This is a Phase 1 study with 2 parallel groups of healthy participants. Participants will be randomized to receive either a subcutaneous (SC) dose of dupilumab coformulated with berahyaluronidase alfa or a SC dose of dupilumab without berahyaluronidase alfa.

The purpose of this study is to assess the pharmacokinetic (PK) characteristics of a single SC dose of dupilumab coformulated with berahyaluronidase alfa and dupilumab without berahyaluronidase alfa in healthy participants aged ≥18 and ≤60 years.

Study details include:

• The study duration will be approximately up to 12 to 15 weeks.
• The treatment will be administered as a single dose on Day 1.
• The number of visits will be 14.

Inclusion Criteria:

• Male and/or female participant, between 18 and 60 years of age, inclusive, at the time of signing the informed consent.
• Determined to be healthy by the Investigator using a comprehensive clinical assessment (detailed medical history and complete physical examination).
• Body weight between 50.0 and 100.0 kg, inclusive.
• BMI between 18.0 and 32.0 kg/m2 (inclusive).

Exclusion Criteria:

• Any history or presence of clinically relevant cardiovascular, pulmonary, gastrointestinal, hepatic, renal, metabolic, hematological, neurological, dermatological, osteomuscular, articular, psychiatric, systemic, ocular, gynecologic (if female), or infectious disease, or signs of acute illness.
• Frequent headaches and/or migraine, recurrent nausea and/or vomiting (for vomiting only: more than twice a month).
• Blood donation, any volume, within 2 months before inclusion.
• Symptomatic postural hypotension, irrespective of the decrease in blood pressure, or asymptomatic postural hypotension defined as a decrease in SBP of ≥30 mmHg within 3 minutes when changing from supine to standing position.
• Presence or history of drug hypersensitivity, or clinically significant allergic disease as diagnosed and treated by a physician. Participants with known hypersensitivity to any of the study interventions, or components thereof.
• History or presence of drug or alcohol abuse (alcohol consumption more than 40 g per day on a regular basis).
• Regular smoking of more than 5 cigarettes or equivalent in nicotine per week, unable to stop smoking during the study (occasional smoker can be enrolled).
• Excessive consumption of beverages containing xanthine bases (more than 4 cups or glasses per day).
• If female, pregnancy (defined as positive urine pregnancy test); breast-feeding.

The above information is not intended to contain all considerations relevant to a participant's 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

This study is open-label. Participants, investigators, and study members have access to treatment assignment.