Phase 3 Study of Pyrotinib Versus Docetaxel in Patients With Advanced Non-squamous NSCLC Harboring a HER2 Exon 20 Mutation Who Failed Platinum Based Chemotherapy

150 eligible subjects will be randomized in a 2:1 ratio (Study treatment Arm: Control Arm = 100 : 50 subjects) to receive pyrotinib or docetaxel monotherapy. Each treatment cycle is defined as 21 days for subjects in both arms. Treatment regimen of pyrotinib (Study treatment Arm): 400 mg/d (QD) oral pyrotinib will be administered within 30 minutes after completion of a meal. Treatment regimen of docetaxel (Control Arm): 75 mg/m2 (Q3W) of docetaxel will be administered via intravenous infusion. In this study, crossover treatment is allowed for subjects in Control Arm. Within the specified time window of each cycle, subjects should complete physical examinations, laboratory tests, quality of life questionnaires and other tests to assess the safety and quality of life of the subjects. During study treatment, tumor radiological assessments will be performed every 6 weeks (42 ± 7 days) in the first 52 weeks and every 12 weeks (84 ± 7 days) thereafter. After the end of treatment and safety follow-up, all subjects will be followed for survival (every 56 ± 7 days) until death, withdrawal of informed consent, lost to follow-up, or termination of the study (whichever occurs first).