Ceritinib versus chemotherapy in patients with ALK-rearranged non-small-cell lung cancer previously given chemotherapy and crizotinib (ASCEND-5): a randomised, controlled, open-label, phase 3 trial

BACKGROUND

Ceritinib is a next-generation anaplastic lymphoma kinase (ALK) inhibitor, which has shown robust anti-tumour efficacy, along with intracranial activity, in patients with ALK-rearranged non-small-cell lung cancer. In phase 1 and 2 studies, ceritinib has been shown to be highly active in both ALK inhibitor-naive and ALK inhibitor-pretreated patients who had progressed after chemotherapy (mostly multiple lines). In this study, we compared the efficacy and safety of ceritinib versus single-agent chemotherapy in patients with advanced ALK-rearranged non-small-cell lung cancer who had previously progressed following crizotinib and platinum-based doublet chemotherapy.

METHODS

In this randomised, controlled, open-label, phase 3 trial, we recruited patients aged at least 18 years with ALK-rearranged stage IIIB or IV non-small-cell lung cancer (with at least one measurable lesion) who had received previous chemotherapy (one or two lines, including a platinum doublet) and crizotinib and had subsequent disease progression, from 99 centres across 20 countries. Other inclusion criteria were a WHO performance status of 0-2, adequate organ function and laboratory test results, a life expectancy of at least 12 weeks, and having recovered from previous anticancer treatment-related toxicities. We randomly allocated patients (1:1; with blocking [block size of four]; stratified by WHO performance status [0 vs 1-2] and presence or absence of brain metastases) to oral ceritinib 750 mg per day fasted (in 21 day treatment cycles) or chemotherapy (intravenous pemetrexed 500 mg/m² or docetaxel 75 mg/m² [investigator choice], every 21 days). Patients who discontinued chemotherapy because of progressive disease could cross over to the ceritinib group. The primary endpoint was progression-free survival, assessed by a masked independent review committee using Response Evaluation Criteria in Solid Tumors 1.1 in the intention-to-treat population, assessed every 6 weeks until month 18 and every 9 weeks thereafter. This trial is registered with ClinicalTrials.gov, number NCT01828112, and is ongoing but no longer recruiting patients.

FINDINGS

Between June 28, 2013, and Nov 2, 2015, we randomly allocated 231 patients; 115 (50%) to ceritinib and 116 (50%) to chemotherapy (40 [34%] to pemetrexed, 73 [63%] to docetaxel, and three [3%] discontinued before receiving treatment). Median follow-up was 16·5 months (IQR 11·5-21·4). Ceritinib showed a significant improvement in median progression-free survival compared with chemotherapy (5·4 months [95% CI 4·1-6·9] for ceritinib vs 1·6 months [1·4-2·8] for chemotherapy; hazard ratio 0·49 [0·36-0·67]; p<0·0001). Serious adverse events were reported in 49 (43%) of 115 patients in the ceritinib group and 36 (32%) of 113 in the chemotherapy group. Treatment-related serious adverse events were similar between groups (13 [11%] in the ceritinib group vs 12 [11%] in the chemotherapy group). The most frequent grade 3-4 adverse events in the ceritinib group were increased alanine aminotransferase concentration (24 [21%] of 115 vs two [2%] of 113 in the chemotherapy group), increased γ glutamyltransferase concentration (24 [21%] vs one [1%]), and increased aspartate aminotransferase concentration (16 [14%] vs one [1%] in the chemotherapy group). Six (5%) of 115 patients in the ceritinib group discontinued because of adverse events compared with eight (7%) of 116 in the chemotherapy group. 15 (13%) of 115 patients in the ceritinib group and five (4%) of 113 in the chemotherapy group died during the treatment period (from the day of the first dose of study treatment to 30 days after the final dose). 13 (87%) of the 15 patients who died in the ceritinib group died because of disease progression and two (13%) died because of an adverse event (one [7%] cerebrovascular accident and one [7%] respiratory failure); neither of these deaths were considered by the investigator to be treatment related. The five (4%) deaths in the chemotherapy group were all due to disease progression.

INTERPRETATION

These findings show that patients derive significant clinical benefit from a more potent ALK inhibitor after failure of crizotinib, and establish ceritinib as a more efficacious treatment option compared with chemotherapy in this patient population.

FUNDING

Novartis Pharmaceuticals Corporation.

Baseline frequency of brain metastases and outcomes with multikinase inhibitor therapy in patients with RET-rearranged lung cancers

9069

Background: In phase 2 trials, multikinase inhibitors with activity against RET are active in a subset of patients (pts) with RET-rearranged lung cancers (response rate of 28%, phase 2 study of cabozantinib; Drilon et al Lancet Oncol 2016). Data on the incidence of brain metastases and outcomes with multikinase inhibitor therapy in pts with intracranial disease have not previously been reported. Methods: The frequency of brain metastases at diagnosis of metastatic disease was evaluated in pts accrued to a global registry of RET-rearranged lung cancer pts identified by a multicenter network of thoracic oncologists (Gautschi et al JCO 2017). A proportion of pts were treated with 9 multikinase inhibitors including cabozantinib, vandetanib, lenvatinib, alectinib, and ponatinib. On a prospective phase 2 trial (NCT01639508), patients with asymptomatic brain metastases were eligible. Intracranial response to cabozantinib (RECIST v1.1) was evaluated in an exploratory fashion. Results: 114 registry pts with RET-rearranged lung cancers had metastatic disease at diagnosis. Baseline brain metastases were identified in 27% (95%CI 18-34%, n = 20/75) of pts with available information. No differences (p > 0.05) in age, smoking history, or upstream fusion partner ( KIF5B100% vs 84%, with and without brain metastases, p = 0.53) were noted. In 37 pts treated with multikinase inhibitors with activity against RET, there were no significant differences in median PFS (2.1 vs 2.1 months, p = 0.41) or median OS (3.9 vs 7.0 months, p = 0.10) in pts with (n = 10) and without (n = 27) brain metastases. On a phase 2 trial of cabozantinib, baseline untreated brain metastases were present in 5 pts. Intracranial disease control (stable disease; -34% and -1% in 2 pts with measurable disease) was achieved in 4 of 4 pts with measurable or evaluable intracranial disease with time to treatment discontinuation ranging from 2.4 months to 2.9 years. Conclusions: Brain metastases are present in a substantial proportion of RET-rearranged lung cancer pts. Intracranial disease control can be achieved in select pts by a multikinase inhibitor. Novel RET-directed targeted therapy strategies should address intracranial disease. Clinical trial information: NCT01639508.

Molecular panel sequencing of pre-treatment samples to reveal mechanisms of innate resistance to 3rd generation EGFR TKI treatment in T790M-positive NSCLC patients

9041

Background: Resistance to early generation epidermal growth factor receptor ( EGFR) tyrosine kinase inhibitors (TKI) inevitably develops in EGFR-mutant lung cancer. The secondary EGFR p.T790M mutation is the driving factor in 60% of cases and 3rd generation EGFR TKIs have been developed to overcome T790M-mediated resistance. However, besides T790M other genetic aberrations such as amplifications of MET may contribute to resistance to EGFR inhibition in the same patient. We here report on the systematic analysis of co-occurring genetic aberrations that may influence response to 3rd generation EGFR TKIs. Methods: Thirty-six patients were treated with 3rd generation EGFR TKIs in the setting of acquired resistance to EGFR inhibition in cancer centers in Germany and Switzerland. Pre-treatment samples were analyzed for co-occurring genetic aberrations in a subset of resistance-related genes including MET, HER2, RAS-gene family, PIK3CA, CTNNB1 and PTEN using next-generation sequencing and fluorescence in-situ hybridization assays. We investigated the association between clinical, epidemiological and molecular data and response to treatment (RECIST 1.1). Results: Co-occurring genetic aberrations were found in 68% of the pre-treatment samples where both, analyses by sequencing and FISH were feasible (N = 25). Efficacy of 3rd generation EGFR TKIs significantly dropped in the presence of high-level MET amplification as compared to wild-type MET (ORR, 0.0%; 95% CI, 0.0-60.4 vs. 70.0%; 95% CI, 45.7-87.2; p = 0.02; median PFS, 1.0 month; 95% CI, 0.37-1.72 months vs. 8.2 months; 95% CI, 1.69-14.77 months; p ≤ 0.001). No statistically significant association was found between treatment efficacy and the molecular status of the genes analyzed or the number of prior EGFR TKIs. Conclusions: Prevalence of additional genetic aberrations is frequent in the setting of acquired resistance to early generation EGFR TKIs and may not necessarily mediate resistance to 3rd generation EGFR TKIs. However, in our analysis high-level amplification of MET was associated with primary treatment failure and might be the main factor underlying resistance in this setting.

Immune response and adverse events to influenza vaccine in cancer patients undergoing PD-1 blockade

e14523

Background: Cancer patients (pts) are at risk to develop complications when infected with seasonal influenza viruses. Current guidelines propose that pts on PD-1 directed therapies may receive concurrent inactivated influenza immunization if not medically contraindicated. In this observational study, we aimed to assess the vaccine induced immune response and safety of immunotherapy and influenza vaccine. Methods: Metastatic cancer pts treated with at least one dose of either nivolumab or pembrolizumab were vaccinated with a trivalent inactive influenza vaccination between October and November 2015. Partners of the pts were vaccinated and included in our analysis as age-matched controls. Antibody titers against vaccine virus strains were measured by hemagglutination inhibition assay at days 7, 30, 60 and 180. Cytokine/chemokine profile and changes in peripheral immune cells were assessed in cancer pts at the same time points. Immune-related adverse events (irAE) were documented according to CTCAE v4.0. Results: We included 23 pts and 7 age-matched healthy controls. Median time between initiation of PD-1 inhibition and influenza vaccination was 74 days (range, 44-57). 22 pts were treated with nivolumab and 1 pt with pembrolizumab. 16 pts had a diagnosis of non-small cell lung cancer, 3 pts had renal cell carcinoma and 3 pts a malignant melanoma. In total, 12 pts (52.2%) experienced an irAE. 6 pts (26.1%) had grade 3 or 4 (G3/4) irAEs. This frequency seems to be higher than reported in the literature. G3/4 irAEs include colitis (n = 2), encephalitis (n = 1), vasculitis (n = 1), pneumonitis (n = 1), peripheral neuritis (n = 1). There was no major difference over time in the generation of antibody titers against strains in the vaccine. Peripheral leukocyte counts and cytokine/inflammatory chemokine levels were unchanged after vaccination. We did not observe unexpected local toxicities at the injection site. Conclusions: The seasonal influence vaccination reaches a protective range in these pts. Unexpectedly, however, an increased rate of clinically relevant irAEs was observed. Confirmation in a larger population and mechanistic understanding is required.

Afatinib in patients with metastatic HER2-mutant lung cancers: An international multicenter study

9071

Background: Human epidermal growth factor 2 ( HER2, ERBB2) mutations have been identified as oncogenic drivers in 3% of lung cancers. Afatinib is an irreversible tyrosine kinase inhibitor of HER1 (EGFR), HER2 and HER4 and has been described in case reports to have activity in HER2-mutant lung cancers. However, there is little data to inform the clinical use of afatinib. Methods: We reviewed patients with metastatic HER2-mutant lung cancers treated with afatinib among 7 institutions between 2009 and 2016. The primary endpoint was investigator assessed overall response rate using RECIST v1.1. Other data collected included types of HER2mutations, duration of afatinib treatment and overall survival. Results: We identified 27 patients with metastatic HER2-mutant lung cancers treated with afatinib. Median age at diagnosis was 63 (range 40 to 84); majority were men (n = 16; 59%) and never-smokers (n = 18; 67%). All tumors were adenocarcinomas, and the majority were Stage IV at initial diagnosis (n = 16; 59%). A 12-base pair (bp) in-frame insertion YVMA in exon 20 (p.A775_G776insYVMA) was present in 16 patients (59%). In addition, there were three 9-bp insertions, two 3-bp insertions and two single bp substitutions (L755F and D769H) in exon 20; two single bp substitutions (S310F) in exon 8; one exon 17 V659E mutation; and one single-nucleotide polymorphism (Ile655Val). Median duration on afatinib was 2 months (range 1 to 27); median line of prior treatment was 3 (range 1 to 6). Eight patients had previously received trastuzumab prior to afatinib and one concurrently with afatinib. Overall response rate was 15% (n = 4; 95% CI 4 to 34%); the four partial responses lasted 5, 5, 6 and 10 months. The 3 longest partial responders had a 12-bp insertion in exon 20 (YVMA); the remaining partial responder had a 9-bp insertion in exon 20. Median overall survival from diagnosis date of metastatic disease was 23 months (95% CI 18 to 62). Conclusions: Afatinib produced partial responses in 15% of patients with metastatic HER2-mutant lung cancers, including insertion YVMA. Our findings confirm the activity of afatinib and provide data supporting a framework for its use in the care of patients with HER2-mutant lung cancers.

Erlotinib and bevacizumab in patients with advanced non-small-cell lung cancer and activating EGFR mutations (BELIEF): an international, multicentre, single-arm, phase 2 trial

BACKGROUND

The tyrosine kinase inhibitor erlotinib improves the outcomes of patients with advanced non-small-cell lung carcinoma (NSCLC) harbouring epidermal growth factor receptor (EGFR) mutations. The coexistence of the T790M resistance mutation with another EGFR mutation in treatment-naive patients has been associated with a shorter progression-free survival to EGFR inhibition than in the absence of the T790M mutation. To test this hypothesis clinically, we developed a proof-of-concept study, in which patients with EGFR-mutant NSCLC were treated with the combination of erlotinib and bevacizumab, stratified by the presence of the pretreatment T790M mutation.

METHODS

BELIEF was an international, multicentre, single-arm, phase 2 trial done at 29 centres in eight European countries. Eligible patients were aged 18 years or older and had treatment-naive, pathologically confirmed stage IIIB or stage IV lung adenocarcinoma with a confirmed, activating EGFR mutation (exon 19 deletion or L858R mutation). Patients received oral erlotinib 150 mg per day and intravenous bevacizumab 15 mg/kg every 21 days and were tested centrally for the pretreatment T790M resistance mutation with a peptide nucleic acid probe-based real-time PCR. The primary endpoint was progression-free survival. The primary efficacy analysis was done in the intention-to-treat population and was stratified into two parallel substudies according to the centrally confirmed pretreatment T790M mutation status of enrolled patients (T790M positive or negative). The safety analysis was done in all patients that have received at least one dose of trial treatment. This trial was registered with ClinicalTrials.gov, number NCT01562028.

FINDINGS

Between June 11, 2012, and Oct 28, 2014, 109 patients were enrolled and included in the efficacy analysis. 37 patients were T790M mutation positive and 72 negative. The overall median progression-free survival was 13·2 months (95% CI 10·3-15·5), with a 12 month progression-free survival of 55% (95% CI 45-64). The primary endpoint was met only in substudy one (T790M-positive patients). In the T790M-positive group, median progression-free survival was 16·0 months (12·7 to not estimable), with a 12 month progression-free survival of 68% (50-81), whereas in the T790M-negative group, median progression-free survival was 10·5 months (9·4-14·2), with a 12 month progression-free survival of 48% (36-59). Of 106 patients included in the safety analysis, five had grade 4 adverse events (one acute coronary syndrome, one biliary tract infection, one other neoplasms, and two colonic perforations) and one died due to sepsis.

INTERPRETATION

The BELIEF trial provides further evidence of benefit for the combined use of erlotinib and bevacizumab in patients with NSCLC harbouring activating EGFR mutations.

FUNDING

European Thoracic Oncology Platform, Roche.

Targeting RET in Patients With RET-Rearranged Lung Cancers: Results From the Global, Multicenter RET Registry

Purpose In addition to prospective trials for non-small-cell lung cancers (NSCLCs) that are driven by less common genomic alterations, registries provide complementary information on patient response to targeted therapies. Here, we present the results of an international registry of patients with RET-rearranged NSCLCs, providing the largest data set, to our knowledge, on outcomes of RET-directed therapy thus far. Methods A global, multicenter network of thoracic oncologists identified patients with pathologically confirmed NSCLC that harbored a RET rearrangement. Molecular profiling was performed locally by reverse transcriptase polymerase chain reaction, fluorescence in situ hybridization, or next-generation sequencing. Anonymized data-clinical, pathologic, and molecular features-were collected centrally and analyzed by an independent statistician. Best response to RET tyrosine kinase inhibition administered outside of a clinical trial was determined by RECIST v1.1. Results By April 2016, 165 patients with RET-rearranged NSCLC from 29 centers across Europe, Asia, and the United States were accrued. Median age was 61 years (range, 29 to 89 years). The majority of patients were never smokers (63%) with lung adenocarcinomas (98%) and advanced disease (91%). The most frequent rearrangement was KIF5B-RET (72%). Of those patients, 53 received one or more RET tyrosine kinase inhibitors in sequence: cabozantinib (21 patients), vandetanib (11 patients), sunitinib (10 patients), sorafenib (two patients), alectinib (two patients), lenvatinib (two patients), nintedanib (two patients), ponatinib (two patients), and regorafenib (one patient). The rate of any complete or partial response to cabozantinib, vandetanib, and sunitinib was 37%, 18%, and 22%, respectively. Further responses were observed with lenvantinib and nintedanib. Median progression-free survival was 2.3 months (95% CI, 1.6 to 5.0 months), and median overall survival was 6.8 months (95% CI, 3.9 to 14.3 months). Conclusion Available multikinase inhibitors had limited activity in patients with RET-rearranged NSCLC in this retrospective study. Further investigation of the biology of RET-rearranged lung cancers and identification of new targeted therapeutics will be required to improve outcomes for these patients.

Randomized Phase III Trial of Erlotinib versus Docetaxel in Patients with Advanced Squamous Cell Non-Small Cell Lung Cancer Failing First-Line Platinum-Based Doublet Chemotherapy Stratified by VeriStrat Good versus VeriStrat Poor. The European Thoracic Oncology Platform (ETOP) EMPHASIS-lung Trial

INTRODUCTION

Docetaxel and erlotinib are registered second-line treatments for wild-type EGFR NSCLC. Previous studies suggested a predictive value of the VeriStrat test in second-line therapy of NSCLC, classifying patients as either VeriStrat good or VeriStrat poor. EMPHASIS-lung aimed at exploring this predictive effect in patients with squamous cell NSCLC. The trial closed prematurely because of low accrual and results from other trials. Our analysis includes an exploratory combined analysis with results from the PROSE trial.

METHODS

EMPHASIS-lung was a randomized phase III multicenter trial exploring the differential effect of second-line erlotinib versus docetaxel on progression-free survival (PFS) in VeriStrat good versus VeriStrat poor patients with squamous cell NSCLC.

RESULTS

A total of 80 patients were randomized, with 72.5% categorized as VeriStrat good. Patient characteristics were balanced between VeriStrat status and treatment groups. The median PFS times with docetaxel and erlotinib treatment in the VeriStrat good cohort were 4.1 and 1.6 months, respectively, versus 1.9 and 2.1 months, respectively, in the VeriStrat poor cohort. The median overall survival (OS) times with docetaxel and erlotinib treatment in the VeriStrat good cohort were 7.8 and 8.4 months, respectively, and 4.4 and 5.2 months, respectively, in the VeriStrat poor cohort. An additional exploratory analysis was performed; in it, 47 patients from the squamous cell subgroup of PROSE were included in a combined analysis, contributing with 45 PFS and 41 OS events.

CONCLUSIONS

The final analysis of EMPHASIS-lung did not show a differential effect on PFS for erlotinib versus docetaxel stratified by VeriStrat status. Similarly, in the combined analysis, no significant treatment by VeriStrat status interaction was observed (interaction p = 0.24 for PFS and 0.45 for OS, stratified by study).

Bevacizumab Plus Pemetrexed Versus Pemetrexed Alone as Maintenance Therapy for Patients With Advanced Nonsquamous Non-Small-cell Lung Cancer: Update From the Swiss Group for Clinical Cancer Research (SAKK) 19/09 Trial

BACKGROUND

Pemetrexed and bevacizumab as single agents have been approved for maintenance therapy after platinum-based induction in patients with advanced nonsquamous non-small-cell lung cancer. It is currently unknown whether bevacizumab plus pemetrexed is superior to pemetrexed alone.

PATIENTS AND METHODS

We conducted a nonrandomized phase II trial with 2 sequential cohorts. In the first cohort, 77 patients were treated with 4 cycles of cisplatin, bevacizumab, and pemetrexed every 3 weeks, followed by bevacizumab plus pemetrexed maintenance until progression. In the second cohort, we treated 52 patients without bevacizumab, using maintenance with pemetrexed alone. Progression-free survival (PFS), overall survival (OS), overall response rate (ORR), adverse events, and the treatment costs of the 2 cohorts were compared.

RESULTS

The median PFS from the time of registration was 6.9 months in cohort 1 and 5.6 months in cohort 2. The ORR was 62.3% in cohort 1% and 44.2% in cohort 2. The PFS (hazard ratio, 0.7; 95% confidence interval [CI], 0.5-1.0; P = .041) and ORR (odds ratio, 2.1; 95% CI, 1.0-4.3; P = .049) were better in cohort 1 than in cohort 2. No OS difference was found (hazard ratio, 1.0; 95% CI, 0.7-1.6; P = .890) after a median follow-up period of 47 months for cohort 1 and 27 months for cohort 2. The rate of grade ≥ 3 adverse events was greater in cohort 1. The treatment costs per patient were on average 1.4 times greater for cohort 1.

CONCLUSION

The addition of bevacizumab increased the ORR and PFS, but not OS, in our nonrandomized trial. Furthermore, the addition of bevacizumab was associated with greater toxicity and higher costs.

Clinicopathological Characteristics of RET Rearranged Lung Cancer in European Patients

INTRODUCTION

Rearrangements of RET are rare oncogenic events in patients with non-small cell lung cancer (NSCLC). While the characterization of Asian patients suggests a predominance of nonsmokers of young age in this genetically defined lung cancer subgroup, little is known about the characteristics of non-Asian patients. We present the results of an analysis of a European cohort of patients with RET rearranged NSCLC.

METHODS

Nine hundred ninety-seven patients with KRAS/EGFR/ALK wildtype lung adenocarcinomas were analyzed using fluorescence in situ hybridization for RET fusions. Tumor specimens were molecularly profiled and clinicopathological characteristics of the patients were collected.

RESULTS

Rearrangements of RET were identified in 22 patients, with a prevalence of 2.2% in the KRAS/EGFR/ALK wildtype subgroup. Co-occurring genetic aberrations were detected in 10 patients, and the majority had mutations in TP53. The median age at diagnosis was 62 years (range, 39-80 years; mean ± SD, 61 ± 11.7 years) with a higher proportion of men (59% versus 41%). There was only a slight predominance of nonsmokers (54.5%) compared to current or former smokers (45.5%).

CONCLUSIONS

Patients with RET rearranged adenocarcinomas represent a rare and heterogeneous NSCLC subgroup. In some contrast to published data, we see a high prevalence of current and former smokers in our white RET cohort. The significance of co-occurring aberrations, so far, is unclear.

Abstract 269: The role of BRCA1 and AEG1 mRNA expression in advanced non-small-cell lung cancer (NSCLC) patients (p) with EGFR activating and pretreatment T790M mutations receiving the combination of erlotinib plus bevacizumab (E+B) in the BELIEF trial

The BELIEF trial (NCT01562028) examined the efficacy of E+B for the 1st line treatment of European p with advanced NSCLC harboring exon 19 deletion or exon 21 L858R epidermal growth factor receptor (EGFR) mutations with or without pretreatment T790M. Median progression-free survival (mPFS) was 13.8 months (m) (95% CI 10.3-16.2) for the 109 p enrolled in the study. mPFS was 16m (95% CI 13.1-not estimable [NE]) and 10.4m (95% CI 9.2-15.6) for the 37 T790M(+) p and 72 T790M(-) p, respectively (P = 0.089). We have previously shown that low BRCA1 levels neutralize the negative effect of pretreatment T790M and are associated with longer PFS to erlotinib. Low astrocyte elevated gene 1 (AEG1) levels are associated with longer PFS to erlotinib. A secondary objective of the BELIEF trial was the assessment of the prognostic impact of BRCA1 and AEG1 mRNA expression in the baseline tumor tissue.

We assessed the baseline mRNA expression levels of BRCA1 and AEG1 and correlated them with PFS and response in the 109 EGFR-mutant NSCLC p of the BELIEF trial. BRCA1 and AEG1 mRNA levels were estimable by quantitative-real time PCR in 46 and 61 p respectively. Expression levels were divided into two groups according to their median.

No statistically significant associations were found among the expression of the two biomarkers and gender, smoking status, histology, PS or type of EGFR mutation. The association of BRCA1 and AEG1 mRNA with PFS did not differ according to T790M status (interaction P = 0.81 and 0.42, respectively). Among the T790M (+) p, those with low BRCA1 mRNA had a longer mPFS of 24.6m (95% CI: 4.9-NE) compared to 15.4 m (95% CI: 2.7-NE) for p with high BRCA1 mRNA; P = 0.63. For all and T790M (-) p, BRCA1 levels did not differentiate mPFS to E+B (low vs high BRCA1 mRNA, 11.0 m [95% CI: 6.0-NE] vs 9.5 m [95% CI: 7.2-NE]; P = 0.99 and 6.9 m [95% CI: 2.1-NE] vs 9.4 m [95% CI: 4.1-NE]; P = 0.71, respectively). Similarly, among the T790M (+) p, those with low AEG1 expression had a longer mPFS of 24.6m (95% CI: 4.9-NE) compared to 15.4 m (95% CI: 5.2-NE) for those with high AEG1 mRNA; P = 0.93. For all and T790M(-) p, AEG1 levels did not differentiate mPFS to E+B (low vs high AEG1 mRNA, 10.3 m [95% CI: 8.4-24.6] vs 15.4 m [95% CI: 6.0-33.9]; P = 0.90 and 10.3m [95% CI: 8.4-NE] vs 13.3m [95% CI: 4.7-33.9] P = 0.67). No statistically or clinically significant associations were found among BRCA1, AEG1 mRNA levels and response to E+B.

The BELIEF trial reconfirms our previous findings that pretreatment EGFR T790M is present in 34% of the patients. E+B is associated with a prolonged mPFS of 24.6m for EGFR-mutant p with both pretreatment EGFR T790M and low BRCA1 mRNA expression, as observed in our previous study with erlotinib alone. Similar results were observed for AEG1 levels though the interaction was not statistically significant for either biomarker.

Citation Format: Rafael Rosell, Niki Karachaliou, Ana Giménez-Capitán, Carles Codony-Servat, Oliver Gautschi, Enriqueta Felip, Alessandra Curioni-Fontecedro, Solange Peters, Santiago Ponce-Aix, Martin Früh, Miklos Pless, Sanjay Popat, Sinead Cuffe, Paolo Bidoli, Adolfo Favaretto, Roswitha Kammler, Urania Dafni, Zoi Tsourti, Miguel Angel Molina-Vila, Rolf A. Stahel. The role of BRCA1 and AEG1 mRNA expression in advanced non-small-cell lung cancer (NSCLC) patients (p) with EGFR activating and pretreatment T790M mutations receiving the combination of erlotinib plus bevacizumab (E+B) in the BELIEF trial. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 269.

MicroRNA-106a targets autophagy and enhances sensitivity of lung cancer cells to Src inhibitors

OBJECTIVES

Src tyrosine kinase inhibitors (TKIs) significantly inhibit cell migration and invasion in lung cancer cell lines with minor cytotoxic effects. In clinical trials, however, they show modest activity in combination with chemotherapeutic agents. Possible resistance mechanisms include the induction of cytoprotective autophagy upon Src inhibition. Autophagy is a cellular recycling process that allows cell survival in response to a variety of stress stimuli including responses to various treatments.

MATERIAL AND METHODS

We screened autophagic activity in A549, H460, and H1299 NSCLC cell lines treated with two different Src-TKIs (saracatinib, dasatinib) or shRNA targeting SRC. The autophagy response was determined by LC3B-I to -II conversion, increased ULK1 epxression and increased GFP-LC3B dot formation. Autophagy was inhibited by pharmacological (bafilomycin A, chloroquine) or genetic (ULK1 shRNA) means. Expression of miR-106a and miR-20b was analyzed by qPCR, and we used different lentivral vectors for ectopic expression of either miR-106a mimetics, anti-sense miR-106a or different miR-106a-363 cluster constructs.

RESULTS

In the current study we found that Src-TKIs induce autophagy in lung adenocarcinoma cell lines and that a combination of autophagy and Src tyrosine kinase inhibition results in cell death. Moreover, Src-TKI induced autophagy depends on the induction of the key autophagy kinase ULK1. This ULK1 upregulation is caused by downregulation of the ULK1-targeting microRNA-106a. An inverse correlation of miR-106a and ULK1 expression was seen in lung adenocarcinoma. Accordingly, ectopic expression of miR-106a in combination with Src-TKI treatment resulted in significant cell death as compared to control transduced cells.

CONCLUSIONS

Autophagy protects lung adenocarcinoma cells from Src-TKIs via a newly identified miR-106a-ULK1 signaling pathway. The combined inhibition of Src and ULK1/autophagy might represent a promising treatment option for future clinical trials. Lastly, our data might challenge the term "oncogenic" miR-106a as it can promote sensitivity to Src-TKIs thereby underlining the context-dependent function of miRNAs.