Primary Objectives:

• Dose Escalation Part A: To determine the maximum tolerated dose (MTD) of SAR442085 administered as a single agent in patients with relapsed or refractory multiple myeloma (RRMM), and determine the recommended Phase 2 dose (RP2D) for the subsequent Expansion Part B
• Dose Expansion Part B: To assess the antitumor activity of single agent of SAR442085 at the RP2D in patients with RRMM

Secondary Objectives:

• To characterize the safety profile of SAR442085
• To characterize the pharmacokinetics (PK) profile of SAR442085 when administered as a single agent
• To evaluate the potential immunogenicity of SAR442085
• To assess preliminary evidence of antitumor activity in the Dose Escalation Part A

Inclusion criteria :

• Participant must be at least 18 years of age or of the country's legal age of majority if the legal age is >18 years old, at the time of signing the informed consent.
• Participant has given voluntary written informed consent.
• Participant has been previousy diagnosed with multiple myeloma based on standard criteria.
• Part A: (1) participant has received at least 3 prior lines of therapy for multiple myeloma, or at least 2 prior lines of therapy if at least 1 of those lines consisted of 2 or more multi-agent regimens (eg, multi-agent induction regimen with autologous stem cell transplantation, followed by maintenance regimen). (2) Prior therapy for multiple myeloma has included at least 1 proteasome inhibitor (bortezomib, carfilzomib, ixazomib), at least 1 immunomodulatory agent (lenalidomide, thalidomide, pomalidomide), at least 1 anti-CD38 monoclonal antibody and at least 1 steroid. (3) Participant had at least a minimal response (MR) to the anti-CD38 antibody containing regimen and had last dose of anti-CD38 monoclonal antibody at least 9 months prior to study entry, except the last cohort(s) of Part A who are anti CD38 naïve.
• Part B and the last cohort(s) of Part A: (1) participant has received at least 3 prior lines of therapy for multiple myeloma, or at least 2 prior line of therapy if at least 1 of those lines consisted of 2 or more multi-agent regimens (eg, multi-agent induction regimen with autologous stem cell transplantation, followed by maintenance regimen). (2) Prior therapy for multiple myeloma has included at least 1 proteasome inhibitor (bortezomib, carfilzomib, ixazomib), at least 1 immunomodulatory agent (lenalidomide, thalidomide, pomalidomide) and at least 1 steroid. (3) Prior therapy has not included an anti-CD38 monoclonal antibody.
• Participant has myeloma disease progression on or after last therapy.
• Participant must have measurable disease as defined as at least one of the following:
  • Serum M protein ≥0.5 g/dL (≥5 g/L)
  • Urine M protein ≥200 mg/24 hours
  • Serum FLC assay: Involved FLC assay ≥10 mg/dL (≥100 mg/L) and an abnormal serum
  • FLC ratio (<0.26 or >1.65).
• A male participant must agree to use contraception during the intervention period and for at least 150 days after the last dose of study drug and refrain from donating sperm during this period.
• A female participant is eligible to participate if she is not pregnant, not breastfeeding, and at least one of the following conditions applies:
  • Not a woman of childbearing potential (WOCBP)
  • A WOCBP who agrees to follow the contraceptive guidance during the intervention period and for at least 150 days after the last dose of study intervention.

Exclusion criteria:

• Participant is diagnosed or treated for another malignancy within 3 years prior to enrollment, with the exception of basal cell carcinoma or squamous cell carcinoma of the skin, an in situ malignancy, superficial bladder carcinoma or low risk prostate cancer.
• Participant has an Eastern Cooperative Oncology Group (ECOG) performance status score >2.
• Participant has a history of Chronic obstructive pulmonary disease (COPD) or asthma.
• Participant has not recovered from adverse reactions to prior myeloma treatment or procedures (chemotherapy, immunotherapy, radiation therapy) to NCI CTCAE Grade ≤1 or baseline (exception: alopecia).
• Participant has congestive heart failure (New York Heart Association) Grade ≥II; cardiac myopathy, active ischemia, or any other uncontrolled cardiac condition such as angina pectoris, clinically significant arrhythmia requiring therapy including anticoagulants, or clinically significant uncontrolled hypertension, QT interval corrected by the Fridericia method >480 msec (Grade ≥2).
• Participant has had acute myocardial infarction within 6 months before first dose of study medication.
• Participant has ongoing sensory or motor neuropathy of National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE) Grade ≥3.
• Participant has active autoimmune disease including autoimmune hemolytic anemia, idiopathic thrombocytopenic purpura, inflammatory bowel syndrome, pneumonitis or any chronic condition requiring a higher corticosteroid systemic equivalent than prednisone 10 mg daily.
• Known acquired immunodeficiency syndrome (AIDS) or related illnesses or human immunodeficiency virus (HIV) disease requiring antiretroviral treatment, or to have active hepatitis A, B (defined as a known positive hepatitis B surface antigen (HBsAg) result), or C (defined as a known quantitative hepatitis C [HCV] ribonucleic acid RNA results greater than the lower limits of detection of the assay or positive HCV antigen) infection.
• Participant has positive Coombs test at baseline.

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