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D.L. Aisner



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    P1.02 - Poster Session with Presenters Present (ID 454)

    • Event: WCLC 2016
    • Type: Poster Presenters Present
    • Track: Biology/Pathology
    • Presentations: 1
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      P1.02-084 - Polo-Like Kinase 1 (PLK1) Inhibition Decreases Mutational Activity in Bronchial Epithelial Cells Exposed to Tobacco Carcinogens (ID 6206)

      14:30 - 14:30  |  Author(s): D.L. Aisner

      • Abstract

      Background:
      Persistence of bronchial dysplasia (BD) is associated with increased risk for the development of squamous cell carcinoma (SCC) of the lung. A comparison of persistent and regressive BD demonstrated that alterations in gene expression can distinguish these types of lesions. Using the genes that differentiate persistent and regressive BD we have identified PLK1 as a key mediator of persistence and have hypothesized that the role it plays in abrogating G2-M cell cycle arrest in the presence of mutational alterations may be central to progression of premalignant airway lesions to invasive SCC.

      Methods:
      Cultures of the bronchial epithelium derived BEAS-2B (B2B) cell line were exposed to airway mutagens (cigarette smoke condensate [CSC, Kentucky Reference Cigarette 3R4F] or Benzo[A]pyrene, [BaP]) alone or in the presence of 100 nM PLK1 inhibitor Volasertib. Following treatment, clones were selected by ring isolation and DNA was collected to assess mutational events as compared to untreated controls using the TruSightOne targeted next generation sequencing panel (12 megabase coverage, >4800 genes, Illumina, San Diego, CA). Modal distribution of mutation frequencies indicated that ring clones were composed of between 1 - 3 distinct clones. Mutation rates were calculated using these adjusted clone counts for standardization.

      Results:
      Using the untreated B2B cultures as reference sequence, CSC or BaP alone induced mean incidences of mutations of 15.7 and 60.9 per clone, respectively, although the induction of fewer mutations by CSC made accurate estimates of clonal numbers more difficult. B2B cultures treated with the same concentration and duration of mutagen in the presence of Volasertib showed mean mutational incidences of 13 and 17 per clone, respectively. The ratio of mutation rate for the CSC and BaP treated groups with versus without Volasertib were 0.83 and 0.28, respectively. All mutations detected were single nucleotide variants and characteristic patterns of base changes were noted between mutagen groups with C>A and G>T transversions being more prominent in BaP treated cultures. Ongoing analyses using whole genome sequencing will allow for more accurate enumeration of clones represented and a richer assessment of mutation rates including rearrangements and copy number variants in mutagen treated cells in the presence and absence of PLK1 inhibition.

      Conclusion:
      Preliminary analyses of bronchial epithelial cell cultures treated with mutagens show reduction of BaP induced mutations in the presence of PLK1 inhibition. The results suggest PLK1 overexpression in BD may promote genomic instability.

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    P2.06 - Poster Session with Presenters Present (ID 467)

    • Event: WCLC 2016
    • Type: Poster Presenters Present
    • Track: Scientific Co-Operation/Research Groups (Clinical Trials in Progress should be submitted in this category)
    • Presentations: 1
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      P2.06-019 - A Phase II Study of Atezolizumab as Neoadjuvant and Adjuvant Therapy in Patients (pts) with Resectable Non-Small Cell Lung Cancer (NSCLC) (ID 4642)

      14:30 - 14:30  |  Author(s): D.L. Aisner

      • Abstract

      Background:
      There is no curative treatment for patients with NSCLC who develop metastatic disease after resection. Trials of neoadjuvant and adjuvant chemotherapy have demonstrated an absolute survival benefit of 5% for patients with stages IB, II, and IIIA disease. Clearly, developing new treatment strategies to improve survival following resection is critical to improving outcomes for this patient population. Immunotherapy with checkpoint inhibitors such as antibodies to PD-1 and PD-L1 has demonstrated superior survival compared to chemotherapy in randomized clinical trials. PD-L1 expression is being investigated as a predictive biomarker for these therapies, but its ability to predict response has varied in published trials. Atezolizumab is a humanized IgG1 monoclonal PD-L1 antibody that was recently evaluated in the POPLAR trial (NCT01903993), a phase II randomized trial of patients with NSCLC who progressed on platinum based chemotherapy. Atezolizumab therapy improved overall survival compared with docetaxel (12.6 months vs. 9.7 months, HR 0.73 [95% CI 0.53 – 0.99]) with a manageable safety profile. Improvement in survival correlated with PD-L1 immunohistochemistry expression of tumor and tumor-infiltrating immune cells.

      Methods:
      Trial design: This phase II, open-label, single-arm study is designed to evaluate the efficacy and safety of atezolizumab as a neoadjuvant therapy in patients with Stage IB, II, or IIIA NSCLC prior to curative-intent resection. Approximately 180 patients with NSCLC will be enrolled in this study at 15 academic medical centers in the United States. There are two parts to this study: the first/primary part will evaluate the ability of neoadjuvant atezolizumab to produce objective pathologic responses in patients with early stage NSCLC. Atezolizumab 1200 mg IV will be given every 3 weeks for two doses. Surgical resection of tumors following treatment will allow determination of pathologic response rates and potential predictive biomarkers. Part 2 is exploratory and will evaluate atezolizumab adjuvant therapy for up to 12 months in patients who demonstrate clinical benefit (evidence of pathologic response or absence of radiographic progression) in Part 1. After surgical resection, patients may receive SOC adjuvant chemotherapy (with or without radiation) before starting atezolizumab adjuvant therapy in Part 2. The primary objectives are safety and major pathologic response based on surgical resection. Secondary objectives include overall response rate based on PD-L1 status, mutational load, antigen burden, and RNA-sequencing. This trial presents a unique opportunity to evaluate exploratory biomarkers, including pre- and post-treatment biopsy assessment of evolution of immune related markers associated with response.

      Results:
      Section not applicable

      Conclusion:
      Section not applicable