A Study to Evaluate the Safety of Concurrent Durvalumab With CRT Followed by Durvalumab for Chinese Unresectable Stage III NSCLC

Inclusion Criteria: * Subjects with histologically or cytologically-documented NSCLC * Locally advanced, unresectable (Stage III) NSCLC * World Health Organization (WHO) performance status 0-1 * At least one measurable lesion, not previously irradiated * Must have a life expectancy of at least 12 weeks at randomization * Adequate lung function: Pre- or post-bronchodilator forced expiratory volume 1 of 1.0 L or \>40% predicted value and DLCO \>30% predicted value * Must provide an archived tumor tissue block(or at least 15 newly cut unstained slides)≤3 years old; if archived sample unavailable then must provide a recent(≤3 months) tumor biopsy. Exclusion Criteria: * Mixed small-cell and NSCLC histology * Receipt of prior or current cancer treatment, including but not limited to, radiation therapy, investigational agents, chemotherapy, Durvalumab and mAbs. * Prior exposure to immune-mediated therapy, including but not limited to, other anti- CTLA-4, anti-PD-1, anti-PD-L1, and anti-PD-L2 antibodies. * Patients whose radiation treatment plans are likely to encompass a volume of whole lung receiving ≥20 Gy in total (V20) of more than 35% of lung volume * Planned radiation cardiac dose V50\>25% * Any medical contraindication of platinum-based doublet chemotherapy as listed in the local labelling or known allergy/hypersensitivity to investigational product and/or its excipients * History of the following: allogeneic organ transplantation, active or prior autoimmune or inflammatory disorders, another primary malignancy, leptomeningeal carcinomatosis, active primary immunodeficiency * Uncontrolled intercurrent illness or active infection