Inclusion Criteria:

• Cancer diagnosis for participants for Part 1A and Part 1B:
  1. Metastatic and/or unresectable HCC diagnosed by histology and/or cytology, or diagnosed clinically by the American Association for the Study of Liver Diseases (AASLD) criteria for participants with liver cirrhosis (participants without liver cirrhosis must be diagnosed histologically) OR Other histology/cytology proven advanced and/or metastatic non-HCC solid tumors
  2. Not amenable to available standard of care: participants must have experienced disease progression on/after standard of care, or no acceptable standard curative or palliative treatments exist (or are no longer effective), according to Investigator judgement, or the participant declines standard of care therapy.
• Cancer diagnosis for participants for Part 2A:
  1. Metastatic NSCLC with no actionable driver gene mutants (such as epidermal growth factor receptor (EGFR), anaplastic lymphoma kinase (ALK)), diagnosed by histology and/or cytology not amenable to available standard of care and must have progressed on/after therapy that included an anti-PD(L)-1 agent with or without platinum-based chemotherapy.
  2. Progressive disease should be observed during the course of anti-PD(L)-1 therapy or within 12 weeks from the last dose of anti-PD(L)-1 therapy
• Additional for Part 2A: At least 1 measurable lesion per RECIST 1.1 criteria
• For all participants:
  1. Positive GPC3 expression on tumor tissue as determined locally or centrally
  2. 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: Child Pugh Class B or C liver score within 14 days of initiation of IMP. Participants with Child Pugh Class B-7 score are allowed for Part 1A.
• Known active brain metastases or leptomeningeal metastases.
• History of allogenic or solid organ transplant
• Treatment-related immune-mediated (or immune-related) AEs from immune-modulatory agents (including but not limited to anti-PD1/PD-L1 agents and anti-cytotoxic T lymphocyte associated protein 4 monoclonal antibodies) that caused permanent discontinuation of the agent, or that were Grade 4 in severity
• Significant cardiovascular disease within 3 months prior to initiation of IMP, uncontrolled arrhythmia requiring medication, or unstable angina.
• Ongoing AEs caused by any prior anti-cancer therapy >Grade 2
• Known uncontrolled human immunodeficiency virus (HIV), hepatitis B infection, or known untreated current hepatitis C infection
• Known second malignancy either progressing or requiring active treatment within the last year.
• For combination therapy: Ongoing or recent (within 5 years) evidence of significant autoimmune disease that required treatment with systemic immunosuppressive treatments, which may suggest risk for immune-related adverse events
• Receipt of a live-virus vaccination within 28 days of planned treatment start.
• For Part 2A, has received prior GPC3 targeted anticancer treatment.
• Current pneumonitis or interstitial lung disease, or history of interstitial lung disease or pneumonitis that required oral or IV glucocorticoids to assist with management.

NOTE: Other Inclusion/Exclusion criteria may apply. The above information is not intended to contain all considerations relevant to a participant's potential participation in a clinical trial.