Participants successfully enrolled into the study will receive 80mg osimertinib QD p.o. plus standard chemotherapy composed of cisplatin or carboplatin and pemetrexed i.v. on Day 1 of a 21 day cycle (every 3 weeks) for 4 to 6 cycles, followed by osimertinib 80 mg QD p.o. plus pemetrexed maintenance i.v. every 3 weeks until RECIST 1.1-defined radiological progression as judged by the investigator.~Tumour assessments will be performed as per RECISTv1.1 criteria, using computed tomography (CT)/magnetic resonance imaging (MRI). The baseline assessment is part of the screening procedures and should be performed before the start of study intervention.~safety will be assessed in the whole treatment period as well as 28 days after study drug termination for any reason.
This is an open-label, single-arm, multicenter, exploratory Phase II study sponsored by Astrazeneca Investment (China) Co., LTD. to evaluate the efficacy and safety of Osimertinib with Platinum plus Pemetrexed Chemotherapy, as First-line Treatment in Recurrent or Locally Advanced or Metastatic Non-small Cell Lung Cancer (NSCLC) Patients with Uncommon Epidermal Growth Factor Receptor Mutations (EGFRm).