Dose Escalation and Expansion Study of SAR443216 in Participants With Relapsed/Refractory HER2 Expressing Solid Tumors

Primary Objectives:

Part 1 (Dose Escalation)

* To determine the MTD/maximum administered dose (MAD) of SAR443216 administered as a single agent in participants with HER2 expressing solid tumors and determine the RD(s) for intravenous (IV) and subcutaneous (SC) administration in the dose escalation part.
* To determine the safety of SAR443216 after intravenous (IV) and subcutaneous (SC) administration.

Part 2 (Dose expansion)

• To assess preliminary clinical activity of single agent SAR443216 at the RD(s) in participants with HER2 expressing solid tumors, with various levels of HER2 expression.

Secondary Objectives:

Part 1 • To assess preliminary clinical activity of single agent SAR443216 after IV and SC administration at the RD(s) in participants with HER2 expressing solid tumors, with various levels of HER2 expression.

Part 2

• To determine the safety of SAR443216.

Part 1 and 2

* To characterize the pharmacokinetic (PK) profile of SAR443216 when administered as a single agent after IV and SC (Part 1 only) administration.
* To evaluate the immunogenicity of SAR443216 after IV and SC administration.
* To assess preliminary clinical activity of single agent SAR443216 at the RD(s) in participants with HER2 expressing solid tumors, with various levels of HER2 expression.

The expected duration of study intervention for participants may vary, based on progression date; median expected duration of study per participant is estimated to be:

* 7.5 months (up to 1 month for screening, a median of 3.5 months for treatment, and a median of 3 months for long term follow-up) in escalation.
* 9.5 months (up to 1 month for screening, a median of 5.5 months for treatment, and a median of 3 months for long term follow-up) in expansion.

Eligibility Criteria:
Inclusion Criteria:

* Participants must be ≥ 18 years of age
* Histologically or cytologically confirmed diagnosis of metastatic solid tumors
* Eastern Cooperative Oncology Group (ECOG) performance status 0-1
* All participants should have at least 1 measurable disease per RECIST v1.1. An irradiated lesion can be considered measurable only if progression has been demonstrated on the irradiated lesion.
* Body weight within \[45 - 150 kg\] (inclusive)
* All Contraceptive use by men and women should be consistent with local regulations regarding the methods of contraception for those participating in clinical studies.
* Capable of giving signed informed consent

Exclusion Criteria:

* Any clinically significant cardiac disease
* History of or current interstitial lung disease or pneumonitis
* Uncontrolled or unresolved acute renal failure
* Prior solid organ or hematologic transplant.
* Known positivity with human immunodeficiency virus (HIV), known active hepatitis A, B, and C, or uncontrolled chronic or ongoing infectious requiring parenteral treatment.
* Receipt of a live-virus vaccination within 28 days of planned treatment start
* Participation in a concurrent clinical study in the treatment period.
* Inadequate hematologic, hepatic and renal function
* Participant not suitable for participation, whatever the reason, as judged by the Investigator, including medical or clinical conditions.

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