AE=any new unfavorable symptom, sign, or disease or worsening of a preexisting condition that may not have a causal relationship with treatment. SAE=a medical event that at any dose results in death, persistent or significant disability/incapacity, or drug dependency/abuse; is life-threatening, an important medical event, or a congenital anomaly/birth defect; or requires or prolongs hospitalization.

All participants who received at least 1 dose of study drug

Estimated using linear regression model, with baseline CD56^dim cells as the independent covariate, and maximal percent reduction in serum M protein as the dependent variable. For 1 patient who had nonmeasurable disease at baseline, the percent change in serum kappa-lambda difference was used instead of the percent change in serum M protein. Unit of measure=percent change from baseline in M protein cells/ percent change in CD56^dim cells (% chg from BL in M pro/% chg CD56^dim cs)

All participants who received at least 1 dose of study drug and had the required data (4 participants did not have baseline data available).

Clinical laboratory evaluations included hematology, chemistry, and liver and renal functioning.

All participants who received at least 1 dose of study drug

All on-treatment electrocardiograms (ECGs) were performed in triplicates ( 1 ECG test equaled 3 consecutive individual 12-lead ECGs performed within a 4-minute period). The timing of the ECG was critical to the endpoint of the study. The investigative site documented any deviations from the protocol or procedures related to ECG collection or serum sampling. No ECGs were excluded due to timing deviations; no deviations were considered clinically relevant and all ECG data were included.

All participants who received at least 1 dose of study drug

The probability was estimated from the K-M curve of subjects being alive and without disease progression (modified IMWG criteria) at 2 years from the initiation of study therapy by dose cohort

All treated participants

ORR is defined as the number of participants with stringent compete response [SCR], complete response [CR], very good partial response [VGPR], and partial response [PR])/number of participants in arm, expressed as a percentage. Confidence intervals computed using the Clopper and Pearson method. SCR=CR plus normal free light chain ratio and absence of clonal cells in bone marrow by immunohistochemistry or immunofluorescence. CR=Negative immunofixation on serum and urine and 5% or fewer plasma cells in bone marrow. VGPR=Serum and urine monoclonal (M) protein detectable by immunofixation but not on electrophoresis or 90% reduction in serum M protein level plus urine M protein level <100 mg/24 hour. PR=50% reduction of serum M protein and reduction in 24-hour urinary M protein by 90% or to <200 mg/24 hour

All treated participants