Phase II Trial to Evaluate the Efficacy and Safety of HM61713 as the 1st-line NSCLC Anticancer Therapy

Inclusion Criteria: * Aged at least 19 years at the time of signing informed consent * Cytologically or histologically confirmed, advanced or metastatic NSCLC which is not amenable to curative surgery (Stage IIIb or IV) * Documented EGFR mutations (excluding exon 20 insertion) * At least one lesion that can be used as a measurable lesion per RECIST version 1.1 * Performance status under 1 per ECOG score * Life expectancy of at least 12 weeks * Adequate hematological and biological functions * Provide voluntary consent to participate the study and sign the written consent form Exclusion Criteria: * Treatment of chemotherapy, biological therapy or immunotherapy for anticancer therapies of stage IIIb or IV NSCLC (excluding adjuvant/neoadjuvant chemotherapy, radiotherapy or radiochemotherapy prior to more than 6 months from the first dose of study treatment * History of treatment with an EGFR targeting small molecule or antibodies * Any non-study related significant surgical procedures requires general anesthesia or breathing apparatus within the past 4 weeks of the first dose of study treatment (excluding video-assisted thoracoscopic surgery or open-and-closed surgery prior to the past 2 weeks of the first dose of study treatment) * History of any other malignancy within 5 years of study participation (other than curatively treated cervical cancer in situ, non-melanoma skin cancer, superficial bladder tumors unless it has been definitively treated with no evidence of relapse or recurrence within the past 3 years) * Clinically significant uncontrolled conditions of infectious disease including active infection that requires parenteral antibiotics (except when conditions are definitively treated or controlled) * Spinal cord compression, leptomeningeal carcinomatosis, symptomatic or uncontrolled brain metastasis * Presence or history of ILD or pulmonary fibrosis * NYHA class III or IV cardiac insufficiency, uncontrolled hypertension, experienced unstable angina pectoris or cardiac infarction within 6 months, uncontrolled cardiac arrhythmia or clinically significant abnormal cardiovascular activities * LVEF \< 40% * Presence or history of pancreatitis or serum amylase \> 1.5xULN * Inability to swallow the formulated product or gastrointestinal tract abnormalities which would preclude administration or absorption of study medication * Mental or congenital disabilities (e.g. dementia or epilepsy) which would preclude understanding of informed consent or following the study protocol * History of hypersensitivities to investigational drug or related similar class drugs * Pregnant or breast feeding * Unwillingness of adequate contraception during study treatment and at least 2 months after treatment * Unwillingness of following procedures of study protocol or follow-up assessments; Unable to follow up for long term for psychological, social, family problem or geographical reasons * History of treatment with other investigational drugs or investigational medical devices prior to 28 days of the first dose of study treatment * In the opinion of the investigator, the patient is an unsuitable candidate to the study * ECG finding of QTcF \> 450 msec at rest