Progression free survival was defined as the time from randomization to the first documented disease progression, or death due to any cause, whichever occurred first. PFS was assessed by CAC blinded central review according to the IMWG criteria based on the development of new bone lesions or soft tissue plasmacytomas or on a definite increase in the size of existing bone lesions or soft tissue plasmacytomas. Median PFS was calculated from the product-limit (Kaplan-Meier) method for censored data. The database cutoff date was July 9, 2018.

The analysis population included all randomized participants. Participants were included in the treatment group to which they were randomized.

Overall survival is defined as the time from randomization to death due to any cause. Participants without documented death at the time of the final analysis were censored at the date of the last follow-up. Median overall survival was calculated from the product-limit (Kaplan-Meier) method for censored data. The database cutoff date was August 3, 2020.

The analysis population included all randomized participants. Participants were included in the treatment group to which they were randomized.

ORR was defined as the percentage of the participants in the analysis population who achieved at least a partial response (stringent complete response [sCR]+complete response [CR]+very good partial response [VGPR]+partial response [PR]) according to the IMWG. CR = negative immunofixation of serum and urine AND disappearance of any soft tissue plasmacytomas AND <5% plasmacytomas in the bone marrow; sCR=stringent complete response, CR as above PLUS normal serum free light-chain (FLC) assay ratio and absence of clonal cells in bone marrow by immunohistochemistry or immunofluorescence; VGPR = serum and urine M-component detectable by immunofixation but not on electrophoresis OR ≥ 90% reduction in serum M-component plus urine M-component <100 mg/24 hr; PR = ≥50% reduction of serum M-protein and reduction in 24-hour urinary M-protein by ≥90% or to <200 mg/24 hours. The database cutoff date was July 9, 2018.

The analysis population included all randomized participants. Participants were included in the treatment group to which they were randomized.

An adverse event (AE) was defined as any unfavorable and unintended sign including an abnormal laboratory finding, symptom or disease associated with the use of a medical treatment or procedure, regardless of whether it was considered related to the medical treatment or procedure, that occurred during the course of the study. Database cutoff was August 3, 2020.

The analysis population consisted of all randomized participants who received at least one dose of study treatment. Participants were included in the treatment group corresponding to the study treatment they actually received.

An adverse event was defined as any unfavorable and unintended sign including an abnormal laboratory finding, symptom or disease associated with the use of a medical treatment or procedure, regardless of whether it was considered related to the medical treatment or procedure, that occurred during the course of the study. Database cutoff was August 3, 2020.

The analysis population consisted of all randomized participants who received at least one dose of study treatment. Participants were included in the treatment group corresponding to the study treatment they actually received.

Disease control rate was the percentage of participants who achieved confirmed sCR, CR, VGPR, PR, minimal response (MR) or have demonstrated stable disease (SD) for at least 12 weeks prior to any evidence of progression. PD was development of or an increase in the size of bone lesions or soft tissue plasmacytomas. CR = negative immunofixation of serum and urine AND disappearance of any soft tissue plasmacytomas AND <5% plasmacytomas in the bone marrow; sCR=stringent complete response, CR as above PLUS normal serum FLC assay ratio and absence of clonal cells in bone marrow by immunohistochemistry/fluorescence; VGPR = serum and urine M-component detectable by immunofixation but not on electrophoresis OR ≥ 90% reduction in serum M-component plus urine M-component <100 mg/24 hr; PR = ≥50% reduction of serum M-protein and reduction in 24-hour urinary M-protein by ≥90% or to <200 mg/24 hours. The data cutoff date was July 9, 2018.

The analysis population included all randomized participants. Participants were included in the treatment group to which they were randomized.

PFS2 was defined as the time from randomization to subsequent disease progression after initiation of new anti-cancer therapy, or death from any cause, whichever occurred first, by investigator assessment. As a result of a full clinical hold by FDA that led to discontinuation of study enrollment, no data was collected for analysis of PFS2.

The analysis population was to include all randomized participants. Study treatment was terminated early and no data was collected for analysis of PFS2.