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Patrick Pauwels



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    MA26 - New Therapies and Emerging Data in ALK, EGFR and ROS1 (ID 930)

    • Event: WCLC 2018
    • Type: Mini Oral Abstract Session
    • Track: Targeted Therapy
    • Presentations: 2
    • Moderators:
    • Coordinates: 9/26/2018, 13:30 - 15:00, Room 201 BD
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      MA26.06 - Crizotinib-Treated ALK Immunopositive Metastasized NSCLC is Associated with an Unfavorable Prognosis when FISH Negative  (ID 13179)

      14:05 - 14:10  |  Author(s): Patrick Pauwels

      • Abstract
      • Presentation
      • Slides

      Background

      Metastasized NSCLC with an ALK fusion are sensitive to a range of tyrosine kinase inhibitors. ALK-positive NSCLC has been identified in the pivotal phase III trial with fluorescence in situ hybridization (ALK FISH+). These tumors are also expressing the fusion product (ALK immunohistochemistry (IHC)+). However, discrepant cases occur, including ALK IHC+ FISH-. The aim of this study was to collect ALK IHC+ cases and compare within this group response to crizotinib treatment of ALK FISH+ cases with ALK FISH- cases.

      a9ded1e5ce5d75814730bb4caaf49419 Method

      A prospective multicenter investigator initiated research study was started in Europe. Stage IV ALK IHC+ NSCLC cases treated with crizotinib were collected centrally. Slides were validated centrally for ALK IHC (with 5A4 ETOP and D5F3 Ventana protocol) and ALK FISH (Vysis probes).

      4c3880bb027f159e801041b1021e88e8 Result

      The study started April 1, 2014 and closed in November 2017. Fifteen centers participated. Registration of 3523 ALK IHC tests revealed prevalence of 2.6% ALK IHC+ cases. Local ALK FISH analysis resulted in 46 concordant (ALK IHC+/FISH+) and 18 discordant (ALK IHC+/FISH-) cases. Central validation revealed 37 concordant and 6 discordant cases, 5 of which had follow-up. Validation was hampered by limited amount of tissue in biopsy samples. The time to treatment failure did not differ for concordant nor discordant cases, and neither for local nor validated ALK testing (HR=0.78; 95% CI= 0.27-2.3; p=0.64) and (HR=2.2; 95% CI= 0.72-6.5; p=0.16), respectively). However, overall survival was significantly better for concordant cases than discordant cases after central validation (HR=4.5; 95% CI= 1.2-15.9; p=0.010), but not according to local testing (HR=1.7; 95% CI= 0.45-6.2; p=0.44).

      8eea62084ca7e541d918e823422bd82e Conclusion

      ALK IHC+ FISH- NSCLC cases are an infrequent finding. We recommend such cases to be validated carefully because our data indicate that ALK IHC+ FISH- cases have a worse survival when treated by crizotinib compared to ALK IHC+ FISH+ cases.

      This study was funded by an independent research grant by Pfizer

      6f8b794f3246b0c1e1780bb4d4d5dc53

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      MA26.07 - ROS1 (SP384) Immunohistochemistry Inter-Reader Precision Between 12 Pathologists (ID 12387)

      14:10 - 14:15  |  Author(s): Patrick Pauwels

      • Abstract
      • Presentation
      • Slides

      Background

      ROS1 positive non-small cell lung cancer (NSCLC) patients can be treated with specific tyrosine kinase inhibitors including crizotinib. ROS1 positivity is often clinically detected by fluorescence in situ hybridization (FISH), however ROS1 IHC can be used to screen samples prior to FISH confirmation of ROS1 status. The ROS1 (SP384) antibody detects ROS1 with high sensitivity, specificity, and consistency. Consistent interpretation of a ROS1 IHC assay between pathologists is important patient evaluation. Here we present inter-reader precision of 12 pathologists across 60 FFPE cases stained with ROS1 (SP384).

      a9ded1e5ce5d75814730bb4caaf49419 Method

      A retrospective cohort of 60 FFPE NSCLC cases stained with H&E, Rabbit Monoclonal Negative Control Ig, and ROS1 (SP384) were selected to represent positive, negative, and borderline ROS1 IHC status. Twelve practicing lung pathologists independently scored the cases as positive or negative around a cutoff of cytoplasm staining in > 30% tumor cells at a ≥2+ intensity level using Pathotrainer software (Pathomation bvba). Scoring was blinded to other readers and ROS1 status of the cases. Overall percent agreement (OPA), negative percent agreement (NPA), and positive percent agreement (PPA) were calculated in comparison to the group mode. Average overall percent agreement (AOPA), average positive agreement (APA), and average negative agreement (ANA) were calculated pairwise for each reader pair. Following independent assessment, participating pathologists conducted a discordant case review establishing consensus reads for all 60 cases and compared 44 cases to available FISH results.

      4c3880bb027f159e801041b1021e88e8 Result

      OPA of each of the 12 readers to the mode was 96.4% (95% CI 93.9-98.6) with PPA of 96.3% (95% CI 92.7-99.4) and NPA of 96.5% (95% CI 92.8-99.5). Pairwise AOPA between each of the 12 readers was 94.5% (95%CI 91.2-97.7) with APA 94.0% (95% CI 89.5-97.6) and ANA 95.0% (95%CI 91.2-97.9).

      Consensus IHC scores were concordant with FISH 90.0% (40/44 cases).

      8eea62084ca7e541d918e823422bd82e Conclusion

      Inter-reader precision around a cutoff of >30% tumor cells with cytoplasmic staining at a ≥2+ intensity level was high in interpreting ROS1 (SP384) in NSCLC samples. Case review highlighted confirmation with FISH in questionable cases and staining patterns to be considered when interpreting ROS1 (SP384) IHC.

      6f8b794f3246b0c1e1780bb4d4d5dc53

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    P2.06 - Mesothelioma (Not CME Accredited Session) (ID 955)

    • Event: WCLC 2018
    • Type: Poster Viewing in the Exhibit Hall
    • Track:
    • Presentations: 1
    • Moderators:
    • Coordinates: 9/25/2018, 16:45 - 18:00, Exhibit Hall
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      P2.06-25 - Combined Immune Checkpoint Blockade in Malignant Pleural Mesothelioma: In Vivo Validation of in Vitro Results (ID 12075)

      16:45 - 18:00  |  Author(s): Patrick Pauwels

      • Abstract
      • Slides

      Background

      Till today, human malignant pleural mesothelioma (MPM) remains an aggressive cancer with a poor prognosis due to the limited impact on overall survival of the current treatments. Data from us and others about the presence of the immune checkpoint-related molecules PD-1, PD-L1, TIM-3 and LAG-3 in MPM lay the basis to evaluate their suitability as immunotherapeutic targets. Two clinical trials that investigated PD-1 and PD-L1 inhibition in mesothelioma (KEYNOTE-28, JAVELIN trial) have shown promising results with room for improvement. It is of great interest to investigate the effect of combined treatments and compare them to stand-alone treatment to select the best therapeutic strategy for MPM.

      a9ded1e5ce5d75814730bb4caaf49419 Method

      Human cell lines representative for the epithelioid (NCI-H2818 and NCI-H2795) and sarcomatoid (NCI-H2731) subtypes of MPM were placed in allogeneic co-cultures with healthy donor peripheral blood mononuclear cells. The co-cultures were treated with the following immune checkpoint blocking antibodies: anti PD-1 (Nivolumab®, BMS) or anti PD-L1 (Durvalumab®, AstraZeneca) in combination with anti TIM-3 or anti LAG-3. Supernatant was collected and enzyme-linked immunosorbent assays and multiplex electrochemo-luminescence were used to look at the secretion of 7 cytokines, being IFNg, IL-2/5/6/10, IL-1b and TNF-a, as well as the enzyme granzyme B. Statistical analysis was done to investigate the differences between the treatment conditions.

      4c3880bb027f159e801041b1021e88e8 Result

      Treatment with immune checkpoint blockers as monotherapy or in combination resulted in a significant increase in the secretion of granzyme B and the cytokines IFNg, IL-2, IL-5 and IL-10. Although the increased secretion was not always statistically significant for all 3 MPM cell lines of the two subtypes, the same trends were observed among them. Interestingly, highest concentrations of granzyme B and these 4 cytokines were noticed for monotherapy treatment with anti PD-1, anti PD-L1 or either of these antibodies with anti TIM-3. In vivo investigation of PD-1 or PD-L1 blockade in combination with TIM-3 or LAG-3 blockade is currently ongoing to validate our in vitro results.

      8eea62084ca7e541d918e823422bd82e Conclusion

      Our data show that treatment with anti PD-1, anti PD-L1 or their respective combination with anti TIM-3 resulted in the highest secretion of cytokines and granzyme B, suggesting that these treatments stimulate the antitumor response the most. In vivo experiments are currently ongoing for validation.

      6f8b794f3246b0c1e1780bb4d4d5dc53

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