Study of Ociperlimab Plus Tislelizumab Plus Chemoradiotherapy in Participants With Untreated Limited-Stage Small Cell Lung Cancer

Key Inclusion Criteria: * Participant has pathologically (histologically or cytologically) proven diagnosis of small cell lung cancer * Has limited-stage disease (stage Tx, T1-T4, N0-3, M0; AJCC staging, 8th edition), and can be safely treated with definitive radiation doses. * Participant has not received any prior treatment for LS-SCLC. * Participant has measurable disease as assessed according to RECIST v1.1 that is appropriate for selection as a target lesion for repeat measurement, as determined by local site investigator/radiology review * ECOG Performance Status ≤ 2 assessed within 7 days before the first administration of study intervention, and must have a life expectancy of ≥ 12 weeks. Key Exclusion Criteria: * Mixed small cell lung cancer histology. Note: mixed SCLC with the component of neuroendocrine carcinoma origin is considered eligible * Have received surgical resection for LS-SCLC * Any participant for whom the tumor is considered resectable by surgery or stereotactic body radiation therapy/stereotactic ablative radiotherapy should be considered ineligible * Is expected to require any other form of antineoplastic therapy while on study. * Prior therapy with an anti-PD-1, anti-PD-L1, anti-PD-L2, anti-TIGIT, or any other antibody or drug specifically targeting T-cell costimulation or checkpoint pathways Note: Other protocol-defined Inclusion/Exclusion criteria may apply