Ascending Dose Study of the Safety and Tolerability of REGN6490 in Healthy Volunteers

Key Inclusion Criteria: 1. Body mass index between 18 and 31 kg/m2 (inclusive) at screening visit 2. Is judged by the investigator to be in good health based on medical history, physical examination, vital sign measurements, and ECG's performed at screening and/or prior to administration of initial dose of study drug 3. Is in good health based on laboratory safety testing obtained at the screening visit 4. Willing and able to comply with clinic visits and study-related procedures 5. Provide informed consent signed by study participant Key Exclusion Criteria: 1. History of clinically significant cardiovascular, dermatological, respiratory, hepatic, renal, gastrointestinal, endocrine, hematological, psychiatric, or neurological disease, as assessed by the investigator, that may confound the results of the study or poses an additional risk to the participant by study participation 2. Presents any concern to the study investigator that might confound the results of the study or poses an additional risk to the participant by their participation in the study 3. Has any physical examination findings and/or history of any illness that, in the opinion of the study investigator, might confound the results of the study or poses an additional risk to the participant by study participation 4. Hospitalization (\>24 hours) for any reason within 30 days of the screening visit 5. Is a current smoker, including e-cigarettes. Former smokers may be enrolled if they have stopped smoking for at least 3 months (90 days) prior to the screening visit Note: Other protocol defined Inclusion/Exclusion criteria apply