Multinational Clinical Study Comparing Isatuximab, Carfilzomib And Dexamethasone To Carfilzomib And Dexamethasone In Relapse And/Or Refractory Multiple Myeloma Patients

OR: participants with sCR, CR, VGPR \& partial response (PR) as best overall response assessed by IRC using IMWG response criteria (from start of treatment until disease progression, death, initiation of further anti-myeloma treatment/cutoff date, whichever occurs 1st). sCR: negative immunofixation on serum \& urine, disappearance of soft tissue plasmacytoma, <5% plasma cells in bone marrow aspirate (BMA) + normal FLC ratio (0.26-1.65), absence of clonal cells in bone marrow biopsy. CR: negative immunofixation on serum \& urine, disappearance of soft tissue plasmacytoma, <5% plasma cells in BMA. VGPR: serum \& urine M-protein detectable by immunofixation, not on electrophoresis/,>=90% reduction in serum M-protein + urine M-protein level <100mg/24h/,>=90% decrease in SPD compared to baseline in soft tissue plasmacytoma. PR:>=50% reduction of serum M-protein \& decrease in 24h urinary M-protein by >=90%/<200mg/24h, if present at baseline,>=50% decrease in SPD of soft tissue plasmacytoma.

VGPR or better: defined as participants with sCR, CR and VGPR as the best overall response (defined as best response from start of treatment until disease progression, death, initiation of further anti-myeloma treatment or cut-off date whichever occurs first) as per IRC. As per IMWG response criteria: sCR: negative immunofixation on serum and urine, disappearance of any soft tissue plasmacytomas, <5% plasma cells in BMAs plus normal FLC ratio (0.26-1.65), absence of clonal cells in bone marrow biopsy. CR: negative immunofixation on serum and urine, disappearance of any soft tissue plasmacytomas, <5% plasma cells in BMAs. VGPR: serum and urine M-protein detectable by immunofixation, not on electrophoresis/,>=90% reduction in serum M-protein plus urine M-protein level <100mg/24h/,>=90% decrease in SPD compared to baseline in soft tissue plasmacytoma.

Percentage of participants with sCR, CR and VGPR for whom MRD assessed by sequencing was negative at any time after first dose of study treatment. MRD was assessed centrally by next-generation sequencing in bone marrow aspiration samples from participants who achieve VGPR or better, to determine depth of response at molecular level. VGPR or better: percentage of participants with sCR, CR and VGPR. sCR: negative immunofixation on serum and urine, disappearance of any soft tissue plasmacytomas, <5% plasma cells in BMAs plus normal FLC ratio (0.26-1.65), absence of clonal cells in bone marrow biopsy. CR: negative immunofixation on serum and urine, disappearance of any soft tissue plasmacytomas, <5% plasma cells in BMAs. VGPR: serum and urine M-protein detectable by immunofixation, not on electrophoresis/,>=90% reduction in serum M-protein plus urine M-protein level <100mg/24h/,>=90% decrease in SPD compared to baseline in soft tissue plasmacytoma.

Percentage of participants with sCR, CR and VGPR for whom MRD assessed by sequencing was negative at any time after first dose of study treatment. MRD was assessed centrally by next-generation sequencing in BM aspiration samples from participants who achieve VGPR or better, to determine depth of response at molecular level. VGPR or better: percentage of participants with sCR, CR and VGPR. sCR: negative immunofixation on serum and urine, disappearance of any soft tissue plasmacytomas, <5% plasma cells in bone marrow aspirates plus normal FLC ratio, absence of clonal cells in bone marrow biopsy. CR: negative immunofixation on serum and urine, disappearance of any soft tissue plasmacytomas, <5% plasma cells in bone marrow aspirates. VGPR: serum and urine M-protein detectable by immunofixation, not on electrophoresis/,>=90% reduction in serum M-protein plus urine M-protein level <100mg/24h/,>=90% decrease in SPD compared to baseline in soft tissue plasmacytoma.

Complete response was defined as the participants with sCR and CR. IMWG response criteria for sCR: negative immunofixation on serum and urine, disappearance of any soft tissue plasmacytomas, <5% plasma cells in bone marrow aspirates plus normal free light chain (FLC) ratio (0.26-1.65), absence of clonal cells in bone marrow biopsy. CR: negative immunofixation on serum and urine, disappearance of any soft tissue plasmacytomas, <5% plasma cells in bone marrow aspirates. Complete response at the time of the final analysis was assessed with hydrashift isatuximab immunofixation electrophoresis (IFE) assay, which separated immunoglobulin G (IgG) isatuximab from IgG M protein.

MRD negativity was defined as the percentage of participants for whom MRD was negative by next-generation sequencing at any timepoint after first dose of study treatment. Threshold for negativity is 10^-5. MRD status in a participant was negative if at least one result of the assessment was negative in the participant otherwise MRD was considered as positive (MRD status reported as positive, missing or unevaluable). CR: participants with sCR and CR. IMWG response criteria for sCR: negative immunofixation on serum and urine, disappearance of any soft tissue plasmacytomas, <5% plasma cells in bone marrow aspirates plus normal FLC ratio (0.26-1.65), absence of clonal cells in bone marrow biopsy. CR: negative immunofixation on serum and urine, disappearance of any soft tissue plasmacytomas, <5% plasma cells in bone marrow aspirates. Complete response at the time of the final analysis was assessed with Hydrashift isatuximab IFE assay, which separated IgG isatuximab from IgG M protein.

Overall survival, defined as the time from the date of randomization to death from any cause. The data reported is based on cut-off date of 7 Feb 2023.

DOR: time (in months) from date of 1st IRC determined response for participants achieving PR/better to date of 1st documented PD determined by IRC/death, whichever happens 1st. If disease progression/death before analysis cut-off date was not observed, DOR was censored at date of last valid disease assessment performed prior to initiation of further anti-myeloma treatment/data cut-off date, whichever was 1st. PD (IMWG criteria): inc of >=25% from lowest confirmed value in any 1 of following criteria: serum M-protein (absolute inc must be >=0.5 g/dL), serum M-protein inc >=1g/dL if lowest M component was >=5g/dL; urine M-component (absolute inc must be >=200mg/24 hour),appearance of new lesion(s), >=50% inc from nadir in SPD of >1 lesion, or >=50% inc in the longest diameter of previous lesion >1 cm in short axis. PR: >=50% reduction of serum M-protein \& reduction in 24h urinary M-protein by >=90%/<200mg/24 h. Estimated by Kaplan Meier method.

TTP was defined as time in months from randomization to the date of first documentation of PD (as determined by the IRC). If progression was not observed before the analysis cut-off date or the date of initiation of further anti-myeloma treatment, TTP was censored at the date of the last valid disease assessment not showing disease progression performed prior to initiation of a further anti-myeloma treatment (if any) or the analysis cut-off date, whichever comes first. As per IMWG criteria, PD was defined for participants with inc of >= 25% from lowest confirmed value in any one of the following criteria: serum M-protein (the absolute inc must be >= 0.5 g/dL), serum M-protein inc >=1 g/dL if the lowest M component was >=5 g/dL; urine M-component (the absolute inc must be >=200 mg/24hour), appearance of new lesion(s), >=50% inc from nadir in SPD of >1 lesion, or >=50% inc in the longest diameter of a previous lesion >1 centimeter in short axis.

Time to first response was defined as the time (in months) from randomization to the date of first IRC determined response (PR or better) that is subsequently confirmed. In the absence of response, participants were censored at the earliest of the date of the last valid disease assessment before disease progression or death, the date of the last valid disease assessment before initiation of a further anti-myeloma treatment (if any) or the analysis cut-off date, whichever comes first. PR per IMWG criteria was defined as >=50% reduction of serum M-protein and reduction in 24 hours urinary M-protein by >=90% or to <200 mg/24 h. In addition to the above listed criteria, if present at baseline, a >=50% reduction in the size (SPD) of soft tissue plasmacytomas was also required.

Time to best response was defined as time (in months) from randomization to the date of first occurrence of IRC determined as best overall response (PR or better) that is subsequently confirmed. In absence of response, participants were censored at earliest date of last valid disease assessment before disease progression/death, date of last valid disease assessment before initiation of further anti-myeloma treatment (if any)/ analysis cut-off date, whichever was 1st. PR (IMWG criteria) was defined as >=50% reduction of serum M-protein and reduction in 24 hours urinary M-protein by >=90% or to <200 mg/24 h. In addition to above listed criteria, if present at baseline, a >=50% reduction in the size (SPD) of soft tissue plasmacytomas was also required. Best Overall Response was defined as the best response, using the IRC's assessment of response, from start of treatment until disease progression, death, initiation of further anti-myeloma treatment or cut-off date, whichever occurs 1st.

PFS2 defined as time (in months) from date of randomization to date of 1st documentation of PD (as assessed by investigator) after initiation of further anti-myeloma treatment /death from any cause, whichever comes 1st. Participants alive without progression after initiation of further anti-myeloma treatment before analysis cut-off date, PFS2 censored at date of last follow-up visit not showing disease progression after initiation of further anti-myeloma treatment /analysis cut-off date, whichever comes 1st. As per IMWG criteria, PD: defined for participants with increase of >= 25% from lowest confirmed value in any 1 of following criteria: serum M-protein (absolute increase must be >= 0.5 g/dL), serum M-protein increase >=1 g/dL if lowest M component was >=5 g/dL; urine M-component (absolute increase must be >=200 mg/24hour), appearance of new lesion(s), >=50% increase from nadir in SPD of >1 lesion, or >=50% increase in longest diameter of previous lesion >1 centimeter short axis.

PFS2 defined as time (in months) from date of randomization to date of 1st documentation of PD (as assessed by investigator) after initiation of further anti-myeloma treatment /death from any cause, whichever comes 1st. Participants alive without progression after initiation of further anti-myeloma treatment before analysis cut-off date, PFS2 censored at date of last follow-up visit not showing disease progression after initiation of further anti-myeloma treatment /analysis cut-off date, whichever comes 1st. As per IMWG criteria, PD: defined for participants with increase of >= 25% from lowest confirmed value in any 1 of following criteria: serum M-protein (absolute increase must be >= 0.5 g/dL), serum M-protein increase >=1 g/dL if lowest M component was >=5 g/dL; urine M-component (absolute increase must be >=200 mg/24hour), appearance of new lesion(s), >=50% increase from nadir in SPD of >1 lesion, or >=50% increase in longest diameter of previous lesion >1 centimeter short axis.

RR comprises of complete RR (CR renal), partial RR (PR renal) \& minor RR (MR renal). CR renal was defined as an improvement in estimated glomerular filtration rate (eGFR) from <50 mL/min/1.73m^2 at Baseline to >=60 mL/min/1.73m^2 in at least 1 assessment during the treatment period (time from first dose of study treatment up to 30 days after last dose of study treatment); PR renal was defined as improvement in eGFR from <15 mL/min/1.73m^2 at baseline to at least 1 assessment in the range of 30 to 60 mL/min/1.73m^2 during the on-treatment-period and MR renal was defined as an improvement in eGFR from <15 mL/min/1.73m^2 at Baseline to at least 1 assessment in the range of 15 to 30 mL/min/1.73m^2 during the on-treatment-period or from 15 to 30 mL/min/1.73m^2 at Baseline to at least 1 assessment in the range of 30 to 60 mL/min/1.73m^2 during the on-treatment-period.

EORTC QLQ-C30 is a cancer-specific instrument that contains 30 items \& provides multidimensional assessment of HRQL. EORTC QLQ-C30 includes global health status/quality of life (GHS/QOL), functional scales (physical, role, cognitive, emotional, social), symptom scales (fatigue, pain, nausea/vomiting), and 6 single items (dyspnea, appetite loss, insomnia, constipation, diarrhea, financial difficulties). Most questions from QLQ-C30 are 4-point scale (1/Not at All to 4/Very Much), except Items 29-30, which comprise GHS scale \& are 7-point scale (1/Very Poor to 7/Excellent). GHS total score is calculated as ([{Q29+Q30}/2]-1)/6*100. Answers are converted into grading scale, with values between 0 (worse outcome) to100 (best outcome). High score represents a favorable outcome with best quality of life for participant. Results reported for primary analysis with data cut-off date 7-Feb-2020.

EORTC QLQ-MY20 is a validated questionnaire to assess the overall quality of life in participants with multiple myeloma. It is used in conjunction with the EORTC QLQ-C30 to assess symptoms and side effects due to treatment or the disease. Disease symptoms domain is one of the four domain scores. Disease symptoms domain consist of 6 questions and the score uses 4-point scale (1 'Not at All' to 4 'Very Much'). Disease Symptoms Domain Score is calculated as ([{Q31+Q32+Q33+Q34+Q35+Q36}/6]-1)/3*100. Scores are averaged, and transformed to 0-100 scale, where higher scores = more symptoms and lower HRQL.

EORTC QLQ-MY20 is a validated questionnaire to assess the overall quality of life in participants with multiple myeloma. Side effects of treatment domain is one of the four domain scores. Side effects of treatment domain consists of 10 questions and the score uses a 4-point scale (1 'Not at All' to 4 'Very Much'). Side Effects of Treatment Score (MYSE) is calculated as ([{Q37+Q38+Q39+Q40+Q41+Q42+Q43+Q44+Q45+Q46}/10]-1)/3*100. Scores are averaged, and transformed to 0-100 scale, where higher scores = more side effects and lower HRQL and lower scores = less side effects and better HRQL.

EORTC QLQ-MY20 is a validated questionnaire to assess the overall quality of life in participants with multiple myeloma. It is used in conjunction with the EORTC QLQ-C30 to assess symptoms and side effects due to treatment or the disease. It consists of one question and scores are based on the 4-point Likert scale ranging from "Not at all" to "Very much". Body image score is calculated as: (1 - [Q47-1]/3)*100. Scores are averaged, and transformed to scale ranging from 0 to 100. A higher score represents a better quality of life.

EORTC QLQ-MY20 is a validated questionnaire to assess the overall quality of life in participants with multiple myeloma. It is used in conjunction with the EORTC QLQ-C30 to assess symptoms and side effects due to treatment or the disease. It consists of three questions and the scores are based on the 4-point Likert scale ranging from "Not at all" to "Very much". Future Perspective score is calculated as (1 - ([{Q48+Q49+Q50}/3] -1)/3)*100. Scores are averaged and transformed to scale ranging from 0 to 100. A higher score represents a better quality of life.

The EQ-5D-5L is a standardized measure of health status that provides a general assessment of health utility and consist in 2 sections a descriptive system comprising 5 dimensions (mobility, self-care, usual activities, pain/discomfort and anxiety/depression) and Visual Analog Scale (VAS). Each dimension has a 5-level response: no problems, slight problems, moderate problems, severe problems, and extreme problems. Response options are measured with a 5-point Likert scale. The 5D-5L systems are converted into a single index utility score between 0 to 1, where higher score indicates a better health state and lower score indicate worse health state.

The EQ-5D-5L is a standardized measure of health status that provides a general assessment of health utility and consist of 2 sections; descriptive system comprises 5 dimensions (mobility, self-care, usual activities, pain/discomfort and anxiety/depression) and a VAS. The VAS records the respondent's self-rated health on a 20 centimeter (cm) vertical VAS; the scale went from 0 (worst imaginable health state) to 100 (best imaginable health state). This information can be used as a quantitative measure of health as judged by the individual respondents.

Ceoi is the plasma concentration observed at the end of intravenous infusion.

Ctrough was the plasma concentration observed just before treatment administration during repeated dosing.

Cmax was defined as the maximum concentration observed after the first infusion calculated using the non-compartmental analysis after the intravenous infusion of carfilzomib with isatuximab.

Clast was defined as the last concentration observed above the lower limit of quantification.

Tmax was defined as the time to reach Cmax, calculated using the non-compartmental analysis after the intravenous infusion of carfilzomib with isatuximab.

Tlast was defined as the time of last concentration observed above the lower limit of quantification, calculated using the non-compartmental analysis after the intravenous infusion of carfilzomib with isatuximab.

AUC was defined as area under the plasma concentration-time curve extrapolated to infinity according to the equation: AUC= AUClast + Clast/λz. AUC was calculated using the non-compartmental analysis after the intravenous infusion of carfilzomib with isatuximab.

AUClast was defined as area under the plasma concentration versus time curve calculated from time 0 to last quantifiable concentration. AUClast was calculated using the non-compartmental analysis after the intravenous infusion of carfilzomib with isatuximab.

AUCext was defined as the percentage of the extrapolation of AUC, calculated using the non-compartmental analysis after the intravenous infusion of carfilzomib with isatuximab.

T1/2 was defined as the time required for the concentration of the drug to reach half of its original value, calculated using the non-compartmental analysis after the intravenous infusion of carfilzomib with isatuximab.

CLss was defined as a quantitative measure of the rate at which a drug substance is removed from the body at steady state, calculated using the non-compartmental analysis after the intravenous infusion of carfilzomib with isatuximab.

Volume of Distribution was defined as the theoretical volume in which the total amount of drug would need to be uniformly distributed to produce the desired plasma concentration of a drug. Vss is the apparent volume of distribution at steady-state, calculated using the non-compartmental analysis after the intravenous infusion of carfilzomib with isatuximab.

ADA were categorized as: pre-existing, treatment induced, and treatment boosted response. Pre-existing ADA was defined as ADA that were present in samples drawn during the pretreatment period (i.e., before the first isatuximab administration). Treatment-induced ADA was defined as ADA that developed at any time during the ADA on-study observation period in participants without pre-existing ADA, including participants without pretreatment samples. Treatment boosted ADA was defined as pre-existing ADA with an increase in titer during the ADA on-study observation period.

Adverse Event (AE) was defined as any untoward medical occurrence in a participant who received study drug and did not necessarily had a causal relationship with the treatment. TEAEs were defined as AEs that developed, worsened, or became serious during the treatment period (time from the first dose of study treatments up to 30 days after last dose of study treatments). An SAE was any untoward medical occurrence that at any dose: resulted in death, was life-threatening, required inpatient hospitalization or prolongation of existing hospitalization, resulted in persistent or significant disability / incapacity, was a congenital anomaly/birth defect, was a medically important event.