SCT-I10A or Placebo Plus Docetaxel With Previously Treated Squamous Cell Non-small Cell Lung Cancer

Inclusion Criteria:

1. Patients should be voluntarily sign the written informed consent.
2. Histologically or cytologically confirmed diagnosis of locally advanced or metastatic squamous NSCLC. Or recurrent squamous NSCLC according UICC/AJCC 8th edition.
3. At least one measurable tumor lesion per RECIST 1.1 criteria. A lesion previously irradiated could be considered as a target lesion only in the condition that progression occurred at the time of 3 months after the end of radiotherapy.
4. Previously treated with one platinum based regimen (including platinum and endostar regimen) and progression occur during or after treatment or unbearable treatment related adverse events.
5. Progression after EGFR-TKIs in patients with driver gene mutation.
6. Eastern Cooperative Oncology Group (ECOG) performance score 0 or 1.

Exclusion Criteria:

1. Patient who is allergic to recombinant humanized PD-1 monoclonal antibody or the components of the drug.
2. Patient who is allergic to taxane.
3. Previously treated with any of the antibodies targeted on PD-1, PD-L1, PD-2, CD137, CTLA-4, T cell, co-stimulation or drugs targeted on the checkpoint signal pathway.
4. Previously treated with docetaxel.
5. The histopathological subtype is not squamous cell non-small cell lung cancer, or squamous cell \< 90% in a mixed carcinoma.