Comparison of Effectiveness of Gefitinib, Erlotinib, and Afatinib in Advanced Non-small Cell Lung Cancer Patients with EGFR Mutation Positive in Indonesian Population

BACKGROUND: EGFR-tyrosine kinase inhibitors (EGFR-TKIs) were used to treat non-small cell lung cancer (NSCLC) patients with EGFR mutation positive. This study aims to compare the effectiveness of first line TKIs; gefitinib, erlotinib, and afatinib in the treatment of advanced stage NSCLC patients with EGFR mutation positive in the Indonesian population. METHODS: A retrospective cohort study of 88 NSCLC patients with EGFR mutation positive treated with gefitinib (n=59), erlotinib (n=22), and afatinib (n=7) was performed in national cancer hospital in Indonesia.Inclusion criteria were stage IIIb or IV NSCLC with adenocarcinoma subtype. Subjects less than 18 years or with a history of other malignancy were excluded. Outcomes were treatment response, progression-free survival (PFS), and mortality rate. RESULTS: Complete response, partial response, and stable disease were shown in 1.1%, 35.2%, and 31.8% of subjects, respectively. There were 31.8% of subjects developed progressive disease during treatment. Regarding EGFR mutation positive profile, a total of 56.8% subjects had deletion in exon 19, 42% subjects had mutation in exon 21, and rare mutation in exon 18 was found in 3.4% of total subjects. Demography and clinical characteristics had no significant association with the risk of progressive disease. The median PFS of subjects was 11 months (95%CI: 6.8-15.2 months). There was no statistical difference of PFS between treatment groups.
 CONCLUSIONS: Gefitinib, erlotinib, and afatinib have similar effectiveness in advanced stage NSCLC with EGFR mutation positive. Afatinib tends to be associated with longer PFS but further investigation is required.