Switching from first or second generation EGFR-TKI to osimertinib in EGFR mutation-positive NSCLC.

Aim: We evaluated the efficacy of a novel switch protocol for EGFR-TKIs for EGFR mutation-positive NSCLC.

Materials & methods: Clinical records were collected from the patients who had received one of two sequential combination strategies of EGFR-TKIs: Salvage use of osimertinib for T790M-mediated acquired resistance to an prior EGFR-TKI or switch use of osimertinib where an EGFR-TKI was switched to osimertinib before disease progression.

Results: Progression-free survival of osimertinib and time from the start of treatment until progression to osimertinib was comparable between the salvage use and switch use of osimertinib.

Conclusion: Switch use of osimertinib seemed to produce improved efficacy for patients with activating EGFR mutations, because of the lack of patient selection via T790M.