Author of

• 30943

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  P2.04 - Immuno-oncology (ID 167)

  • Event: WCLC 2019
  • Type: Poster Viewing in the Exhibit Hall
  • Track: Immuno-oncology
  • Presentations: 1
  • Moderators:
  • Coordinates: 9/09/2019, 10:15 - 18:15, Exhibit Hall

  • 30944

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    P2.04-01 - Changes of BCR Repertoire Are Predictive Biomarker for the Efficacy of Immune Checkpoint Inhibitor in NSCLC (ID 1688)

    10:15 - 18:15  |  Author(s): Tetsuro Sasada
    • Abstract

    Background
    

    Clonal diversity of T cell receptor (TCR) and/or B cell receptor (BCR) repertoires might play a major role in antitumor immunity in cancer patients. Assessment of TCR and BCR repertoires might enable us to predict the efficacy of immune checkpoint inhibitors (ICI).

    Method
    

    The study population comprised 30 patients with non-small-cell lung cancer (NSCLC), who started treatment with nivolumab (3mg/kg, every two weeks) or pembrolizumab (200mg, every three weeks) between February 2016 and August 2017. Patient blood samples were collected before and four to six weeks after the initiation of treatment. TCR and BCR chain sequences were determined by using the unbiased gene amplification method with Adaptor-Ligation PCR. The diversity of TCR and BCR repertoires was evaluated with inverse Shannon-Weaver index (iSWI).

    Result
    

    We compared the iSWI between before and after treatment. The fold changes of iSWI in BCR repertoire after treatment in patients with PR were significantly higher than those with SD or PD. In contrast, the fold changes of iSWI in TCR repertoire after treatment were not associated with tumor responses. When the cut-off value of fold change of iSWI in BCR repertoire after treatment was determined as 0.85, 25 (83%) and 5 (17%) patients were considered as high and low fold change group, respectively. Progression free survival in the high fold change group was significantly longer compared with that in the low fold change group (182 vs 49 days; 95% confidence interval (CI);99-N.R. vs 31-168 days, respectively; P=0.01).

    Conclusion
    

    Our findings suggest that reduced repertoire diversity in BCR, but not in TCR, might be associated with better clinical outcomes in advanced NSCLC patients treated with ICI. Assessment of the changes of BCR repertoire after treatment might be useful for predicting the efficacy of ICI. The present results require confirmation in a large-scale prospective study.