Author of

• 17629

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  P2.03b - Poster Session with Presenters Present (ID 465)

  • Event: WCLC 2016
  • Type: Poster Presenters Present
  • Track: Advanced NSCLC
  • Presentations: 1
  • Moderators:
  • Coordinates: 12/06/2016, 14:30 - 15:45, Hall B (Poster Area)

  • 17706

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    P2.03b-077 - EGFR/ALK+ Patient-Derived Xenografts from Advanced NSCLC for TKI Drug Selection & Resistance Development: The REAL-PDX Study (ID 6081)

    14:30 - 14:30  |  Author(s): J. McConnell
    • Abstract

    Background:
    Lung cancer patient-derived xenografts (PDX) have shown to be representative models for individual patient tumors. Theoretically, such models could inform the choice of subsequent lines of therapy, since PDX development, TKI resistance induction, and subsequent drug-screening can be completed before TKI resistance develops in the patient. The goal of Resistance modeling in EGFR and ALK Lung cancer (REAL)-PDX is to develop PDX models for real-time treatment selection of subsequent lines of therapy in advanced-stage NSCLC patients.
    
    Methods:
    Since August 2015, Princess Margaret Cancer Centre patients with EGFR/ALK+, as well as lifetime never-smoking lung cancer patients with unknown mutation status, were consented to have additional tumor sampling for PDX development during routine- or trial-related biopsies. Tumor sufficiency was confirmed prior to implantation into non-obese severe combined immunodeficient (NOD-SCID) mice, with successful engraftment defined as propagation beyond first passage; unsuccessful implantations had no palpable tumor after 6 months.
    
    Results:
    72/82 (88%) approached patients consented; 49/72 (68%) had adequate tumor tissue for implantation (71% stage III/IV): 46 adenocarcinomas, 2 squamous cell carcinoma, 1 LCNEC. 36/49 (73%) were lifetime never smokers. Patients received adjuvant chemotherapy (3), TKI therapy (15), both (5), or no treatment (26) prior to sampling. Tumor samples were taken from surgically resected lung (18), metastatic adrenal (1) and brain (2), CT-guided lung biopsies (5), endoscopic ultrasound-guided (EBUS) biopsies (6), and thoracentesis pleural fluid (17) specimens. Twenty-eight implanted tumors were EGFR+ (12 exon19 deletions, 2 exon19 deletion/T790M, 1 exon19 del/exon18 mutation, 12 L858R, and 1 L858R/T790M); 7 had ALK-rearrangements, and 1 had ROS1-rearrangement. Engraftment rates of 31 assessable implanted tumors were as follows: lung resections 12/12 (100%), metastatic resections 2/3 (67%), CT- or EBUS-guided biopsies 1/5 (20%), and pleural fluid 2/11 (18%); Engraftment rate was associated with no prior treatment (14/17 no treatment vs 3/14 any treatment, p=0.001). Of 17 assessable tumors with EGFR activating mutations, 9 engrafted (53%). Of 3 assessable tumors with ALK-rearrangement, 1 was successful (33%).
    
    Conclusion:
    PDX development of EGFR/ALK+ models for testing with novel therapeutics from various tumor biopsy sites is feasible and will provide valuable real-time information for subsequent treatment decisions in advanced NSCLC patients. Updated engraftment and drug screening data will be presented.