CONFERENCE UPDATE: ESMO 2025

Osimertinib + plat-pem shows consistent OS benefits in EGFRm advanced NSCLC irrespective of poor baseline prognostic factors: Exploratory OS analyses from FLAURA2

STUDY DESIGN

In the phase 3 FLAURA2 study, osimertinib + platinum-pemetrexed (plat-pem) demonstrated statistically significant improvements in progression-free survival (PFS) and overall survival (OS) vs. osimertinib monotherapy in epidermal growth factor receptor-mutated (EGFRm) advanced non-small cell lung cancer (NSCLC), achieving a median OS of 47.5 months.1 These findings, along with a manageable safety profile, establish osimertinib + plat-pem combination as a recommended first-line treatment for EGFRm advanced NSCLC.1 Prior studies in EGFRm NSCLC have identified baseline factors associated with poorer prognosis, including L858R mutation (vs. Ex19del), presence of central nervous system (CNS), liver or bone metastases, TP53 alterations, and detectable plasma EGFRm circulating tumor DNA (ctDNA).1 The captioned analyses hence analyzed OS outcomes in FLAURA2 based on baseline prognostic factors.1

FLAURA2 was a global, randomized, open-label phase 3 study enrolling 557 patients with untreated, locally advanced or metastatic EGFRm non-squamous NSCLC.1 Eligible patients were aged ≥18 years, had pathologically confirmed EGFR Ex19del or L858R mutations, a World Health Organization Performance Status (WHO-PS) of 0 or 1, and underwent mandatory baseline CNS imaging, with stable CNS metastases allowed.1 Patients were stratified by race, the type of EGFR mutation test used, and WHO-PS prior to randomization.1

Patients were randomized 1:1 to receive osimertinib 80mg once daily (QD) alone, or osimertinib 80mg QD + pemetrexed 500mg/m² with either cisplatin or carboplatin.1 Radiological assessments were performed at week 6 and 12, then every 12 weeks until disease progression, with survival follow-up every 12 weeks until the data cut-off for the planned final OS analysis.1 The proportion of patients in each prognostic subgroup was generally balanced across treatment arms.1

At the ESMO Congress 2025, results from the exploratory OS analyses were presented, focusing on key baseline prognostic factors, including L858R mutation, CNS, liver, or bone metastases, TP53 alterations, and detectable plasma EGFRm ctDNA.1

FINDINGS

 Exploratory outcomes:
  • The exploratory outcomes presented were OS across key baseline prognostic factors, including L858R mutation, CNS, liver or bone metastases, TP53 alterations, and detectable plasma EGFRm ctDNA1
  • In line with the overall population data, median OS consistently favored osimertinib + plat-pem vs. osimertinib monotherapy across all subgroups, including patients with poorer baseline prognostic factors (e.g. CNS, bone, liver metastases, L858R and Ex19del mutation, detectable plasma EGFRm ctDNA, and altered TP53):1
    • Baseline CNS metastases
      • With CNS metastases: 40.9 vs. 29.7 months (HR=0.72; 95% CI: 0.52-0.99); three-year OS 57% vs. 40%
      • Without CNS metastases: Not reached (NR) vs. 43.9 months (HR=0.77; 95% CI: 0.57-1.05); three-year OS 67% vs. 58%
    • EGFR mutation type
      • L858R: 38.1 vs. 32.4 months (HR=0.76; 95% CI: 0.55-1.07); three-year OS 54% vs. 42%
      • Ex19del: NR vs. 43.0 months (HR=0.76; 95% CI: 0.56-1.02); three-year OS 69% vs. 57%
    • Plasma EGFRm ctDNA detection
      • Detected: 38.4 vs. 32.5 months (HR=0.79; 95% CI: 0.60-1.03); three-year OS 53% vs. 42%
      • Undetected: NR vs. NR (HR=0.79; 95% CI: 0.44-1.44); three-year OS 83% vs. 77%
    • Baseline liver metastases
      • With liver metastases: 36.6 vs. 28.0 months (HR=0.66; 95% CI: 0.41-1.05); three-year OS 54% vs. 35%
      • Without liver metastases: 49.6 vs. 41.8 months (HR=0.83; 95% CI: 0.64-1.07); three-year OS 65% vs. 56%
    • Baseline bone metastases
      • With bone metastases: 40.2 vs. 32.3 months (HR=0.76; 95% CI: 0.56-1.02); three-year OS 55% vs. 42%
      • Without bone metastases: NR vs. 44.5 months (HR=0.79; 95% CI: 0.57-1.10); three-year OS 71% vs. 60%
    • TP53 alterations
      • Altered TP53: 51.1 vs. 43.1 months (HR=0.71; 95% CI: 0.40-1.27); three-year OS 65% vs. 58%
      • Wild-type TP53: NR vs. NR (HR=0.70; 95% CI: 0.32-1.54); three-year OS 85% vs. 76%

 

“Survival benefit consistently favored osimertinib + plat-pem vs. monotherapy regardless of baseline prognostic factors, reinforcing its first-line use as standard of care in EGFRm advanced NSCLC.

Dr. Pasi A. Jänne
Dana-Farber Cancer Institute,
Boston, United States

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