An Investigational Immuno-therapy Study of Nivolumab, or Nivolumab in Combination With Ipilimumab, or Placebo in Patients With Extensive-Stage Disease Small Cell Lung Cancer (ED-SCLC) After Completion of Platinum-based Chemotherapy

OS was defined as the time from randomization to the date of death. A participant who had not died was censored at last known alive date. OS was followed up during the blinded study drug treatment and every 3 months via in-person or phone contact after participant discontinued the blinded study drug

Time frame: From randomization to 400 deaths across the two treatment groups (Nivo+Ipi vs Placebo) (up to approximately 37 months)

Population: All randomized participants in the nivolumab + ipilimumab and placebo arms in the global population

Tumor mutational burden (TMB) is measured using FoundationOne CDxTM (F1CDx) assay, a comprehensive genomic profile (CGP) assay based on baseline tumor tissue. TMB is defined as the number of somatic, coding, base substitution, and indel mutations per megabase of genome examined. OS in TMB by the following cutoff points: ≥10 mutations/mb, \< 10 mutations/mb, ≥13 mutations/mb, \<13 mutations/mb

Time frame: From randomization to the date of death or last known alive date (up to approximately 73 months)

Population: All TMB evaluable participants in the global population

Overall Survival (OS) comparing Nivolumab + Ipilimumab Versus Nivolumab. OS was defined as the time from randomization to the date of death. A participant who had not died was censored at last known alive date. OS was followed up during the blinded study drug treatment and every 3 months via in-person or phone contact after participant discontinued the blinded study drug.

Time frame: From randomization to the date of death or last known alive date (up to approximately 73 months)

Population: All randomized participants in the Nivolumab + Ipilimumab and Nivolumab arms

Overall Survival (OS) comparing nivolumab monotherapy versus placebo. OS was defined as the time from randomization to the date of death. A participant who had not died was censored at last known alive date. OS was followed up during the blinded study drug treatment and every 3 months via in-person or phone contact after participant discontinued the blinded study drug.

Time frame: From randomization to the date of death or last known alive date (up to approximately 73 months)

Population: All randomized participants in the nivolumab monotherapy and placebo arms

PFS was defined as the time between the date of randomization and the first date of documented progression as determined by Blind Independent Central Review (BICR) or death due to any cause, whichever occurred first. Participants who died with no reported progression were considered to have progressed on the date of death. Participants who did not progress or die were censored on the date of their last evaluable tumor assessment on or prior to initiation of the subsequent anti-cancer therapy. Participants who did not have any on study tumor assessments and did not die (or died after initiation of the subsequent anti- cancer therapy) were censored on their date of randomization. Participants who started any subsequent anti- cancer therapy without a prior reported Progressive Disease (PD) per BICR were censored at the last evaluable tumor assessment on or prior to initiation of the subsequent anti-cancer therapy.

Time frame: From randomization to the date of the first documented tumor progression or death due to any cause (up to approximately 73 months)

Population: All randomized participants

Tumor mutational burden (TMB) is measured using FoundationOne CDxTM (F1CDx) assay, a comprehensive genomic profile (CGP) assay based on baseline tumor tissue. TMB is defined as the number of somatic, coding, base substitution, and indel mutations per megabase of genome examined. PFS in TMB by the following cutoff points: ≥10 mutations/mb, \< 10 mutations/mb, ≥13 mutations/mb, \<13 mutations/mb.

Time frame: From randomization to the date of the first documented tumor progression or death due to any cause (up to approximately 73 months)

Population: All TMB evaluable participants in the global population

Overall survival (OS) comparing nivolumab + ipilimumab versus placebo. OS was defined as the time from randomization to the date of death. A participant who had not died was censored at last known alive date. OS was followed up during the blinded study drug treatment and every 3 months via in-person or phone contact after participant discontinued the blinded study drug. Note: This outcome measure represents an updated version of the primary endpoint to include additional data collection that has occurred after the primary completion date. (Assessments were made until 11-Nov-2021).

Time frame: From randomization to the date of death or last known alive date (up to approximately 73 months)

Population: All randomized participants in the nivolumab + ipilimumab and placebo arms