Addition of Thoracic Consolidation Radiotherapy to the Maintenance Immunotherapy for ES-SCLC (STONE-001)

Inclusion criteria

• Fully informed written consent.
• Age ≥ 18 years.
• Confirmed Extensive Stage Small Cell Lung Cancer (ES-SCLC).
• ECOG PS 0-1.
• No previous systemic therapy except for induction immunochemotherapy for ES-SCLC.
• Partial response or stable disease after 4-6 cycles of induction immunochemotherapy (PD-L1 inhibitor + cisplatin/carboplatin + etoposide). No more than 28 days between last tumor assessment before randomization and randomization.
• Eligible for thoracic radiotherapy as assessed by the radiotherapy physician (The dose limits predicted for the organs at risk are as follows: bilateral lung V20 ≤ 25%, V5 ≤ 48%).
• Patients with stable, asymptomatic CNS metastases are allowed.
• Adequate bone marrow, renal function, and hepatic function.
• Male or female patients of childbearing potential volunteered to use effective contraception during the study and within 6 months of the last dose of study drug.

Exclusion criteria

• Prior thoracic radiotherapy.
• History of interstitial lung disease (including but not limited to idiopathic pulmonary fibrosis), pneumonitis, drug-induced pneumonitis, idiopathic pneumonitis, or evidence of active pneumonitis on screening chest CT scan.
• Positive testing for hepatitis B virus surface antigen (HBV sAg), hepatitis C virus ribonucleic acid (HCV RNA), or human immunodeficiency virus (HIV).
• Leptomeningeal metastasis.
• Uncontrolled tumor-related pain.
• Uncontrolled pleural effusion, pericardial effusion, or ascites requiring recurrent drainage procedures (once monthly or more frequently).
• Malignancies other than NSCLC within 5 years prior to enrollment, with the exception of those treated with expected curative outcome.
• Active or history of autoimmune disease or immune deficiency.
• Significant cardiovascular disease, such as New York Heart Association cardiac disease (Class II or greater), myocardial infarction, or cerebrovascular accident within 3 months prior to enrollment, unstable arrhythmias, or unstable angina.
• Major surgical procedure other than for diagnosis within 4 weeks prior to enrollment or anticipation of need for a major surgical procedure during the course of the study.