A First-in-human, Dose Escalation and Dose Expansion Study of SAR445877 in Adult Participants With Advanced Solid Tumors

Inclusion Criteria:

1. Dose escalation Part 1

• Participants with advanced unresectable or metastatic solid tumors for which,in the judgement of the investigator, no standard alternative therapy isavailable or is not in the best interest of the participant

2. Dose expansion/optimization Part 2

Cancer diagnosis:

• Participants in Cohorts A1 and A2: Histologically or cytologically confirmeddiagnosis of metastatic non-small cell lung cancer (NSCLC)

• Participants in Cohort B: Histologically or cytologically confirmed diagnosis ofadvanced unresectable or metastatic hepatocellular carcinoma (HCC), or clinically byAmerican Association for the Study of Liver Diseases (AASLD) criteria in cirrhoticpatients (patients without cirrhosis must have had histological confirmation ofdiagnosis).

• Participants in Cohorts C1 and C2: Histologically or cytologically confirmeddiagnosis of advanced unresectable or metastatic gastric cancer (GC) or Siewert Type 2 & 3 gastro esophageal junction (GEJ) adenocarcinoma.

• For participants in Cohorts C1 and C2: Disease with CPS scoring of <1 as determinedat local laboratory with an Agency approved test (for the other cohorts: Diseasewith any CPS scoring. No need for CPS determination at local laboratory).

• For participants in Cohorts C1 and C2: Participants must have MSI (metastaticmicrosatellite instability) or MMR (mismatch repair) status known or determinedlocally and must have non-MSI-H or proficient MMR (pMMR) disease to be eligible.

• For participants in Cohorts C1 and C2: Participants with unknown HER2/neu statusmust have their HER2/neu status determined locally. Participants with HER2/neunegative are eligible. Participants with HER2/neu positive tumors must havedocumentation of disease progression on treatment containing an approved HER2targeted therapy to be eligible.

Measurable Disease:

• At least 1 measurable lesion per RECIST 1.1 criteria

Participants in Cohorts E1, E2 and E3

• Histologically or cytologically confirmed diagnosis of advanced unresectable ormetastatic colorectal cancer

• Participants must have MSI status known or determined locally and must havenon-MSI-H disease to be eligible.

• Participants with RAS-mutant and BRAF-mutant colorectal cancer are eligible forenrollment.

Capable of giving signed informed consent.

Exclusion Criteria:

• Eastern Cooperative Oncology Group (ECOG) performance status of ≥2.

• Predicted life expectancy ≤3 months.

• For participants with HCC- Cohort B (Part 2): Child Pugh Class B or C liver score.Participants with Child Pugh Class B-7 score are allowed for Part 1.

• Diagnosed of any other malignancies, either progressing or requiring activetreatments, within 2 years prior to enrollment.

• Known active brain metastases or leptomeningeal metastases.

• History of treatment-related immune-mediated (or immune-related) AEs fromimmune-modulatory agents (including but not limited to anti-PD1/PD-L1 agents andanti-cytotoxic T lymphocyte associated protein 4 monoclonal antibodies) that causedpermanent discontinuation of the agent, or that were Grade 4 in severity or have notresolved to Grade ≤1.

• Has any condition requiring ongoing/continuous corticosteroid therapy (>10 mgprednisone/day or an anti-inflammatory equivalent) within 1 week prior to the firstdose of the study medicine.

• Any clinically significant cardiac (including valvular) or vascular (thromboembolicdisorders) disease, within 6 months prior to the first IMP administration.

• Ongoing or recent (within 2 years) evidence of significant autoimmune disease thatrequired treatment with systemic immunosuppressive treatments, which may suggestrisk for immune-related adverse events.

• Has a known history or any evidence of interstitial lung disease or active,non-infectious pneumonitis within 3 years prior to the first dose of the study drug.

• Organ transplant requiring immunosuppressive treatment.

• Uncontrolled or active infection with human immunodeficiency virus (HIV), hepatitisB, or hepatitis C infection, or has a diagnosis of immunodeficiency.

NOTE: Other Inclusion/Exclusion criteria may apply.

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