Safety, Preliminary Efficacy and PK of Isatuximab (SAR650984) Alone or in Combination With Atezolizumab in Patients With Advanced Malignancies

Inclusion criteria:

* Participants must have a known diagnosis of either unresectable HCC, platinum-refractory recurrent/metastatic SCCHN, platinum-resistant/refractory EOC with evidence of measurable disease or recurrent GBM.
* Greater than or equal to (\>=)18 years of age.
* For participants with HCC: Documentation of progressive disease (PD) during or after treatment with either sorafenib or lenvatinib, or intolerance to the therapy.
* For participants with SCCHN: Received and failed up to 2 lines of prior systemic anti-cancer therapy with documentation of tumor recurrence or PD within 6 months of last platinum-based therapy in primary, recurrent, or metastatic setting.
* For participants with EOC: Received up to 3 lines of prior platinum-containing therapy when the disease was platinum-sensitive, and the participants should not have received any systemic therapy for platinum-resistant/refractory disease. Specific to France only: Documentation of PD on or after 1 line of anti-cancer therapy for platinum resistant/refractory disease (unless participants are ineligible or intolerant to standard of care for platinum-resistant/refractory disease).
* For participants with GBM: Documentation of PD or first recurrence during or after temozolomide maintenance therapy for newly diagnosed GBM treated with 1st line radiotherapy plus concurrent temozolomide.

Exclusion criteria:

* Prior exposure to agent that blocks CD38 or participation in clinical studies with isatuximab.
* For participants with HCC, SCCHN, EOC or GBM prior exposure to any agent (approved or investigational) that blocks the PD-1/PD-L1 pathway.
* Evidence of other immune related disease /conditions.
* History of non-infectious pneumonitis requiring steroids or current pneumonitis; history of the thoracic radiation.
* Received a live-virus vaccination within 28 days of planned treatment start. Seasonal flu vaccines that do not contain live virus are permitted.
* Prior solid organ or bone marrow transplantation.
* Eastern Cooperative Oncology Group performance status \>=2 for participants with HCC, SCCHN or EOC or Karnofsky performance score less than or equal to (\<=) 70 for participants with GBM.
* Poor bone marrow reserve.
* Poor organ function.

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