mPFS was defined as the time from the date of randomization to the date of the first of documentation of progressive disease (PD), death due to any cause, or for participants who were confirmed non complete responders per IRF, receipt of subsequent anticancer therapy for Hodgkin lymphoma (HL) after completion of frontline therapy. PD was defined as any new lesion or increase by greater than or equal to (\>=) 50 percent (%) of previously involved sites from nadir. Frontline therapy is the part of standard set of treatments.

ORR4 was determined by an Independent Review Facility (IRF) based on Global Response Score (GRS) which consisted of a skin assessment by the investigator using the modified severity-weighted assessment tool (mSWAT), nodal and visceral radiographic assessment by an IRF and for the participants with mycosis fungoides (MF) only, detection of circulation Sezary cells. Participants whose first response occurred after the start of subsequent anticancer therapy were excluded. Response Criteria was based on International Society for Cutaneous Lymphomas (ISCL), United States Cutaneous Lymphoma Consortium (USCLC) and Cutaneous Lymphoma Task Force (CLTF) of the European Organisation for Research and Treatment of Cancer (EORTC) Consensus guidelines (Olsen, 2011).

2-year progression-free survival (PFS)

ORR by IRF assessment following the completion of study treatment was defined as the percentage of participants who achieved a complete response (CR) or partial response (PR) by IRF assessment using the International Working Group (IWG) Revised Response criteria following the completion of study treatment. CR was defined as disappearance of all evidence of disease. PR was defined as regression of measurable disease and no new sites.

An adverse event (AE) is defined as any untoward medical occurrence in a participant administered a pharmaceutical product; it does not necessarily have to have a causal relationship with this treatment. An AE can therefore be any unfavorable and unintended sign (e.g., a clinically significant abnormal laboratory finding), symptom, or disease temporally associated with the use of a drug, whether or not it is considered related to the drug. A TEAE is defined as an adverse event that occurs after administration of the first dose of study treatment and up through 30 days after the last dose of study treatment.

Laboratory parameters like Potassium, Aspartate Aminotransferase (AST), Bilirubin, Serum Gamma-glutamyl Transferase (GGT), High Glucose (Hyperglycemia), Neutrophils, Leukocytes, Platelets, and Hemoglobin were assessed. Intensity of changes in laboratory parameters were evaluated using the National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events (CTCAE) version 5.0.

ORR is defined as the percentage of participants who have achieved complete remission (CR)=disappearance of all evidence of disease or partial remission (PR)=regression of greater than or equal to 50% of measurable disease and no new site by end of treatment (EOT) per Cheson 2007 Revised Response Criteria for Malignant Lymphoma.

An Adverse Event (AE) is defined as any untoward medical occurrence in a clinical investigation participant administered a drug; it does not necessarily have to have a causal relationship with this treatment. An AE can therefore be any unfavorable and unintended sign (eg, a clinically significant abnormal laboratory finding), symptom, or disease temporally associated with the use of a drug, whether or not it is considered related to the drug. A treatment-emergent adverse event (TEAE) is defined as an adverse event with an onset that occurs or worsens after receiving study drug.

Clinical Laboratory tests included tests of Chemistry, Hematology and Urinalysis prespecified in the protocol. Abnormal laboratory values assessed by the investigator that lead to discontinuation or delay in treatment, dose modification, therapeutic intervention, or were considered by the investigator to be clinically significant changes from Baseline were recorded as Adverse Events. Neutropenia (pooled) includes preferred terms Neutropenia and Neutrophil count decreased.

Vital signs included blood pressure in the sitting position, pulse rate, axillary temperature and weight. Abnormal vital sign values considered by the investigator to be clinically significant were recorded as Adverse Events.

The recommended dose was determined after considering all safety data in phase 1 and assessing for dose limiting toxicities (DLTs) which are defined as the dose range at which less than or equal to (\<=) 1 of 6 evaluable participants experience DLT within the defined observation period (Cycle 1 + 28 days). This outcome measure is planned to be assessed only for participants treated in Phase 1 arm.

AE means any untoward medical occurrence in a participant administered a pharmaceutical product; the untoward medical occurrence does not necessarily have a causal relationship with this treatment. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease temporally associated with the use of a medicinal (investigational) product whether or not it is related to the medicinal product. This outcome measure is planned to be assessed only for participants treated in Phase 1 arm.

AE means any untoward medical occurrence in a participant administered a pharmaceutical product; the untoward medical occurrence does not necessarily have a causal relationship with this treatment. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease temporally associated with the use of a medicinal (investigational) product whether or not it is related to the medicinal product. SAE is defined as any untoward medical occurrence that at any dose results in death, Is life-threatening, requires inpatient hospitalization or prolongation of an existing hospitalization, results in persistent or significant disability or incapacity, Is a congenital anomaly/birth defect, Is a medically important event.

CR was defined as the disappearance of all evidence of disease as assessed by IRF as per IWG Criteria. The confidence interval was based on exact binomial distribution (Clopper-Pearson method). This outcome measure was planned to be assessed for all participants treated at the recommended dose in Phase 2. As prespecified in the statistical analysis plan (SAP) , data for Phase 2 was summarized and reported in two arms: Phase 2 and Phase 1 + Phase 2.

The Deauville score according to IRF assessment of response was used to evaluate the results of PET scans. PET negative after Cycle 2 was defined as an IRF Deauville score of (1 or 2 or 3). This outcome measure was planned to be assessed for all participants treated at the recommended dose in Phase 2. As prespecified in SAP, data for Phase 2 was summarized and reported in two arms: Phase 2 and Phase 1 + Phase 2.

PR was defined as regression of measurable disease and no new sites as assessed by IRF as per IWG criteria. Percentage of participants in the response-evaluable population who achieved a partial response based on the IRF assessment at the EOT visit based on the IWG criteria are reported. The confidence interval was based on exact binomial distribution (Clopper-Pearson method). This outcome measure was planned to be assessed for all participants treated at the recommended dose in Phase 2. As prespecified in SAP, data for Phase 2 was summarized and reported in two arms: Phase 2 and Phase 1 + Phase 2.

Overall response rate was defined as the percentage of participants with CR or PR as assessed by IRF using IWG criteria. CR was defined as the disappearance of all evidence of disease and PR was defined as regression of measurable disease and no new diseases. The confidence interval was based on exact binomial distribution (Clopper-Pearson method). This outcome measure was planned to be assessed for all participants treated at the recommended dose in Phase 2. As prespecified in SAP, data for Phase 2 was summarized and reported in two arms: Phase 2 and Phase 1 + Phase 2.

This outcome measure was planned to be assessed for all participants treated at the recommended dose in Phase 2. As prespecified in SAP, data for Phase 2 was summarized and reported in two arms: Phase 2 and Phase 1 + Phase 2.

An Adverse Event (AE) is defined as any untoward medical occurrence in a clinical investigation participant administered a drug; it does not necessarily have to have a causal relationship with this treatment. A Serious Adverse Event (SAE) is any experience that suggests a significant hazard, contraindication, side effect or precaution that: results in death, is life-threatening, required in-patient hospitalization or prolongation of existing hospitalization, results in persistent or significant disability/incapacity, is a congenital anomaly/birth defect or is medically significant. A treatment-emergent adverse event (TEAE) is defined as an adverse event with an onset that occurs after receiving study drug. AE severity was graded according to National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE) version 4.03.

Abnormal clinical laboratory values (serum chemistry and hematology) were reported as AEs if they were considered by the investigator to be a clinically significant change from Baseline or led to premature discontinuation of study treatment, dose modification, or other therapeutic intervention.

Vital signs measurements included supine (after 3-5 minutes in this position) and standing (after 3-5 minutes in this position) measurements of diastolic and systolic blood pressure, heart rate, and oral temperature.

Blood samples were collected and tested for serum concentrations of brentuximab vedotin antibody-drug conjugate.

Blood samples were collected and tested for conjugated and unconjugated antibodies.

Blood samples were collected and tested for MMAE plasma concentrations.

Overall response rate is defined as the percentage of participants with complete remission (CR) or partial remission (PR) as assessed by an independent review facility (IRF) using International Working Group (IWG) Revised Response Criteria for Malignant Lymphoma. CR is defined as the disappearance of all evidence of disease and PR is defined as regression of measurable disease and no new sites.