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.

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.

Qualified researchers may request access to patient level data and related study documents including the clinical study report, study protocol with any amendments, blank case report form, statistical analysis plan, and dataset specifications. Patient level data will be anonymized and study documents will be redacted to protect the privacy of trial participants. Further details on Sanofi's data sharing criteria, eligible studies, and process for requesting access can be found at: https://vivli.org