Motion Recognition and Planning Using Gaussian Process Dynamical Models

학위논문 (박사)-- 서울대학교 대학원 공과대학 기계항공공학부, 2017. 8. 박종우.본 논문에서는 로봇이 해석적으로 정의되지 않은 환경에 대응하는 문제에 관해 다룬다. 이 환경에는 로봇이 피해야 하는 장애물과 하지 외골격 로봇 착용자의 동작 의도와 밀접하게 연관된 지형지물이 있다. 관절 공간과 그 저차원 공간에서의 경로 계획법을 통해 장애물을 회피 하였고 기계학습 기법을 통해 지형지물에 기인한 사람의 동작 의도를 추정하였다. 먼저 Gaussian process dynamical models (GPDM) 기반으로 하지 외골격 로봇 착용자의 운동 의도를 추정하는 알고리즘을 제안하였다. 관측한 짧은 시계열 입력 값에 대하여 이에 상응하는 저차원 공간 좌표를 Gaussian process regression 을 통해 얻는다. 각 모델에 대한 유사도는 학습 데이터에 대한 관측 값과 그 저차원 공간 좌표의 로그 조건부 확률분포 형태로 표현된다. 이 유사도를 비교하여 가장 가능성 있는 동작을 추정한다. 하지 외골격 로봇 프로토타입 및 동작 추적 시스템을 이용한 물리적 실험을 통해 우리의 알고리즘을 검증하였다. 다음으로는 적응적으로 스텝사이즈를 결정하는 RRT 알고리즘을 제안하였다. 지수 곱(Product of Exponentials, PoE) 형태로 표현된 로봇의 정기구학과 표준 작용소 노름 부등식으로부터 직렬 개 연쇄 로봇의 엔드이펙터의 작업공간에서의 최대 변위와 관절 공간에서의 변위에 대한 부등식으로 유도하였다. 이 부등식을 이용하여 주어진 장애물의 최소 크기에 대하여 적응적으로 스텝사이즈를 결정하였다. 10 자유도 평면 개 연쇄 로봇과 7축 산업용 매니퓰레이터를 이용하여 우리의 알고리즘을 검증하였다. 마지막으로 사람의 시연 동작을 GPDM을 이용해 저차원 공간으로 학습하여, 사람과 유사한 동작을 생성하는 저차원 공간에서의 경로 계획 방법을 제안하였다. 앞서 유도한 부등식을 저차원 공간에서의 변위와 작업공간에서의 각 링크의 변위에 대한 부등식으로 확장하였다. 이를 이용하여 작업공간에서 정의된 장애물을 샘플링 기반으로 저차원 공간으로 매핑하였다. 그리고 학습한 동작과 새롭게 생성한 동작 사이의 유사성을 측정하는 측도를 GPDM 커널함수를 기반으로 정의하였다. 시뮬레이터와 실제 로봇에 적용해 봄으로써 제안한 방법의 유효성을 검증하였다.In this thesis, we deal with the problems that the robot copes with unstructured environments. Examples of such environments are obstacles that robots should avoid and terrain features that are closely related to the intentions of the wearer of an exoskeleton robot. We make robots to avoid obstacles through path planning algorithms in joint space and its low-dimensional space. We also estimate human motion intentions caused by terrain features using machine learning techniques. First, we propose an algorithm based on Gaussian process dynamical models (GPDM) to estimate motion intention of the wearer of exoskeleton robot. For the observed short time series input values, the corresponding low dimensional space coordinates are obtained via Gaussian process regression. The similarity for each model is expressed in the form of the logarithm of the conditional probability distribution of observed values and its low-dimensional coordinates given the training data. This similarity is compared to estimate the most likely motion. We validate our algorithm through physical experiments using an exoskeleton robot prototype and motion tracking system. Next, we propose a rapidly-exploring random tree (RRT) algorithm that adaptively determines an appropriate stepsize. Using a standard operator norm inequality and the forward kinematics equations expressed as the product of exponentials, we derive an approximate bound on the Cartesian displacement of the open chain tip for a given joint space displacement. Using this inequality bound, we adaptively determine the stepsize for a given minimum obstacle size. We verify our algorithm by numerical experiments using a ten-dof planar open chain robot and a seven-axis industrial manipulator. Finally, we propose a path planning method in a low-dimensional space that generates a human-like motion by learning the human demonstration motion using GPDM. We extend the above inequality to the inequality between displacement in the low-dimensional space and displacement of each links in the workspace. We use this to map the obstacles defined in the workspace to the low-dimensional space based on the uniform sampling. In addition, we define a measure based on the GPDM kernel function to measure the similarity between the learned motion and the newly generated motion. We validate the proposed method by applying it to a simulator and an actual robot.Abstract iii List of Tables xi List of Figures xiii 1 Introduction 1 1.1 Contributions of This Thesis . . . . . . . . . . . . . . . . . . . . . . 4 1.1.1 GPDM-Based Human Motion Intention Recognition for Lower-Limb Exoskeleton . . . . . . . . . . . . . . . . . . . . . . . . 4 1.1.2 An Adaptive Stepsize RRT Planning Algorithm for Open Chain Robots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1.1.3 A Gaussian Process Dynamical Model-Based Planning Method 8 1.2 Organization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2 Preliminaries 11 2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 2.2 Gaussian Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 2.2.1 Gaussian Process Regression . . . . . . . . . . . . . . . . . . 12 2.2.2 Gaussian Process Latent Variable models . . . . . . . . . . . 16 2.2.3 Gaussian Process Dynamical Models . . . . . . . . . . . . . . 19 2.3 Forward Kinematics of Open Chains . . . . . . . . . . . . . . . . . . 23 3 GPDM-Based Human Motion Intention Recognition for Lower-Limb Exoskeleton 27 3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 3.2 Human Motion Intention Recognition using GPDM . . . . . . . . . 29 3.3 Data Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 3.3.1 Human Motion Capture Data . . . . . . . . . . . . . . . . . 30 3.3.2 Sensor Mock-up Data . . . . . . . . . . . . . . . . . . . . . . 33 3.4 Experiments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 3.4.1 Previous Research . . . . . . . . . . . . . . . . . . . . . . . . 35 3.4.2 Human Motion Capture Data . . . . . . . . . . . . . . . . . 40 3.4.3 Sensor Mock-up Data . . . . . . . . . . . . . . . . . . . . . . 44 3.5 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 3.5.1 Comparison both Data Sets . . . . . . . . . . . . . . . . . . . 45 3.5.2 Sensitivity Analysis . . . . . . . . . . . . . . . . . . . . . . . 49 3.6 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 4 An Adaptive Stepsize RRT Planning Algorithm for Open Chain Robots 53 4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 4.2 A Cartesian Displacement Bound for Open Chains . . . . . . . . . 54 4.3 Adaptive Stepsize RRT . . . . . . . . . . . . . . . . . . . . . . . . . 58 4.4 Experiments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 4.4.1 Ten-Dof Planar Robot . . . . . . . . . . . . . . . . . . . . . . 65 4.4.2 Ten-Dof Planar Robot Case II: Latent Space RRT . . . . . 70 4.4.3 Seven-DoF Industrial Robot Arm . . . . . . . . . . . . . . . 77 4.5 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 5 A Gaussian Process Dynamical Model-Based Planning Method 85 5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 5.2 Learning from Demonstration Framework . . . . . . . . . . . . . . . 88 5.2.1 Learning a New Pose in the Latent Space . . . . . . . . . . 90 5.2.2 Constraints in Latent Space . . . . . . . . . . . . . . . . . . 91 5.2.3 Mapping Obstacle into Latent Space . . . . . . . . . . . . . 92 5.2.4 Motion Planning in Latent Space . . . . . . . . . . . . . . . 102 5.3 Experiments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108 5.3.1 Grasping Experiments . . . . . . . . . . . . . . . . . . . . . . 108 5.4 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 6 Conclusion 117 Bibliography 121 Abstract 128Docto

SKI-G-801, an AXL kinase inhibitor, blocks metastasis through inducing anti-tumor immune responses and potentiates anti-PD-1 therapy in mouse cancer models

Objectives: AXL-mediated activation of aberrant tyrosine kinase drives various oncogenic processes and facilitates an immunosuppressive microenvironment. We evaluated the anti-tumor and anti-metastatic activities of SKI-G-801, a small-molecule inhibitor of AXL, alone and in combination with anti-PD-1 therapy. Methods: In vitro pAXL inhibition by SKI-G-801 was performed in both human and mouse cancer cell lines. Immunocompetent mouse models of tumor were established to measure anti-metastatic potential of SKI-G-801. Furthermore, SKI-G-801, anti-PD-1 or their combination was administered as an adjuvant or neoadjuvant in the 4T1 tumor model to assess their potential for clinical application. Results: SKI-G-801 robustly inhibited pAXL expression in various cell lines. SKI-G-801 alone or in combination with anti-PD-1 potently inhibited metastasis in B16F10 melanoma, CT26 colon and 4T1 breast models. SKI-G-801 inhibited the growth of B16F10 and 4T1 tumor-bearing mice but not immune-deficient mice. An antibody depletion assay revealed that CD8+ T cells significantly contributed to SKI-G-801-mediated survival. Anti-PD-1 and combination group were observed the increased CD8+Ki67+ and effector T cells and M1 macrophage and decreased M2 macrophage, and granulocytic myeloid-derived suppressor cell (G-MDSC) compared to the control group. The neoadjuvant combination of SKI-G-801 and anti-PD-1 therapy achieved superior survival benefits by inducing more profound T-cell responses in the 4T1 syngeneic mouse model. Conclusion: SKI-G-801 significantly suppressed tumor metastasis and growth by enhancing anti-tumor immune responses. Our results suggest that SKI-G-801 has the potential to overcome anti-PD-1 therapy resistance and allow more patients to benefit from anti-PD-1 therapy.ope

Incorporation of SKI-G-801, a Novel AXL Inhibitor, With Anti-PD-1 Plus Chemotherapy Improves Anti-Tumor Activity and Survival by Enhancing T Cell Immunity

A recently developed treatment strategy for lung cancer that combines immune checkpoint inhibitors with chemotherapy has been applied as a standard treatment for lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC), and it has improved the outcomes of chemotherapy. Maintenance treatment with anti-PD-1 antibody (aPD-1) enhances the effect of immunochemical combination therapy and improves therapeutic efficacy, which contributes toward a significant improvement in patient survival rates. The AXL receptor tyrosine kinase (AXL), which is expressed in tumor cells, plays an essential role in the resistance of cancers to chemotherapy and immunotherapy, and stimulates signaling associated with epithelial-mesenchymal transition (EMT) in metastatic cancer. AXL is thus an attractive target for controlling resistance to anti-tumor therapies. In this study, we examined the effect of AXL inhibitors on immune activation and tumor growth in TC1 and C3PQ mouse tumor models, in the context of clinical immunotherapy/chemotherapy and maintenance treatment, using an aPD-1 with/without pemetrexed. To determine the optimal timing for administration of SKI-G-801, an AXL inhibitor, we investigated its anti-tumor effects based on inclusion at the immunochemotherapy and maintenance therapy stages. We also performed flow cytometry-based immune profiling of myeloid cells and lymphoid cells at different points in the treatment schedule, to investigate the immune activation and anti-tumor effects of the AXL inhibitor. The addition of SKI-G-801 to the immune checkpoint inhibitor and chemotherapy stage, as well as the maintenance therapy stage, produced the best anti-tumor results, and significant tumor growth inhibition was observed in both the TC1 and C3PQ models. Both models also exhibited increased proportion of effector memory helper T cells and increased expression of CD86+ macrophages. Especially, regulatory T cells were significantly reduced in the TC1 tumor model and there was an increase in central memory cytotoxic T cell infiltration and an increased proportion of macrophages with high CD80 expression in the C3PQ tumor model. These results suggest increased infiltration of T cells, consistent with previous studies using AXL inhibitors. It is expected that the results from this study will serve as a stepping stone for clinical research to improve the existing standard of care.ope

Patient-Derived Cells to Guide Targeted Therapy for Advanced Lung Adenocarcinoma

Adequate preclinical model and model establishment procedure are required to accelerate translational research in lung cancer. We streamlined a protocol for establishing patient-derived cells (PDC) and identified effective targeted therapies and novel resistance mechanisms using PDCs. We generated 23 PDCs from 96 malignant effusions of 77 patients with advanced lung adenocarcinoma. Clinical and experimental factors were reviewed to identify determinants for PDC establishment. PDCs were characterized by driver mutations and in vitro sensitivity to targeted therapies. Seven PDCs were analyzed by whole-exome sequencing. PDCs were established at a success rate of 24.0%. Utilizing cytological diagnosis and tumor colony formation can improve the success rate upto 48.8%. In vitro response to a tyrosine kinase inhibitor (TKI) in PDC reflected patient treatment response and contributed to identifying effective therapies. Combination of dabrafenib and trametinib was potent against a rare BRAF K601E mutation. Afatinib was the most potent EGFR-TKI against uncommon EGFR mutations including L861Q, G719C/S768I, and D770_N771insG. Aurora kinase A (AURKA) was identified as a novel resistance mechanism to olmutinib, a mutant-selective, third-generation EGFR-TKI, and inhibition of AURKA overcame the resistance. We presented an efficient protocol for establishing PDCs. PDCs empowered precision medicine with promising translational values.ope

A study on Risk Premium in Ship Finance: Focused on Collateral vlaue of ships

2008년 9월 금융위기 발생 이후 선박금융 시장은 커다란 변화를 겪고 있다. 해운산업이 장기침체를 벗어나지 못하면서 선박의 현금흐름 창출능력이 저하되어 선박의 담보가치에 대한 근본적인 의문이 제기되고 있다. 선박금융은 항공기금융과 더불어 대표적인 자산담보부금융의 하나로 인식되어왔다. 선박금융의 발달과정을 살펴보면 선박이 안정적 담보가치를 가진 자산으로 인식되면서 금융기관은 선박을 인플레 방어수단으로 여겨 선박금융을 자산담보부금융으로 발전시켰다. 그러나 2008년 이후 운임시장의 장기 불황은 선박의 담보가치에 대한 근본적인 변화를 야기 시켰다. 본 연구는 선박금융의 리스크 프리미엄에 선박의 담보가치이외에 어떠한 요소들이 영향을 미치는지 비재무적 요소들인 선가, 대출규모, 대출시기, 선종, 대출연도를 중심으로 분석하였다. 분석결과 선가, 대출규모, 대출시기, 선종은 리스크 프리미엄에 영향을 미치지 못하고 대출시기(2008년 이후 대출분)만 영향을 미치는 것으로 나타났다. 이는 기존의 선박금융에서 중요하게 다뤄지던 요소들이 시장변화에 따라 바뀌고 있음을 시사한다. 주제어 : 선박의 담보가치, 리스크 프리미엄, 시장상황제1장 서론 1 1.1 연구 배경과 연구 목적 1 1.2 연구 방법과 연구 범위 3 1.3 논문의 구성 4 제2장 선행연구 5 제3장 선박금융 9 3.1 선박금융개요 9 3.2 선박금융시장 동향 10 3.3 선박금융의 종류 11 3.4 본 연구의 대상 14 제4장 자산담보부금융 및 리스크 프리미엄 15 4.1 자산담보부금융의 의의 15 4.2 차주의 성격에 따른 담보가치의 변화 16 4.3 DSCR, LTV 등에 따른 담보가치의 변화 17 4.4 리스크 프리미엄 18 4.5 위험과 수익의 교환관계 18 제5장 연구방법 20 5.1 분석방법 20 5.2 변수의 선정 21 5.2.1 선가지수 22 5.2.2 대출규모 23 5.2.3 대출기간 23 5.2.4 선종 24 5.2.5 대출연도 25 5.3 리스크 프리미엄 26 제6장 분석결과 28 6.1 선가지수 29 6.2 대출규모 33 6.3 대출기간 34 6.4 선종 34 6.5 대출시기 34 제7장 결론 36 7.1 연구결과 요약 36 7.2 시사점 및 한계 37 참고문헌 39Maste

Prognostic implications of PD-L1 expression in patients with angiosarcoma

Aim: There are limited data on the feasibility of programmed death ligand-1 (PD-L1) expression as a prognostic biomarker in metastatic angiosarcoma. Patients & methods: We retrospectively collected and analyzed the data on PD-L1 expression in 70 angiosarcoma patients who were diagnosed at our center between 2005 and 2019. Results: Thirteen (19%) patients had PD-L1 expression. Metastatic angiosarcoma patients who were PD-L1-negative (n = 24) showed longer median progression-free survival (4.9 vs 1.6 months; p = 0.04) and median overall survival (OS; 10.9 vs 5.4 months; p = 0.01) than those who were PD-L1-positive (n = 4). PD-L1 status proved to be a significant factor for OS. Conclusion: Metastatic angiosarcoma patients with PD-L1 expression showed shorter survival. PD-L1 status is an independent prognostic factor for OS in metastatic angiosarcoma patients.ope

A phase II study of poziotinib in patients with recurrent and/or metastatic head and neck squamous cell carcinoma

Background: In phase I studies, poziotinib has shown meaningful efficacy against various types of cancers. This phase 2 study aimed to investigate the efficacy and safety of poziotinib in recurrent and/or metastatic head and neck squamous cell carcinoma (R/M-HNSCC). Methods: Overall, 49 patients were enrolled (median age, 62 years; age range, 21-78 years). Patients received a median of two prior treatments including chemotherapy and others and received 12 mg poziotinib orally once daily as part of a 28-day cycle. The primary endpoint was objective response rate (ORR), and the secondary endpoints were progression-free survival (PFS) and overall survival (OS). Targeted capture sequencing was performed using available tissues to identify translational biomarkers related to clinical response. Results: ORR was 22.4%, median PFS was 4.0 months (95% confidence interval [CI], 1.8-6.2 months), and median OS was 7.6 months (95% CI, 4.4-10.8 months). The most common treatment-related adverse events were acneiform rash (85%) and mucositis (77%). A grade 3 or higher adverse event was acneiform rash (3%). Targeted capture sequencing was performed in 30 tissue samples. TP53 and PIK3CA were the most frequently mutated genes (43%), followed by CCND1 (33%) and EGFR (30%). Mutations in ERBB2, ERBB3, and ERBB4, which are HER family genes, were observed in 17%, 13%, and 10% samples, respectively. There was no difference in the frequency of somatic mutations in the HER family genes between the clinically benefitted and non-benefitted groups. Conclusion: Compared to other pan-HER inhibitors, poziotinib showed clinically meaningful efficacy in heavily treated R/M-HNSCC. Clinical trial registration number: NCT02216916.ope

Real World Characteristics and Clinical Outcomes of HER2-Mutant Non-Small Cell Lung Cancer Patients Detected by Next-Generation Sequencing

Purpose This study was conducted to investigate the clinical characteristics of patients with advanced non–small cell lung cancer (NSCLC) harboring human epidermal growth factor receptor 2 (HER2) mutations and to evaluate response to standard treatment and HER2-targeted agents. Materials and Methods Using tissue and/or blood next-generation sequencing, we identified 44 patients with NSCLC harboring HER2 mutations who were treated at Severance Hospital between December 2016 and February 2021. Clinical data, including patient characteristics, mutation status, incidence of metastasis for distant lesions, and response to chemotherapy, were retrospectively analyzed. Results The median age was 58 years, and 61% of the patients were female. Most patients (64%) were never-smokers. Adenocarcinoma was the most predominant subtype (98%). A total of 66% of the patients had extrathoracic metastatic lesions, and 32% had intracranial lesions at initial presentation. The median time to the development of brain metastasis was 15.6 months (range, 2.4 to 43.7). The most common type of HER2 mutation was 12 base pair in-frame insertion in exon 20, A775_G776insYVMA. Of the 44 patients, two had concomitant driver mutations, one with epidermal growth factor receptor (EGFR) mutation (V769M), and one with BRAF mutation (V600E). Patients treated with pemetrexed-based chemotherapy (75%) had an overall response rate (ORR) and progression-free survival (PFS) of 30% and 8.3 months (95% confidence interval [CI], 3.9 to 12.7), respectively. The ORR and PFS of HER2-targeted agent treated patients (14%) were 0.0% and 1.9 months (95% CI, 0.1 to 2.8), respectively. Conclusion Given its distinct characteristics and treatment responses, novel treatment strategies for HER2-mutant NSCLC should be developed promptly to improve survival outcomes of patients.ope

Analyses of CNS Response to Osimertinib in Patients with T790M-Positive Advanced NSCLC from ASTRIS Korean Subset, Open-Label Real-World Study

Up to 40% of patients with epidermal growth factor receptor (EGFR) mutation-positive non-small-cell lung cancer (NSCLC) may develop central nervous system (CNS) metastases throughout their disease. Moreover, the first- and second-generation EGFR-tyrosine kinase inhibitors have limited efficacy because of their poor blood–brain barrier permeability. Therefore, we conducted preplanned analyses of ASTRIS, a clinical study of the third-generation EGFR-TKI osimertinib to demonstrate its potential role in intracranial response efficacies. We retrospectively examined 89 NSCLC patients with brain evaluation who were not amenable to curative surgery or radiotherapy and received osimertinib upon confirmation of the presence of the T790M mutation. We collected the information regarding patients’ baseline characteristics, baseline intracranial status, including leptomeningeal metastases (LM), and intracranial responses measured by Response Evaluation Criteria in Solid Tumors version 1.1, using independent central review. The median age was 60 years, and 69.7% of the patients were female. Sixty-five patients (73.0%) had brain metastases (BM) at baseline and nineteen patients (23.5%) had additional LM. Among patients with brain metastases, 24 (36.9%) had ≥1 measurable brain metastases and 16 were evaluated for the objective response. In the CNS evaluable for response set, the intracranial objective response rate (cORR) and disease control rate (cDCR) were 62.5% (95% confidence interval (CI), 38.3–82.6%) and 93.8% (95% CI, 74.3–99.3%), respectively. The median intracranial progression-free survival (cPFS) was 13.0 (95% CI, 7.21–18.8) months, including patients with measurable and non-measurable BM or LM. Our cORR, cDCR, and cPFS were comparable to those observed in previous clinical trials. The outcome of this study helps to demonstrate the potential role of intracranial efficacies of osimertinib 80 mg administration in T790M-positive advanced NSCLC with/without BM or LM. View Full-ope

Real-World Analysis of the Efficacy of Rebiopsy and EGFR Mutation Test of Tissue and Plasma Samples in Drug-Resistant Non-Small Cell Lung Cancer

PURPOSE: Standard treatment for cases of non-small cell lung cancer (NSCLC) exhibiting acquired drug resistance includes tumor rebiopsy, epidermal growth factor receptor (EGFR) mutation testing (e.g., for T790M mutations), and the subsequent administration of third-generation EGFR-tyrosine kinase inhibitors (EGFR-TKIs). However, rebiopsies are typically invasive, costly, and occasionally not feasible. Therefore, the present study aimed to assess rebiopsy procedures by analyzing real-world data collected by the ASTRIS study of patients with resistant NSCLC. MATERIALS AND METHODS: The present study used statistical models to evaluate data collected by the ASTRIS trial (NCT02474355) conducted at Yonsei Cancer Center, including the rebiopsy success rate, incidence of T790M mutations in collected tissue and plasma samples, and association of administered osimertinib treatment efficacy. RESULTS: In a total of 188 screened patients, 112 underwent rebiopsy. An adequate tumor specimen was obtained in 95 of these patients, the greatest majority of whom (43.8%) were subjected to bronchoscopy. T790M mutations were detected in 53.3% of successfully EGFR-tested rebiopsy samples. A total of 88 patients received osimertinib treatment, and the objective response rate and median progression-free survival time was 44.3% and 32.7 weeks, respectively, among the treated patients overall, but 57.8% and 45.0 weeks, and 35.2% and 20.4 weeks among patients who exhibited T790M-positive tissue (n=45) and plasma (n=54) samples, respectively. CONCLUSION: Approximately 60% of patients in the analyzed real-world cohort were eligible for tissue rebiopsy upon NSCLC progression. Osimertinib activity was higher in patients in whom T790M mutations were detected in tissues rather than in plasma samples.ope