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Yoo Duk Choi



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    P1.01 - Advanced NSCLC (Not CME Accredited Session) (ID 933)

    • Event: WCLC 2018
    • Type: Poster Viewing in the Exhibit Hall
    • Track:
    • Presentations: 1
    • Moderators:
    • Coordinates: 9/24/2018, 16:45 - 18:00, Exhibit Hall
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      P1.01-77 - Osimertinib in the First-Line Treatment of Non-Small Cell Lung Cancer Harboring Activating EGFR Mutation from Circulating Tumor DNA (ID 13686)

      16:45 - 18:00  |  Author(s): Yoo Duk Choi

      • Abstract
      • Slides

      Background

      Osimertinib is a potent, irreversible third-generation epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) for both EGFR activating and T790M resistant mutation. In this trial, the treatment efficacy of osimertinib was assessed in previously untreated patients with advanced or metastatic non-small cell lung carcinoma (NSCLC) harboring the EGFR activating mutation, which was detected from circulating tumor DNA (ctDNA) combined with tumor genotyping.

      a9ded1e5ce5d75814730bb4caaf49419 Method

      Venous blood sampling was performed from the patients with EGFR activating mutation confirmed by tissue genotyping. To extract ctDNA from the plasma, 15 mL of peripheral blood was withdrawn and centrifuged, immediately before storage. CobasTM v2 and PANA MutyperTM were used for ctDNA genotyping. Patients with the EGFR activating mutation, detected from ctDNA, were enrolled and received a once-daily administration of osimertinib, 80 mg. The primary endpoint was objective response rate (ORR), and secondary endpoints were ctDNA test sensitivity, progression-free survival (PFS), duration of response (DoR), and safety of osimertinib treatment (ClinicalTrials.gov, Identifier: NCT02769286).

      4c3880bb027f159e801041b1021e88e8 Result

      Thirty-nine patients with activating EGFR mutations in tumor genotyping were screened from February 2017, and the enrollment of the last patient was completed in March 2018. The ctDNA of 29 patients was positive for activating EGFR mutation, and 19 patients were enrolled (exon 19 deletion, n=11; L858R or L861Q, n=7; G719A, n=1). Median age was 70 years (range 32-84) and the majority of patients had brain metastasis (15/19, 78.9%). In the response-evaluable population (n=17), ORR was 64.7% (11/17) and DCR was 94.1% (16/17). According to EGFR mutation type of tumor genotyping, patients with exon 19 deletion showed more favorable ORR (8/9, 88.9%) than patients with exon 21 L858R/L861Q (3/7, 42.9%). In patients evaluable for CNS response (n=14), DCR of brain metastasis was 100.0% (14/14). The sensitivity of the ctDNA tests for activating EGFR mutation was 74.4% when using both tests, and 61.5% (Mutyper) or 64.1% (Cobas V2) with either test. Only one patient experienced drug-related interstitial pneumonia of grades ≥3 and resulted in drug discontinuation. Survival data including PFS was not matured (2/19, 10.5%) and the analysis will be followed.

      8eea62084ca7e541d918e823422bd82e Conclusion

      Osimertinib had favorable efficacy in first-line treatment of NSCLC harboring the EGFR activating mutation, detected from ctDNA combined with tumor genotyping, even though in patients with old age and brain metastasis.

      6f8b794f3246b0c1e1780bb4d4d5dc53

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    P3.01 - Advanced NSCLC (Not CME Accredited Session) (ID 967)

    • Event: WCLC 2018
    • Type: Poster Viewing in the Exhibit Hall
    • Track:
    • Presentations: 1
    • Moderators:
    • Coordinates: 9/26/2018, 12:00 - 13:30, Exhibit Hall
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      P3.01-77 - Clinical Characteristics of Korean Lung Cancer Patients with Programmed Death-Ligand 1 Expression (ID 12770)

      12:00 - 13:30  |  Author(s): Yoo Duk Choi

      • Abstract
      • Slides

      Background

      Programmed death-ligand 1 (PD-L1) is a transmembrane protein that binds to the programmed death-1 (PD-1) receptor and anti-PD-1 therapy enables the immune response against tumors. The aim of this study was to assess the clinical and pathologic characteristics of PD-L1 positive lung cancer patients in Korea. And we examined correlation between immunohistochemical assays.

      a9ded1e5ce5d75814730bb4caaf49419 Method

      We retrospectively reviewed the clinical and pathologic data of pathologically proven lung cancer patients, and collected 267 cases of formalin-fixed, paraffin-embedded tissue sample from single institution. PD-L1 expression was detected by qualitative immunohistochemical assay using Monoclonal Mouse Anti-PD-L1, Clone 22C3. PD-L1 protein expression is determined by using Tumor Proportion Score (TPS), which is the percentage of viable tumor cells showing partial or complete membrane staining. We categorized according to the percentage of TPS; more than 1% or more than 50%. Among 267 patients, 34 were analyzed by both 22C3 and SP263 assays. We examined the concordance correlation between IHC assays.

      4c3880bb027f159e801041b1021e88e8 Result

      A total of 267 patients were enrolled and major histologic types were adenocarcinoma (69.3%). The majority was smoker (67.4%) and clinical stage IV (60.7%). Thirty one (11.6%) cases of EGFR mutation and 17 (6.4%) cases of ALK FISH positive were included. The patients who showed TPS ≥ 1% and 50% were 116 (42%) and 58 (21%), respectively. More than 1% of TPS group was consisted of adenocarcinoma (67.8%), squamous cell carcinoma (29.6%), and small cell carcinoma (1.9%) histology. And more than 50% of TPS group was composed of adenocarcinoma (72.4%), squamous cell carcinoma (22.4%). More than 1% of TPS group was significantly older than less than 1% of TPS group (64.83 ± 9.38 vs. 61.73 ± 10.78 years, p=0.014). The rate of poorly differentiated pathology was significantly higher in TPS ≥ 1% group (40.8% vs. 25.8%) and TPS ≥ 50% group (53.2% vs. 27.2%). There was no difference in smoking, EGFR mutation, ALK rearrangement status or biopsy site. Among 34 patients analyzed by both 22C3 and SP 263, 27 patients showed positive by both 22C3 and SP263, at the cut-off of 1% or higher. The concordance correlation coefficient was 0.826 (95% confidence interval: 0.736-0.916).

      8eea62084ca7e541d918e823422bd82e Conclusion

      In Korean lung cancer patients, PD-L1 positive group defined as TPS ≥ 1% was older than negative group. And major histology was poorly differentiated non-small cell lung cancer in both TPS ≥ 1% and 50% groups. And our results showed a high correlation between PD-L1 IHC expression data analyzed by 22C3 and SP263 assays.

      6f8b794f3246b0c1e1780bb4d4d5dc53

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