A Study of Mobocertinib in Japanese Adults With Non-Small Cell Lung Cancer

The drug being tested in this study is called Mobocertinib. Mobocertinib is being tested to treat Japanese participants with NSCLC. This study has two parts (Phase 1 part and Phase 2 part), Phase 1 part of this study will look at the safety, efficacy, tolerability and PK of Mobocertinib orally administered once daily, and will determine a RP2D. Phase 2 study will look at the efficacy and safety of Mobocertinib in treatment naive Japanese NSCLC patients with epidermal growth factor receptor (EGFR) exon 20 insertion mutation. All participants will be assigned to Phase 1 part or Phase 2 part and will be asked to take Mobocertinib capsule as following dosage and regimen; Phase 1 part; Mobocertinib, 40 mg as starting dose, once daily, and escalating up to 160 mg until a Maximum Tolerated Dose (MTD). An expansion phase may be followed at any dose to further confirm safety observations following identification of MTD/RP2D. Phase 2 part; Mobocertinib, 160 mg, once daily The study will enroll approximately 58-63 participants (Phase 1 part; 28-33 and Phase 2 part; 30). This multi-center trial will be conducted in Japan. The overall time to participate in this study of Phase 1 part is approximately 3 years and Phase 2 part is approximately 4 years. Participants will make multiple visits to the clinic in the treatment period, and the post-treatment period including follow-up assessments after the last dose of the study drug.