Older patients with EGFR mutation-positive non-small cell lung cancer treated with afatinib in clinical practice: A subset analysis of the non-interventional GIDEON study

Introduction: Lung cancer is most common in older patients; despite this, older patients are historically under-represented in clinical studies. Here we present data from GIDEON, a study undertaken in Germany in patients with epidermal growth factor receptor mutation-positive (EGFRm+) non-small cell lung cancer (NSCLC) receiving first-line afatinib. GIDEON enrolled a high proportion of patients aged ≥70 years, providing an opportunity to study afatinib use in older patients.

Materials and methods: In GIDEON (NCT02047903), a prospective non-interventional study, patients with EGFRm+ NSCLC received first-line afatinib in routine clinical practice until disease progression, death or intolerable adverse events. Key objectives were twelve-month progression-free survival (PFS) rate and objective response rate (ORR). Overall survival (OS) and safety were also assessed. This post hoc analysis explores outcomes of patients grouped by age (≥70 and <70 years).

Results: In the 152 patients enrolled in GIDEON (69.7% female, 64.5%/22.4%/13.2% with Del19/L858R/other exon 18-21 mutations, 33.6% with brain metastases), the median age was 67 years (range 38-89) and 43.4% were aged ≥70 years. In the ≥70 years age group and the <70 years age group, twelve-month PFS rate was 58.9% and 43.9%, median PFS was 17.2 months and 10.6 months, ORR was 72.0% and 76.5%, twelve-month OS rate was 79.1% and 79.2%, 24-month OS rate was 52.0% and 61.7%, and median OS was 30.4 months and 27.4 months, respectively. In the ≥70 years age group and the <70 years age group, grade ≥3 adverse drug reactions (ADRs) were observed in 34.8% and 40.7% of patients, respectively; the most common were diarrhea (13.6% and 14.0%), acneiform dermatitis (7.6% and 7.0%), stomatitis (1.5% and 4.7%) and maculopapular rash (1.5% and 4.7%).

Discussion: Patients with EGFRm+ NSCLC aged ≥70 years showed clinical benefit from first-line afatinib with no unexpected safety signals, supporting the use of afatinib in this setting.