A Phase 1/2 Study of Lazertinib 240 mg in Patients With Advanced EGFR T790M-Positive NSCLC After Previous EGFR Tyrosine Kinase Inhibitors
Byoung Chul Cho, Ji‐Youn Han, Sang‐We Kim, Ki Hyeong Lee, Eun Kyung Cho, Yun‐Gyoo Lee, Dong‐Wan Kim, Joo-Hang Kim, Gyeong‐Won Lee, Jong-Seok Lee, Byoung Yong Shim, Jin-Soo Kim, Sang Hoon Chun, Sung Sook Lee, Hye Ryun Kim, Min Hee Hong, Jin Seok Ahn, Jong‐Mu Sun, Youngjoo Lee, Ki Hyeong Lee, Ji Ah Kang, NaMi Lee, Mijung Kwon, Carin R. Espenschied, Arielle Yablonovitch, Myung‐Ju Ahn
Abstract
INTRODUCTION: This integrated analysis of a phase 1/2 study (NCT03046992) evaluated the efficacy and safety of lazertinib, a third-generation EGFR tyrosine kinase inhibitor (TKI), in patients with advanced EGFR T790M-positive NSCLC after previous EGFR TKI therapy. METHODS: Adults with EGFR mutation-positive NSCLC that progressed after prior EGFR-directed TKIs received once daily oral lazertinib 240 mg continuously until disease progression. Prior TKIs to treat T790M-positive NSCLC were prohibited. Primary endpoints were safety and objective response rate (ORR). Secondary endpoints included progression-free survival, overall survival, and intracranial ORR. RESULTS: A total of 78 patients received lazertinib 240 mg at 17 centers in South Korea. Among patients with T790M-positive tumors at baseline (N = 76), one (1.3%) had a complete response and 41 (53.9%) had partial responses, giving an ORR of 55.3% (95% confidence interval [CI]: 44.1-66.4). Median progression-free survival was 11.1 months (95% CI: 5.5-16.4). Median overall survival was not reached (median follow-up = 22.0 mo). In patients with measurable intracranial lesions (n = 7), one (14.3%) had a complete intracranial response and five (71.4%) had partial responses, giving an intracranial ORR of 85.7% (95% CI: 59.8%-100.0%). The most common treatment-emergent adverse events were rash (37.2%), pruritus (34.6%), and paresthesia (33.3%); most were mild to moderate in severity. Serious drug-related adverse events occurred in three patients (gastritis, pneumonia, pneumonitis). The major mechanism of resistance was EGFR T790M loss. CONCLUSIONS: Lazertinib 240 mg/d has a manageable safety profile with durable antitumor efficacy, including brain metastases, in patients with advanced T790M-positive NSCLC after previous EGFR TKI therapy.