Author of

• 18502

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  P3.02c - Poster Session with Presenters Present (ID 472)

  • Event: WCLC 2016
  • Type: Poster Presenters Present
  • Track: Advanced NSCLC
  • Presentations: 1
  • Moderators:
  • Coordinates: 12/07/2016, 14:30 - 15:45, Hall B (Poster Area)

  • 18582

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    P3.02c-080 - The Beneficial Effect of Platelet Binding to Monocytes on the Clinical Response to Checkpoint Inhibitors (ID 6032)

    14:30 - 14:30  |  Author(s): C. Zamora
    • Abstract

    Background:
    Nivolumab is an immune checkpoint inhibitor that reactivates cytotoxic T cells against tumor cells in non-small cell lung cancer (NSCLC) patients (pts). There are many ongoing efforts to find predictive biomarkers for immune checkpoint inhibitors. We have previously reported that platelet can selectively bind to leukocytes and, as a consequence, modify their function. To evaluate whether this modification is relevant for the response to checkpoint inhibitors, we determined the percentage of different subsets of leukocytes with bound platelets in the peripheral blood of pts before starting treatment with Nivolumab.
    
    Methods:
    Peripheral blood samples were collected at baseline from patients with NSCLC candidates for receiving Nivolumab. After labeling cells with antibodies specific for lymphocytes, monocytes and neutrophils, we added anti-CD41a mAbs (specific for platelets). We next determined the percentage of PDL1+ cells and CD41+ cells in each leukocyte subset by flow cytometry. These results were compared in patients with different clinical response by one-way ANOVA. The clinical response was determined by RECIST v1.1 criteria.
    
    Results:
    From January 2015 to February 2016, we collected peripheral blood from 12 pts (4 females and 8 males). Mean age at time to starting Nivolumab was 73 (range 53-86). 4 pts were smokers and 8 former smokers. 5 pts were had squamous cell carcinoma and 6 non-squamous cell carcinoma. 6 Pts received Nivolumab in second line and 6 patients in third line. Response after 3 months with Nivolumab: 4 patients with partial or complete response, 4 patients with stable disease and 4 with progressive disease. There were no differences in the baseline percentages of CD4+, CD8+, Natural Killer cells, B lymphocytes, monocytes and neutrophils among the three groups of response. By contrary, the proportion of monocytes with bound platelets (CD14+CD41+/ total monocytes) was significantly higher in patients with response to nivolumab than those with stable or progressive disease (90.28+7.63%, 33.92+7.02 and 61.44+19.5% respectively, p=0.002). And Also, the PDL1 expression on monocytes was different between the three groups (1.9+0.16, 4.37+1.05 and 2.39+0.73 respectively, p=0.003).
    
    Conclusion:
    The functional modification induced by the platelet binding to the monocytes seems to be beneficial for the clinical response to checkpoint inhibitors.