Start Your Search
MA15 - Colliding Approaches - EGFR and Immunotherapy (ID 916)
- Event: WCLC 2018
- Type: Mini Oral Abstract Session
- Track: Targeted Therapy
- Presentations: 1
- Coordinates: 9/25/2018, 13:30 - 15:00, Room 107
MA15.03 - PD-L1 Expression in Untreated EGFRm Advanced NSCLC and Response to Osimertinib and SoC EGFR-TKIs in the FLAURA Trial (ID 12989)
13:40 - 13:45 | Author(s): Craig Barker
In the Phase III FLAURA trial (NCT02296125), osimertinib significantly improved PFS relative to SoC EGFR-TKIs (gefitinib/erlotinib) in patients with untreated Ex19del/L858R positive (EGFRm) NSCLC. EGFRm NSCLC tumors can exhibit high PD-L1 expression, an important biomarker for immunotherapy treatment decisions. The frequency and clinical relevance of exhibiting both biomarkers prior to treatment are unclear. We report PD-L1 expression in patients with EGFRm advanced NSCLC and association with clinical outcomes following EGFR-TKI treatment.a9ded1e5ce5d75814730bb4caaf49419 Method
Tissue samples from 994 patients with advanced NSCLC were screened for EGFR Ex19del/L858R mutations for enrolment in FLAURA; 556 were randomized to treatment. 197 tissue-blocks from the screened population (including EGFR mutation-positive and -negative samples) were tested for PD-L1 using the SP263 (Ventana) immunohistochemical assay; positive tumour cell (TC) staining PD-L1 TC≥25% and TC≥1% thresholds were applied. PFS was investigator-assessed, per RECIST 1.1, according to PD-L1-expressers (TC≥1%) or -negatives (TC<1%) in randomized patients.4c3880bb027f159e801041b1021e88e8 Result
193/197 blocks had sufficient tumor tissue for staining. 65/193 patients were EGFR mutation-negative. 128/193 patients were EGFR mutation-positive: 106/128 were randomized to treatment (osimertinib: 54; SoC: 52). The table presents PD-L1 expression according to EGFR mutation status. For PD-L1-expressers (TC≥1%), median PFS was 18.4 months for osimertinib and 6.9 months for SoC (HR 0.30 [95% CI 0.15, 0.60]). For PD-L1-negative patients (TC<1%), median PFS was 18.9 months for osimertinib and 10.9 months for SoC (HR 0.37 [95% CI 0.17, 0.74]).
PD-L1 TC≥1%, n (%)
PD-L1 TC≥25%, n (%)
EGFR mutation-negative (n=65)
Screened population (n=65)
EGFR mutation-positive (n=128)
Screened population (n=128)
Randomized to treatment (n=106)
Randomized to osimertinib (n=54)
Randomized to SoC EGFR-TKI (n=52)
There was PFS benefit with osimertinib versus SoC regardless of whether tumors were PD-L1-expressers (TC≥1%) or -negatives (TC<1%). Using the TC≥25% threshold, PD-L1 prevalence was lower in EGFR mutation-positive than mutation-negative samples; there were insufficient patients with TC≥25% tumors for PFS assessment.
These results support the efficacy of EGFR-TKIs, including osimertinib, as first-line treatment of EGFRm advanced NSCLC, irrespective of PD-L1 expression.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.