A phase II study of single-agent gefitinib as first-line therapy in patients with stage IV non-small-cell lung cancer

A fluorogenic probe for predicting treatment response in non-small cell lung cancer with EGFR-activating mutations

Therapeutic responses of non-small cell lung cancer (NSCLC) to epidermal growth factor receptor (EGFR) - tyrosine kinase inhibitors (TKIs) are known to be associated with EGFR mutations. However, a proportion of NSCLCs carrying EGFR mutations still progress on EGFR-TKI underlining the imperfect correlation. Structure-function-based approaches have recently been reported to perform better in retrospectively predicting patient outcomes following EGFR-TKI treatment than exon-based method. Here, we develop a multicolor fluorescence-activated cell sorting (FACS) with an EGFR-TKI-based fluorogenic probe (HX103) to profile active-EGFR in tumors. HX103-based FACS shows an overall agreement with gene mutations of 82.6%, sensitivity of 81.8% and specificity of 83.3% for discriminating EGFR-activating mutations from wild-type in surgical specimens from NSCLC patients. We then translate HX103 to the clinical studies for prediction of EGFR-TKI sensitivity. When integrating computed tomography imaging with HX103-based FACS, we find a high correlation between EGFR-TKI therapy response and probe labeling. These studies demonstrate HX103-based FACS provides a high predictive performance for response to EGFR-TKI, suggesting the potential utility of an EGFR-TKI-based probe in precision medicine trials to stratify NSCLC patients for EGFR-TKI treatment.

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.

Establishment and genomic characterizations of patient-derived esophageal squamous cell carcinoma xenograft models using biopsies for treatment optimization

Background

Squamous cell carcinoma is the dominant type of esophageal cancer in China with many patients initially diagnosed at advanced stage. Patient-derived xenografts (PDX) models have been developed to be an important platform for preclinical research. This study aims to establish and characterize PDX models using biopsy tissue from advanced esophageal cancer patients to lay the foundation of preclinical application.

Methods

Fresh endoscopic biopsy tissues were harvested from patients with advanced esophageal cancer and implanted subcutaneously into NOD/SCID mice. Then, the PDXs were serially passaged for up to four generations. Transplantation was analyzed and genomic characteristics of xenografts were profiled using next-generation sequencing.

Results

Twenty-five PDX models were established (13.3%, 25/188). The latency period was 75.12 ± 19.87 days (50–120 days) for the first passage and it decreased with increasing passaging. Other than tumor stages, no differences were found between transplantations of xenografts and patient characteristics, irrespective of chemotherapy. Histopathological features and chemosensitivity of PDXs were in great accordance with primary patient tumors. Each PDX was assessed for molecular characteristics including copy number variations, somatic mutations, and signaling pathway abnormalities and these were similar to patient results.

Conclusions

Our PDX models were established from real time biopsies and molecularly profiled. They might be promising for drug development and individualized therapy.

Electronic supplementary material

The online version of this article (10.1186/s12967-018-1379-9) contains supplementary material, which is available to authorized users.

Molecular Targeted Drugs and Biomarkers in NSCLC, the Evolving Role of Individualized Therapy

Lung cancer first line treatment has been directed from the non-specific cytotoxic doublet chemotherapy to the molecular targeted. The major limitation of the targeted therapies still remains the small number of patients positive to gene mutations. Furthermore, the differentiation between second line and maintenance therapy has not been fully clarified and differs in the clinical practice between cancer centers. The authors present a segregation between maintenance treatment and second line and present a possible definition for the term “maintenance” treatment. In addition, cancer cell evolution induces mutations and therefore either targeted therapies or non-specific chemotherapy drugs in many patients become ineffective. In the present work pathways such as epidermal growth factor, anaplastic lymphoma kinase, met proto-oncogene and PI3K are extensively presented and correlated with current chemotherapy treatment. Future, perspectives for targeted treatment are presented based on the current publications and ongoing clinical trials.

First-line management of EGFR-mutated advanced lung adenocarcinoma: recent developments

Gefitinib and erlotinib are small-molecule reversible tyrosine kinase inhibitors (TKIs) of epidermal growth factor receptor (EGFR). Objective responses have been observed frequently in patients with non-small cell lung cancer (NSCLC) harbouring activating EGFR mutations, the most common being deletions in exon 19 and the exon 21 L858R mutation. EGFR mutations are prevalent in female patients, those who have never smoked, those of Asian ethnicity and those who have adenocarcinoma histology. Given the efficacy of EGFR TKIs in advanced NSCLC in the salvage setting, and their favourable toxicity profile compared with conventional chemotherapy, there is considerable interest in evaluating their efficacy in the first-line treatment of advanced NSCLC. To date, there have been several phase II and phase III studies that have examined the efficacy of first-line single-agent EGFR TKIs in unselected, clinically selected or molecularly selected populations. Here we review and compare the differences in these phase III trials. Most phase III trials chose progression-free survival (PFS) rather than overall survival (OS) as their primary endpoint. PFS was prolonged but OS was not. The recent development of novel irreversible EGFR TKIs, such as afatinib and dacomitinib, is also reviewed.

A phase II trial of erlotinib as front-line treatment in clinically selected patients with non-small-cell lung cancer

BACKGROUND

The purpose of this study was to evaluate the efficacy of erlotinib as front-line treatment in clinically selected patients with non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

Forty-nine previously untreated white patients who had stage IIIB/IV pulmonary adenocarcinoma or bronchoalveolar carcinoma and who were nonsmokers or former light smokers were treated with erlotinib 150 mg daily, irrespective of the EGFR mutation status.

RESULTS

In an intention-to-treat analysis, the overall response rate (ORR) was 24.5%. The median progression-free survival (PFS) was 6.7 months, the median overall survival (OS) was 15.5 months, and the 1-year survival rate was 61.3%. Among the 36 patients for whom tumor material was available, 9 (25%) had activating EGFR mutations. The ORR was 66.7% in patients with activating EGFR mutations and 14.8% in patients with wild-type EGFR (2P = .006). In patients with activating EGFR mutations, the OS has not been reached, whereas it was 12.9 months in patients with EGFR wild type (2P = .045). Twenty-four patients had a PFS of > 6 months; 11 (45.8%) of them had EGFR wild type and 7 (29.1%) had EGFR mutation.

CONCLUSIONS

The selection of patients for treatment with EGFR-directed tyrosine kinase inhibitors (TKIs) should be based on mutation testing. However use of clinical (smoking status) and pathologic (adenocarcinoma) criteria may identify a subgroup of patients with advanced/metastatic NSCLC who can benefit from front-line treatment with erlotinib when mutation testing is not feasible.

Gefitinib in non small cell lung cancer

Gefitinib is an oral, reversible, tyrosine kinase inhibitor of epidermal growth factor receptor (EGFR) that plays a key role in the biology of non small cell lung cancer (NSCLC). Phase I studies indicated that the recommended dose of gefitinib was 250 mg/day. Rash, diarrhea, and nausea were the most common adverse events. The positive results obtained in early phase 2 clinical trials with gefitinib were not confirmed in large phase 3 trials in unselected patients with advanced NSCLC. The subsequent discovery that the presence of somatic mutations in the kinase domain of EGFR strongly correlates with increased responsiveness to EGFR tyrosine kinase inhibitors prompted phase 2 and 3 trials with gefitinib in the first line-treatment of EGFR-mutated NSCLC. The results of these trials have demonstrated the efficacy of gefitinib that can be now considered as the standard first-line treatment of patients with advanced NSCLC harbouring activating EGFR mutations.

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.

Gefitinib in the treatment of advanced non-small-cell lung cancer

Most patients with non-small-cell lung cancer (NSCLC) present with advanced disease and their long-term prognosis remains poor, even after platinum-based chemotherapy. EGF receptor (EGFR)-targeted therapies, such as gefitinib, have been subject to comprehensive clinical development. Several Phase II and III trials have evaluated the clinical efficacy of gefitinib as monotherapy in pretreated patients with advanced NSCLC, as well as both monotherapy and combined with chemotherapy in chemo-naive patients. A Phase III trial in heavily pretreated advanced NSCLC patients, 90% of whom were refractory, demonstrated some improvement in survival with gefitinib compared with placebo; however, the difference was not statistically significant in the overall population. A second large Phase III trial in patients with pretreated advanced NSCLC (INTEREST) demonstrated the noninferiority of gefitinib in comparison with docetaxel for overall survival together with an improved quality of life and tolerability profiles. As a result, gefitinib is expected to have a large impact in the management of pretreated patients with NSCLC.

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

Gefitinib is an orally bioavailable, EGF receptor tyrosine kinase inhibitor and was the first targeted drug to be approved for non-small-cell lung cancer (NSCLC). Identification of objective tumor regressions with gefitinib in NSCLC patients has resulted in intense, worldwide clinical and basic research directed toward finding the optimal use of gefitinib in NSCLC. A recent large international Phase III study (IRESSA NSCLC Trial Evaluating Response and Survival Against Taxotere [INTEREST]) comparing gefitinib and docetaxel in unselected pretreated patients showed equivalent survival with better tolerability and quality of life. In addition, a Phase III study (WJTOG0203) evaluating gefitinib as sequential therapy after platinum-doublet chemotherapy showed the improved progression-free survival time. Furthermore, a large-scale randomized study (IRESSA Pan-Asia study [IPASS]) comparing gefitinib monotherapy with carboplatin/paclitaxel for previously untreated patients with adenocarcinoma who were never- or light-smokers showed an improved progression-free survival time in the gefitinib arm. A smaller Phase III study of pretreated Japanese patients (V-15-32) also demonstrated no difference in overall survival compared with docetaxel, with a statistically greater overall response rate. Somatic mutations in the EGFR gene, the target of gefitinib, were associated with dramatic and durable regressions in patients with NSCLC. Currently, investigators are trying to determine the optimal approach to select patients for treatment with gefitinib. This article aims to briefly summarize the profile of gefitinib, EGFR mutations, landmark trials with gefitinib and, also, ongoing trials that may herald an era of individualized therapy in at least some NSCLC patients.

The role of the epidermal growth factor receptor tyrosine kinase inhibitors as therapy for advanced, metastatic, and recurrent non-small-cell lung cancer: a Canadian national consensus statement

PURPOSE

To provide consensus recommendations on the use of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIS) in patients with advanced or meta-static non-small-cell lung cancer (NSCLC).

METHODS

Using a systematic literature search, phase II trials, randomized phase III trials, and meta-analyses were identified for inclusion.

RESULTS

A total of forty-six trials were included. Clear evidence is available that EGFR-TKIS should not be administered concurrently with platinum-based chemotherapy as first-line therapy in advanced or metastatic nsclc. Evidence is currently insufficient to recommend single-agent EGFR-TKIS as first-line therapy either in unselected populations or in populations selected on the basis of molecular or clinical characteristics. Following failure of platinum-based chemotherapy, the evidence suggests that second-line EGFR-TKIS or second-line chemotherapy result in similar survival. Quality of life and symptom improvement for patients treated with an EGFR-TKI appear better than they do for patients treated with second-line docetaxel. Sequence of therapy may not appear to be important, but if survival is the outcome of interest, the goal should be to optimize the number of patients receiving three lines of therapy. Based on available data, molecular markers and clinical characteristics do not appear to be predictive of a differential survival benefit from an EGFR-TKI and therefore those factors should not be used to select patients for EGFR-TKI therapy.

CONCLUSIONS

The EGFR-TKIS represent an additional therapy in the treatment of advanced or metastatic NSCLC. The results of ongoing clinical trials may define the optimal role for these agents and the effectiveness of combinations of these agents with other targeted agents.

Selective targeting of the tumour vasculature

Selective targeting of the tumour vasculature in the treatment of solid organ malignancies is an alternative to conventional chemotherapy treatment. As the tumour progressively increases in size, angiogenesis or the formation of new vasculature is essential to maintain the tumour's continual growth and survival. Therefore disrupting this angiogenic process or targeting the neovasculature can potentially hinder or prevent further tumour expansion. Many anti angiogenic agents have been investigated with many currently in clinical trials and exhibiting varied results. Vascular disrupting agents such as the Combretastatins and OXi 4503 have shown promising preclinical results and are currently being examined in clinical trials.

Overview of gefitinib in non-small cell lung cancer: an Asian perspective

Clinical experience with the EGFR-TKI gefitinib in Asian patients with NSCLC will be reviewed, both in patients who have previously failed chemotherapy and in the first-line setting (gefitinib is currently not licensed for first-line treatment). Tolerability and specific adverse events in patients of Asian origin will be discussed. Differing objective response rates between patients of Asian and non-Asian origin when treated with gefitinib (and standard cytotoxics) will also be discussed along with EGFR mutations and drug resistance. Reports of Phase II/III clinical experience with gefitinib 250 mg/day in Asia were identified by searching in Medline and ASCO databases for publications between 1993 and 2008. Defined search criteria included (gefitinib OR Iressa OR ZD1839) AND NSCLC AND (Asia OR Japan OR China OR Taiwan OR Korea) or 'Clinical trial' type, with additional searches, including AND 'interstitial lung disease (ILD)' or 'EGFR mutation'. Numerous Phase II/III trials including patients of Asian origin with previously treated advanced NSCLC report a consistent clinical benefit of gefitinib. Gefitinib is generally well tolerated by patients with NSCLC although the incidence of ILD in Japanese patients must be noted. Studies analyzing EGFR mutations indicate that these mutations occur at a much higher rate in patients of Asian origin than in non-Asian patients. Data from several studies indicate that EGFR mutation-positive patients of Asian origin have better efficacy outcomes with first-line gefitinib when compared with those who are EGFR mutation-negative. Research is ongoing to evaluate the role of tailoring patients' treatment according to their genetic phenotype.

A population-based study of gefitinib in patients with non-small cell lung cancer

Survival data for non-small cell lung cancer is typically reported from clinical trials that include patients fit enough to meet treatment criteria. The denominator of all patients from which the gefitinib-treated population is derived has rarely been reported and the impact of gefitinib on population-based outcomes is difficult to measure. We have retrospectively reviewed data of 626 patients who received gefitinib in Ibaraki Prefecture (with a population of 3 million) in Japan from July 2002 until September 2007. Overall response rate was found to 30.8%, and the median survival time was 8.0 months (95% confidence interval: 7.0-9.0 months). Female gender, good PS, and adenocarcinoma were significantly associated with prolonged survival. Adverse events were generally mild and were mostly skin reactions and diarrhea. Our population-based study has generated similar results to those previously reported in published clinical trials, which had restrictive criteria for eligible patients.

Specific EGFR mutations predict treatment outcome of stage IIIB/IV patients with chemotherapy-naive non-small-cell lung cancer receiving first-line gefitinib monotherapy

PURPOSE

To explore predictive factors for time to treatment failure (TTF) in chemotherapy-naive non-small-cell lung cancer (NSCLC) patients receiving gefitinib treatment.

PATIENTS AND METHODS

We designed a phase II study to test gefitinib antitumor efficacy in advanced-stage, chemotherapy-naive NSCLC patients. Patients were treated with gefitinib 250 mg/d. Tumor assessments were performed every 2 months. Responding or stable patients were treated until progression or unacceptable toxicity. All scans were reviewed independently. EGFR exons 18-21 sequence, K-ras exon 2 sequence, and MET gene copy numbers were examined in available samples. Clinical or molecular predictors of TTF were examined by multivariate analysis.

RESULTS

One hundred six patients were enrolled. Ninety patients had tumor samples for biomarker tests. Overall response rate was 50.9% (95% CI, 41.4% to 60.4%). Median TTF was 5.5 months, and median overall survival (OS) was 22.4 months. The response rate and median TTF of the patients with exon 19 deletion (n = 20) were 95.0% and 8.9 months, for exon 21 L858R mutation (n = 23) were 73.9% and 9.1 month, and for other types of EGFR mutations (N = 12) were 16.7% and 2.3 months, respectively. In multivariate analysis, the presence of EGFR deletion exon 19 or L858R EGFR mutations in adenocarcinoma patients predicted longer TTF. High copy number of MET seemed to correlate with shorter TTF in patients with gefitinib-sensitive activating EGFR mutations.

CONCLUSION

In this prospective study, EGFR exon 19 deletion or L858R mutations in adenocarcinoma were the best predictors for longer TTF in stage IIIB/IV chemotherapy-naive NSCLC patients receiving first-line gefitinib monotherapy.

Targeting the epidermal growth factor receptor in non-small-cell lung cancer: who, which, when, and how?

Aberrations in the signaling cascade of the epidermal growth factor receptor are common to several solid tumors. Compounds aimed at targeting this pathway have been approved for use by the US Food and Drug Administration for lung, head and neck, pancreas, and colorectal carcinomas. Unfortunately, only the minority of patients treated with this class of agents will have responses or improvements in survival. This article reviews the data on agents that exploit tumor dependency on epidermal growth factor receptor cascade and describes the knowledge on how to discern the appropriate patient population for receiving these agents.

Pharmacogenomics of lung cancer: with a view to address EGFR-targeted therapies

Epidermal growth factor receptor (EGFR)-targeted therapies have demonstrated variable success in treating individuals with non-small-cell lung cancer. Understanding the molecular mechanisms of response and resistance to this class of treatment has led to patient selection strategies that may improve outcomes. The second generation of EGFR-targeted therapies is now under clinical evaluation and may prove to be successful at circumventing a portion of primary or acquired resistance to first-generation tyrosine kinase inhibitors. These principles are generally applicable to the field of targeted therapy and predictive pharmacogenomics.

Lung cancer: Future directions

Increasingly, basic research is being translated into clinical benefits for patients. Recent studies have shed more light on the clinical use of targeted therapies such as tyrosine kinase and angiogenesis inhibitors, and predictive factors for their clinical benefit and their role in different clinical settings are now being elucidated. New insights into the basic biology of lung cancer hold translational promise in risk assessment, early detection, molecular staging, treatment response prediction and novel therapies. New targeted agents directed at apoptotic and developmental pathways have the potential to exploit newly discovered vulnerabilities in the basic machinery of cancer. In addition, exploration of the cancer stem cell phenomenon in lung cancer may generate new approaches to prevent recurrence in surgically respectable lung cancer, and for the long-term control of extensive disease. Molecular profiling may also allow for highly individualized prognostic, predictive and therapeutic treatment plans tailored for each patient based on the molecular diagnostic profile of their tumour. Advances in genetic susceptibility, early detection and individualized therapy based on each tumour's unique biological properties all hold promise for the future management of lung cancer.

Phase II prospective study of the efficacy of gefitinib for the treatment of stage III/IV non-small cell lung cancer with EGFR mutations, irrespective of previous chemotherapy

PURPOSE

Mutations in the epidermal growth factor receptor (EGFR) gene are associated with increased sensitivity of non-small cell lung cancer (NSCLC) to gefitinib, an EGFR tyrosine kinase inhibitor. The objective of this study was to prospectively evaluate the efficacy of gefitinib in patients with stage III/IV NSCLC whose tumors carried EGFR mutations, irrespective of previous chemotherapy.

EXPERIMENTAL DESIGN

Genomic DNA was extracted from tumor specimens and EGFR mutations in exons 19 and 21 analyzed by direct sequencing. Patients with stage III/IV NSCLC whose tumors had the EGFR mutations received gefitinib (250 mg/day orally). Response, toxicity and survival data were assessed.

RESULT

From November 2004-May 2006, 21 patients with EGFR mutations received gefitinib (median age: 59 years; 17 females; 19 non-smokers; all had adenocarcinomas). Two patients discontinued gefitinib and withdrew from the study 3 weeks after gefitinib initiation (interstitial pneumonitis, 1 patient; facial acne, 1 patient). Of 19 patients, 3 achieved complete response, 13 exhibited partial response and 3 had stable disease. Response and disease control rates were 76% (95% confidence interval [CI] 53-92) and 90% (95% CI 70-99), respectively. The most common adverse event was skin toxicity (67%); however, no grade 4 skin toxicities were seen. Ten patients relapsed and three died at a median follow-up period of 12.6 months (range 5.6-23.8 months); median progression-free survival was 12.9 months.

CONCLUSION

Analysis of tumor EGFR mutations in patients with NSCLC could be used to identify patients suitable for treatment with gefitinib to obtain optimum response and disease control rates.

Epidermal growth factor receptor mutations in lung cancer

The development and clinical application of inhibitors that target the epidermal growth factor receptor (EGFR) provide important insights for new lung cancer therapies, as well as for the broader field of targeted cancer therapies. We review the results of genetic, biochemical and clinical studies focused on somatic mutations of EGFR that are associated with the phenomenon of oncogene addiction, describing 'oncogenic shock' as a mechanistic explanation for the apoptosis that follows the acute treatment of susceptible cells with kinase inhibitors. Understanding the genetic heterogeneity of epithelial tumours and devising strategies to circumvent their rapid acquisition of resistance to targeted kinase inhibitors are essential to the successful use of targeted therapies in common epithelial cancers.

Gefitinib as front-line treatment in Chinese patients with advanced non-small-cell lung cancer

PURPOSE

This phase II single arm, open label study was designed to evaluate the efficacy and toxicity of oral gefitinib (250mg) daily in previously untreated patients with advanced non-small-cell lung cancer (NSCLC).

METHODS

Eligible patients had stage IIIB or IV NSCLC with adequate organ functions, and were chemonaïve. All eligible patients were treated with oral administration of 250mg of gefitinib until intolerable toxicity, disease progression or death occurred. Responses were assessed after every 8 weeks of therapy.

RESULTS

For a total of 53 patients, the objective response rate (ORR) was 32.1% and overall disease control rate (DCR) was 52.8%. Median overall and progression-free survivals (PFS) were 9.4 (95% CI, 8.8-13.3) and 3.2 months (95% CI, 1.1-5.2) months, and 1-year survival rate was 41.5%. Patients with adenocarcinoma (n=35) had a higher response rate. Adenocarcinoma, female gender (n=24), and response to gefitinib were predictive factors for better survival. The most commonly seen adverse events (AEs) were skin toxicity (54.7%), diarrhea (43.4%) and nail change (16.9%). Most AEs were mild to moderate and considered manageable. Drug-related interstitial pneumonia was clinically diagnosed in four cases (7.5%).

CONCLUSIONS

Oral gefitinib, as compared to conventional chemotherapy, has comparable effect but less toxicity as a first-line treatment in Chinese patients who have advanced NSCLC, especially in those with adenocarcinoma histology. A further phase III prospective study comparing gefitinib to standard chemotherapy to define the efficacy of gefitinib is appropriate in advanced NSCLC patients.