A Study of Nivolumab Plus Brentuximab Vedotin Versus Brentuximab Vedotin Alone in Patients With Advanced Stage Classical Hodgkin Lymphoma, Who Are Relapsed/ Refractory or Who Are Not Eligible for Autologous Stem Cell Transplant,

Complete Response Rate (CRR):

Complete Response Rate (CRR) is defined as the number of participants who have achieved complete response (Lugano 2014 classification) per investigator assessment. Complete response is considered a score of 1, 2, or 3. Per the Lugano criteria: Positron emission tomography (PET) negative scans are defined on the 5-point scale as scores of 1, 2, or 3 (where 1 = no uptake above background; 2 = uptake \</= mediastinum; and 3 = uptake \> mediastinum but \</= liver) and PET-positive scans, as scores of 4 or 5 (where 4 = uptake moderately higher than liver; 5 = uptake markedly higher than liver and/or new lesions). Response on PET scans should be reported as complete metabolic response (CMR) partial metabolic response (PMR), SMD (stable metabolic disease), or PMD (progressive metabolic disease).

Time frame: From randomization up to approximately 45 months

Objective Response Rate (ORR)

Objective Response Rate (ORR) is defined as the number of participants with a Best Overall Response (BOR) of complete response (CR) or partial response (PR) (Lugano 2014 classification) per investigator assessment. Complete response is considered a score of 1, 2, or 3. Partial response is considered a score of 4 or 5. Per the Lugano criteria: Positron emission tomography (PET) negative scans are defined on the 5-point scale as scores of 1, 2, or 3 (where 1 = no uptake above background; 2 = uptake \</= mediastinum; and 3 = uptake \> mediastinum but \</= liver) and PET-positive scans, as scores of 4 or 5 (where 4 = uptake moderately higher than liver; 5 = uptake markedly higher than liver and/or new lesions). Response on PET scans should be reported as complete metabolic response (CMR) partial metabolic response (PMR), SMD (stable metabolic disease), or PMD (progressive metabolic disease).

Time frame: From randomization up to approximately 45 months

Duration of Response (DOR)

The time from first response (Complete response (CR) or partial response (PR)) to the date of initial objectively documented progression (2014 Lugano classification) or death due to any cause per investigator assessment estimated using the Kaplan-Meier (KM) product-limit method. Complete response is considered a score of 1, 2, or 3. Partial response is considered a score of 4 or 5. Per the Lugano criteria: Positron emission tomography (PET) negative scans are defined on the 5-point scale as scores of 1, 2, or 3 (where 1 = no uptake above background; 2 = uptake \</= mediastinum; and 3 = uptake \> mediastinum but \</= liver) and PET-positive scans, as scores of 4 or 5 (where 4 = uptake moderately higher than liver; 5 = uptake markedly higher than liver and/or new lesions). Response on PET scans should be reported as complete metabolic response (CMR) partial metabolic response (PMR), SMD (stable metabolic disease), or PMD (progressive metabolic disease).

Time frame: From randomization to date of documented progression or death (up to approximately 45 months)

Duration of Complete Response (DOCR)

Duration of complete response (DOR) is defined as the time from first complete response to the date of initial objectively documented progression (2014 Lugano classification) or death due to any cause per investigator assessment estimated using the Kaplan-Meier (KM) product-limit method. Complete response is considered a score of 1, 2, or 3. Per the Lugano criteria: Positron emission tomography (PET) negative scans are defined on the 5-point scale as scores of 1, 2, or 3 (where 1 = no uptake above background; 2 = uptake \</= mediastinum; and 3 = uptake \> mediastinum but \</= liver) and PET-positive scans, as scores of 4 or 5 (where 4 = uptake moderately higher than liver; 5 = uptake markedly higher than liver and/or new lesions). Response on PET scans should be reported as complete metabolic response (CMR) partial metabolic response (PMR), SMD (stable metabolic disease), or PMD (progressive metabolic disease).

Time frame: From randomization to date of documented progression or death (up to approximately 45 months)

Overall Survival (OS)

Overall Survival (OS) is defined as the time between the date of randomization and the date of death estimated using the Kaplan-Meier (KM) product-limit method

Time frame: From randomization to the date of death (up to approximately 3 years 7 months)