Updated overall survival and ctDNA analysis in patients with EGFR T790M-positive advanced non-small cell lung cancer treated with lazertinib in the phase 1/2 LASER201 study.

Background: Lazertinib is a potent, irreversible, third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) with significant efficacy in patients with EGFR T790M-mutated non-small cell lung cancer (NSCLC). This is the final overall survival (OS) report from the phase 1/2 LASER201 study in patients with advanced NSCLC with disease progression on or after prior EGFR TKI therapy.

Methods: Eligible patients were aged ≥ 20 years, with advanced EGFR-mutated NSCLC and previous therapy with EGFR TKI. Patients in this integrated analysis received oral lazertinib 240 mg/day. Endpoints included efficacy and safety; exploratory analyses included associations between circulating EGFR-mutant tumor DNA (ctDNA) and efficacy parameters.

Results: This integrated analysis included 78 patients in Korea who received second- or later-line lazertinib. The median OS was 38.9 months; estimated survival rates at 12, 24, and 36 months were 89.5%, 73.9%, and 52.8%, respectively. The cumulative 12-month incidence of central nervous system progression was 9.4%. EGFR-mutant ctDNA was detected in 46 patients (62.2%) at baseline. The presence of ctDNA at baseline significantly predicted progression-free survival (PFS), disease control rate (DCR), and OS. PFS, response rate, and DCR were significantly associated with EGFR-mutant ctDNA clearance at cycle 3; PFS and OS were significantly associated with ctDNA clearance at cycle 5. The safety profile of lazertinib 240 mg/day was consistent with previous findings.

Conclusions: Lazertinib is a promising treatment option for patients with EGFR T790M-positive NSCLC following disease progression on prior EGFR-directed TKIs. Patients in LASER201 experienced prolonged OS, regardless of their EGFR mutation, brain metastases, or prior brain radiation status. Clearance of plasma EGFR mutations after lazertinib was associated with patient outcomes.

Trial Registration: ClinicalTrials.gov identifier NCT03046992.