Lung cancers harboring mutations in the epidermal growth factor receptor (EGFR) respond to EGFR tyrosine kinase inhibitors, but drug resistance invariably emerges. To elucidate mechanisms of acquired drug resistance, we performed systematic genetic and histological analyses of tumor biopsies from 37 patients with drug-resistant non–small cell lung cancers (NSCLCs) carrying EGFR mutations. All drug-resistant tumors retained their original activating EGFR mutations, and some acquired known mechanisms of resistance including the EGFR T790M mutation or MET gene amplification. Some resistant cancers showed unexpected genetic changes including EGFR amplification and mutations in the PIK3CA gene, whereas others underwent a pronounced epithelial-to-mesenchymal transition. Surprisingly, five resistant tumors (14%) transformed from NSCLC into small cell lung cancer (SCLC) and were sensitive to standard SCLC treatments. In three patients, serial biopsies revealed that genetic mechanisms of resistance were lost in the absence of the continued selective pressure of EGFR inhibitor treatment, and such cancers were sensitive to a second round of treatment with EGFR inhibitors. Collectively, these results deepen our understanding of resistance to EGFR inhibitors and underscore the importance of repeatedly assessing cancers throughout the course of the disease.
EML4-ALK defines a molecular subset of NSCLC with distinct clinical characteristics. Patients who harbor this mutation do not benefit from EGFR TKIs and should be directed to trials of ALK-targeted agents.
Advanced, anaplastic lymphoma kinase (ALK)-positive lung cancer is currently treated with the first-generation ALK inhibitor crizotinib followed by more potent, second-generation ALK inhibitors (e.g., ceritinib, alectinib) upon progression. Second-generation inhibitors are generally effective even in the absence of crizotinib-resistant ALK mutations, likely reflecting incomplete inhibition of ALK by crizotinib in many cases. Herein, we analyzed 103 repeat biopsies from ALK-positive patients progressing on various ALK inhibitors. We find that each ALK inhibitor is associated with a distinct spectrum of ALK resistance mutations and that the frequency of one mutation - ALK G1202R - increases significantly after treatment with second-generation agents. To investigate strategies to overcome resistance to second-generation ALK inhibitors, we examine the activity of the third-generation ALK inhibitor lorlatinib in a series of ceritinib-resistant, patient-derived cell lines, and observe that the presence of ALK resistance mutations is highly predictive for sensitivity to lorlatinib, whereas those cell lines without ALK mutations are resistant.
Nivolumab monotherapy produced durable responses and encouraging survival rates in patients with heavily pretreated NSCLC. Randomized clinical trials with nivolumab in advanced NSCLC are ongoing.
BACKGROUNDAmong patients with non-small-cell lung cancer (NSCLC), MET exon 14 skipping mutations occur in 3 to 4% and MET amplifications occur in 1 to 6%. Capmatinib, a selective inhibitor of the MET receptor, has shown activity in cancer models with various types of MET activation.
METHODSWe conducted a multiple-cohort, phase 2 study evaluating capmatinib in patients with MET-dysregulated advanced NSCLC. Patients were assigned to cohorts on the basis of previous lines of therapy and MET status (MET exon 14 skipping mutation or MET amplification according to gene copy number in tumor tissue). Patients received capmatinib (400-mg tablet) twice daily. The primary end point was overall response (complete or partial response), and the key secondary end point was response duration; both end points were assessed by an independent review committee whose members were unaware of the cohort assignments.
RESULTSA total of 364 patients were assigned to the cohorts. Among patients with NSCLC with a MET exon 14 skipping mutation, overall response was observed in 41% (95% confidence interval [CI], 29 to 53) of 69 patients who had received one or two lines of therapy previously and in 68% (95% CI, 48 to 84) of 28 patients who had not received treatment previously; the median duration of response was 9.7 months (95% CI, 5.6 to 13.0) and 12.6 months (95% CI, 5.6 to could not be estimated), respectively. Limited efficacy was observed in previously treated patients with MET amplification who had a gene copy number of less than 10 (overall response in 7 to 12% of patients). Among patients with MET amplification and a gene copy number of 10 or higher, overall response was observed in 29% (95% CI, 19 to 41) of previously treated patients and in 40% (95% CI, 16 to 68) of those who had not received treatment previously. The most frequently reported adverse events were peripheral edema (in 51%) and nausea (in 45%); these events were mostly of grade 1 or 2.
CONCLUSIONSCapmatinib showed substantial antitumor activity in patients with advanced NSCLC with a MET exon 14 skipping mutation, particularly in those not treated previously. The efficacy in MET-amplified advanced NSCLC was higher in tumors with a high gene copy number than in those with a low gene copy number. Low-grade peripheral edema and nausea were the main toxic effects. (Funded by Novartis Pharmaceuticals; GEOMETRY mono-1 ClinicalTrials.gov number, NCT02414139.
Purpose In two phase III studies, nivolumab, a programmed death-1 (PD-1) inhibitor antibody, improved overall survival (OS) versus docetaxel in pretreated advanced non-small-cell lung cancer (NSCLC). We report 5-year follow-up results from an early phase I study of nivolumab in this patient population and describe characteristics of 5-year survivors. Patients and Methods Patients with pretreated, advanced NSCLC received nivolumab 1, 3, or 10 mg/kg every 2 weeks in 8-week cycles for up to 96 weeks. OS from the time of first dose was estimated by the Kaplan-Meier method. Results The estimated 5-year OS rate was 16% for all treated patients (N = 129); 5-year OS rates were similar for squamous (16%) and nonsquamous (15%) NSCLC. Of 16 5-year survivors, most (88%) were known current or former smokers. Of 10 5-year survivors with quantifiable PD-1 ligand 1 expression, 70% had ≥ 1% PD-1 ligand 1 expression at baseline. Twelve 5-year survivors (75%) achieved a partial response to nivolumab per Response Evaluation Criteria in Solid Tumors, version 1.0, and two each (12%) had stable disease and progressive disease as best response. Nine 5-year survivors (56%) completed the maximum 96 weeks of nivolumab; four (25%) discontinued owing to adverse events and three (19%) owing to disease progression. As of a November 2016 database lock, 12 5-year survivors (75%) received no subsequent therapy and were without evidence of progressive disease at last follow-up. Conclusions Nivolumab treatment resulted in long-term OS and durable responses in a proportion of patients with pretreated advanced NSCLC. Long-term survivors had diverse baseline and on-treatment characteristics.
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