A Study to Examine the Safety, Tolerability and Biological Effects of REGN4461 in Healthy Volunteers

Key Inclusion Criteria Part A: * Males and females 18 to 50 years of age, inclusive * Body mass index (BMI) from 18.5 to \<30.0 kg/m\^2 * Participant is judged by the investigator to be in good health and free from major comorbidities based on medical history, physical examination, laboratory safety tests performed at screening and/or prior to administration of initial dose of study drug Part B: * Males and females 18 to 65 years of age, inclusive * Have a body mass index (BMI) from 25.0 to 40.0 kg/m\^2 * Participant is judged by the investigator to be free from major comorbidities based upon medical history, physical examination, laboratory safety tests performed at screening and/or prior to administration of initial dose of study drug. Participants can have a history of mild hyperlipidemia and/or mild hypertension but should be on stable doses of lipid lowering or blood pressure lowering medicines for at least 2 months prior to screening Key Exclusion Criteria Part A: * History of type 1 or 2 diabetes or prediabetes or with fasting blood glucose (FBG) at screening ≥ 100mg/dL or with HbA1c at screening of ≥ 5.7%. * Fasting LDL-C ≥ 130mg/dL, TG ≥ 250 mg/dL Part B: * History of type 1 or 2 diabetes or with FBG at screening ≥ 126 mg/dL or with HbA1c at screening of ≥ 6.5%. A diagnosis of "pre-diabetes" is allowed. * Fasting LDL-C ≥ 160 or TG ≥ 500 mg/dL Key Exclusion Criteria (Parts A and B): * Hospitalization (ie, \>24 hours) for any reason within 60 days of the screening visit * History of hypothalamic amenorrhea or lipodystrophy. * Change in body weight of more than 5% over the past 3 months prior to screening. * Previous history of bariatric procedures for obesity (eg, sleeve gastrectomy, gastric bypass, banding, etc). * Procedures for weight reduction (eg, liposuction) or body contouring in the past 6 months. * Treatment with medications for (over-the-counter \[OTC\] or prescribed) weight loss (eg, lorcaserin, phentermine/topiramate, naltrexone HCl/bupropion HCl, liraglutide) in the past 3 months. * History of major psychiatric disorders, eating disorders (eg, bulimia, anorexia). * Current cigarette smoker or former smoker (cigarettes or e-cigarettes) who stopped smoking within 3 months prior to screening. * History of recreational drug (including marijuana) or alcohol abuse (\>2 drinks per day) within a year prior to the screening visit. * History of hepatitis B infection or a positive hepatitis B surface antigen (HbsAg+) at screening * History of HIV infection or HIV seropositive at the screening visit. * History of hepatitis C infection or positive hepatitis C antibody test result at screening. * Pregnant or breastfeeding women. Note: Other inclusion/ exclusion criteria apply