A Study to Evaluate the Efficacy and Safety of Ixazomib in Combination With Lenalidomide and Dexamethasone in Patients With Relapsed and/or Refractory Multiple Myeloma Initially Treated With an Injection of Proteasome Inhibitor-Based Therapy

OS was defined as the period from the first dose of treatment in Treatment Period I to the time when death (regardless of the cause of death) was confirmed. Participants who were still alive were censored at the last confirmed date of survival or the date of data cut-off, whichever was earlier.

PFS was defined as the period from the first dose of treatment in Treatment Period I to the time of confirmed PD or confirmed death (regardless of the cause of death), whichever is earlier. PFS was assessed by IMWG Criteria.

VGPR or better (CR + VGPR) were assessed by IMWG Criteria. Per IMWG criteria, PR (partial response): ≥50% reduction of serum M protein+reduction in 24-hour urinary M protein by ≥90%/ to <200 mg/24-hour or ≥50% decrease in difference between involved and uninvolved free light chain (FLC) levels/ ≥50% reduction in bone marrow plasma cells, if ≥30% at baseline/ ≥50% reduction in size of soft tissue plasmacytomas. VGPR (very good PR): serum+urine M-protein detectable by immunofixation but not on electrophoresis/ ≥90% reduction in serum M-protein+urine Mprotein level <100 mg/24-hour. CR (complete response): negative immunofixation on serum+urine+disappearance of soft tissue plasmacytomas+<5% plasma cells in bone marrow.

MRD was measured by the flow cytometry method using bone marrow aspiration. Reported data were numbers of participants with MRD positive and negative in bone marrow in participants who achieved CR. MRD positive was categorized into three sensitivity levels with the numbers of cells counted (10^-4 to - Max; 10^-5 to 10^-4; 10^-6 to 10^-5). MRD negativity is defined as absence of MRD and MRD positivity is defined as presence of MRD. If a participant is MRD-positive at their first evaluation and MRD-negative after re-examination, the participant will be considered to be MRD-negative. CR will be assessed by IMWG Criteria.

Best response is defined as the cumulative numbers of participants who achieve each level of best response including PR, VGPR and CR assessed with IMWG Criteria, after each cycle of treatment. Per IMWG criteria, PR (partial response): ≥50% reduction of serum M protein+reduction in 24-hour urinary M protein by ≥90%/ to <200 mg/24-hour or ≥50% decrease in difference between involved and uninvolved free light chain (FLC) levels/ ≥50% reduction in bone marrow plasma cells, if ≥30% at baseline/ ≥50% reduction in size of soft tissue plasmacytomas. VGPR (very good PR): serum+urine M-protein detectable by immunofixation but not on electrophoresis/ ≥90% reduction in serum M-protein+urine Mprotein level <100 mg/24-hour. CR (complete response): negative immunofixation on serum+urine+disappearance of soft tissue plasmacytomas+<5% plasma cells in bone marrow.

ORR is defined as the percentage of participants who achieve a best response of PR or better including stringent complete response (sCR), VGPR and PR assessed with IMWG Criteria, after the start of the study treatment. Per IMWG criteria, PR (partial response): ≥50% reduction of serum M protein+reduction in 24-hour urinary M protein by ≥90%/ to <200 mg/24-hour or ≥50% decrease in difference between involved and uninvolved free light chain (FLC) levels/ ≥50% reduction in bone marrow plasma cells, if ≥30% at baseline/ ≥50% reduction in size of soft tissue plasmacytomas. VGPR (very good PR): serum+urine M-protein detectable by immunofixation but not on electrophoresis/ ≥90% reduction in serum M-protein+urine Mprotein level <100 mg/24-hour. CR (complete response): negative immunofixation on serum+urine+disappearance of soft tissue plasmacytomas+<5% plasma cells in bone marrow.

DOR is defined as the time from the date of first documentation of response ≥PR to the date of first documentation of PD or death due to any cause. PR and PD will be assessed with IMWG Criteria. Per IMWG criteria, PR (partial response): ≥50% reduction of serum M protein+reduction in 24-hour urinary M protein by ≥90%/ to <200 mg/24-hour or ≥50% decrease in difference between involved and uninvolved free light chain (FLC) levels/ ≥50% reduction in bone marrow plasma cells, if ≥30% at baseline/ ≥50% reduction in size of soft tissue plasmacytomas. VGPR (very good PR): serum+urine M-protein detectable by immunofixation but not on electrophoresis/ ≥90% reduction in serum M-protein+urine Mprotein level <100 mg/24-hour. CR (complete response): negative immunofixation on serum+urine+disappearance of soft tissue plasmacytomas+<5% plasma cells in bone marrow.

TTNT is defined as the period from the start of study treatment Period I to the start of next line treatment.

DOT is defined as the treatment duration of study drug at study treatment Period I.

EORTC QLQ-C30 contains 30 items across 5 functional scales (physical, role, cognitive, emotional, and social), 9 symptom scales (fatigue, nausea and vomiting, pain, dyspnea, sleep disturbance, appetite loss, constipation, diarrhea, and financial difficulties) and a global health status/QOL scale (Global Health Status). EORTC QLQ-C30 contains 28 questions (4-point scale where 1=Not at all [best] to 4=Very Much [worst]) and 2 questions (7-point scale where 1=Very poor [worst] to 7= Excellent [best]). Raw scores are converted into scale scores ranging from 0 to 100. For the functional scales and the global health status/QOL scale, higher scores represent better QOL; for the symptom scales, lower scores represent better QOL.

EORTC QLQ-MY20 has 20 items across 4 independent subscales, 2 functional subscales (body image, future perspective), and 2 symptoms scales (disease symptoms, and side effects of treatment). Scores are averaged, and transformed to 0-100 scale. For the functional scales, high scores represent improvement. For the symptom scales, higher scores represent worsening.

Modified QALYs was calculated from the score of EORTC QLQ-C30. The health-related quality of life scale score of EORTC QLQ-C30 was converted into a utility value ranging from 0 (dead) to 1 (perfect health), and used to adjust the value of survival years; this value was assessed as the modified QALY.

HCRU was calculated from Exposure-adjusted rate of hospitalization events (per participants-months) and the duration of hospitalization among participants in Treatment Period I and Treatment Period II. Number of events with hospitalization per participants-month in Treatment Period I and Treatment Period II was reported.

HCRU was calculated from Exposure-adjusted rate of hospitalization events (per participants-months) and the duration of hospitalization among participants in Treatment Period I and Treatment Period II. Duration of hospital stay per participants in Treatment Period I and Treatment Period II was reported.

RDI for each study drug is defined as 100*(Total amount of dose taken)/(Total prescribed dose of treated cycles), where total prescribed dose equals [dose prescribed at enrollment* number of prescribed doses per cycle* the number of treated cycles].

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 TEAE is defined as an adverse event with an onset that occurs after receiving study drug.