Purpose: The third-generation EGFR tyrosine kinase inhibitor osimertinib is approved to treat patients with EGFR T790M-positive non–small cell lung cancer (NSCLC) who have developed resistance to earlier-generation drugs. Acquired EGFR C797S mutation has been reported to mediate osimertinib resistance in some patients. However, the remaining resistance mechanisms are largely unknown. Experimental Design: We performed mutation profiling using targeted next-generation sequencing (NGS) for 416 cancer-relevant genes on 93 osimertinib-resistant lung cancer patients' samples, mainly cell-free DNAs (cfDNAs), and matched pretreatment samples of 12 patients. In vitro experiments were conducted to functionally study the secondary EGFR mutations identified. Results: EGFR G796/C797, L792, and L718/G719 mutations were identified in 24.7%, 10.8%, and 9.7% of the cases, respectively, with certain mutations coexisting in one patient with different prevalence. L792 and L718 mutants markedly increased the half inhibitory concentration (IC₅₀) of osimertinib in vitro, among which the L718Q mutation conferred the greatest resistance to osimertinib, as well as gefitinib resistance when not coexisting with T790M. Further analysis of the 12 matched pretreatment samples confirmed that these EGFR mutations were acquired during osimertinib treatment. Alterations in parallel or downstream oncogenes such as MET, KRAS, and PIK3CA were also discovered, potentially contributing to the osimertinib-resistance in patients without EGFR secondary mutations. Conclusions: We present comprehensive mutation profiles of a large cohort of osimertinib-resistance lung cancer patients using mainly cfDNA. Besides C797 mutations, novel secondary mutations of EGFR L718 and L792 residues confer osimertinib resistance, both in vitro and in vivo, and are of great clinical and pharmaceutical relevance. Clin Cancer Res; 24(13); 3097–107. ©2018 AACR.

Objectives: The objective of this study is to evaluate whether PIV (Pan-Immune-Inflammation Value) and PILE [a score derived from PIV, lactate dehydrogenase (LDH), and Eastern Cooperative Oncology Group Performance Status (ECOG PS)] can predict clinical outcome of anti-PD-1/PD-L1 inhibitor combined with chemotherapy in patients with extensive-stage (ES) small cell lung cancer (SCLC).Methods: A total of 53 patients with ES-SCLC in the control group of clinical trial (NCT03041311) were included in this study. PIV was calculated as follows: (neutrophil count × platelet count × monocyte count)/lymphocyte count. The PILE scores were composited based on PIV, LDH levels, and ECOG PS. The Kaplan–Meier method and Cox hazards regression models were used for survival analyses. Moreover, the predictive ability of PIV and PILE was validated in an independent real-world group consisting of 84 patients.Results: Patients in the low PIV group (PIV < median) had longer progression-free survival (PFS) and overall survival (OS) than those in the high PIV group (PIV ≥ median), along with the HR, which was 2.157 and 2.359, respectively (PFS HR 95% CI: 1.181–3.940, p = 0.012; OS HR 95% CI: 1.168–4.762, p = 0.020). High PILE score was observed relating to worse treatment efficacy (disease control rate (DCR): 84.21% vs. 100%, p = 0.047; durable clinical benefit (DCB) rate: 10% vs. 48.5%, p = 0.060) and poor clinical outcome (median PFS: 4.75 vs. 5.53 m, p = 0.043; median OS: 7.13 vs. 15.93 m, p = 0.002). Similar results were obtained about the predictive and prognostic abilities of PIV and PILE scores in the validation group.Conclusions: High PIV and high PILE were correlated with worse clinical outcomes in ES-SCLC patients treated with anti-PD-1/PD-L1 inhibitor combined with chemotherapy, reflecting that PIV and PILE might be useful to identify patients unlikely to benefit from anti-PD-1/PD-L1 therapy.

Bevacizumab, which is a humanized anti-VEGF antibody, has been successfully applied in clinics since 2004. Bevacizumab in combination with chemotherapy showed high safety and has been applied to solid tumors. However, studies on the insight into the mechanism about the antiangiogenesis activity of bevacizumab were mostly done on mice models, and so there are no visual and intuitive models to observe the process of antiangiogenesis. Here, we first used a zebrafish model to investigate the angiogenesis suppressing behavior of bevacizumab. Our results showed that bevacizumab inhibited formation of zebrafish subintestinal veins, which mimics the process of tumor angiogenesis in vivo. Meanwhile, bevacizumab caused specific vasculature formation defects in subintestinal veins but not in the trunk. Our study also indicated that bevacizumab could inhibit zebrafish retinal angiogenesis with therapeutic potential.

Background: The rechallenge of immune checkpoint inhibitors (ICI) is now an optional strategy for patients who discontinued ICI due to immune-related adverse events (irAEs) or disease progression. However, little data is available for the prognosis and prognostic factors of patients receiving ICI rechallenge treatment in advanced lung cancer patients. Our study aimed to explore the efficacy, prognosis and safety of patients who received anti-programmed cell death-1/programmed cell death ligand 1 (anti-PD-1/PD-L1) inhibitor rechallenge. Methods: In our retrospective cohort study, data of advanced lung cancer patients who received anti-PD-1/PD-L1 inhibitor and discontinued due to irAEs or disease progression were collected from December 2016 to August 2021. Enrolled patients were categorized into two groups: rechallenge group (R group) and non-rechallenge group (NR group). Progression-free survival (PFS), overall survival (OS), disease control rate (DCR) and safety data were analyzed. Cox model and subgroup analysis were analyzed according to baseline characteristics, ICI type, the reason for discontinuing ICI, etc. According to Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST 1.1), evaluation was performed routinely every 6–8 weeks after initiating treatment with the PD-1/PD-L1 inhibitor. The last follow-up in the study was on September 20, 2021. Results: Eighty-one patients who met our inclusion criteria were enrolled. In the whole cohort, the R group achieved better OS than the NR group [hazard ratio (HR) =0.176; 95% confidence interval (CI): 0.065–0.477; P=0.001). In the irAEs group, the survival analyses showed a trend toward improved OS in the rechallenge subgroup (HR =0.287; 95% CI: 0.081–1.025; P=0.055), and a promising DCR of 75% after an ICI rechallenge. Additionally, the exploration of safety outcomes indicated an acceptable recurrence rate (22.5%) of irAEs and an early onset of irAEs after an ICI rechallenge. In the disease progression group, the rechallenge subgroup did not improve OS (HR =0.214; 95% CI: 0.027–1.695; P=0.144), and the DCR of the rechallenge subgroup was 40% after ICI rechallenge. Conclusions: ICI rechallenge might be an attractive option for patients who discontinue treatment due to irAEs. For patients with disease progression, further research should be conducted. The recurrence of irAEs and their early onset during the second round of ICI should be considered.

Cancer Drug Resistance is an open access journal, focusing on pharmacological aspects of drug resistance and its reversal, molecular mechanisms of drug resistance and drug classes, etc. Both clinical and experimental aspects of drug resistance in cancer are included.