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MA 02 - Emerging Targets (ID 656)
- Event: WCLC 2017
- Type: Mini Oral
- Track: Clinical Design, Statistics and Clinical Trials
- Presentations: 1
MA 02.06 - BRAF Mutant NSCLC: Correlation with PD-L1 Expression,TMB, MSI and Response to ICPi and Anti-BRAF Therapy (ID 10473)
11:00 - 12:30 | Author(s): Jair Bar
The efficacy of immune check-point inhibitors (ICPi) in BRAF mutant non-small cell lung cancer (NSCLC) is largely unknown. The correlation with different parameters predicting efficacy of ICPi (e.g., PD-L1 expression, tumor mutational burden (TMB) and microsatellite instability status (MSI) in these tumors needs further evaluation.
A retrospective analysis of 30 patients with BRAF mutant advanced NSCLC treated between Aug 2013 and May 2017 was performed. The patients were divided into 2 groups: BRAF V600 E (Group A, N=16), non-V600E BRAF (Group B, N=14). PD-L1 was assessed by immunohistochemistry using 22C3 Dako antibody clone on Dako or Ventana's platform in 16 patients. TMB and MSI were assessed in 9 and 11 patients, respectively. Median progression-free survival (mPFS) with ICPi and targeted agents as well as median overall survival (mOS) were assessed in each group by Kaplan-Meier method.
Baseline characteristics of the cohort: median age 66y (range 39-98); males 53%; current/past smokers/never smokers/NA 13%/44%/40%/3%; adenocarcinoma/other histology 80%/20%; ECOG PS 0/1/2/3/4/NA 27%/33%/10%/13%/0%/17%. The distribution of TMB, PD-L1 expression and MSI status between the 2 groups is presented in Table 1. Ten patients received ICPi (nivolumab-8, pembrolizumab-2), and thirteen patients received anti-BRAF therapy (dabrafenib+trametinib-6, dabrafenib-4, vemurafenib-3). mOS and mPFS with ICPi and anti-BRAF therapy are summarized in Table 1. Four patients with BRAF V600 E PD-L1 ≥ 50% tumors were included in the series; one patients responded to dabrafenib+trametinib combination (response ongoing, 7.1months+); in two patients ICPi were initiated, response assessment pending. One patient with a non-V600E BRAF mutant NSCLC responded to dabrafenib for 6.7 months.Figure 1
BRAF mutant NSCLC tumors are associated with high level of PD-L1 expression, low/intermediate TMB and MSI stable status. ICPi may induce prolonged responses both in BRAF V600E and non-V600E BRAF mutant NSCLC. Some non-V600E BRAF mutant NSCLC may benefit from anti-BRAF targeted therapy.
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