This is a randomized, positive-controlled, open-label, international multicenter, Phase 3 clinical study to compare the efficacy and safety 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).

Inclusion Criteria:

• Signed and dated written informed consent which is approved by IRB/EC, willing and able to comply with scheduled treatment, all examinations at study visits, and other study procedures.
• ECOG PS 0-1.
• Have histologically or cytologically confirmed locally advanced or metastatic non-squamous NSCLC disease.
• Before enrollment, a documented confirmed presence of activating mutations in exon 20 of the HER2 gene must be provided. Sufficient tumor tissue samples should be provided to retrospectively confirm the mutation status of the HER2 gene.
• Must have measureable disease per RECIST v1.1.
• For advanced NSCLC, patients must have had progressive disease on or after a platinum based chemotherapy, with or without immune checkpoint inhibitors (PD-1/PD-L1 inhibitors) and/or anti-angiogenic drugs. No more than 2 prior lines of systemic therapy are allowed.
• The laboratory test values must meet the following standards to manifest that the functional level of important organs/systems meets the requirements.
• Female patient of childbearing potential (WOCBP) and male patient whose - partner is WOCBP must agree to use effective contraception method during the study period.

Exclusion Criteria:

• Malignant tumors with other pathological types.
• Medical history of other active malignancies within last 5 years.
• Subjects with active CNS metastases.
• Previously treated with targeted drugs for HER2 gene mutations,or previously treated with docetaxel.
• Prior to the first dose of study treatment, patients with severe effusions with clinical symptoms, severe cardiac disease, or severe infection.
• Prior to the first dose of study treatment, patients with diseases or special conditions that affect drug administration and absorption.
• Congenital or acquired immunodeficiency.
• History of allergy to the study drugs or components.
• Prior to the first dose of study treatment, or during the study period, patients receive or are anticipated to receive continuous strong CYP3A4 inducers or inhibitors, P-gp inhibitors, or medications that are known to cause QT/QTc prolongation.

In this study, the Blinded Independent Review Committee (BIRC) will perform a blinded evaluation on the primary endpoint.