Elotuzumab

PFS is defined as the time from randomization to the date of the first documented tumor progression (as determined by the Independent Review Committee (IRC)) or death due to any cause. The IRC conducted a blinded, independent review of the tumor assessments based on the European Group for Blood and Bone Marrow Transplant (EBMT) criteria. Censoring rules applied: * Participants receiving subsequent systemic anti-myeloma therapy prior to documented progression were censored at the date of the last adequate tumor assessment prior to new therapy. * Participants who had an event (progression or death) \> 10 weeks after their last tumor assessment were censored at their last adequate tumor assessment prior to the event. * Participants without progression or death (and not receiving subsequent therapy prior to progression) were censored at their last adequate tumor assessment. * Participants without any post-baseline tumor assessments were censored on the date of randomization

Primary definition of Progression-free survival (PFS) defined as the time from randomization to the date of first documented tumor progression or death due to any cause. Participants were censored at the last adequate assessment prior to the start of any subsequent systemic-therapy or at the last adequate assessment prior to 2 missing assessments (\> 10 weeks). Participants who died more than 10 weeks after the randomization date and had no on-treatment assessment were censored at the randomization date. Clinical deterioration was not considered progression. The primary analysis of PFS was based on the primary definition using the Independent Review Committee (IRC) tumor assessment using the European Group for Blood and Bone Marrow Transplant (EBMT) criteria. Tumor assessments were made every 4 weeks (±1 week) relative to the first dose of study medication.

Objective response rate (ORR) defined as the percentage of participants with a best response on-study of partial response (PR) or better (stringent CR \[sCR\], complete response \[CR\], very good partial response \[VGPR\], and partial response \[PR\]) based on the Independent Review Committee (IRC) assessment of best response using the European Group for Blood and Bone Marrow Transplant (EBMT) assessment criteria. Participants were censored at the last adequate assessment prior to the start of any subsequent systemic-therapy or at the last adequate assessment prior to 2 missing assessments (\> 10 weeks). Participants who died more than 10 weeks after the randomization date and had no on-treatment assessment were censored at the randomization date. Clinical deterioration was not considered progression. Assessments were made every 4 weeks.

Defined as the percentage of patients who successfully complete four 28-day cycles of induction therapy with elotuzumab, lenalidomide and dexamethasone (ERd) and start autologous stem cell transplantation (ASCT).

PFS is defined as the time from randomization to the date of the first documented tumor progression or death due to any cause. Progressive disease response criteria were defined as an increase of 25% from lowest response value in any one or more of the following: 1\. Serum M-component and/or 2. Urine M-component and/or 3. Only in patients without measurable serum and urine M-protein levels: the difference between involved and uninvolved FLC levels 4. Bone marrow plasma cell percentage; Definite development of new bone lesions or soft tissue plasmacytomas or definite increase in the size of existing bone lesions or soft tissue plasmacytomas; Development of hypercalcemia that can be attributed solely to the plasma cell proliferative disorder

Disease response was defined as the proportion of patients who achieved a response of partial response or better using International Myeloma Working Group (IMWG) response criteria. Partial Response (PR) defined as 50% reduction of serum M-protein and reduction in 24h urinary M-protein by ≥90% or to \<200mg/24h; Very Good Partial Response (VGPR) defined as serum and urine M-protein detectable by immunofixation but not on electrophoresis or ≥90% reduction in serum M-protein plus urine M-protein level \<100mg/24h; Complete Response (CR) defined as negative immunofixation on serum and urine and, disappearance of any soft tissue plasmacytomas and, \<5% plasma cells in BM; Stringent Complete Response (sCR) defined as normal FLC ratio and absence of clonal cells in BM by immunohistochemistry or 2-4 color flow cytometry. The Clopper and Pearson method was used to estimate the 95% CIs for the response rate at Week 12.

ORR is the proportion of randomized participants who achieve a stringent complete response (sCR), complete response (CR), very good partial response (VGPR) or PR as determined by investigator using the International Myeloma Working Group (IMWG) response criteria. SCR: CR and normal free light chain (FLC) ratio and no clonal cells in bone marrow; CR: Negative serum and urine on immunofixation, disappearance of any soft tissue plasmacytomas and ≤ 5% plasma cells in bone marrow; VGPR: Serum and urine M-protein detectable by immunofixation but not on electrophoresis or ≥ 90% reduction in serum M-protein and urine M-protein level \< 100 mg/24 hours; PR: ≥ 50% reduction of serum M-Protein and reduction in urinary M-protein by ≥ 90% or to \< 200 mg/24 hours. In addition to the above, if present at baseline a ≥ 50% reduction in the size of soft tissue plasmacytomas is also required.

Percent of patients who are alive and without documented progression after at least 2-years of follow-up. All patients who receive study treatment are assessed including those who have died or lost to follow-up prior to 2-years. Progression was defined as an increase in SPEP \[25% and an absolute increase of 0.5g/d\] or UPEP \[25% and an absolute increase of 200mg/24hours\] on 2 successive evaluations as determined by the IMWG response criteria or documented progression by the FreeLite progressive disease criteria in the absence of serum or urine involvement.

Infusion reaction was defined as any relevant sign or symptom occurring during or after elotuzumab infusion and considered by the investigator as an infusion reaction. Grade (Gr) 1=Mild, Gr 2=Moderate, Gr 3=Severe, Gr 4=Potentially Life-threatening or disabling, Gr 5=Death.

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. Treatment-related=having certain, probable, possible, or unknown relationship to study drug. Grade (Gr) 1=Mild, Gr 2=Moderate, Gr 3=Severe, Gr 4=Life-threatening or disabling, Gr 5=Death.

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. Treatment-related=having certain, probable, possible, or unknown relationship to study drug. Grade (Gr) 1=Mild, Gr 2=Moderate, Gr 3=Severe, Gr 4=Life-threatening or disabling, Gr 5=Death.

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)

PE was planned for after at least 103 events; it was analyzed after 111 events. Response was assessed: Day 1 (± 7 days) of each cycle per modified International Myeloma Working Group (IMWG) criteria; assessed using adequate tumor assessment (ATA) (ie, serum and urine M-protein tests performed within 14 days of each other; imaging if baseline measurable extramedullary plasmacytoma existed). Progression: Any of following: Increase of 25% from lowest response in 1 or more: serum and/or urine M-component; in those without measurable serum and urine M-protein levels, difference between involved and uninvolved free light chain (FLC) levels (absolute increase \> 100 mg/L); Bone marrow plasma cell percentage (≥10%). Definite new bone lesions or soft tissue plasmacytomas or definite increase in the size of existing lesions or plasmacytomas. Development of hypercalcemia attributed solely to the plasma cell proliferative disorder.

PE planned for after at least 103 events (progression/death); analyzed at 111 events. Those who neither progressed nor died were censored on the date of last adequate tumor assessment (ATA), which requires both serum and urine M-protein tests. If no post-baseline tumor assessments/no death, then censored on randomization day. Response assessed: Day 1 (± 7 days) each cycle; 30 and 60 days post treatment. Modified IMWG criteria used. Progression: Any of following: Increase of 25% in serum and/or urine M-component; if no measurable serum, urine M-protein levels, then difference between involved and uninvolved free light chain (FLC) levels (absolute increase \> 100 mg/L) ; Bone marrow plasma cell percentage (≥10%). New bone lesions or soft tissue plasmacytomas or increase in size of existing lesions, plasmacytomas. Development of hypercalcemia attributed solely to plasma cell proliferative disorder. First dose occurs within 3 days of randomization.

PFS rate=Percentage probability of participants experiencing no progression or death up to 1 year, estimated using the Kaplan-Meier method. Response assessed by the investigator: Day 1 (± 7 days) of each cycle per modified IMWG criteria; assessed using ATA (ie, serum and urine M-protein tests performed within 14 days of each other; imaging done if baseline measurable extramedullary plasmacytoma existed). Progression: Any of the following: Increase of 25% from lowest response in 1 or more: serum and/or urine M-component; in those without measurable serum and urine M-protein levels, difference between involved and uninvolved FLC levels (absolute increase \> 100 mg/L) ; Bone marrow plasma cell percentage (≥10%). Definite new bone lesions or soft tissue plasmacytomas or definite increase in the size of existing lesions or plasmacytomas. Development of hypercalcemia attributed solely to the plasma cell proliferative disorder.

Safety and tolerability will be measured by the number of evaluable patients who complete the treatment protocol.

Toxicities are to be assess according to the CTCAE v5. DLT criteria could be referred as follow: * Grade ≥3 non-hematologic toxicity that cannot be clearly related to disease progression or other circumstances clearly not linked to study treatment. * Grade 4 thrombocytopenia (platelet count \< 25,000 cells/ mm3) on more than one occasion that cannot be attributed to underlying disease * Grade 3 thrombocytopenia with bleeding * Grade 4 neutropenia (ANC \< 500 cells/mm3) lasting for \>7 days * Any Grade 5 event, unless due to progressive disease

The MTD is defined as the highest dose level where at most 1 participant (of the 6 treated) develops a DLT, and 2 or more of the 3 to 6 participants developed a DLT at the next higher dose level unless the MTD is identified as dose level 1.

rPFS12 is defined as the proportion fo participants who are alive and progression-free at 12 months after treatment initiation. Participants who have died, progressed, or lost to follow-up prior to the primary assessment visit 12 months after treatment initiation will be counted in the denominator for the primary endpoint.

adverse events (AEs), serious adverse events (SAEs)

The quantification of elotuzumab in human serum was performed using a validated Enzyme-linked immunoassay (ELISA). Cycle 1, day 1 sample times for all participants: 0 hour (h) pre-dose, end of infusion, 30 minutes (min) post end of infusion, 2 h, 4 h , and 24 h post end of infusion. Trough samples were obtained in subsequent cycles and at 30 day and 60 day follow-up visits at end of treatment. ESRD had 2 additional samples: immediately prior to and immediately after dialysis. Cmax was measured in micrograms per milliliter (µg/mL). Pharmacokinetic (PK) parameter renal function group assignment criteria differed slightly from the criteria for safety and efficacy analyses (specifically for the SRI group). PK criteria: All participants with at least one pretreatment value ≥ 90 mL/min were assigned to the NRF group. All those with at least one pretreatment value \< 30 mL/min were assigned to the SRI group. All those with a screening diagnosis of ESRD, were assigned to the ESRD group.

The quantification of elotuzumab in human serum was performed using validated ELISA. Cycle 1, day 1 sample times for all participants: 0 hour (h) pre-dose, end of infusion, 30 minutes (min) post end of infusion, 2 h, 4 h , and 24 h post end of infusion. Trough samples were obtained in subsequent cycles and at 30 day and 60 day follow-up visits at end of treatment. ESRD participants had 2 additional sample times: immediately prior to and immediately after dialysis. AUC was measured in µg\*h/mL. PK parameter renal function group assignment criteria differed slightly from the criteria for safety and efficacy analyses (specifically for the SRI group). PK criteria: All participants with at least one pretreatment value ≥ 90 mL/min were assigned to the NRF group. All those with at least one pretreatment value \< 30 mL/min were assigned to the SRI group. All those with a screening diagnosis of ESRD, were assigned to the ESRD group