The primary objective of the study is to compare the pharmacokinetic(PK) profile of pozelimab produced by the original manufacturing process (Process A) compared to a second manufacturing process (Process B)

The secondary objectives of the study are:

• Assess the safety and tolerability of a single SC dose of pozelimab produced by the 2 manufacturing processes
• Assess the immunogenicity of pozelimab produced by the 2 manufacturing processes

Key Inclusion Criteria:

• Has a body weight of 55 kg to 100 kg and a body mass index between 18 kg/m2 and 30 kg/m2 inclusive at the screening visit
• Judged to be in good health based on medical history, physical examination, vital signs measurements, and ECG performed at screening and/or prior to administration of initial dose of study drug
• Is in good health based on laboratory safety testing obtained at the screening visit. NOTE: Subject with a history of Gilbert's disease can be enrolled in the study
• Willing to undergo vaccination against N meningitidis unless subjects have documentation of completed series of vaccinations within the past 2 years of the screening visit
• Must have two negative COVID-19 tests within 7 days prior to study drug administration as defined in the protocol

Key Exclusion Criteria:

• History of clinically significant cardiovascular, respiratory, hepatic, renal, gastrointestinal, endocrine, hematological, psychiatric or neurological disease, as assessed by the investigator
• Hospitalization (>24 h) for any reason within 90 days of the screening visit
• Has a confirmed positive drug test result at the screening visit and/or prior to enrollment; and/or a history of recreational drug use (eg, marijuana) and/or drug or alcohol abuse within a year prior to the screening visit
• Is positive for HIV, hepatitis B, or hepatitis C antibody as defined in the protocol
• Known or suspected COVID-19 disease
• History of tuberculosis, systemic fungal diseases, or meningococcal infection
• Known allergy or intolerance to penicillin class antibiotics or macrolides; any contraindication to azrithromycin per local prescribing information

Note: Other protocol-defined Inclusion/ Exclusion criteria apply

All Individual Patient Data (IPD) that underlie publicly available results will be considered for sharing

Individual anonymized participant data will be considered for sharing once the indication has been approved by a regulatory body, if there is legal authority to share the data and there is not a reasonable likelihood of participant re-identification.

Qualified researchers may request access to anonymized patient level data or aggregate study data when Regeneron has received marketing authorization from major health authorities (e.g., FDA, European Medicines Agency [EMA], Pharmaceuticals and Medical Devices Agency [PMDA], etc) for the product and indication, has the legal authority to share the data, and has made the study results publicly available (eg, scientific publication, scientific conference, clinical trial registry).