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Treatment with epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) improves the overall survival of patients with EGFR-mutated non-small-cell lung cancer (NSCLC). First-generation EGFR-TKIs (e.g., gefitinib and erlotinib) or second-generation EGFR-TKIs (e.g., afatinib and dacomitinib) are effective for the treatment of EGFR-mutated NSCLC, especially in patients with EGFR exon 19 deletions or an exon 21 L858R mutation. However, almost all cases experience disease recurrence after 1 to 2 years due to acquired resistance. The EGFR T790M mutation in exon 20 is the most frequent alteration associated with the development of acquired resistance. Osimertinib—a third-generation EGFR-TKI—targets the T790M mutation and has demonstrated high efficacy against EGFR-mutated lung cancer. However, the development of acquired resistance to third-generation EGFR-TKI, involving the cysteine residue at codon 797 mutation, has been observed. Other mechanisms of acquired resistance include the activation of alternative pathways or downstream targets and histological transformation (i.e., epithelial–mesenchymal transition or conversion to small-cell lung cancer). Furthermore, the development of primary resistance through overexpression of the hepatocyte growth factor and suppression of Bcl-2-like protein 11 expression may lead to problems. In this report, we review these mechanisms and discuss therapeutic strategies to overcome resistance to EGFR-TKIs.

IMPORTANCE Although treatment with first-generation epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) plus antiangiogenic inhibitor has shown promising efficacies in patients with EGFR-mutated lung adenocarcinoma, recent single-arm studies have suggested that osimertinib plus antiangiogenic inhibitor might not work synergistically. OBJECTIVE To explore the efficacy and safety of osimertinib plus bevacizumab compared with osimertinib alone in patients with lung adenocarcinoma with EGFR T790M mutation. DESIGN, SETTING, AND PARTICIPANTS Patients with advanced lung adenocarcinoma that progressed with prior EGFR-TKI treatment (other than third-generation TKI) and acquired EGFR T790M mutation were enrolled. This study comprises a lead-in part with 6 patients and a subsequent phase 2 part. In phase 2, patients were randomized to osimertinib plus bevacizumab or osimertinib alone in a 1:1 ratio. INTERVENTIONS The combination arm received oral osimertinib (80 mg, every day) plus intravenous bevacizumab (15 mg/kg, every 3 weeks) until progression or unacceptable toxic effects. The control arm received osimertinib monotherapy. MAIN OUTCOMES AND MEASURES The primary end point was progression-free survival (PFS) assessed by investigators. Secondary end points consisted of overall response rate, time to treatment failure, overall survival, and safety. RESULTS From August 2017 through September 2018, a total of 87 patients were registered (6 in the lead-in part and 81 in the phase 2 part [intention-to-treat population]). Among those randomized, the median (range) age was 68 (41-82) years; 33 (41%) were male; 37 (46%) had an Eastern Cooperative Oncology Group performance status of 0; and 21 (26%) had brain metastasis. Although the overall response rate was better with osimertinib plus bevacizumab than osimertinib alone (68% vs 54%), median PFS was not longer with osimertinib plus bevacizumab (9.4 months vs 13.5 months; adjusted hazard ratio, 1.44; 80% CI, 1.00 to 2.08; P = .20). Median time to treatment failure was also shorter in the combination arm vs the osimertinib arm (8.4 months vs 11.2 months; P = .12). Median overall survival was not different in the combination arm vs osimertinib arm (not reached vs 22.1 months; P = .96). In the combination arm, common adverse events of grade 3 or higher were proteinuria (n = 9; 23%), hypertension (n = 8; 20%). CONCLUSIONS AND RELEVANCE In this randomized clinical trial comparing osimertinib plus bevacizumab vs osimertinib alone, the combination arm failed to show prolongation of PFS in patients with advanced lung adenocarcinoma with EGFR T790M mutation.

BackgroundNivolumab improves the survival of advanced non-small cell lung cancer (NSCLC), but a significant number of patients still fail to benefit from this treatment. In this study, we evaluated the efficacy of the time-series behavior of neutrophil-to-lymphocyte ratio (NLR) in a complete blood count from advanced NSCLC patients as a predictive marker of the anticancer effect of nivolumab.MethodsWe performed a retrospective review of medical records and collected data on patients with advanced NSCLC treated with nivolumab as second- and further-line treatments from December 2015 to March 2017. The NLRs were calculated before each treatment cycle for four cycles. These parameters were tested for its association with the overall survival (OS), progression-free survival (PFS) and time to treatment failure (TTF).ResultsNineteen patients were treated with nivolumab. Stratified by the response to nivolumab, the median OS was 2.8 months in progressive disease (PD) and 14.0 months in non-PD (p = 0.002). Before discontinuation of PD or toxicity, an NLR is rising from baseline in 5 out of 7 patients with PD and all of 4 patients with discontinuation due to toxicity. Patients with an >30% increase in NLR were associated with a significantly shorter TTF compared with those with stable or decrease in NLR both after first cycle (p = 0.014) and second cycle (p < 0.001).ConclusionsThe NLR is suggested to be useful not only as a prognostic marker but also as a predictive marker for treatment with nivolumab. Further prospective study is warranted to develop a predictive algorithm to detect PD cases as early as possible by focusing the time-series behavior of NLR.

Background/Aim: Immune checkpoint inhibitors (ICI) are a novel medication for non-small cell lung cancer (NSCLC). Recent reports indicated that baseline tumor size (BTS) relates to the efficacy of ICI therapy for melanoma, but no study exists for NSCLC. This study aimed to evaluate the utility of BTS for ICI therapy. Patients and Methods: Data from 58 patients diagnosed with NSCLC who underwent ICI monotherapy, were retrospectively analyzed. Patients were divided into two groups according to BTS (below 101 mm, above 101 mm). The primary endpoint was progression-free survival (PFS) and the secondary endpoint was overall survival (OS). Results: PFS of patients with a large BTS was significantly shorter than that of those with a small BTS (median; 2.07 [95% confidence interval [CI]=0.99-6.77] months versus 6.39 [95%CI=4.17-11.50] months) (p=0.044). OS of patients with large BTS was also significantly shorter (p<0.01). Conclusion: BTS is a predictive and prognostic negative factor of ICI therapy for NSCLC. Lung cancer is one of the leading causes of cancer-related death worldwide (1). Advanced non-small cell lung cancer (NSCLC) is treated using systemic therapies, including chemotherapy, epidermal growth factor receptor-tyrosine kinase inhibitor (TKI), anaplastic lymphoma kinase-TKI, c-ros oncogene 1 inhibitor, a combination of BRAF/MET inhibitor, and an immune checkpoint inhibitor (ICI) (2). The immune system protects the host against cancer cells via seven steps termed the cancer-immunity cycle (3). The seven steps include 'priming and activation' and 'recognition of cancer by T cells' (3). These processes are regulated and activated by various molecules and cytokines, including programmed death-ligand 1 (PD-L1) and programmed death-1 (PD-1), which suppress the cancer-immune cycle (3, 4). Cancer cells can express PD-L1 on their surfaces, facilitating recognition by PD-1, which is expressed on the surface of T-cells and acts as a PD-L1 receptor. Binding of PD-L1 to T cells has a profound inhibitory effect on immune functions such as cytokine secretion, growth, and cytotoxicity. Hence, PD-1 and PD-L1 are thought to be important target molecules for the control of cancer. ICI is a novel and promising medication for NSCLC. Nivolumab, a fully human IgG4 anti-PD-1 receptor-blocking monoclonal antibody (5), was the first ICI available for treatment of NSCLC in Japan. The Checkmate 017 and Checkmate 057 studies indicated the superiority of nivolumab over docetaxel for patient progression-free survival (PFS) and overall survival (OS) (6, 7). In addition to nivolumab, various other ICIs are now available, including pembrolizumab (an anti-PD-1 blocking antibody), atezolizumab and durvalumab (anti-PD-L1 blocking antibodies). Use of these ICIs has also been shown to lead to superior PFS and OS (8-10). Previous studies (Checkmate 017, 057, and Keynote-010) showed that the effects of ICI differed according to PD-L1 expression. As ICI is more effective against NSCLC expressing a higher tumor proportion score (TPS) of PD-L1 (6, 7),...