Primary Objective:

• To evaluate tolerability and safety of SAR408701 when administered as a single agent according to the investigational medicinal product (IMP) related dose limiting toxicities (DLTs) to determine the recommended dose (RD) of SAR408701 in Japanese patients with advanced malignant solid tumors.

Secondary Objectives:

• To characterize the overall safety profile of SAR408701 monotherapy.
• To characterize the pharmacokinetic (PK) profile of SAR408701 and its metabolites.
• To evaluate the pharmacodynamic (PDy) effect of SAR408701 on levels of circulating carcinoembryonic antigen-related cell adhesion molecule 5 (CEACAM5) for main dose escalation part.
• To assess preliminary efficacy according to Response Evaluation Criteria in Solid Tumor (RECIST) 1.1 criteria and other indicators of antitumor activity.
• To assess the potential immunogenicity of SAR408701.

The study duration per participant will include a period to assess eligibility (screening period) of up to approximately 4 weeks (28 days), a treatment period and an End-of-Treatment (EOT) visit around 30 days after the last administration of IMP, and at least one follow-up (FU) visit after the EOT visit.

Inclusion criteria:

• Locally advanced or metastatic solid malignant tumor disease for which, in the judgement of the investigator, no standard alternative therapy is available.
• Inclusion is likely to be expressing CEACAM5.
• At least 6 x 5 μm slides from formalin-fixed paraffin-embedded (FFPE) archival tissue should be available for retrospective central evaluation of CEACAM5 expression.
• Patient understands and has signed the Written Informed Consent form and is willing and able to comply with the requirements of the trial.

Exclusion criteria:

• Patient less than 20 years old.
• Eastern Cooperative Oncology Group (ECOG) performance status (PS) ≥2.
• Life expectancy <12 weeks.
• Known or symptomatic brain metastasis (other than totally resected or previously irradiated and non-progressive/relapsing) or lepto-meningeal carcinomatosis.
• Female patients of childbearing potential and male patients with female partners of childbearing potential who do not agree to use accepted and effective method of contraception during the study treatment period and for 6 months following discontinuation of IMP.
• Significant concomitant illnesses, including all severe medical conditions which, in the opinion of the Investigator or Sponsor, would impair the patient's participation in the study or interpretation of the results.
• Prior therapy targeting CEACAM5.
• Prior maytansinoid treatments (maytansinoid derivative 1 [DM1] or maytansinoid derivative 4 [DM4] antibody drug conjugates).
• Previous history and or unresolved corneal disorders.
• Medical conditions requiring concomitant administration of medications with narrow therapeutic window, metabolized by cytochrome P450 (CYP) and for which a dose reduction cannot be considered.
• Medical conditions requiring concomitant administration of strong CYP3A inhibitor, unless it can be discontinued at least 2 weeks before first administration of SAR408701.

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

Qualified researchers may request access to patient level data and related study documents including the clinical study report, study protocol with any amendments, blank case report form, statistical analysis plan, and dataset specifications. Patient level data will be anonymized and study documents will be redacted to protect the privacy of trial participants. Further details on Sanofi's data sharing criteria, eligible studies, and process for requesting access can be found at: https://vivli.org