A Study to Investigate the Safety and Efficacy of SAR446523 Injected Subcutaneously in Adult Participants With Relapsed/Refractory Myeloma

Number of participants with treatment emergent adverse events (TEAEs), injection related reactions (IRRs), injection site reactions (ISRs), serious adverse events (SAEs), adverse event of special interests (AESIs)

Measured as per NCI CTCAE v 5.0

Time frame: From the signing of informed consent to 30 days after the date of the last study treatment administration i.e., approximately 5 years

Change from baseline in laboratory abnormalities

Measured as per NCI CTCAE v 5.0.

Time frame: From the signing of informed consent to 30 days after the date of the last study treatment administration i.e., approximately 5 years

ORR- Dose escalation (Part A)

ORR defined as the proportion of participants with stringent complete response (sCR), complete response (CR), very good partial response (VGPR), and partial response (PR) assessed as per Investigator according to the 2016 International Myeloma Working Group (IMWG) response criteria.

Time frame: 24 months after the Last Participant In (LPI)

VGPR or better rate

VGPR or better rate defined as the proportion of participants with sCR, CR, and VGPR assessed as per Investigator according to the 2016 IMWG response criteria.

Time frame: 24 months after the Last Participant In (LPI)

Clinical benefit rate (CBR)

CBR defined as the rate of participants with confirmed sCR, CR, VGPR, or PR at any time or minimal response (MR) of at least 6 months from the first IMP administration determined per 2016 IMWG response criteria.

Time frame: 24 months after the Last Participant In (LPI)

Duration of response (DoR)

DoR defined as the time from the date of the first response (PR or better) to the date of first documentation of progressive disease (PD) as defined in the 2016 IMWG response criteria, or date of death, whichever occurs first.

Time frame: 24 months after the Last Participant In (LPI)

Time to response (TTR)

TTR defined as the time from the first administration of study IMP to the date of first response (PR or better) that is subsequently confirmed.

Time frame: 24 months after the Last Participant In (LPI)

Progression free survival (PFS)

PFS defined as the time interval from the date of first administration of study IMP to the date of first documentation of PD per 2016 IMWG criteria assessed by study Investigator, or date of death from any cause, whichever comes first.

Time frame: 24 months after the Last Participant In (LPI)

Minimal residual disease (MRD) status negativity

MRD status negative by nextgeneration sequencing (NGS) in bone marrow of participants with a response of CR (or VGPR in case of suspected interference).

Time frame: 24 months after the Last Participant In (LPI)

Number of participants with symptomatic AEs -Part B

The incidence and evaluation of symptomatic AEs from participants' perspective will be measured by using specific items from National Cancer Institute (NCI) patient-reported outcome (PRO) common terminology criteria for adverse events (CTCAE) library.

Time frame: From Cycle 1 Day 1 to 30 days after the date of the last study treatment administration i.e., approximately 5 years

Change from baseline in overall side effect bother as measured by the Functional Assessment of Cancer Therapy item 5 (FACT-GP5)- Part B

The FACT GP5 is an assessment focused on the overall side effect impact to inform the tolerability of a treatment. The FACT GP5 ("I am bothered by side effects of treatment") responses are given on a 5 point Likert type scale recalling the past 7 days. Higher scores indicate a higher degree of side effect bother.

Time frame: From Cycle 1 Day 1 to 30 days after the date of the last study treatment administration i.e., approximately 5 years

Maximum observed concentration (Cmax)

To characterize the pharmacokinetics (PK) of SAR446523.

Time frame: Multiple timepoints from Cycle 1 Day 1 to Cycle 1 Day 8 (cycle 1=28 days)

First time to reach Cmax (tmax)

To characterize the PK of SAR446523.

Time frame: Multiple timepoints from Cycle 1 Day 1 to Cycle 1 Day 8 (cycle 1=28 days)

Area under the concentration versus time curve calculated from 0 to 168 hours (AUC0-168h)

To characterize the PK of SAR446523.

Time frame: Multiple timepoints from Cycle 1 Day 1 to Cycle 1 Day 8 (cycle 1=28 days)

Proportion of participants with presence of anti-drug antibody (ADA) against SAR446523.

To evaluate potential immunogenicity.

Time frame: From Cycle 1 Day 1 to 30 days after the date of the last study treatment administration i.e., approximately 5 years