Chong-Jen Yu

MET amplification occurs with or without T790M mutations in EGFR mutant lung tumors with acquired resistance to gefitinib or erlotinib

In human lung adenocarcinomas harboring EGFR mutations, a second-site point mutation that substitutes methionine for threonine at position 790 (T790M) is associated with approximately half of cases of acquired resistance to the EGFR kinase inhibitors, gefitinib and erlotinib. To identify other potential mechanisms that contribute to disease progression, we used array-based comparative genomic hybridization (aCGH) to compare genomic profiles of EGFR mutant tumors from untreated patients with those from patients with acquired resistance. Among three loci demonstrating recurrent copy number alterations (CNAs) specific to the acquired resistance set, one contained the MET proto-oncogene. Collectively, analysis of tumor samples from multiple independent patient cohorts revealed that MET was amplified in tumors from 9 of 43 (21%) patients with acquired resistance but in only two tumors from 62 untreated patients (3%) (P = 0.007, Fishers Exact test). Among 10 resistant tumors from the nine patients with MET amplification, 4 also harbored the EGFRT790M mutation. We also found that an existing EGFR mutant lung adenocarcinoma cell line, NCI-H820, harbors MET amplification in addition to a drug-sensitive EGFR mutation and the T790M change. Growth inhibition studies demonstrate that these cells are resistant to both erlotinib and an irreversible EGFR inhibitor (CL-387,785) but sensitive to a multikinase inhibitor (XL880) with potent activity against MET. Taken together, these data suggest that MET amplification occurs independently of EGFRT790M mutations and that MET may be a clinically relevant therapeutic target for some patients with acquired resistance to gefitinib or erlotinib.

MicroRNA Signature Predicts Survival and Relapse in Lung Cancer

We investigated whether microRNA expression profiles can predict clinical outcome of NSCLC patients. Using real-time RT-PCR, we obtained microRNA expressions in 112 NSCLC patients, which were divided into the training and testing sets. Using Cox regression and risk-score analysis, we identified a five-microRNA signature for the prediction of treatment outcome of NSCLC in the training set. This microRNA signature was validated by the testing set and an independent cohort. Patients with high-risk scores in their microRNA signatures had poor overall and disease-free survivals compared to the low-risk-score patients. This microRNA signature is an independent predictor of the cancer relapse and survival of NSCLC 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.

Lung Cancer with Epidermal Growth Factor Receptor Exon 20 Mutations Is Associated with Poor Gefitinib Treatment Response

Purpose: Clinical reports about responsiveness to gefitinib treatment in patients of non-small cell lung cancer (NSCLC) with mutations in exon 20 of epidermal growth factor receptor (EGFR) are limited. To increase understanding of the influence of exon 20 mutations on NSCLC treatment with gefitinib, we investigated the clinical features of lung cancer in patients with exon 20 mutations and analyzed the gefitinib treatment response. Experimental Design: We surveyed the clinical data and mutational studies of NSCLC patients with EGFR exon 20 mutations in the National Taiwan University Hospital and reviewed the literature reports about EGFR exon 20 mutations and the gefitinib treatment response. Results: Twenty-three patients with mutations in exon 20 were identified. Nine (39%) had coexisting mutations in EGFR exons other than exon 20. Sixteen patients received gefitinib treatment, and a response was noted in 4 patients. The gefitinib response rate of NSCLC with exon 20 mutations was 25%, far lower than those with deletions in exon 19 and L858R mutations. Interestingly, different exon 20 mutations and coexisting mutations seemed to have a different influence on gefitinib response. Conclusions: EGFR exon 20 mutations of NSCLC patients result in poorer responsiveness to gefitinib treatment, but variability exists between different individuals.

Vascular Endothelial Growth Factor 189 mRNA Isoform Expression Specifically Correlates With Tumor Angiogenesis, Patient Survival, and Postoperative Relapse in Non–Small-Cell Lung Cancer

PURPOSE The purpose of this study was to evaluate the correlation between the expression of four different vascular endothelial growth factor (VEGF) mRNA isoforms (VEGF121, VEGF165, VEGF 189, and VEGF206) and the clinicopathologic characteristics, tumor angiogenesis, and outcome of patients with non-small-cell lung cancer. PATIENTS AND METHODS We examined the expression of four different VEGF mRNA isoforms in 57 non-small-cell lung cancers using reverse transcriptase polymerase chain reaction and the tumor angiogenesis using immunohistochemical staining. RESULTS All 57 lung cancer samples expressed the VEGF121, VEGF165, and VEGF189 mRNA isoforms, and three expressed the VEGF206 mRNA isoform. A high tumoral VEGF189 mRNA isoform expression ratio was associated with a high intratumoral microvessel count (P = .013), short survival (< 24 months; P = .001), and early postoperative relapse (< 12 months; P = .001). Survival and postoperative relapse time were significantly shorter in patients with a high compared with a low tumor VEGF189 mRNA isoform expression ratio (P = .0001 and P = .0086, respectively, log-rank test). In contrast, the VEGF165 and VEGF 206 mRNA isoform expression ratios showed no statistical correlation with tumor angiogenesis, postoperative relapse time, or survival. A high VEGF121 mRNA isoform expression ratio was associated with short survival (< 24 months) and early relapse (< 12 months). Multivariate analysis showed that VEGF 189 mRNA isoform expression, microvessel count, and nodal status were the most important independent prognostic factors for patient survival and postoperation recurrence. CONCLUSION The VEGF189 mRNA isoform expression ratio shows a greater correlation with tumor angiogenesis, postoperative relapse time, and survival than do the expression ratios for the VEGF121, VEGF165, and VEGF206 mRNA isoforms and can be used as a prognostic indicator for patients with non-small-cell lung cancers.

Effectiveness of Tyrosine Kinase Inhibitors on “Uncommon” Epidermal Growth Factor Receptor Mutations of Unknown Clinical Significance in Non–Small Cell Lung Cancer

Purpose: Clinical features of epidermal growth factor receptor (EGFR) mutations, L858R, deletions in exon 19, T790M, and insertions in exon 20, in non–small cell lung cancer (NSCLC) are well known. The clinical significance of other uncommon EGFR mutations, such as their association with the effectiveness of EGFR tyrosine kinase inhibitors (TKI), is not well understood. This study aimed to improve the understanding of these uncommon EGFR mutations of unknown clinical significance. Patients and Methods: Specimens from 1,261 patients were tested for EGFR mutations. We surveyed the clinical data and the effectiveness of gefitinib and erlotinib in NSCLC patients with uncommon EGFR mutations. Results: Of the 1,261 patients, 627 (49.8%) had EGFR mutations. This included 258 patients with deletions in exon 19, 260 patients with L858R, 25 patients with insertions or duplications in exon 20, 6 patients with de novo T790M, and 78 (12.4%) patients with uncommon mutations. Of the 78 patients, 62 received either gefitinib or erlotinib treatment. The response rate of TKIs treatment was 48.4%, and the median progression-free survival (PFS) was 5.0 months. Mutations on G719 and L861 composed a major part (28 of 62) of uncommon mutations, and were associated with a favorable effectiveness of EGFR TKIs (response rate, 57.1%; median PFS, 6.0 months). Mutations other than G719 and L861 led to a worse response to EGFR TKIs (response rate, 20.0%; median PFS, 1.6 months). Conclusions: Uncommon EGFR mutations constituted a distinct part of the whole group of EGFR mutations. Their composition was heterogeneous, and their associations with EGFR TKIs differed. Clin Cancer Res; 17(11); 3812–21. ©2011 AACR.

Randomized, Placebo-Controlled, Phase II Study of Sequential Erlotinib and Chemotherapy As First-Line Treatment for Advanced Non–Small-Cell Lung Cancer

PURPOSE This study investigated whether sequential administration of erlotinib and chemotherapy improves clinical outcomes versus chemotherapy alone in unselected, chemotherapy-naïve patients with advanced non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS Previously untreated patients (n = 154) with stage IIIB or IV NSCLC and Eastern Cooperative Oncology Group performance status of 0 or 1 were randomly assigned to receive erlotinib (150 mg/d) or placebo on days 15 to 28 of a 4-week cycle that included gemcitabine (1,250 mg/m(2) days 1 and 8) and either cisplatin (75 mg/m(2) day 1) or carboplatin (5 x area under the serum concentration-time curve, day 1). The primary end point was nonprogression rate (NPR) at 8 weeks. Secondary end points included tumor response rate, NPR at 16 weeks, duration of response, progression-free survival (PFS), overall survival (OS), and safety. RESULTS The NPR at 8 weeks was 80.3% in the gemcitabine plus cisplatin or carboplatin (GC)-erlotinib arm (n = 76) and 76.9% in the GC-placebo arm (n = 78). At 16 weeks, the NPR was 64.5% for GC-erlotinib versus 53.8% for GC-placebo. The response rate was 35.5% for GC-erlotinib versus 24.4% for GC-placebo. PFS was significantly longer with GC-erlotinib than with GC-placebo (adjusted hazard ratio, 0.47; log-rank P = .0002; median, 29.4 v 23.4 weeks); this benefit was consistent across all clinical subgroups. There was no significant difference in OS. The addition of erlotinib to chemotherapy was well tolerated, with no increase in hematologic toxicity, and no treatment-related interstitial lung disease. CONCLUSION Sequential administration of erlotinib following gemcitabine/platinum chemotherapy led to a significant improvement in PFS. This treatment approach warrants further investigation in a phase III study.

Intercalated combination of chemotherapy and erlotinib for patients with advanced stage non-small-cell lung cancer (FASTACT-2): a randomised, double-blind trial

BACKGROUND The results of FASTACT, a randomised, placebo-controlled, phase 2 study, showed that intercalated chemotherapy and erlotinib significantly prolonged progression-free survival (PFS) in patients with advanced non-small-cell lung cancer. We undertook FASTACT-2, a phase 3 study in a similar patient population. METHODS In this phase 3 trial, patients with untreated stage IIIB/IV non-small-cell lung cancer were randomly assigned in a 1:1 ratio by use of an interactive internet response system with minimisation algorithm (stratified by disease stage, tumour histology, smoking status, and chemotherapy regimen) to receive six cycles of gemcitabine (1250 mg/m(2) on days 1 and 8, intravenously) plus platinum (carboplatin 5 × area under the curve or cisplatin 75 mg/m(2) on day 1, intravenously) with intercalated erlotinib (150 mg/day on days 15-28, orally; chemotherapy plus erlotinib) or placebo orally (chemotherapy plus placebo) every 4 weeks. With the exception of an independent group responsible for monitoring data and safety monitoring board, everyone outside the interactive internet response system company was masked to treatment allocation. Patients continued to receive erlotinib or placebo until progression or unacceptable toxicity or death, and all patients in the placebo group were offered second-line erlotinib at the time of progression. The primary endpoint was PFS in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, number NCT00883779. FINDINGS From April 29, 2009, to Sept 9, 2010, 451 patients were randomly assigned to chemotherapy plus erlotinib (n=226) or chemotherapy plus placebo (n=225). PFS was significantly prolonged with chemotherapy plus erlotinib versus chemotherapy plus placebo (median PFS 7·6 months [95% CI 7·2-8·3], vs 6·0 months [5·6-7·1], hazard ratio [HR] 0·57 [0·47-0·69]; p<0·0001). Median overall survival for patients in the chemotherapy plus erlotinib and chemotherapy plus placebo groups was 18·3 months (16·3-20·8) and 15·2 months (12·7-17·5), respectively (HR 0·79 [0·64-0·99]; p=0·0420). Treatment benefit was noted only in patients with an activating EGFR gene mutation (median PFS 16·8 months [12·9-20·4] vs 6·9 months [5·3-7·6], HR 0·25 [0·16-0·39]; p<0·0001; median overall survival 31·4 months [22·2-undefined], vs 20·6 months [14·2-26·9], HR 0·48 [0·27-0·84]; p=0·0092). Serious adverse events were reported by 76 (34%) of 222 patients in the chemotherapy plus placebo group and 69 (31%) of 226 in the chemotherapy plus erlotinib group. The most common grade 3 or greater adverse events were neutropenia (65 [29%] patients and 55 [25%], respectively), thrombocytopenia (32 [14%] and 31 [14%], respectively), and anaemia (26 [12%] and 21 [9%], respectively). INTERPRETATION Intercalated chemotherapy and erlotinib is a viable first-line option for patients with non-small-cell lung cancer with EGFR mutation-positive disease or selected patients with unknown EGFR mutation status. FUNDING F Hoffmann-La Roche.

Sialylation and fucosylation of epidermal growth factor receptor suppress its dimerization and activation in lung cancer cells

Protein glycosylation is an important posttranslational process, which regulates protein folding and functional expression. Studies have shown that abnormal glycosylation in tumor cells affects cancer progression and malignancy. In the current study, we have identified sialylated proteins using an alkynyl sugar probe in two different lung cancer cell lines, CL1-0 and CL1-5 with distinct invasiveness derived from the same parental cell line. Among the identified sialylated proteins, epidermal growth factor receptor (EGFR) was chosen to understand the effect of sialylation on its function. We have determined the differences in glycan sequences of EGFR in both cells and observed higher sialylation and fucosylation of EGFR in CL1-5 than in CL1-0. Further study suggested that overexpression of sialyltransferases in CL1-5 and α1,3-fucosyltransferases (FUT4 or FUT6) in CL1-5 and A549 cells would suppress EGFR dimerization and phosphorylation upon EGF treatment, as compared to the control and CL1-0 cells. Such modulating effects on EGFR dimerization were further confirmed by sialidase or fucosidase treatment. Thus, increasing sialylation and fucosylation could attenuate EGFR-mediated invasion of lung cancer cells. However, incorporation of the core fucose by α1,6-fucosylatransferase (FUT8) would promote EGFR dimerization and phosphorylation.

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

BACKGROUND Most patients with non-small-cell lung cancer tumours that have EGFR mutations have deletion mutations in exon 19 or the Leu858Arg point mutation in exon 21, or both (ie, common mutations). However, a subset of patients (10%) with mutations in EGFR have tumours that harbour uncommon mutations. There is a paucity of data regarding the sensitivity of these tumours to EGFR inhibitors. Here we present data for the activity of afatinib in patients with advanced non-small-cell lung cancer that have tumours harbouring uncommon EGFR mutations. METHODS In this post-hoc analysis, we used prospectively collected data from tyrosine kinase inhibitor-naive patients with EGFR mutation-positive advanced (stage IIIb-IV) lung adenocarcinomas who were given afatinib in a single group phase 2 trial (LUX-Lung 2), and randomised phase 3 trials (LUX-Lung 3 and LUX-Lung 6). Analyses were done in the intention-to-treat population, including all randomly assigned patients with uncommon EGFR mutations. The type of EGFR mutation (exon 19 deletion [del19], Leu858Arg point mutation in exon 21, or other) and ethnic origin (LUX-Lung 3 only; Asian vs non-Asian) were pre-specified stratification factors in the randomised trials. We categorised all uncommon mutations as: point mutations or duplications in exons 18-21 (group 1); de-novo Thr790Met mutations in exon 20 alone or in combination with other mutations (group 2); or exon 20 insertions (group 3). We also assessed outcomes in patients with the most frequent uncommon mutations, Gly719Xaa, Leu861Gln, and Ser768Ile, alone or in combination with other mutations. Response was established by independent radiological review. These trials are registered with ClinicalTrials.gov, numbers NCT00525148, NCT00949650, and NCT01121393. FINDINGS Of 600 patients given afatinib across the three trials, 75 (12%) patients had uncommon EGFR mutations (38 in group 1, 14 in group 2, 23 in group 3). 27 (71·1%, 95% CI 54·1-84·6) patients in group 1 had objective responses, as did two (14·3%, 1·8-42·8) in group 2 and two (8·7%, 1·1-28·0) in group 3. Median progression-free survival was 10·7 months (95% CI 5·6-14·7) in group 1, 2·9 months (1·2-8·3) in group 2; and 2·7 months (1·8-4·2) in group 3. Median overall survival was 19·4 months (95% CI 16·4-26·9) in group 1, 14·9 months (8·1-24·9) in group 2, and 9·2 months (4·1-14·2) in group 3. For the most frequent uncommon mutations, 14 (77·8%, 95% CI 52·4-93·6) patients with Gly719Xaa had an objective response, as did nine (56·3%, 29·9-80·2) with Leu861Gln, and eight (100·0%, 63·1-100·0) with Ser768Ile. INTERPRETATION Afatinib was active in non-small-cell lung cancer tumours that harboured certain types of uncommon EGFR mutations, especially Gly719Xaa, Leu861Gln, and Ser768Ile, but less active in other mutations types. Clinical benefit was lower in patients with de-novo Thr790Met and exon 20 insertion mutations. These data could help inform clinical decisions for patients with non-small-cell lung cancer harbouring uncommon EGFR mutations. FUNDING Boehringer Ingelheim.