A Study in Healthy Adult Male & Female Participants to Assess the Amount of the Study Medicine (SAR443820) Absorbed by the Body, When Given Orally in Fasted Condition as a Tablet Versus as a Capsule (Part 1) and When Given Orally as a Tablet in Fasted Condition Versus as a Tablet After Food (Part 2)

Part 1:

This is an open label, balanced randomized, single dose, 2-sequence, 2-period (period 1 and period 2), 2-treatment crossover (between Treatment A and Treatment B for Part 1), study part to determine the relative bioavailability of SAR443820 in tablet formulation versus capsule formulation under fasted conditions.

Two treatments are as follows:

* Treatment A: SAR443820 - tablet formulation in fasted condition
* Treatment B: SAR443820 - capsule formulation in fasted condition Each administration will be a single dose of SAR443820 separated by a wash out of at least 5 days.

Part 2:

This is an open-label, balanced randomized, single dose, 2-sequence, 2-period (period 1 and period 2), 2-treatment crossover (between Treatment C and Treatment D for Part 2) study part to perform a preliminary assessment of the effect of a high-fat meal on pharmacokinetic parameters of single dose of SAR443820 in tablet formulation.

Two treatments are as follows:

* Treatment C: SAR443820 - tablet formulation in fasted condition
* Treatment D: SAR443820 - tablet formulation in fed condition Each administration will be a single dose of SAR443820 separated by a wash out of at least 5 days.

Participants are not allowed to participate in more than one part of the study. In both Parts 1 and 2, the assessment of pharmacokinetic, safety and tolerability are performed at each treatment period at baseline (prior single dosing) up to 48-hour postdosing in healthy adult male and female participants.

Screening period: up to 4 weeks (Day -28 to Day -2). In both Part 1 and Part 2: Period 1: Day -1 to Day 3 and 5 days wash out period. Period 2: Day -1 to Day 3 and until end-of-study visit at Day 6.

Eligibility Criteria:
Inclusion Criteria:

* Male or female participant must be 18 to 55 years of age inclusive, at the time of signing the informed consent
* Participants who are overtly healthy as determined by medical evaluation including medical history, physical examination, laboratory tests, and cardiac monitoring
* Body weight between 50.0 and 100.0 kg, inclusive, if male, and between 40.0 and 90.0 kg, inclusive, if female, body mass index between 18.0 and 30.0 kg/m\^2, 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
* Having given written informed consent prior to undertaking any study-related procedure

Exclusion Criteria:

* Any history or presence of clinically relevant cardiovascular, pulmonary, gastrointestinal, hepatic, renal, metabolic, hematological, neurological, osteomuscular, articular, psychiatric, systemic, ocular, or infectious disease, or signs of acute illness
* Any medication (including St John's Wort) within 14 days before inclusion or within 5 times the elimination half-life or pharmacodynamic half-life of the medication, with the exception of hormonal contraception or menopausal hormone replacement therapy; any non-live Covid-19 vaccine within the last 2 weeks before randomization, any live attenuated vaccine within the last 28 days before randomization and any other non-vaccine biological drugs given within 4 months before randomization
* Positive result for hepatitis B, C or human immunodeficiency virus (HIV)
* Positive result on urine drug screen
* Positive urine alcohol test
* Positive severe acute respiratory syndrom coronavirus 2 (SARS-CoV-2) test
* Any consumption of citrus fruits (grapefruit, orange, etc) or their juices within 5 days before inclusion

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