Tumor immune microenvironment and nivolumab efficacy in EGFR mutation-positive non-small-cell lung cancer based on T790M status after disease progression during EGFR-TKI treatment.

BACKGROUND: The efficacy of programmed death-1 blockade in epidermal growth factor receptor gene (EGFR) mutation-positive non-small-cell lung cancer (NSCLC) patients with different mechanisms of acquired resistance to EGFR tyrosine kinase inhibitors (TKIs) is unknown. We retrospectively evaluated nivolumab efficacy and immune-related factors in such patients according to their status for the T790M resistance mutation of EGFR. PATIENTS AND METHODS: We identified 25 patients with EGFR mutation-positive NSCLC who were treated with nivolumab after disease progression during EGFR-TKI treatment (cohort A). Programmed death-ligand 1 (PD-L1) expression and tumor-infiltrating lymphocyte (TIL) density in tumor specimens obtained after acquisition of EGFR-TKI resistance were determined by immunohistochemistry. Whole-exome sequencing of tumor DNA was carried out to identify gene alterations. The relation of T790M status to PD-L1 expression or TIL density was also examined in an independent cohort of 60 patients (cohort B). RESULTS: In cohort A, median progression-free survival (PFS) was 2.1 and 1.3 months for T790M-negative and T790M-positive patients, respectively (P = 0.099; hazard ratio of 0.48 with a 95% confidence interval of 0.20-1.24). Median PFS was 2.1 and 1.3 months for patients with a PD-L1 expression level of ≥1% or <1%, respectively (P = 0.084; hazard ratio of 0.37, 95% confidence interval of 0.10-1.21). PFS tended to increase as the PD-L1 expression level increased with cutoff values of ≥10% and ≥50%. The proportion of tumors with a PD-L1 level of ≥10% or ≥50% was higher among T790M-negative patients than among T790M-positive patients of both cohorts A and B. Nivolumab responders had a significantly higher CD8+ TIL density and nonsynonymous mutation burden. CONCLUSION: T790M-negative patients with EGFR mutation-positive NSCLC are more likely to benefit from nivolumab after EGFR-TKI treatment, possibly as a result of a higher PD-L1 expression level, than are T790M-positive patients.

Clinical application of amplicon-based next-generation sequencing to therapeutic decision making in lung cancer.

BACKGROUND: The clinical implementation of genomic profiling for lung cancer with high-throughput, multiplex tests is warranted to allow prioritization of appropriate therapies for individual patients. We have now applied such testing to detect actionable mutations that may inform treatment recommendations in lung cancer. PATIENTS AND METHODS: We prospectively applied amplicon sequencing panels that cover both mutational hotspots in 22 genes related to lung and colon tumorigenesis as well as 72 major variants of ALK, RET, ROS1, and NTRK1 fusion transcripts. We then determined the proportion of patients who received genotype-directed therapy and their overall survival (OS). RESULTS: Tumor specimens from 110 patients with lung cancer recruited between July 2013 and March 2015 were analyzed. The most common genetic alterations were TP53 mutations in 42 patients, followed by EGFR mutations in 25, STK11 mutations in 12, and KRAS mutations in 10. Potentially actionable mutations were identified in 44 patients including 50% of those with adenocarcinoma and 14% of those with squamous cell carcinoma. The OS of patients with advanced or recurrent cancer who had an actionable mutation and received targeted therapy (median OS not achieved) was significantly longer than that of those with no mutation (18.1 months, P = 0.041) or of those with a mutation not so treated (6.1 months, P = 0.0027). CONCLUSIONS: Multiplex genomic testing was performed on formalin-fixed, paraffin-embedded tumor specimens with a success rate of ≥95%. Such testing can assist physicians in matching patients with approved or experimental targeted treatments. CLINICAL TRIAL REGISTRATION: The University Medical Hospital Information Network (UMIN) Clinical Trials Registry under the identifier UMIN000014782.

A phase I dose-escalation study of eribulin and S-1 for metastatic breast cancer.

BACKGROUND: We evaluated the safety, maximum-tolerated dose (MTD), pharmacokinetics, recommended dose for phase II (P2RD), and preliminary anticancer activity of a combination eribulin and S-1 therapeutic in metastatic breast cancer patients pretreated with anthracycline and taxane. METHOD: Patients aged 20-74 years were recruited. In level 1, patients received S-1 (65 mg m(-2)) from day 1 to 14, and eribulin (1.1 mg m(-2)) on day 1 and 8 in a 21-day cycle. In level 2, eribulin was increased to 1.4 mg m(-2). In level 3, S-1 was increased to 80 mg m(-2). RESULTS: Twelve patients were enrolled into three cohorts. Planned dose escalation was completed, with one case exhibiting dose-limiting toxicity (grade 3 hypokalaemia) at level 3, without reaching the MTD. The P2RD was determined to be level 2 (eribulin 1.4 mg m(-2) and S-1 65 mg m(-2)). The most common grade 3 or 4 toxicity was neutropenia (83.3%), followed by febrile neutropenia (25.0%). Five of eleven patients (41.7%) with measurable disease had a partial response. Pharmacokinetics were characterised by dose-dependent elimination and nonlinear exposure. CONCLUSION: Dose level 3 was not tolerated owing to febrile neutropenia development. Thus, intermediate dose level 2 was recommended for further evaluation. Preliminary antitumour activity warrants further investigation in this setting.