib between July 2002 and December 2005 were reviewed. Levels of serum soluble EGFR (sEGFR) were determined by a sandwich quantitative enzyme-linked immunosorbent assay. A chemiluminescence immunoassay was used for CEA. The relation between sEGFR and survival was investigated.

RESULTS

One hundred and two NSCLC patients, mainly stage IV (80%), were identified. Mean sEGFR at baseline was 55.9 μg/l (range 35.3-74.5 μg/l). The median CEA level was 11.1 μg/l (range <1.0-2938.0 μg/l). Median overall survival was 5.2 months (range 1-52 months). Decreasing log CEA values (HR 1.51, 95% CI 1.11-2.04, multivariate analysis) and increasing sEGFR values (HR 0.96, 95% CI 0.93-0.99, multivariate analysis) were both independently associated with prolonged survival. Higher levels of pre-treatment sEGFR were associated with lower risk of progressive disease within three months (p=0.04).

CONCLUSIONS

Both baseline sEGFR and CEA levels in NSCLC patients receiving EGFR-TKIs showed a significant correlation with survival. To distinguish whether these factors have a predictive or a prognostic value, validation is warranted in an independent patient series containing a control arm without EGFR-TKI treatment.

Anaplastic lymphoma kinase inhibition in non-small-cell lung cancer

BACKGROUND

Oncogenic fusion genes consisting of EML4 and anaplastic lymphoma kinase (ALK) are present in a subgroup of non-small-cell lung cancers, representing 2 to 7% of such tumors. We explored the therapeutic efficacy of inhibiting ALK in such tumors in an early-phase clinical trial of crizotinib (PF-02341066), an orally available small-molecule inhibitor of the ALK tyrosine kinase.

METHODS

After screening tumor samples from approximately 1500 patients with non-small-cell lung cancer for the presence of ALK rearrangements, we identified 82 patients with advanced ALK-positive disease who were eligible for the clinical trial. Most of the patients had received previous treatment. These patients were enrolled in an expanded cohort study instituted after phase 1 dose escalation had established a recommended crizotinib dose of 250 mg twice daily in 28-day cycles. Patients were assessed for adverse events and response to therapy.

RESULTS

Patients with ALK rearrangements tended to be younger than those without the rearrangements, and most of the patients had little or no exposure to tobacco and had adenocarcinomas. At a mean treatment duration of 6.4 months, the overall response rate was 57% (47 of 82 patients, with 46 confirmed partial responses and 1 confirmed complete response); 27 patients (33%) had stable disease. A total of 63 of 82 patients (77%) were continuing to receive crizotinib at the time of data cutoff, and the estimated probability of 6-month progression-free survival was 72%, with no median for the study reached. The drug resulted in grade 1 or 2 (mild) gastrointestinal side effects.

CONCLUSIONS

The inhibition of ALK in lung tumors with the ALK rearrangement resulted in tumor shrinkage or stable disease in most patients. (Funded by Pfizer and others; ClinicalTrials.gov number, NCT00585195.).

Epidermal growth factor receptor mutations detected by denaturing high-performance liquid chromatography in nonsmall cell lung cancer: impact on response to therapy with epidermal growth factor receptor-tyrosine kinase inhibitors

BACKGROUND

Somatic mutations in the epidermal growth factor receptor (EGFR) kinase domain are associated with sensitivity to EGFR-tyrosine kinase inhibitors (EGFR-TKI) in patients with nonsmall cell lung cancer (NSCLC).

METHODS

The authors tested the possibility that nucleotide sequencing may be poorly suited for detection of mutations in tumor samples and found that denaturing high-performance liquid chromatography (dHPLC) was an efficient and more sensitive method for screening.

RESULTS

These results suggested that some reports based on standard DNA sequencing techniques may have underestimated mutation rates. In the present report, the authors examined the relationship between the presence and type of EGFR mutations detected by dHPLC and various clinicopathologic features of NSCLC, including response to therapy with EGFR-TKI. Among 251 patients with advanced disease, 100 individuals received EGFR-TKI. Those whose tumors harbored a detectable EGFR kinase mutation were much more likely to have a partial response (PR) or stable disease (SD) with EGFR-TKI therapy than patients whose tumor contained no mutation (80% vs 35%; P = .001). Among the individual genotype subgroups, the frequency of a PR or SD was significantly different between patients with an exon 19 deletion compared with those with no detectable mutation (86% vs 35%; P < .001). Furthermore, patients whose tumors expressed an exon 19 mutant EGFR isoform exhibited a trend toward better EGFR-TKI response (86% vs 67%; P = .171) and improved survival compared with patients whose tumors expressed an exon 21 mutation.

CONCLUSIONS

Our findings warrant confirmation in large prospective trials and exploration of the biological mechanisms of the differences between mutation types.

A major step towards individualized therapy of lung cancer with gefitinib: the IPASS trial and beyond

Most patients with non-small-cell lung cancer (NSCLC) present with advanced disease and have poor long-term prognosis. Gefitinib, a targeted therapy that prevents ATP binding in the tyrosine kinase domain of the EGF receptor, has been subject to comprehensive clinical development. A Phase III trial has demonstrated that gefitinib is superior to carboplatin/paclitaxel in terms of progression-free survival and objective response rate, as first-line treatment for pulmonary adenocarcinoma among never-smokers or former light smokers in East Asia (the IRESSA Pan-Asia Study), with the presence of an EGFR mutation being a strong predictor of the effect of gefitinib compared with carboplatin/paclitaxel. In this article, these results are discussed in the context of other recently reported studies of EGFR mutation-positive patients in both Asian and non-Asian countries. Furthermore, the clinical implications and future challenges for gefitinib are highlighted.

Single-agent gefitinib with concurrent radiotherapy for locally advanced non-small cell lung cancer harboring mutations of the epidermal growth factor receptor

INTRODUCTION

A feasibility study was performed to examine the safety and toxicity profile of daily gefitinib (250 mg) administration with concurrent definitive thoracic radiation therapy (TRT) in patients with unresectable non-small cell lung cancer (NSCLC) of stage III.

METHODS

Patients received a 14-day induction therapy with gefitinib at 250 mg daily. TRT was initiated on day 15 in 2-Gy fractions administered five times weekly to a total dose of 60 Gy. The primary end point of the study was the rate of treatment completion. Mutation status of the epidermal growth factor receptor gene (EGFR) was evaluated for patients with available tumor specimens.

RESULTS

Nine eligible patients enrolled in the study received induction gefitinib monotherapy. Two patients were unable to begin TRT because of the development of progressive disease during the first 2 weeks of the protocol. Three of the remaining seven patients treated with gefitinib and concurrent TRT were unable to complete the planned treatment (two because of pulmonary toxicity and one because of progressive disease), and the study was therefore closed according to the protocol definition. Tumor samples were available for eight patients. EGFR mutations (deletion in exon 19) were detected in two patients, both of whom achieved a partial response and exhibited an overall survival of >5 years.

CONCLUSIONS

Our results do not support further trials of gefitinib and TRT for unselected NSCLC patients. This therapeutic strategy may hold promise, however, for locally advanced NSCLC in patients with sensitizing EGFR mutations.

Understanding resistance to EGFR inhibitors-impact on future treatment strategies

EGFR is a tyrosine kinase that participates in the regulation of cellular homeostasis. Following ligand binding, EGFR stimulates downstream cell signaling cascades that influence cell proliferation, apoptosis, migration, survival and complex processes, including angiogenesis and tumorigenesis. EGFR has been strongly implicated in the biology of human epithelial malignancies, with therapeutic applications in cancers of the colon, head and neck, lung, and pancreas. Accordingly, targeting EGFR has been intensely pursued, with the development of a series of promising molecular inhibitors for use in clinical oncology. As is common in cancer therapy, challenges with respect to treatment resistance emerge over time. This situation is certainly true of EGFR inhibitor therapies, where intrinsic and acquired resistance is now well recognized. In this Review, we provide a brief overview regarding the biology of EGFR, preclinical and clinical development of EGFR inhibitors, and molecular mechanisms that underlie the development of treatment resistance. A greater understanding of the mechanisms that lead to EGFR resistance may provide valuable insights to help design new strategies that will enhance the impact of this promising class of inhibitors for the treatment of cancer.

[American Society of Clinical Oncology Clinical Practice Guideline update on chemotherapy for stage IV non-small-cell lung cancer]

本文旨在为Ⅳ期非小细胞肺癌患者的治疗提供更新版推荐。本文资料检索源自2002年以来公布的相关随机试验文献。此指南范围限于化疗与生物治疗。更新委员会对这些文献进行了总结并提供了推荐更新。162篇文献符合标准被纳入参考。本推荐基于可改善总生存期的治疗方法。仅改善无进展生存期的治疗方法推动了对毒性及生存质量的监测。对于体力状态评分为0分或1分患者的一线治疗，可推荐以铂类为基础的细胞毒性药物的两药联用。对铂类治疗有禁忌的患者，可采用非铂类细胞毒性两药联合。对于体力状态评分为2分的患者，单一细胞毒性药物即可。对于疾病进展或经过4个周期的治疗仍对治疗无反应的患者，应停止一线细胞毒性化疗。即使在6个周期后患者对治疗仍有反应，亦应停止两药细胞毒性化疗。对于伴有明确的表皮生长因子受体（epidermal growth factor receptor, EGFR）突变的患者，可推荐一线采用吉非替尼治疗；对于EGFR突变为阴性或不明确的患者，细胞毒性化疗更佳。除具有特定临床特征的患者外，可推荐贝伐单抗与卡铂-紫杉醇联用。对于通过免疫组化证实EGFR阳性的肿瘤患者，可推荐西妥昔单抗与顺铂-长春瑞滨联用。多西紫杉醇、厄洛替尼、吉非替尼或培美曲塞被推荐作为二线治疗。对于未曾接受过厄洛替尼或吉非替尼治疗的患者，可推荐厄洛替尼作为三线治疗。现有数据不足以推荐常规三线采用细胞毒性药物。已有的证据也不足以推荐常规应用分子标记物选择化疗。

Effect of gefitinib on the survival of patients with recurrence of lung adenocarcinoma after surgery: a retrospective case-matching cohort study

BACKGROUND

Patients with lung adenocarcinoma who carry epidermal growth factor receptor (EGFR) gene mutations respond remarkably well to EGFR tyrosine kinase inhibitor (EGFR-TKI), gefitinib, or erlotinib. However, the effect of EGFR-TKI treatment on the prolongation of overall survival (OS) of these patients remains uncertain, although several recent studies have shown prolongation of progression free survival compared with cytotoxic chemotherapy.

METHODS

A total of 304 patients with lung adenocarcinoma who had postoperative recurrent disease were studied. To eliminate potential biases as possible, the matching of four potential predictive factors of responsiveness to EGFR-TKI led to the identification of 81 pairs of patients (those who were treated with gefitinib and those who were not). A deletion mutation in exon 19 and a point mutation (L858R) in exon 21 of the EGFR gene were also analyzed. We compared the OS between the two groups.

RESULTS

OS in the gefitinib group was significantly longer than in the control group (median, 63 vs. 41 months; p = 0.015). EGFR mutations were detected in 65 out of 129 patients (50%) in the whole sample. EGFR mutational status was not an independent prognostic factor of gefitinib benefit; rather, it was a predictive factor.

CONCLUSIONS

This study strongly suggested that gefitinib treatment improved OS of lung adenocarcinoma patients who had postoperative recurrence, especially those carrying EGFR mutations.

Quantifying the sensitivities of EGF receptor (EGFR) tyrosine kinase inhibitors in drug resistant non-small cell lung cancer (NSCLC) cells using hydrogel-based peptide array

Epidermal growth factor receptor (EGFR) signaling plays an important role in non-small cell lung cancer (NSCLC) and therapeutics targeted against EGFR have been effective in treating a subset of patients bearing somatic EFGR mutations. However, the cancer eventually progresses during treatment with EGFR inhibitors, even in the patients who respond to these drugs initially. A large variety of distinct irreversible inhibitors have been developed, which may combat therapeutic resistance. Nonetheless, major challenges in tailoring patient-specific treatment regimens involve predicting the most effective inhibitors and monitoring for acquisition of resistance. A patient-customized, predictive diagnostic that quantifies the effects of specific anti-EGFR therapies may improve outcomes in cancers where EGFR plays a mechanistic role. In this study we used an EGFR-phosphorylatable peptide, AEEEEYFELVAKKK, immobilized within a polyacrylamide hydrogel as a substrate for profiling the activation status of EGFR in the cellular extracts of erlotinib-resistant cancer cells. The hydrogel array was able to detect therapeutic resistance as well as identify inhibitors capable of combating therapeutic resistance. These findings establish the potential of this protein-acrylamide copolymer hydrogel array to not only evaluate EGFR status in cancer cell lysates but also to screen for the most promising therapeutics for individual patients and monitor effects of treatment on acquisition of resistance to EGFR inhibitors.

Gefitinib for the treatment of non-small-cell lung cancer

IMPORTANCE OF THE FIELD

The epidermal growth factor receptor (EGFR) is a leading target for treatment of non-small-cell lung cancer (NSCLC). Recent trials of the small-molecule EGFR inhibitor gefitinib have now more clearly defined indications for usage, and clinical and molecular factors predictive of benefit.

AREAS COVERED IN THIS REVIEW

A systematic search of the literature (Medline, ASCO, WCLC meeting abstracts) was performed from January 2000 to January 2010. The Phase III INTEREST study found gefitinib in unselected, pretreated patients was not inferior to docetaxel chemotherapy in overall survival, offering improved quality of life and superior toxicity profile. The Phase III IPASS study demonstrated improved progression-free survival with gefitinib compared with paclitaxel-carboplatin chemotherapy in chemotherapy-naive, never/light ex-smokers with adenocarcinoma histology. Stratifying for EGFR mutation revealed mutation-positive patients had superior outcomes with gefitinib compared with chemotherapy. Subsequent studies (WJOG4305, NEJ002), selecting only EGFR mutation-positive patients prospectively confirm this finding.

WHAT THE READER WILL GAIN

The profile of gefitinib and landmark trials in NSCLC are summarized. How biomarkers may further optimize therapeutic benefit is highlighted.

TAKE HOME MESSAGE

Gefitinib is expected to have an important impact on management of pretreated and selected chemotherapy-naive patients with advanced NSCLC. In addition, activating EGFR mutations are proven to be of value for prediction of those who will derive most benefit.

Polysomy and amplification of chromosome 7 defined for EGFR gene in squamous cell carcinoma of the lung together with exons 19 and 21 wild type

PURPOSE

The epidermal growth factor receptor (EGFR) is overexpressed in the majority of nonsmall- cell lung cancers (NSCLC) and is a major target specific EGFR tyrosine kinase inhibitors (TKIs) developed and used for the treatment of advanced NSCLC. A number of biological factors are also associated with EGFR-TKIs responsiveness. This study was focused on EGFR somatic mutations and amplifications in squamous cell lung cancer.

MATERIAL AND METHODS

Representative sections of squamous cell carcinoma were selected from 54 surgical specimens from formalin-fixed paraffin-embedded tissues and submitted to TMA construction. Determination of EGFR protein expression was done by immunohistochemistry( IHC) (Zymed, Laboratories). Fluorescence in situ hybridization (FISH) was performed with LSI EGFR/CEP 7 (Vysis; Abbott Molecular, USA). Genomic DNA was extracted from 48 cases and exon 19 was amplified by polymerase chain reaction (PCR) for search deletions and point mutations for exon 21. All cases expressed high weigh cytokeratin and were observed negativity for CK7, CD56 and chromogranin.

RESULTS

EGFR protein overexpression was identified in 49 cases, by the application of Hirsh's scoring system. The chromosome 7 and EGFR gene were analyzed by FISH and scored according to Cappuzzo's method that showed high polysomy in 31 cases and amplification in 7 cases. Deletion in exon 19 of EGFR was detected in 3 cases of 48 samples; the exon 21 of EGFR was expressed in its wild type by RFLP in all cases.

CONCLUSIONS

Detection of common EGFR deletion and mutation showed to be a rare event in Squamous cell carcinoma of the lung. While EGFR mutation is the most effective molecular predictor or sensitivity in patients with advanced NSCLC submitted to EGFR-TKIs treatment, amplification and polysomy is the most effective molecular predictor for EGFR-TKIs responsiveness in squamous cell carcinoma, when validated isolated from the group of NSCLC.

EGFR mutation status and survival after diagnosis of brain metastasis in nonsmall cell lung cancer

A small subset of patients with nonsmall cell lung cancer (NSCLC) harbors mutations in the epidermal growth factor receptor (EGFR) that predict unique sensitivity to EGFR tyrosine kinase inhibitors (TKIs). The characteristics and behavior of brain metastases (BMs) in these patients have not been well described. The longitudinal records of all NSCLC patients who underwent EGFR mutation screening at our center from August 2004 to November 2008 were reviewed for eligibility, and 93 patients were identified who developed BM during the course of their disease. Survival was estimated using the Kaplan-Meier method and the log-rank test. Multivariable predictors were assessed via the Cox proportional hazards model. Among the 93 patients with BM, 41 (44%) had mutations in EGFR, including 13 exon 19 deletions and 12 L858R mutations. Eighty-three percent of patients with BM were treated initially with whole brain radiation, either alone (53%) or in combination with craniotomy for neurosurgical resection (22%) or stereotactic radiosurgery (8%). Median survival from the time of BM was 11.7 months and was longer for patients with an EGFR mutation (14.5 vs 7.6 months, P = .09). On multivariable analysis, EGFR mutation (HR: 0.50, 95% CI: 0.30-0.82), age (HR: 1.03, 95% CI: 1.00-1.05), and active extracranial disease (HR: 3.30, 95% CI: 1.70-6.41) were independently associated with survival. In NSCLC patients with BM, EGFR mutation status is associated with improved survival, independent of age, functional status, extracranial disease status, and number of BMs.

Gefitinib or chemotherapy for non-small-cell lung cancer with mutated EGFR

BACKGROUND

Non-small-cell lung cancer with sensitive mutations of the epidermal growth factor receptor (EGFR) is highly responsive to EGFR tyrosine kinase inhibitors such as gefitinib, but little is known about how its efficacy and safety profile compares with that of standard chemotherapy.

METHODS

We randomly assigned 230 patients with metastatic, non-small-cell lung cancer and EGFR mutations who had not previously received chemotherapy to receive gefitinib or carboplatin-paclitaxel. The primary end point was progression-free survival; secondary end points included overall survival, response rate, and toxic effects.

RESULTS

In the planned interim analysis of data for the first 200 patients, progression-free survival was significantly longer in the gefitinib group than in the standard-chemotherapy group (hazard ratio for death or disease progression with gefitinib, 0.36; P<0.001), resulting in early termination of the study. The gefitinib group had a significantly longer median progression-free survival (10.8 months, vs. 5.4 months in the chemotherapy group; hazard ratio, 0.30; 95% confidence interval, 0.22 to 0.41; P<0.001), as well as a higher response rate (73.7% vs. 30.7%, P<0.001). The median overall survival was 30.5 months in the gefitinib group and 23.6 months in the chemotherapy group (P=0.31). The most common adverse events in the gefitinib group were rash (71.1%) and elevated aminotransferase levels (55.3%), and in the chemotherapy group, neutropenia (77.0%), anemia (64.6%), appetite loss (56.6%), and sensory neuropathy (54.9%). One patient receiving gefitinib died from interstitial lung disease.

CONCLUSIONS

First-line gefitinib for patients with advanced non-small-cell lung cancer who were selected on the basis of EGFR mutations improved progression-free survival, with acceptable toxicity, as compared with standard chemotherapy. (UMIN-CTR number, C000000376.)

EGFR mutation is a better predictor of response to tyrosine kinase inhibitors in non-small cell lung carcinoma than FISH, CISH, and immunohistochemistry

About 10% of patients with non-small cell lung carcinoma (NSCLC) respond to epidermal growth factor receptor (EGFR)-targeted tyrosine kinase inhibitors (TKIs). More than 75% of "responders" have activating mutations in EGFR. However, mutation analysis is not widely available, and proposed alternatives (in situ hybridization and immunohistochemical analysis) have shown inconsistent associations with outcome. Fluorescence in situ hybridization (FISH), chromogenic in situ hybridization (CISH), immunohistochemical analysis, and DNA sequencing were compared in this study of 40 NSCLC samples from TKI-treated patients. Response rates were 12 of 19 in EGFR-mutant vs 1 of 20 EGFR wild-type tumors (P = .0001), 7 of 19 FISH+ vs 4 of 17 FISH- tumors (not significant [NS]), 5 of 16 CISH+ vs 6 of 21 CISH- tumors (NS), and 3 of 9 immunohistochemically positive vs 7 of 22 immunohistochemically negative tumors (NS). EGFR mutation was associated with improved progression-free survival (P = .0004). Increased copy number (FISH or CISH) and protein expression (immunohistochemical) did not independently predict outcome. Thus, EGFR sequence analysis was the only method useful for predicting response and progression-free survival following TKI therapy in NSCLC.

EGFR(S) inhibitors in the treatment of gastro-intestinal cancers: what's new?

In the past 10 to 15 years, a considerable progress has been made in the treatment of gastrointestinal (GI) related malignancies, as number of agents expanded from only one in 1995 to seven in 2006. Current review describes the recent role of targeted therapies, specifically EGFR inhibitors in the treatment of GI cancers. Importance of dietary agents in the treatment and prevention of GI cancers is also reviewed.

First-line gefitinib treatment for patients with advanced non-small cell lung cancer with poor performance status

BACKGROUND

Best supportive care only is recommended for patients with advanced non-small cell lung cancer (NSCLC) with poor performance status (PS) of Eastern Cooperative Oncology Group 3 or 4. Recently, the possibility of using epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor therapy has been reported for poor PS patients harboring EGFR mutations.

METHODS

We retrospectively analyzed 74 patients with advanced NSCLC who were treated with first-line gefitinib during hospitalization for Eastern Cooperative Oncology Group PS 3 or 4. All patients were classified according to three clinical parameters: smoking history, gender, and histology type.

RESULTS

The median age was 64 years (range, 35-86 years). The proportions of females, never smokers, and adenocarcinoma were 51.4%, 54.1%, and 78.4%, respectively. An overall response rate, median progression-free survival (PFS), and median overall survival (OS) was 27.0%, 32 days (95% confidence interval [CI], 22-48 days), and 61 days (95% CI, 7-115 days), respectively. Female gender, never smoking, and adenocarcinoma histology were strong predictors of tumor response. Never smoking and adenocarcinoma were independent predictors of better PFS but not of OS. Seven patients experienced treatment-related adverse effects of grade 3 to 4, which included anorexia (n = 2), pneumonitis (n = 4), and elevated liver enzymes (n = 1). Never-smoker females with adenocarcinoma exhibited a response rate of 50.0%, median PFS of 130 days (95% CI, 51-209 days), and median OS of 236 days (95% CI, 150-322 days).

CONCLUSIONS

Gefitinib may provide clinical benefits for patients with NSCLC with poor PS who were selected according to clinically favorable parameters.

Management of patients with advanced non-small cell lung cancer: role of gefitinib

Gefitinib is the first epidermal growth factor receptor tyrosine-kinase inhibitor approved for the treatment of advanced non-small cell lung cancer (NSCLC). Its failure to improve survival in a placebo-control study, however, led to its withdrawal in the United States though it is available in many other countries Subsequent studies nevertheless showed comparable efficacy for gefitinib and docetaxel in the second-line therapy. Gefitinib significantly improved progression-free survival compared to chemotherapy in patients with activating mutations in the epidermal growth factor receptor tyrosine kinase mutations. This review will discuss the results of these large randomized studies and discuss the role of gefitinib in the treatment of advanced NSCLC.

Emerging role of gefitinib in the treatment of non-small-cell lung cancer (NSCLC)

Most patients with non-small-cell lung cancer (NSCLC) present with advanced disease and their long-term prognosis remains poor. Epidermal growth factor receptor (EGFR)-targeted therapies, such as gefitinib, have been subjected to comprehensive clinical development. Several phase II and III trials evaluated the clinical efficacy of gefitinib as monotherapy in pretreated patients with advanced NSCLC, as well as both monotherapy and combined with chemotherapy in chemotherapy-naive patients. A phase III trial (ISEL) in heavily pretreated advanced NSCLC patients demonstrated some improvement in survival with gefitinib compared with placebo; however, the difference was not statistically significant within the overall population. A large phase III trial in pretreated patients (INTEREST) demonstrated the non-inferiority of gefitinib in comparison with docetaxel for overall survival, together with an improved quality of life and tolerability profiles. In a large phase III trial (IPASS) in Asian chemotherapy-naive, never or former light-smoker patients with adenocarcinoma, gefitinib was more effective than carboplatin-paclitaxel in prolonging progression-free survival, particularly in patients harboring EGFR gene mutations. Gefitinib was a generally well tolerated treatment, with skin rash and diarrhea being the most common treatment adverse events. As a result, gefitinib is expected to have a large impact on the management of patients with advanced NSCLC, in particular in EGFR mutated patients.

Met activation in non-small cell lung cancer is associated with de novo resistance to EGFR inhibitors and the development of brain metastasis

Most non-small cell lung cancer (NSCLC) patients harboring activating epidermal growth factor receptor (EGFR) mutations respond to tyrosine kinase inhibitor (TKI) therapy. However, about 30% exhibit primary resistance to EGFR TKI therapy. Here we report that Met protein expression and phosphorylation were associated with primary resistance to EGFR TKI therapy in NSCLC patients harboring EGFR mutations, implicating Met as a de novo mechanism of resistance. In a separate patient cohort, Met expression and phosphorylation were also associated with development of NSCLC brain metastasis and were selectively enriched in brain metastases relative to paired primary lung tumors. A similar metastasis-specific activation of Met occurred in vitro in the isogenous cell lines H2073 and H1993, which are derived from the primary lung tumor and a metastasis, respectively, from the same patient. We conclude that Met activation is found in NSCLC before EGFR-targeted therapy and is associated with both primary resistance to EGFR inhibitor therapy and with the development of metastases. If confirmed in larger cohorts, our analysis suggests that patient tumors harboring both Met activation and EGFR mutation could potentially benefit from early intervention with a combination of EGFR and Met inhibitors.

Neratinib, an irreversible pan-ErbB receptor tyrosine kinase inhibitor: results of a phase II trial in patients with advanced non-small-cell lung cancer

PURPOSE

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) have had a significant impact on non-small-cell lung cancer (NSCLC) outcomes, particularly for patients with EGFR mutations. Resistance emerges after 9 to 12 months, primarily mediated by the T790M resistance mutation. We studied neratinib, an irreversible pan-ErbB TKI that may overcome T790M.

PATIENTS AND METHODS

Patients with advanced NSCLC underwent EGFR sequencing of available tumor tissue at enrollment. Those with > or = 12 weeks of prior TKI therapy were placed in arm A if they were EGFR mutation positive or arm B if they were wild-type. Arm C included TKI-naïve patients with adenocarcinoma and light smoking histories (< or = 20 pack-years). All patients received daily oral neratinib, initially at 320 mg but subsequently reduced to 240 mg because of excessive diarrhea. The primary end point was objective response rate (RR).

RESULTS

One-hundred sixty-seven patients were treated: 91 in arm A, 48 in arm B, and 28 in arm C. Diarrhea was the most common toxicity; grade 3 incidence was 50% at 320 mg but improved to 25% after dose reduction. The RR was 3% in arm A and zero in arms B and C. No patients with known T790M responded. Notably, three of four patients with an exon 18 G719X EGFR mutation had a partial response and the fourth had stable disease lasting 40 weeks.

CONCLUSION

Neratinib had low activity in patients with prior benefit from TKIs and in TKI-naïve patients, potentially because of insufficient bioavailability from diarrhea-imposed dose limitation. Responses were seen in patients with the rare G719X EGFR mutation, highlighting the importance of obtaining comprehensive genetic information on trials of targeted agents.

Amrubicin for the treatment of advanced lung cancer

Although the advancement of the chemotherapy of non-small cell lung cancer and small cell lung cancer is remarkable in recent years, it is still unsatisfactory. Therefore, some new agents or a new treatment strategy for lung cancer is required. Amrubicin is a totally synthetic anthracycline anticancer drug that acts as a potent topoisomerase II inhibitor. Recently, amrubicin has been approved in Japan for the treatment of small- and non-small cell lung cancers and some clinical trials about amrubicin were conducted in Japan, and promising results have been reported for the treatment of small cell lung cancer in particular. The preclinical, pharmacology and clinical data of amrubicin for the treatment of advanced lung cancer are reviewed.

Standing the test of time in Europe? Gefitinib in the treatment of non-small-cell lung cancer

Lung cancer is the most common cancer worldwide, with 1.3 million new cases diagnosed every year. Non-small-cell lung carcinoma (NSCLC) has previously had a very poor prognosis with few effective therapies; however, research has identified that it is associated with a high rate of expression of epidermal growth factor receptor (EGFR) tyrosine kinase. This has led to discoveries in drug manipulation of this receptor, to provide effective new therapies against NSCLC. Gefitinib is a small molecule kinase inhibitor which inhibits the cytoplasmic domain of the EGFR; the evidence behind its use and future role is presented in this review.

Impact of biomarkers on non-small cell lung cancer treatment

Chemotherapy represents the mainstay of non-small cell lung cancer (NSCLC) treatment, but response is usually observed in only one out of three patients. Massive efforts have been carried out to identify biomarkers that might help clinicians to choose appropriate drugs, by identifying potentially sensitive subjects and spare toxicities in patients who are unlikely to benefit from treatment. Low excision repair cross-complementation group 1 (ERCC1) and ribonucleotide reductase M1 (RRM1) levels have been associated with increased sensitivity to cisplatin and gemcitabine, respectively, while reduced class III beta-tubulin expression has been associated with taxane activity. Initial prospective studies showed the feasibility of a customized approach based on biomarker assessment, and phase III trials will hopefully provide further validation of this approach. The impact of biomarkers for patient selection has now been well established for tyrosine kinase inhibitors (TKIs) of the epidermal growth factor receptor (EGFR), with EGFR mutations emerging as the most reliable predictor for improved outcome. Relevant clinical issues are represented by the identification of patients who can be reasonably excluded from treatment and by the development of therapeutic approaches able to overcome acquired resistance to anti-EGFR strategies.

Amplification of EGFR T790M causes resistance to an irreversible EGFR inhibitor

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors, gefitinib and erlotinib are effective therapies against mutant non-small cell lung cancers (NSCLCs). Treatment is limited by the development of resistance in part explained by the gain of a secondary EGFR mutation, T790M, at the gatekeeper residue. Irreversible EGFR inhibitors, including PF00299804, are effective in vitro and in vivo against EGFR mutant tumors that contain EGFR T790M and are currently under clinical development. In this study, we generate models of resistance to PF00299804, using cell lines with EGFR T790M and show that the PF00299804-resistant models develop focal amplification of EGFR that preferentially involves the T790M-containing allele. These PF00299804-resistant cell lines remain dependent on EGFR for growth as downregulation of EGFR by shRNA compromises their viability. We show that resistance to PF00299804 arises, at least in part, through selection of a pre-existing EGFR T790M-amplified clone both in vitro and using a xenograft model in vivo. Our findings show that EGFR T790M is a common resistance mechanism to both reversible, and when amplified, the irreversible EGFR kinase inhibitors further emphasizing the need to develop more potent therapies against EGFR T790M. These findings can be used to guide studies of patient tumor specimens from ongoing clinical trials of irreversible EGFR kinase inhibitors.

Histological and genetic markers for non-small-cell lung cancer: customizing treatment based on individual tumor biology

PURPOSE

To describe how molecular and genetic markers influence the response to therapy in patients with advanced non-small-cell lung cancer (NSCLC).

SUMMARY

Cisplatin resistance has been associated with high rates of expression of endonucleases, a family of DNA repair proteins that includes ERCC1 and BRCA1. Gemcitabine is thought to produce its antitumor effects by several mechanisms, including inhibition of ribonucleotide conversion to deoxyribonucleotide through the inactivation of ribonucleotide reductase. One type of gemcitabine resistance occurs when the inactivation of ribonucleotide reductase decreases, which correlates with increased expression of the M1 subunit of ribonucleotide reductase. Taxanes produce their anti-tumor effects by binding to and stabilizing intracellular microtubules, which are necessary for DNA replication and cell division. High expression of beta-tubulin III, a microtubule subunit with low taxane binding affinity, appears to confer resistance to taxane therapy. High expression of thymidylate synthase, an enzyme that is important in purine synthesis and DNA replication, has been associated with decreased response to uracil antimetabolites, and may also be an important prognostic factor in patients receiving pemetrexed. The epidermal growth factor receptor (EGFR) is a cell- surface receptor with an intracellular tyrosine kinase domain that is thought to modulate numerous cellular functions that contribute to tumorigenicity, tumor invasiveness, and resistance to therapy. Recent clinical trials have demonstrated that treatment response to small-molecule and monoclonal antibody inhibitors of EGFR is greatest for patients who have a higher EGFR gene copy number.

CONCLUSION

Several genetic, molecular, and histological markers may affect treatment response in patients with NSCLC. Evaluating patients for such markers is important not only for treatment efficacy, but also to improve safety and tolerability by avoiding exposure to treatments that are unlikely to produce significant benefits. Nearly all of the available information regarding the predictive value of these markers has been derived from retrospective studies. Prospective clinical trials are important to validate marker evaluation methodology and the prospective utility of biomarkers in clinical decision making.

Management of patients with advanced non-small cell lung cancer: current and emerging options

Systemic therapy for advanced non-small cell lung cancer (NSCLC) has evolved over the last two decades, with modest improvements in quality of life and overall survival. A plateau has been reached with traditional chemotherapy, and efforts are now being directed at developing molecularly targeted agents. To date, three such agents have been found to improve overall survival in advanced NSCLC. Erlotinib, a small-molecule inhibitor of the epidermal growth factor receptor, was approved by the US FDA in 2004 as second- or third-line treatment for advanced NSCLC. Bevacizumab, an antibody to vascular endothelial growth factor, a key mediator of angiogenesis, received approval in 2006, after a randomized trial reported a median survival of 1 year when bevacizumab was added to first-line chemotherapy. More recently, cetuximab, an antibody to the epidermal growth factor receptor, was found to improve outcome when added to chemotherapy, and FDA approval is anticipated. Several additional agents are currently being evaluated in randomized trials, with encouraging results from early studies. These and other studies are prospectively investigating predictive clinical and molecular characteristics, with the ultimate goal of individualizing therapy in advanced NSCLC.

Epithelioid sarcoma expresses epidermal growth factor receptor but gene amplification and kinase domain mutations are rare

Epithelioid sarcoma is a rare, malignant, soft tissue neoplasm that can be classified into proximal, distal and fibroma-like subtypes. Regardless of subtype, epithelioid sarcoma often shows morphologic and immunophenotypic evidence of epithelial differentiation. Current therapeutic strategies include surgical resection, amputation, radiation or chemotherapy, although the overall prognosis remains poor. The epidermal growth factor receptor (EGFR) is a novel therapeutic target in carcinomas. In some carcinomas, EGFR kinase domain mutations or gene amplification may correlate with response to specific inhibitors. EGFR expression has been reported in some sarcoma types, but expression, amplification and mutations have not been studied in epithelioid sarcoma. We evaluated 15 cases of epithelioid sarcoma from 14 patients for EGFR expression using immunohistochemistry, EGFR copy number aberration using fluorescence in situ hybridization and screened for mutations in the tyrosine kinase domain of the EGFR gene using direct sequencing. In all, 14 of the 15 epithelioid sarcomas (93%) showed expression of EGFR by immunohistochemistry. A majority of the cases (n=11, 73%) showed strong (2+ to 3+) and homogeneous (>75% of cells) membrane staining. No amplification or polysomy of the EGFR gene or mutations of the tyrosine kinase domain of EGFR (exons 18-21) were detected. These results imply that although EGFR is expressed in most epithelioid sarcomas regardless of subtype, gene amplification and activating mutations in the tyrosine kinase domain appear to be rare or absent. Thus, the benefit of targeted therapy against EGFR in patients with epithelioid sarcoma remains to be determined.

Clinical outcomes of advanced non-small cell lung cancer patients screened for epidermal growth factor receptor gene mutations

PURPOSE

To evaluate the relationship between the epidermal growth factor receptor (EGFR) mutation status and the effectiveness of gefitinib monotherapy or chemotherapy in patients with advanced non-small cell lung cancer (NSCLC).

METHODS

We retrospectively analyzed a cohort of 100 patients with stage IIIB/IV NSCLC screened for two major EGFR mutations (exon 19 deletions and L858R mutation).

RESULTS

Forty-six out of 48 EGFR mutation-positive patients (96%) received gefitinib, whereas only 3 out of 52 EGFR mutation-negative patients (6%) received gefitinib. Favorable objective response rates to gefitinib as first- and second-line treatment (87 and 80%, respectively) were observed in EGFR mutation-positive patients. Overall response rate to chemotherapy as first-line treatment did not differ significantly between patients with EGFR mutations and those without mutation (32 vs. 28%, respectively; P = 0.7198). As to first-line treatment, EGFR mutation-positive patients treated with gefitinib experienced significantly longer progression-free survival (PFS) than did patients who received chemotherapy (median survival, 7.8 months vs. 5.1 months, respectively; P = 0.0323). Similarly, as to second-line treatment, EGFR mutation-positive patients treated with gefitinib had significantly longer PFS than did patients who received chemotherapy (median survival, 6.5 months vs. 4.0 months, respectively; P = 0.0048). Patients with EGFR mutations survived longer than those without EGFR mutations after first-line treatment (median, 24.3 vs. 12.6 months, respectively; P = 0.0029).

CONCLUSION

EGFR mutation-positive patients benefit from either first- or second-line gefitinib monotherapy. Further large-scale prospective studies to confirm this finding are needed.

A phase II trial of erlotinib monotherapy in pretreated patients with advanced non-small cell lung cancer who do not possess active EGFR mutations: Okayama Lung Cancer Study Group trial 0705

BACKGROUNDS

Efficacy of gefitinib therapy strongly depends on epidermal growth factor receptor (EGFR)-mutation status in Asian patients with non-small cell lung cancer. Recently, the survival advantage of erlotinib, another tyrosine kinase inhibitor, was not affected by EGFR mutation status in a phase III trial, indicating that patients with EGFR-wild-type (EGFR-wt) tumors might also benefit from this tyrosine kinase inhibitor. The aim of this trial was to evaluate the efficacy and toxicity of erlotinib in Japanese patients with EGFR-wt tumors.

METHODS

The primary end point was an objective response. Patients with EGFR-wt tumors previously receiving one to three chemotherapy regimens were enrolled in this trial. The mutation status was assessed using the peptide nucleic acid-locked nucleic acid polymerase chain reaction clamp method. Erlotinib was administered (150 mg/d) until disease progression or unacceptable toxicities occurred.

RESULTS

Thirty patients were enrolled between January and December 2008. Objective response was observed in one patient (3.3%), and the disease became stable in 18 patients (60.0%). Skin rash was the most common side effect. Grades 3-4 adverse events included pulmonary embolism, keratitis, and anemia. Two other patients developed interstitial lung disease (grades 1 and 2). Nevertheless, all these events were reversible, resulting in no treatment-related deaths. With a median follow-up time of 10.7 months, the median survival time and median progression-free survival times were 9.2 and 2.1 months, respectively.

CONCLUSION

This is the first prospective biomarker study showing that erlotinib therapy for pretreated patients with EGFR-wt tumors seems to have a modest activity with no irreversible toxicity.

Targeted therapy for nonsmall cell lung cancer: focusing on angiogenesis, the epidermal growth factor receptor and multikinase inhibitors

Chemotherapy used to be the only available option to fight advanced nonsmall cell lung cancer. Platinum-based medication combined with taxanes, vinca alkaloids, and antimetabolites improved patient survival rates. Unfortunately, neoplasmatic diseases remain a global killer because chemotherapy benefits have reached a plateau and most patients are diagnosed at the metastatic stage. The urgent need for therapeutic agents, along with advances in the knowledge of the molecular events of oncogenesis, has resulted in the development of medication that specifically targets processes and pathways critical for tumor growth, such as angiogenesis and the epidermal growth factor receptor. Initially, inhibiting these pathways managed to prolong patient survival, although not to the extent desired. Moreover, targeted therapy combined with conventional cytotoxic agents has shown no superiority to chemotherapy alone in terms of patient survival. Hence, numerous multidynamic agents have appeared in the hope that they might help fight nonsmall cell lung cancer. However, no group of patients who will hopefully gain maximum benefit from such interventions has been clearly identified yet. This paper presents current evidence with regard to such novel agents and angiogenesis and epidermal growth factor inhibitors.

Epidermal growth factor receptor inhibition in lung cancer: the evolving role of individualized therapy

Non-small cell lung cancer (NSCLC) is the major cause of cancer-related deaths in the USA and worldwide. Most patients present with advanced disease, and treatment options for these patients are generally limited to platinum-based chemotherapy and a few targeted therapies. Targeted agents currently in use for NSCLC inhibit oncogenic receptor tyrosine kinase pathways, such as the epidermal growth factor receptor (EGFR) pathway. While current EGFR-targeted agents, including erlotinib and gefitinib, may result in dramatic responses, they demonstrate efficacy in only a fraction of patients, and resistance to these agents frequently develops. In order to select patients most likely to benefit from blockade of EGFR pathways, investigators have focused on identifying molecular correlates of response to anti-EGFR therapy. New strategies to minimize the risk of resistance to EGFR inhibition have been employed in the development of next-generation EGFR tyrosine kinase inhibitors, such as PF00299804 and BIBW 2992; these include irreversibility of target binding, inhibition of multiple EGFR family receptors, and/or simultaneous inhibition of EGFR and other oncogenic pathways.

Phase II study of erlotinib for chemotherapy-naïve patients with advanced or metastatic non-small cell lung cancer who are ineligible for platinum doublets

PURPOSE

This phase II study evaluated efficacy of single-agent erlotinib for chemotherapy-naïve patients with advanced/metastatic NSCLC who were ineligible for platinum doublets.

METHODS

Chemotherapy-naive patients but ineligible for platinum doublets (aged 18-75 with an ECOG performance status [PS] 2-3; or aged 76 or older with an ECOG PS 1-3) were enrolled and treated with erlotinib 100 mg once daily till disease progression, unacceptable toxicity or patient's refusal.

RESULTS

Out of 24 patients enrolled, 5 reached a PR, giving an overall response rate of 21%, but all responders were never-smokers with adenocarcinoma. According to EGFR mutation status, PR was observed in two of three patients having mutant EGFR (67%) but in one of nine having wild-type EGFR (11%). With a median follow-up of 22.6 months, the median progression-free and overall survival was 1.5 months and 3.2 months, respectively. All responders to post-erlotinib chemotherapy had responded to prior erlotinib.

CONCLUSIONS

For unselected chemotherapy-naïve Asian patients with NSCLC but ineligible for platinum doublets, empirical use of upfront erlotinib could not be recommended because of poor survival outcome. However, this can be given to selected subsets based on molecular or clinical predictors.

Rationale of a relaunch of gefitinib in Caucasian non-small cell lung cancer patients

In 2002 results of two-phase II studies with the new epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) gefitinib showed not only promising efficacy in second and third line non-small cell lung cancer (NSCLC) therapies but also an excellent tolerability. Since then, thousands of patients have been treated in one of the largest expanded access programs ever performed and the successful application in daily routine led to a preliminary approval of the drug by the U.S. Food and Drug Administration in 2003. In the light of the negative results of a subsequent phase III trial comparing gefitinib with best supportive care, the approval was withdrawn. In 2009 gefitinib was relaunched for Caucasian patients in the US and Europe based on new data and on the re-interpretation of previous studies. The approval is now recommended exclusively for patients with an activating EGFR mutation. For the first time in lung cancer, molecular work-up is of clinical relevance and will change the diagnostic and therapeutic algorithms. The present review summarizes these data, presents the rationale for this development and proposes a diagnostic work-up.

Small-molecule inhibitors of the human epidermal receptor family

BACKGROUND

Small molecule inhibitors of human epidermal receptors (HER) have become an integral part of the armamentarium available to the medical oncologist in the treatment of solid tumor malignancies. At present, there are two small-molecule inhibitors (erlotinib and lapatinib) approved by the FDA in the USA, and a third inhibitor, gefitinib, is approved in other countries.

OBJECTIVE

To summarize the current standards of care for these new agents in solid tumors, and to discuss ongoing clinical trials; to review the known mechanisms of action of these inhibitors as well as to discuss both the known predictive markers for response and likely mechanisms of resistance.

METHODS

We reviewed key presentations and recent publications on small-molecule inhibitors targeting the HER family in solid tumors.

CONCLUSIONS

Recent data have highlighted the importance of mutations and amplifications of receptors within the HER family. Amplification of HER2 often translates into responses in anti-HER2 therapy. Mutations either enhance sensitivity or confer resistance to small-molecule inhibitors. Other mechanisms of resistance are being elucidated which should lead to the ability to predict both responses and resistance to HER family inhibitors and should translate into improvements in patient care.

Frequency of and variables associated with the EGFR mutation and its subtypes

Mutation in the epidermal growth factor receptor (EGFR) is frequently seen in non-small cell lung cancers (NSCLCs), especially in Asian females with adenocarcinoma. The frequency of mutation and the factors associated requires to be elucidated by analyzing a large number of consecutive clinical samples. We summarized the result of the EGFR mutation analysis for 1,176 patients performed at the time of diagnosis or relapse. The PNA-LNA PCR clamp, a highly sensitive detection method for the EGFR mutation, was employed. For fresh cases a portion of samples isolated to establish the diagnosis of lung cancer was used. For cases with a relapsed disease archival tissue were tested. The variables associated with the EGFR mutation after removing the confound factors were investigated by the logistic analysis using the samples collected in our university (n = 308) where detailed information on patients were available. The frequency of the EGFR mutation and its subtypes were investigated using all samples (n = 1,176). The EGFR mutation was significantly associated with adenocarcinoma (p = 0.006) and light-smoking (p < 0.0001), but not gender. The deletions in exon 19 were more frequently associated with male gender while exon 21 deletions were with female gender (p = 0.0011). The overall frequency of the EGFR mutation was 31%. Our result suggests that the female predominance in the EGFR mutation rate is a reflection of a higher frequency of adenocarcinoma in females. The gender difference in the mutation subtypes may provide a clue for the mechanism of the occurrence of the EGFR mutation.

Preexistence and clonal selection of MET amplification in EGFR mutant NSCLC

MET amplification activates ERBB3/PI3K/AKT signaling in EGFR mutant lung cancers and causes resistance to EGFR kinase inhibitors. We demonstrate that MET activation by its ligand, HGF, also induces drug resistance, but through GAB1 signaling. Using high-throughput FISH analyses in both cell lines and in patients with lung cancer, we identify subpopulations of cells with MET amplification prior to drug exposure. Surprisingly, HGF accelerates the development of MET amplification both in vitro and in vivo. EGFR kinase inhibitor resistance, due to either MET amplification or autocrine HGF production, was cured in vivo by combined EGFR and MET inhibition. These findings highlight the potential to prospectively identify treatment naive, patients with EGFR-mutant lung cancer who will benefit from initial combination therapy.

The marine alkaloid naamidine A promotes caspase-dependent apoptosis in tumor cells

Apoptosis is important for normal development and removal of damaged cells. Evasion of apoptosis by cancer cells is one of the key characteristics of many tumor types. Thus, discovering agents that promote apoptosis in tumor cells could have great therapeutic value. Marine natural products have demonstrated great potential as anticancer agents, and the proapoptotic activity of some of these products is emerging as a potentially useful property for cancer treatments. Using a tumor xenograft assay in rodents, we previously found that the marine alkaloid naamidine A is a potent antitumor agent. In this study, we further characterize the mechanism of action of naamidine A. In cultured tumor cells, we find that naamidine A induces cell death, which is accompanied with annexin V staining, disruption of the mitochondrial membrane potential, and cleavage and activation of caspases 3, 8, and 9, all of which are hallmarks of apoptosis. Furthermore, naamidine A-induced cell death is caspase dependent. We also find that under conditions where naamidine A inhibits tumor xenograft growth, it induces activation of caspase 3, suggesting that apoptosis is part of its antitumorigenic activity in vivo. Apoptosis is not dependent on extracellular signal-regulated kinase 1/2, previously characterized molecular targets of naamidine A, nor does it require functional p53. Our studies support the continued study of naamidine A and its target(s) for the potential development of better clinical treatments for cancer.

Acquired resistance to epidermal growth factor receptor tyrosine kinase inhibitors in non-small-cell lung cancers dependent on the epidermal growth factor receptor pathway

Most advanced non-small-cell lung cancers (NSCLCs) with activating epidermal growth factor receptor (EGFR) mutations (exon 19 deletions or L858R) initially respond to the EGFR tyrosine kinase inhibitors (TKIs) gefitinib and erlotinib. However, over time (median of 6-12 months), most tumors develop acquired resistance to EGFR TKIs. Intense research in these NSCLCs has identified two major mechanisms of resistance to gefitinib/erlotinib: secondary resistance mutations and "oncogene kinase switch" systems. The secondary T790M mutation occurs in 50% of EGFR-mutated patients with TKI resistance, and in vitro, this mutation negates the hypersensitivity of activating EGFR mutations. Sensitive detection methods have identified a proportion of TKI-naive tumors that carry T790M, and these resistant clones may be selected after exposure to gefitinib or erlotinib. Other secondary resistance mutations (D761Y, L747S, T854A) seem to be rare. The amplification of the MET oncogene is present in 20% of TKI-resistant tumors; however, in half of the cases with this "oncogene kinase switch" mechanism the T790M is coexistent. It is possible that other kinases (such as insulin-like growth factor-1 receptor [IGF-1R]) might also be selected to bypass EGFR pathways in resistant tumors. The growing preclinical data in EGFR-mutated NSCLCs with acquired resistance to gefitinib or erlotinib has spawned the initiation or conception of clinical trials testing novel EGFR inhibitors that in vitro inhibit T790M (neratinib, XL647, BIBW 2992, and PF-00299804), MET, or IGF-1R inhibitors in combination with EGFR TKIs, and heat shock protein 90 inhibitors. Ongoing preclinical and clinical research in EGFR-mutated NSCLC has the potential to significantly improve the outcomes of patients with these somatic mutations.

Gefitinib in combination with oral topotecan and cyclophosphamide in relapsed neuroblastoma: pharmacological rationale and clinical response

AIM

Activity and toxiciy of gefitinib in combination with topotecan and cyclophosphamide (CPA) were evaluated in a case-series of relapsed neuroblastoma (NB) patients. The in vitro activity of the combination was also assessed.

PROCEDURE

Gefitinib (250 mg/day), topotecan (0.8 mg/m(2)/day), and CPA (50 mg/m(2)/day) (GTC) were administered orally for 14 consecutive days out of 28 days. Antitumor activity of gefitinib as single agent and in combination with either topotecan or CPA was assessed in a panel of NB cell lines.

RESULTS

Ninety-two courses were given in 10 patients. Grade 4 neutropenia was observed in 7/92 courses (8%) and grade 4 thrombocytopenia in 8/92 (9%). Two patients had a grade 2 liver toxicity, four a grade 1/2 skin toxicity, and two a grade 1/2 diarrhea. Dose reduction of topotecan and/or CPA was required in eight patients. After four courses, three patients were in partial response (PR) and four with a stable disease (SD), while three experienced a progressive disease (PD). Time to progression (TTP) was 9 months (range, 1-27). After a median follow-up of 16 months (range 5-54), seven patients are died of disease (DOD) and three alive with disease (AWD). All but one patient discontinued oral chemotherapy because of a PD, whilst one patient stopped chemotherapy after 27 months with a SD. In vitro, gefitinib was synergistic with topotecan and additive with CPA.

CONCLUSION

The GTC combination was well tolerated and the TTP was encouraging. These promising results, also supported by in vitro evidence, should be further confirmed in a phase II study.

Clinical outcomes in non-small-cell lung cancer patients with EGFR mutations: pooled analysis

Non-small-cell lung cancer (NSCLC) with mutations in the epidermal growth factor receptor (EGFR) is a distinct subgroup of NSCLCs that is particularly responsive to EGFR tyrosine-kinase inhibitors (TKIs). A weighted pooled analysis of available studies was performed to evaluate clinical outcome in patients with EGFR-mutated NSCLC who were treated with chemotherapy or EGFR TKIs. Median progression-free survival (PFS) times were pooled from prospective or retrospective studies that evaluated chemotherapy or single-agent EGFR TKIs (erlotinib or gefitinib) in patients with NSCLC and EGFR mutations. Among the studies identified for inclusion in the analysis, 12 evaluated erlotinib (365 patients), 39 evaluated gefitinib (1069 patients) and 9 evaluated chemotherapy (375 patients). Across all studies, the most common EGFR mutations were deletions in exon 19 and the L858R substitution in exon 21. In the weighted pooled analysis, the overall median PFS was 13.2 months with erlotinib, 9.8 months with gefitinib and 5.9 months with chemotherapy. Using a two-sided permutation, erlotinib and gefitinib produced a longer median PFS versus chemotherapy, both individually (P= 0.000 and P= 0.002, respectively) and as a combined group (EGFR TKI versus chemotherapy, P= 0.000). EGFR TKIs appear to be the most effective treatment for patients with advanced EGFR-mutant NSCLC. Ongoing prospective trials comparing the efficacy of first-line chemotherapy and EGFR TKIs in EGFR-mutant disease should provide further insight into the most appropriate way to treat this specific group of patients.

Gefitinib as first-line therapy for advanced or metastatic non-small cell lung cancer patients in southern Taiwan

Gefitinib, a selective epidermal growth factor receptor tyrosine kinase inhibitor, is effective in treating patients with non-small cell lung cancer (NSCLC) after unsuccessful chemotherapy. However, survival outcomes and predictors for its effectiveness in chemotherapy-naive NSCLC patients are still not clear. The goal of this study was to investigate the response and survival rates and identify the predictive factors for patients with advanced or metastatic disease receiving gefitinib as first-line therapy. We retrospectively analyzed the response and survival rates of patients with advanced or metastatic NSCLC who had received gefitinib as first-line therapy across six medical institutes in Southern Taiwan between May 2004 and April 2006. The relationship between the response and survival rates to the known predictive factors for gefitinib response and survival was also investigated. A total of 97 patients (65 females and 32 males) were enrolled in this study. Seventy-four patients (76%) had never smoked. Eighty-eight patients (91%) had adenocarcinoma or bronchioloalveolar cell carcinoma. The objective response rate was 56% and the disease control rate (partial response plus stable disease) was 76%. Only poor performance status (Eastern Cooperative Oncology Group score, 3-4) was statistically significantly associated with overall response in this study. The 1-year survival rate was 77%. We suggest that first-line gefitinib monotherapy is promising in some subgroups of Asian patients with NSCLC. Further randomized controlled studies are needed to validate the effectiveness of first-line gefitinib therapy.

Hepatocyte growth factor reduces susceptibility to an irreversible epidermal growth factor receptor inhibitor in EGFR-T790M mutant lung cancer

PURPOSE

The secondary T790M mutation in epidermal growth factor receptor (EGFR) is the most frequent cause of acquired resistance to the reversible EGFR tyrosine kinase inhibitors (EGFR-TKI), gefitinib and erlotinib, in lung cancer. Irreversible EGFR-TKIs are expected to overcome the reversible EGFR-TKI resistance of lung cancer harboring T790M mutation in EGFR. However, it is clear that resistance may also develop to this class of inhibitors. We showed previously that hepatocyte growth factor (HGF) induced gefitinib resistance of lung cancer harboring EGFR-activating mutations. Here, we investigated whether HGF induced resistance to the irreversible EGFR-TKI, CL-387,785, in lung cancer cells (H1975) harboring both L858R activating mutation and T790M secondary mutation in EGFR.

EXPERIMENTAL DESIGN

CL-387,785 sensitivity and signal transduction in H1975 cells were examined in the presence or absence of HGF or HGF-producing fibroblasts with or without HGF-MET inhibitors.

RESULTS

HGF reduced susceptibility to CL-387,785 in H1975 cells. Western blotting and small interfering RNA analyses indicated that HGF-induced hyposensitivity was mediated by the MET/phosphoinositide 3-kinase/Akt signaling pathway independent of EGFR, ErbB2, ErbB3, and ErbB4. Hyposensitivity of H1975 cells to CL-387,785 was also induced by coculture with high-level HGF-producing lung fibroblasts. The hyposensitivity was abrogated by treatment with anti-HGF neutralizing antibody, HGF antagonist NK4, or MET-TKI.

CONCLUSIONS

We showed HGF-mediated hyposensitivity as a novel mechanism of resistance to irreversible EGFR-TKIs. It will be clinically valuable to investigate the involvement of HGF-MET-mediated signaling in de novo and acquired resistance to irreversible EGFR-TKIs in lung cancer harboring T790M mutation in EGFR.

Resistance to Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors in Non-Small Cell Lung Cancer

Gefitinib and erlotinib are ATP competitive inhibitors of the epidermal growth factor receptor (EGFR) tyrosine kinase and are approved around the world for the treatment of patients with non-small cell lung cancer (NSCLC). Somatic mutations in the EGFR are found in 10 to 40% of patients with NSCLC. Patients with sensitizing somatic mutations of EGFR treated with gefitinib or erlotinib have an initial clinical response of 60 to 80%, approximately twice as high as the responses associated with the administration of conventional platinum-based chemotherapy. However, the efficacy of EGFR tyrosine kinase inhibitors (TKI) is limited by either primary (de novo) or acquired resistance after therapy and investigations to define the mechanisms of resistance are active areas of ongoing preclinical and clinical studies. Primary resistance is typically caused by other somatic mutations in genes such as KRAS, which also have an impact on the EGFR signaling pathway or by mutations in the EGFR gene that are not associated with sensitivity to EGFR-TKIs. Two established mechanisms of acquired resistance are caused by additional mutations in the EGFR gene acquired during the course of treatment that change the protein-coding sequence or by amplification of another oncogene signaling pathway driven by the MET oncogene. This review focuses on characterized mechanisms of resistance to the EGFR TKIs and efforts to overcome the problem of resistance aimed at improving the therapy of patients with NSCLC. (Clin Cancer Res 2009;15(24):7502-9).

Second-line treatments after first-line gefitinib therapy in advanced nonsmall cell lung cancer

Gefitinib is effective as first-line therapy for advanced nonsmall cell lung cancer (NSCLC). However, after failure of gefitinib, it is unknown whether any second-line regimens could lead to better outcomes. To study the influence of different second-line antitumor regimens on the outcomes of patients with NSCLC after failure of first-line gefitinib, we carried out a retrospective study in a tertiary referral medical center to investigate the prognosis of patients with NSCLC receiving second-line antitumor treatment after gefitinib therapy. Clinical data and epidermal growth factor receptor (EGFR) mutational status of tumors were collected. A total of 195 patients with Stage IIIb or IV NSCLC receiving first-line gefitinib and at least 1 subsequent line therapy were identified. A second-line therapy with a platinum-based combination or taxane-containing regimen were associated with a higher therapy response, whereas a platinum-based combination was linked to better overall survival. Ninety-five patients had tumors with known EGFR mutation status; 61 had EGFR mutations and 34 had wild-type EGFR. A second-line therapy with a gemcitabine/platinum combination regimen resulted in better overall survival than erlotinib in patients with EGFR mutations (p = 0.035) but not in patients with wild-type EGFR (p = 0.785). The study suggested that, after failure of first-line gefitinib therapy, second-line platinum-based combination regimens were associated with a better overall survival than other regimens, including erlotinib. The survival benefit of platinum-based combination regimens existed in patients with mutant EGFR but not wild-type EGFR.