Cohort A Only: Objective Response Rate as Per IMWG Criteria by BICR for Participants With Extramedullary Disease (EMD) at Baseline

ORR: % of participants with best overall response of confirmed stringent complete response (sCR), CR, very good partial response (VGPR) or PR per IMWG criteria. sCR: CR \& normal serum free light chain (sFLC) ratio \& absence of clonal cells in BMB/BMA by IH, IF, or flow cytometry. CR: negative immunofixation on serum \& urine, disappearance of any soft tissue plasmacytoma \& \=90% reduction in serum M-protein \& urine M-protein level \=50% reduction in serum M-protein \& reduction in 24h urinary M-protein by \>=90% or \=90% \& \>=50% decrease in difference respectively between involved \& uninvolved sFLC levels \& if present at baseline, \>=90% \& \>=50% reduction in soft tissue plasmacytomas' size.

From date of first dose until confirmed disease progression, death, start of new anticancer therapy, whichever occurred first (up to approximately 16 months)

Cohort A Only: Objective Response Rate as Per IMWG Criteria by BICR for Participants Without EMD at Baseline

ORR: % of participants with best overall response of confirmed stringent complete response (sCR), CR, very good partial response (VGPR) or PR per IMWG criteria. sCR: CR \& normal serum free light chain (sFLC) ratio \& absence of clonal cells in BMB/BMA by IH, IF, or flow cytometry. CR: negative immunofixation on serum \& urine, disappearance of any soft tissue plasmacytoma \& \=90% reduction in serum M-protein \& urine M-protein level \=50% reduction in serum M-protein \& reduction in 24h urinary M-protein by \>=90% or \=90% \& \>=50% decrease in difference respectively between involved \& uninvolved sFLC levels \& if present at baseline, \>=90% \& \>=50% reduction in soft tissue plasmacytomas' size.

From date of first dose until confirmed disease progression, death, start of new anticancer therapy, whichever occurred first (up to approximately 16 months)

Duration of Response (DOR) as Per IMWG Criteria by BICR

DOR: time from first documentation of objective response subsequently confirmed, until first documentation of confirmed PD or death due to any cause, whichever occurred first. PD= increase of \>=25% from lowest value in \>=1 of following (serum M-protein \[absolute increase \>=0.5g/dL\]; serum M-protein increase \>=1g/dL \[when lowest M-protein \>=5g/dL\]; urine M-protein \[absolute increase \>=200mg/24h\]; participants without measurable serum \& urine M-protein levels, difference between involved \& uninvolved sFLC levels \[absolute increase \>10mg/dL\]; in participants without measurable serum, urine M-protein levels \& involved sFLC levels: bone marrow plasma-cell % irrespective of baseline status \[absolute increase \>=10%\]; appearance of new lesion,\>=50% increase from nadir in SPD of \>1 lesion, or \>=50% increase in longest diameter of previous lesion \>1cm in short axis; \>=50% increase in circulating plasma cells \[\>=200cells/μL\] if this is the only measure of disease.

From first documentation of objective response subsequently confirmed until confirmed PD or death due to any cause, or start of new anticancer therapy, whichever occurred first, or censoring (up to approximately 20.14 months)

Duration of Response as Per IMWG Criteria by Investigator Assessment

DOR: time from first documentation of objective response subsequently confirmed, until first documentation of confirmed PD or death due to any cause, whichever occurred first. PD= increase of \>=25% from lowest value in \>=1 of following (serum M-protein \[absolute increase \>=0.5g/dL\]; serum M-protein increase \>=1g/dL \[when lowest M-protein \>=5g/dL\]; urine M-protein \[absolute increase \>=200mg/24h\]; participants without measurable serum \& urine M-protein levels, difference between involved \& uninvolved sFLC levels \[absolute increase \>10mg/dL\]; in participants without measurable serum, urine M-protein levels \& involved sFLC levels: bone marrow plasma-cell % irrespective of baseline status \[absolute increase \>=10%\]; appearance of new lesion,\>=50% increase from nadir in SPD of \>1 lesion, or \>=50% increase in longest diameter of previous lesion \>1cm in short axis; \>=50% increase in circulating plasma cells \[\>=200cells/μL\] if this is the only measure of disease.

From first documentation of objective response subsequently confirmed until confirmed PD or death due to any cause, or start of new anticancer therapy, whichever occurred first, or censoring (up to approximately 20.14 months)

Complete Response Rate (CRR) as Per IMWG Criteria by BICR

CRR: % of participants with BOR of confirmed sCR/CR per IMWG criteria. sCR: CR \& normal serum free light chain (sFLC) ratio \& absence of clonal cells in BMB/BMA by IH, IF, or flow cytometry. CR: negative immunofixation on serum \& urine, disappearance of any soft tissue plasmacytoma \& \

From date of first dose until confirmed disease progression, death, start of new anticancer therapy, whichever occurred first (up to approximately 20.14 months)

Complete Response Rate as Per IMWG Criteria by Investigator Assessment

CRR: % of participants with BOR of confirmed sCR/CR per IMWG criteria. sCR: CR \& normal serum free light chain (sFLC) ratio \& absence of clonal cells in BMB/BMA by IH, IF, or flow cytometry. CR: negative immunofixation on serum \& urine, disappearance of any soft tissue plasmacytoma \& \

From date of first dose until confirmed disease progression, death, start of new anticancer therapy, whichever occurred first (up to approximately 20.14 months)

Objective Response Rate as Per IMWG Criteria by Investigator Assessment

ORR: % of participants with best overall response of confirmed stringent complete response (sCR), CR, very good partial response (VGPR) or PR per IMWG criteria. sCR: CR \& normal serum free light chain (sFLC) ratio \& absence of clonal cells in BMB/BMA by IH, IF, or flow cytometry. CR: negative immunofixation on serum \& urine, disappearance of any soft tissue plasmacytoma \& \=90% reduction in serum M-protein \& urine M-protein level \=50% reduction in serum M-protein \& reduction in 24h urinary M-protein by \>=90% or \=90% \& \>=50% decrease in difference respectively between involved \& uninvolved sFLC levels \& if present at baseline, \>=90% \& \>=50% reduction in soft tissue plasmacytomas' size.

From date of first dose until confirmed disease progression, death, start of new anticancer therapy, whichever occurred first (up to approximately 20.14 months)

Duration of Complete Response (DOCR) as Per IMWG Criteria by BICR

DOCR: time from first documentation of sCR/CR subsequently confirmed, until first documentation of confirmed PD or death due to any cause, whichever occurred first. PD= increase of \>=25% from lowest value in \>=1 of following (serum M-protein \[absolute increase \>=0.5g/dL\]; serum M-protein increase \>=1g/dL \[when lowest M-protein \>=5g/dL\]; urine M-protein \[absolute increase \>=200mg/24h\]; participants without measurable serum \& urine M-protein levels, difference between involved \& uninvolved sFLC levels \[absolute increase \>10mg/dL\]; in participants without measurable serum, urine M-protein levels \& involved sFLC levels: bone marrow plasma-cell % irrespective of baseline status \[absolute increase \>=10%\]; appearance of new lesion,\>=50% increase from nadir in SPD of \>1 lesion, or \>=50% increase in longest diameter of previous lesion \>1cm in short axis; \>=50% increase in circulating plasma cells \[\>=200cells/μL\] if this is the only measure of disease.

From first documentation of sCR/CR subsequently confirmed until confirmed PD or death due to any cause, or start of new anticancer therapy, whichever occurred first, or censoring (up to approximately 20.14 months)

Duration of Complete Response (DOCR) as Per IMWG Criteria by Investigator Assessment

DOCR: time from first documentation of sCR/CR subsequently confirmed, until first documentation of confirmed PD or death due to any cause, whichever occurred first. PD= increase of \>=25% from lowest value in \>=1 of following (serum M-protein \[absolute increase \>=0.5g/dL\]; serum M-protein increase \>=1g/dL \[when lowest M-protein \>=5g/dL\]; urine M-protein \[absolute increase \>=200mg/24h\]; participants without measurable serum \& urine M-protein levels, difference between involved \& uninvolved sFLC levels \[absolute increase \>10mg/dL\]; in participants without measurable serum, urine M-protein levels \& involved sFLC levels: bone marrow plasma-cell % irrespective of baseline status \[absolute increase \>=10%\]; appearance of new lesion,\>=50% increase from nadir in SPD of \>1 lesion, or \>=50% increase in longest diameter of previous lesion \>1cm in short axis; \>=50% increase in circulating plasma cells \[\>=200cells/μL\] if this is the only measure of disease.

From first documentation of objective sCR/CR subsequently confirmed until confirmed PD or death due to any cause, or start of new anticancer therapy, whichever occurred first, or censoring (up to approximately 20.14 months)

Progression Free Survival (PFS) as Per IMWG Criteria by BICR

PFS was defined as the time from the date of first dose until confirmed PD or death due to any cause, whichever occurred first. PD= increase of \>=25% from lowest value in \>=1 of following (serum M-protein \[absolute increase \>=0.5g/dL\]; serum M-protein increase \>=1g/dL \[when lowest M-protein \>=5g/dL\]; urine M-protein \[absolute increase \>=200mg/24h\]; participants without measurable serum \& urine M-protein levels, difference between involved \& uninvolved sFLC levels \[absolute increase \>10mg/dL\]; in participants without measurable serum, urine M-protein levels \& involved sFLC levels: bone marrow plasma-cell % irrespective of baseline status \[absolute increase \>=10%\]; appearance of new lesion,\>=50% increase from nadir in SPD of \>1 lesion, or \>=50% increase in longest diameter of previous lesion \>1cm in short axis; \>=50% increase in circulating plasma cells \[\>=200cells/μL\] if this is the only measure of disease.

From date of first dose until confirmed PD or death due to any cause, or start of new anticancer therapy, whichever occurred first, or censoring (up to approximately 20.14 months)

Progression Free Survival (PFS) as Per IMWG Criteria by Investigator Assessment

PFS was defined as the time from the date of first dose until confirmed PD or death due to any cause, whichever occurred first. PD= increase of \>=25% from lowest value in \>=1 of following (serum M-protein \[absolute increase \>=0.5g/dL\]; serum M-protein increase \>=1g/dL \[when lowest M-protein \>=5g/dL\]; urine M-protein \[absolute increase \>=200mg/24h\]; participants without measurable serum \& urine M-protein levels, difference between involved \& uninvolved sFLC levels \[absolute increase \>10mg/dL\]; in participants without measurable serum, urine M-protein levels \& involved sFLC levels: bone marrow plasma-cell % irrespective of baseline status \[absolute increase \>=10%\]; appearance of new lesion,\>=50% increase from nadir in SPD of \>1 lesion, or \>=50% increase in longest diameter of previous lesion \>1cm in short axis; \>=50% increase in circulating plasma cells \[\>=200cells/μL\] if this is the only measure of disease.

From date of first dose until confirmed PD or death due to any cause, or start of new anticancer therapy, whichever occurred first, or censoring (up to approximately 20.14 months)

Overall Survival (OS)

Overall survival (OS) was defined as the time from the date of first dose until death due to any cause.

From the date of first dose until death due to any cause. Participants not known to have died were censored on the date of last known alive (up to approximately 20.14 months)

Time-to-Response (TTR) as Per IMWG Criteria by BICR

TTR was defined, for participants with an objective response per IMWG criteria, as the time from the date of first dose to the first documentation of objective response that was subsequently confirmed.

From date of first dose until confirmed disease progression, death, start of new anticancer therapy, whichever occurred first (up to approximately 16 months)

Time-to-Response (TTR) as Per IMWG Criteria by Investigator Assessment

TTR was defined, for participants with an objective response per IMWG criteria, as the time from the date of first dose to the first documentation of objective response that was subsequently confirmed.

From date of first dose until confirmed disease progression, death, start of new anticancer therapy, whichever occurred first (up to approximately 20.14 months)

Minimal Residual Disease (MRD) Negativity Rate Per IMWG Sequencing Criteria

MRD negativity rate was the percentage of participants with CR/sCR and with negative MRD per IMWG sequencing criteria.

From date of first dose until confirmed disease progression, death, start of new anticancer therapy, whichever occurred first (up to approximately 20.14 months)

Number of Participants With Treatment Emergent Adverse Events (TEAE) Graded by National Cancer Institute Common Toxicity Criteria for Adverse Events (NCI CTCAE) Version (v) 5.0

An adverse event (AE) was any untoward medical occurrence in a participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. An AE was considered treatment-emergent relative to study intervention if the adverse event start date was during the on-treatment period (i.e. the time from the first dose of study intervention through the minimum of 90 days after last dose, or \[start day of new anticancer therapy - 1 day\]). CTCAE version 5.0 Grade 1: mild; Grade 2: moderate; Grade 3: severe or clinically significant; Grade 4: life-threatening; Grade 5: death.

From the date of first dose up to 90 days after last dose or new anticancer therapy whichever occurred first (up to approximately 20.14 months)

Number of Participants With Shift From Grade Less Than or Equal to (

CTCAE version 5.0 Grade 1: mild; Grade 2: moderate; Grade 3: severe or clinically significant; Grade 4: life-threatening.

From the date of first dose up to 90 days after last dose or new anticancer therapy whichever occurred first (up to approximately 20.14 months)

Number of Participants With Cytokine Release Syndrome (CRS) Graded According to American Society for Transplantation and Cellular Therapy (ASTCT) Criteria

CRS Grade 1: temperature \>=38°C without hypotension or hypoxia; Grade 2: temperature \>=38°C with hypotension not requiring vasopressors, and/or hypoxia requiring low-flow nasal cannula, facemask or blow-by; Grade 3: temperature \>=38°C with hypotension requiring a vasopressor with or without vasopressin and/or hypoxia requiring high-flow nasal cannula, facemask, nonrebreather mask, or Venturi mask; Grade 4: temperature \>=38°C with hypotension requiring multiple vasopressors (excluding vasopressin) and/or hypoxia requiring positive pressure (eg, continuous positive airway pressure \[CPAP\], bilevel positive airway pressure \[BiPAP\], intubation and mechanical ventilation); Grade 5: death.

From the date of first dose up to 90 days after last dose or new anticancer therapy whichever occurred first (up to approximately 20.14 months)

Number of Participants With Immune Effector Cell-associated Neurotoxicity Syndrome (ICANS) Graded According to American Society for Transplantation and Cellular Therapy (ASTCT) Criteria

ICANS Grade 1: immune effector cell encephalopathy (ICE) score 7-9, participant awakens spontaneously; Grade 2: ICE score 3-6, participant awakens to voice; Grade 3: ICE score 0-2, participant awakens only to tactile stimulus, any clinical seizure focal or generalized that resolved rapidly or nonconvulsive seizures on electroencephalography that resolve with intervention or focal/local edema on neuroimaging; Grade 4: ICE score 0 (participant is unarousable and unable to perform ICE), participant unarousable or requires vigorous or repetitive tactile stimuli to arouse, life-threatening prolonged seizure (\>5 min), repetitive clinical or electrical seizures without return to baseline in between, deep focal motor weakness, diffuse cerebral edema on neuroimaging; decerebrate/decorticate posturing; cranial nerve VI palsy; papilledema, Cushing's triad; Grade 5: death. ICE: measures alterations in speech, orientation, handwriting, attention and receptive aphasia.

From the date of first dose up to 90 days after last dose or new anticancer therapy whichever occurred first (up to approximately 20.14 months)

Serum Concentration of Elranatamab

Total and free concentrations of Elranatamab on Cycle 4 Day 1 (C4D1) and Cycle 7 Day 1 (C7D1) were reported in this outcome measure.

Pre-dose on Day 1 of Cycle 4 and Pre-dose on Day 1 of Cycle 7

Percentage of Participants With Positive Anti-Drug Antibody (ADA) and Neutralizing Antibodies (NAb) Against Elranatamab

From the date of first dose up to 20.14 months