Lazertinib for Patients With NSCLC Harboring Uncommon EGFR Mutations

The primary objective is to evaluate the antitumor efficacy of lazertinib in patients with NSCLC harboring uncommon EGFR mutations. The primary endpoint is objective response rate (ORR), defined as the proportion of patients achieving a complete response or partial response per RECIST v1.1 by investigator's assessments.Secondary endpoints are disease control rate, progression-free survival, overall survival, and duration of response. Secondary objectives are progression-free survival, overall survival, and safety profile according to the National Cancer Institute Common Terminology Criteria for Adverse Events version 5.0. * Progression-free survival :From C1D1 to the date of either disease progression or death * Overall survival: From C1D1 to the date of all-cause mortality * Safety: Evaluated by NCI-CTCAE v5.0 * The exploratory objective is to identify the acquired resistance mechanism to lazertinib in NSCLC with uncommon EGFR mutation. Lazertinib 240mg daily (1 cycle of 21 days) will be applied to the all patients until documented evidence of disease progression, unacceptable toxicity, noncompliance, or withdrawal of consent, or the investigator decides to discontinue treatment, whichever comes first. However, beyond disease progression is allowed based on the investigator's decision. Doses should be taken approximately 24 hours apart at the same time point each day before eating meal under fasting. If it is more than 12 hours after the dose time, the missed dose should not be taken, and patients should be instructed to take the next dose at the next scheduled time.