Durvalumab as Consolidation for Patients LS-SCLC

Inclusion Criteria: * 1.Capable of giving signed informed consent which includes compliance with the requirements and restrictions listed in the informed consent form (ICF) and in this protocol. * 2.Histologically or cytologically confirmed small cell lung cancer * 3.Limited-stage, defined as stage I-III SCLC (T any, N any, M0). Patients who are Stage I or II must be medically inoperable as determined by investigator. * 4.Age \> 18 years. * 5.Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 * 6.Adequate normal organ and marrow function. * 7.Must have a life expectancy of at least 12 week. * 8.At least 1 lesion, not previously irradiated, that qualifies as a RECIST 1.1 target lesion (TL) at baseline. Tumor assessment by computed tomography (CT) scan or magnetic resonance imaging (MRI) must be performed within 28 days prior to enrollment. Exclusion Criteria: * 1.Patients with extensive disease small-cell lung cancer. * 2.Patients who previously received radiotherapy to the thorax or chemotherapy for small cell lung cancer. * 3.Any previous diagnosis of transformed non-small cell lung cancer (NSCLC), epidermal growth factor receptor (EGFR) activating mutation positive NSCLC that has transformed to SCLC, or mixed SCLC NSCLC histology. Patients with mixed histology tumors with predominant SCLC histology are allowed. * 4.Any unresolved toxicity NCI CTCAE Grade ≥2 from previous anticancer therapy with the exception of alopecia, vitiligo, and the laboratory values. * 5.Any concurrent chemotherapy other than study treatment, IP, biologic, or hormonal therapy for cancer treatment. Concurrent use of hormonal therapy for non-cancer-related conditions (e.g., hormone replacement therapy) is acceptable. * 6.History of allogenic organ transplantation. * 7.Active or prior documented autoimmune or inflammatory disorders. * 8.Uncontrolled intercurrent illness. * 9.History of leptomeningeal carcinomatosis. * 10.Mean QT interval corrected for heart rate using Fridericia's formula (QTcF) ≥470 ms calculated from 3 ECGs (within 15 minutes at 5 minutes apart) * 11.History of active primary immunodeficiency * 12.Known active hepatitis infection, positive hepatitis C virus (HCV) antibody, hepatitis B virus (HBV) surface antigen (HBsAg) or HBV core antibody (anti-HBc), at screening. Participants with a past or resolved HBV infection (defined as the presence of antiHBc and absence of HBsAg) and with undetectable HBV DNA (\< 10 IU/ml or under the limit of detection per local lab standard) are eligible. Participants positive for HCV antibody are eligible only if polymerase chain reaction is negative for HCV RNA. * 13.Receipt of live attenuated vaccine within 30 days prior to the first dose of IP. * 14.Prior treatment in a previous durvalumab clinical study. * 15.Known allergy or hypersensitivity to IP or any excipient.