Author of

• 25955

  +

  P3.01 - Advanced NSCLC (Not CME Accredited Session) (ID 967)

  • Event: WCLC 2018
  • Type: Poster Viewing in the Exhibit Hall
  • Track:
  • Presentations: 1
  • Moderators:
  • Coordinates: 9/26/2018, 12:00 - 13:30, Exhibit Hall

  • 27369

    +

    P3.01-18 - Comparison of PD-L1 Immunohistochemical Assays and Clinical Response to Anti PD-1 Checkpoint Inhibitors in Patients with Lung Cancer (ID 14296)

    12:00 - 13:30  |  Author(s): Jiyeon Hyeon
    • Abstract
    • Slides

    Background
    

    The anti-programmed cell death 1 (PD-1) immune checkpoint inhibitors, nivolumab and pembrolizumab, are currently approved for the treatment of patients with NSCLC. The PD-L1 expression represents the most validated predictive marker of response to PD-1 inhibitors. However, there are several different immunohistochemical assays to assess the PD-L1 expression using different antibodies, platforms, and cutoff values. We compared the PD-L1 expression evaluated by IHC 22C3 PharmDx with that observed by Ventana SP263 and analyzed correlation with response to anti PD-1 inhibitors.

    a9ded1e5ce5d75814730bb4caaf49419 Method
    

    We retrospectively analyzed 109 patients with lung cancer to be treated with anti PD-1 inhibitors who have PD-L1 expression levels obtained with both the 22C3 and SP263 assays. We reviewed medical records to obtain information about the patient’s clinical characteristics, response evaluation and survival data. The relationship between PD-L1 expression levels evaluated by the 22C3 and SP263 assays was calculated using the concordance correlation coefficient, Pearson’s precision analysis.

    4c3880bb027f159e801041b1021e88e8 Result
    

    Most patients were male (70%), smoker (65%), ECOG PS 1 (73%), and histologically adenocarcinoma (55%) or squamous cell carcinoma (29%). 30% of patients had EGFR mutations. Patients were treated with pembrolizumab (n=41, 38%), or nivolumab (n=67, 61%). The median cycle of anti PD-1 checkpoint inhibitor was three (range, 1-25). There was moderate analytical correlation between 22C3 and SP263 PD-L1 levels. At the clinically relevant cutoffs ( < 10% vs. ≥10%; and <1% vs. 1-49% vs. ≥50%), the concordance correlation coefficient between 22C3 and SP263 were 0.68 (95%CI: 0.59-0.77) and 0.66 (95%CI: 0.51-0.81), respectively. The overall response rate (ORR) was 25.0% for all patients. The ORR was comparable regardless of the cutoff levels of PD-L1 expression by SP263 assays (ORR 39.6%, 41.7%, and 47.4% respectively for PD-L1 expression by 1%, 10%, 50% cutoff levels). But, the correlation between ORR and PD-L1 expression by 22C3 assays was not statistically significant. At 1% cutoff value, progression free survival was longer in patients with high vs. low tumor PD-L1 expression (2.8 months vs. 1.2 months, HR 0.63, 95%CI: 0.41-0.97, p=0.03) by the 22C3 and (3.1 months vs. 1.3 months, HR 0.61, 95% CI:0.40-0.93, p=0.02) by the SP263, respectively.

    8eea62084ca7e541d918e823422bd82e Conclusion
    

    We showed a moderate correlation between PD-L1 expression data obtained with the 22C3 and SP263 assays. These two assays could be used interchangeably and might be helpful for decision with anti PD-1 checkpoint inhibitors. Further analysis will be updated.

    6f8b794f3246b0c1e1780bb4d4d5dc53

    Only Active Members that have purchased this event or have registered via an access code will be able to view this content. To view this presentation, please login or select "Add to Cart" and proceed to checkout.