Barbara Klughammer

Erlotinib as maintenance treatment in advanced non-small-cell lung cancer: a multicentre, randomised, placebo-controlled phase 3 study

BACKGROUND First-line chemotherapy for advanced non-small-cell lung cancer (NSCLC) is usually limited to four to six cycles. Maintenance therapy can delay progression and prolong survival. The oral epidermal growth factor receptor (EGFR) tyrosine-kinase inhibitor erlotinib has proven efficacy and tolerability in second-line NSCLC. We designed the phase 3, placebo-controlled Sequential Tarceva in Unresectable NSCLC (SATURN; BO18192) study to assess use of erlotinib as maintenance therapy in patients with non-progressive disease following first-line platinum-doublet chemotherapy. METHODS Between December, 2005, and May, 2008, 1949 patients were included in the run-in phase (four cycles of platinum-based chemotherapy). At the end of the run-in phase, 889 patients who did not have progressive disease were entered into the main study, and were randomly allocated using a 1:1 adaptive randomisation method through a third-party interactive voice response system to receive erlotinib (150 mg/day; n=438) or placebo (n=451) until progression or unacceptable toxicity. Patients were stratified by EGFR immunohistochemistry status, stage, Eastern Cooperative Oncology Group performance status, chemotherapy regimen, smoking history, and region. Co-primary endpoints were progression-free survival (PFS) in all analysable patients irrespective of EGFR status, and PFS in patients whose tumours had EGFR protein overexpression, as determined by immunohistochemistry. This study is registered with www.ClinicalTrials.gov, number NCT00556712. FINDINGS 884 patients were analysable for PFS; 437 in the erlotinib group and 447 in the placebo group. After a median follow-up of 11.4 months for the erlotinib group and 11.5 months for the placebo group, median PFS was significantly longer with erlotinib than with placebo: 12.3 weeks for patients in the erlotinib group versus 11.1 weeks for those in the placebo group (HR 0.71, 95% CI 0.62-0.82; p<0.0001). PFS was also significantly longer in patients with EGFR-positive immunohistochemistry who were treated with erlotinib (n=307) compared with EGFR-positive patients given placebo (n=311; median PFS 12.3 weeks in the erlotinib group vs 11.1 weeks in the placebo group; HR 0.69, 0.58-0.82; p<0.0001). The most common grade 3 or higher adverse events were rash (37 [9%] of 443 patients in the erlotinib group vs none of 445 in the placebo group) and diarrhoea (seven [2%] of 443 patients vs none of 445). Serious adverse events were reported in 47 patients (11%) on erlotinib compared with 34 patients (8%) on placebo. The most common serious adverse event was pneumonia (seven cases [2%] with erlotinib and four [<1%] with placebo). INTERPRETATION Maintenance therapy with erlotinib for patients with NSCLC is well tolerated and significantly prolongs PFS compared with placebo. First-line maintenance with erlotinib could be considered in patients who do not progress after four cycles of chemotherapy. FUNDING F Hoffmann-La Roche Ltd.

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

Purpose: Blood-based circulating-free (cf) tumor DNA may be an alternative to tissue-based EGFR mutation testing in NSCLC. This exploratory analysis compares matched tumor and blood samples from the FASTACT-2 study. Experimental Design: Patients were randomized to receive six cycles of gemcitabine/platinum plus sequential erlotinib or placebo. EGFR mutation testing was performed using the cobas tissue test and the cobas blood test (in development). Blood samples at baseline, cycle 3, and progression were assessed for blood test detection rate, sensitivity, and specificity; concordance with matched tumor analysis (n = 238), and correlation with progression-free survival (PFS) and overall survival (OS). Results: Concordance between tissue and blood tests was 88%, with blood test sensitivity of 75% and a specificity of 96%. Median PFS was 13.1 versus 6.0 months for erlotinib and placebo, respectively, for those with baseline EGFR mut+ cfDNA [HR, 0.22; 95% confidence intervals (CI), 0.14–0.33, P < 0.0001] and 6.2 versus 6.1 months, respectively, for the EGFR mut− cfDNA subgroup (HR, 0.83; 95% CI, 0.65–1.04, P = 0.1076). For patients with EGFR mut+ cfDNA at baseline, median PFS was 7.2 versus 12.0 months for cycle 3 EGFR mut+ cfDNA versus cycle 3 EGFR mut− patients, respectively (HR, 0.32; 95% CI, 0.21–0.48, P < 0.0001); median OS by cycle 3 status was 18.2 and 31.9 months, respectively (HR, 0.51; 95% CI, 0.31–0.84, P = 0.0066). Conclusions: Blood-based EGFR mutation analysis is relatively sensitive and highly specific. Dynamic changes in cfDNA EGFR mutation status relative to baseline may predict clinical outcomes. Clin Cancer Res; 21(14); 3196–203. ©2015 AACR.

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

•  Introduction •  Literature review ‐  Molecular biology of EGFR mutations ‐  Clinical characteristics of NSCLC patients with EGFR mutations ‐  Genetic characteristics of EGFR‐mutated tumours ‐  Prognostic significance of NSCLC with EGFR mutations ‐  How do structural changes in EGFR lead to greater sensitivity to EGFR TKIs? •  Methods ‐  Selection criteria ‐  Search strategy ‐  Data extraction and synthesis ‐  Statistical analysis ‐  Sensitivity analysis •  Results ‐  Study characteristics ‐  PFS analysis ‐  Sensitivity analysis ‐  Publication bias •  Discussion •  Conclusions

A multicentre phase II gene expression profiling study of putative relationships between tumour biomarkers and clinical response with erlotinib in non-small-cell lung cancer

Background: Identification of appropriate markers for predicting clinical benefit with erlotinib in non-small-cell lung cancer (NSCLC) may be able to guide patient selection for treatment. This open-label, multicentre, phase II trial aimed to identify genes with potential use as biomarkers for clinical benefit from erlotinib therapy. Methods: Adults with stage IIIb/IV NSCLC in whom one or more chemotherapy regimen had failed were treated with erlotinib (150 mg/day). Tumour biopsies were analysed using gene expression profiling with Affymetrix GeneChip® microarrays. Differentially expressed genes were verified using quantitative RT–PCR (qRT–PCR). Results: A total of 264 patients were enrolled in the study. Gene expression profiles found no statistically significant differentially expressed genes between patients with and without clinical benefit. In an exploratory analysis in responding versus nonresponding patients, three genes on chromosome 7 were expressed at higher levels in the responding group [epidermal growth factor receptor (EGFR), phosphoserine phosphatase (PSPH) and Rap guanine nucleotide exchange factor 5 (RAPGEF5)]. Independent quantification using qRT–PCR validated the association between EGFR and PSPH overexpression, but not RAPGEF5 overexpression, and clinical outcome. Conclusions: This study supports the use of erlotinib as an alternative to chemotherapy for patients with relapsed advanced NSCLC. Genetic amplification of the EGFR region of chromosome 7 may be associated with response to erlotinib therapy.

Tissue sampling in lung cancer: A review in light of the MERIT experience

Lung cancer continues to present an enormous global burden of morbidity and mortality, despite an increasing therapeutic armamentarium of chemotherapy and targeted agents. Recent research efforts have been directed towards identifying predictors of response to treatment, in order to facilitate the selection of patients likely to obtain the greatest benefit from specific therapeutic interventions, with the ultimate goal of providing customized therapy. A strong scientific basis exists for the use of markers to identify patients who are most likely to respond to biological and targeted therapies, based on characteristics such as tumour genotype and histology. Biomarkers have the potential to aid in patient stratification (risk assessment), treatment-response identification (surrogate markers), or differential diagnosis (identifying individuals who are likely to respond well to specific therapies). Numerous trials have demonstrated correlations between molecular biomarkers and the outcome of treatment with targeted therapies such as epidermal growth factor inhibitor tyrosine-kinase inhibitors in patients with non-small-cell lung cancer (NSCLC). The recently completed MarkER Identification Trial (MERIT) found some evidence of a link between the molecular profile of a tumour and the clinical response to erlotinib in patients with relapsed NSCLC. However, MERIT also highlighted the difficulties in obtaining adequate samples for the various procedures involved in genetic analyses in clinical trials. Routine clinical practice brings its own challenges relating to biopsy techniques and tissue availability and this has implications for the application of molecular analyses in treatment decision-making. Applying the lessons learned from tissue sampling and molecular testing in MERIT and other major NSCLC trials will be essential in paving the way for the routine use of biomarker analyses in clinical practice.

Examining Treatment Outcomes with Erlotinib in Patients with Advanced Non-Small Cell Lung Cancer Whose Tumors Harbor Uncommon EGFR Mutations.

Introduction: Exon 19 deletions and the exon 21 L858R mutation of the epidermal growth factor receptor gene (EGFR) predict activity of EGFR tyrosine kinase inhibitors, including erlotinib; however, the ability of less common EGFR mutations to predict efficacy of erlotinib is unclear. Methods: The efficacy of erlotinib in individual patients with rare EGFR mutations from the MERIT, SATURN, TITAN, TRUST, ATLAS, BeTa, and FASTACT‐2 trials was analyzed and compared with data from the literature. Results: In the patients tested for biomarkers, the frequency of rare mutations identified here ranged from 1.7% (eight of 467) in the SATURN study to 7.4% (27 of 364) in ATLAS. Some rare mutations were associated with greater clinical benefit from EGFR tyrosine kinase inhibitor therapy or improved prognosis independent of treatment, whereas others appeared to have a poorer prognosis. In particular, exon 18 G719 mutations, exon 19 K757R and E746G mutations, the exon 20 S768I mutation, and the exon 21 G836S mutation appeared to confer a good outcome with erlotinib treatment, whereas exon 18 S720I showed a particularly poor outcome. Owing to the small number of patients with each mutation, however, it is difficult to confirm whether these rare mutations do indeed confer sensitivity or resistance to erlotinib. Conclusions: Erlotinib can have different efficacy depending on the specific EGFR mutation. More research is needed to create a central database such as the My Cancer Genome database of rare mutations to definitively confirm whether these mutations are activating, resistant, or neutral.

Evaluation of EGFR protein expression by immunohistochemistry using H-score and the magnification rule: Re-analysis of the SATURN study

INTRODUCTION The phase III SATURN study demonstrated that first-line maintenance erlotinib extended progression-free survival (PFS) and overall survival (OS) versus placebo in patients with advanced non-small cell lung cancer (NSCLC). Analysis of epidermal growth factor receptor (EGFR) expression by immunohistochemistry (IHC) found no significant interaction between EGFR IHC status and PFS (p = 0.63) or OS (p = 0.52). The FLEX study of first-line cetuximab plus chemotherapy demonstrated that EGFR IHC expression was predictive of improved OS with cetuximab when assessed by H-score with a magnification rule. This novel method was used to reassess samples from SATURN. METHODS The H-score method assigned a score of 0-300 to each patient, based on the percentage of cells stained at different intensities viewed at various magnifications. The discriminatory threshold was set at 200, per the FLEX study, and existing samples were re-read and classed as low (H-score < 200) or high (≥200) EGFR expression. PFS and OS were re-analyzed based on these new classifications. RESULTS In the overall and EGFR wild-type populations, erlotinib provided a consistent survival benefit versus placebo. Hazard ratios (HRs) in the overall population were similar between EGFR IHC-positive and -negative patients for median PFS (HR 0.68 [95% confidence interval (CI) 0.53-0.86] and 0.76 [95% CI 0.62-0.93], respectively) and OS (HR 0.80 [95% CI 0.62-1.05] and 0.80 [95% CI 0.64-1.01] for IHC-positive and IHC-negative, respectively). In the EGFR wild-type population, HRs were again similar between EGFR IHC-positive and -negative subpopulations for PFS (HR 0.69 [95% CI 0.51-0.95] and 0.84 [95% CI 0.63-1.12], respectively) and OS (HR 0.78 [95% CI 0.55-1.10] and 0.76 [95% CI 0.55-1.05], respectively). CONCLUSIONS These data suggest that EGFR IHC does not have value as a marker to predict erlotinib benefit in the first-line maintenance setting for advanced NSCLC.

A phase II study of erlotinib in combination with bevacizumab versus chemotherapy plus bevacizumab in the first-line treatment of advanced non-squamous non-small cell lung cancer

BACKGROUND Molecularly targeted agents for non-small cell lung cancer (NSCLC) can provide similar efficacy to chemotherapy without chemotherapy-associated toxicities. Combining two agents with different modes of action could further increase the efficacy of these therapies. The TASK study evaluated the efficacy and safety of the epidermal growth factor receptor tyrosine kinase inhibitor erlotinib in combination with the anti-angiogenic agent bevacizumab as first-line therapy in unselected, advanced non-squamous NSCLC patients. METHODS Patients were recruited from December 2007 to September 2008. Planned sample size was 200 patients, a total of 124 patients were randomized. Patients were randomized using a minimization algorithm 1:1 to receive bevacizumab (iv 15 mg/kg day 1 of each 21-day cycle) plus chemotherapy (gemcitabine/cisplatin or carboplatin/paclitaxel standard doses, 4-6 cycles) (BC arm) or bevacizumab plus erlotinib (p.o. 150 mg/day; BE arm) until disease progression or unacceptable toxicity. The primary endpoint was progression-free survival (PFS). If the hazard ratio (HR) of PFS for BE relative to BC was above 1.25 at the pre-planned interim analysis in favor of BC, the study would be re-evaluated. Secondary endpoints included overall survival, response rate and safety. RESULTS All randomized patients (n = 63 BE; n = 61 BC) were evaluated for the efficacy analyses. At the updated interim analysis, median PFS was 18.4 weeks (95% confidence interval [CI] 17.0-25.1) versus 25.0 weeks (95% CI 20.6-[not reached]) for BE versus BC, respectively (HR for death or disease progression, BE relative to BC, 2.05, p = 0.0183). The incidence of death was 19% for BE treatment compared with 11.5% for BC treatment. The HR for PFS at the updated interim analysis was above 1.25, therefore patients on the BE arm were permitted to change arms or switch to another drug and the study was terminated. Adverse events reported were as expected. CONCLUSIONS The TASK study did not show a benefit in terms of PFS for the combination of erlotinib with bevacizumab in unselected first-line advanced non-squamous NSCLC compared with chemotherapy plus bevacizumab.

Clinical validation of a PCR assay for the detection of EGFR mutations in non-small-cell lung cancer: retrospective testing of specimens from the EURTAC trial.

The EURTAC trial demonstrated that the tyrosine kinase inhibitor (TKI) erlotinib was superior to chemotherapy as first-line therapy for advanced non-small cell lung cancers (NSCLC) that harbor EGFR activating mutations in a predominantly Caucasian population. Based on EURTAC and several Asian trials, anti-EGFR TKIs are standard of care for EGFR mutation-positive NSCLC. We sought to validate a rapid multiplex EGFR mutation assay as a companion diagnostic assay to select patients for this therapy. Samples from the EURTAC trial were prospectively screened for EGFR mutations using a combination of laboratory-developed tests (LDTs), and tested retrospectively with the cobas EGFR mutation test (EGFR PCR test). The EGFR PCR test results were compared to the original LDT results and to Sanger sequencing, using a subset of specimens from patients screened for the trial. Residual tissue was available from 487 (47%) of the 1044 patients screened for the trial. The EGFR PCR test showed high concordance with LDT results with a 96.3% overall agreement. The clinical outcome of patients who were EGFR-mutation detected by the EGFR PCR test was very similar to the entire EURTAC cohort. The concordance between the EGFR PCR test and Sanger sequencing was 90.6%. In 78.9% of the discordant samples, the EGFR PCR test result was confirmed by a sensitive deep sequencing assay. This retrospective study demonstrates the clinical utility of the EGFR PCR test in the accurate selection of patients for anti-EGFR TKI therapy. The EGFR PCR test demonstrated improved performance relative to Sanger sequencing.

Quantitative Chemical Proteomics Profiling Differentiates Erlotinib from Gefitinib in EGFR Wild-Type Non–Small Cell Lung Carcinoma Cell Lines

Although both erlotinib and gefitinib target the EGF receptor (EGFR), erlotinib is effective in patients with EGFR wild-type or mutated tumors, whereas gefitinib is only beneficial for patients with activating mutations. To determine whether these differences in clinical outcomes can be attributed to their respective protein interaction profiles, a label-free, quantitative chemical proteomics study was conducted. Using this method, 24 proteins were highlighted in the binding profiles of erlotinib and gefitinib. Unlike gefinitib, erlotinib displaced the ternary complex formed by integrin-linked kinase (ILK), α-parvin, and PINCH (IPP). The docking of erlotinib in the three-dimensional structure of ILK showed that erlotinib has the ability to bind to the ATP-binding site, whereas gefitinib is unlikely to bind with high affinity. As the IPP complex has been shown to be involved in epithelial-to-mesenchymal transition (EMT) and erlotinib sensitivity has been correlated with EMT status, we used a cellular model of inducible transition and observed that erlotinib prevented EMT in a more efficient way than gefitinib by acting on E-cadherin expression as well as on IPP levels. A retrospective analysis of the MERIT trial indicated that, besides a high level of E-cadherin, a low level of ILK could be linked to clinical benefit with erlotinib. In conclusion, we propose that, in an EGFR wild-type context, erlotinib may have a complementary mode of action by inhibiting IPP complex activities, resulting in the slowing down of the metastatic process of epithelial tumors. Mol Cancer Ther; 12(4); 520–9. ©2013 AACR.