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

Inclusion Criteria:

• Participants with a documented diagnosis of multiple myeloma (MM) with measurabledisease.

• Contraceptive use by men and women should be consistent with local regulationsregarding the methods of contraception for those participating in clinical studies.

Dose escalation (Part A)

• Participants must have received at least 3 prior lines of antimyeloma therapy, andmust be either relapsed or refractory to the above therapies, or are intolerant tothem.

• Note: In Part A, prior exposure to anti g-protein-coupled receptor, class c, group 5, member d (GPRC5D) therapy and anti B-cell maturation antigen (BCMA) therapy isallowed.

Dose optimization (Part B)

• Participants must have received at least 3 prior lines of antimyeloma therapy and beeither relapsed or refractory to immunomodulator (IMiD), proteasome inhibitor (PI),anti CD38 monoclonal antibody (mAb), and anti BCMA targeting agent or are intolerantto them.

• Note: In Part B, prior exposure to antiGPRC5D therapy is not allowed.

Exclusion Criteria:

-Participants are excluded from the study if any of the following criteria apply: Eastern cooperative oncology group performance status (ECOG PS) of 2 or greater.

• Primary systemic and localized amyloid light chain (AL) amyloidosis, activepolyneuropathy, organomegaly, endocrinopathy, myeloma protein, and skin changes (POEMS) syndrome, active plasma cell leukemia. Participants with central nervoussystem involvement or with clinical signs of meningeal involvement of multiplemyeloma.

• Systemic antimyeloma treatment within 14 days before the first study treatmentadministration.

• Prior treatment with natural killer (NK)-cell engaging therapy (such as monoclonalantibody with antibody-dependent cellular cytotoxicity as primary mechanism ofaction) within 90 days of the first study treatment administration.

• Inadequate organ and marrow function.

• Participants with significant concomitant illness.

The above information is not intended to contain all considerations relevant to the potential participation in a clinical trial.