This is a Phase 1, randomized, double-blind, placebo-controlled, dose escalation study evaluating the safety, tolerability, pharmacokinetics (PK) and immunogenicity of REGN3470-3471-3479 in healthy adult volunteers.

Inclusion Criteria:

1. Healthy man or woman between the ages of 18 and 60
2. Body mass index (BMI) between 18 and 30 kg/m2, inclusive
3. Willing and able to comply with clinic visits and study-related procedures
4. Provide signed informed consent
5. Able to understand and complete study-related questionnaires

Exclusion Criteria:

1. Use of any medications started within 30 days prior to the screening visit including, prescription medications, nutritional supplements, and over-the-counter medications except for vitamin supplements, and recommended doses of acetaminophen, aspirin or ibuprofen

2. Hospitalization for any reason within 60 days prior to the screening visit

3. History of or positive human immunodeficiency virus (HIV) screen result at the screening visit

4. History of or positive blood test for hepatitis B surface antigen (HBsAg) or hepatitis B core antibody (HBcAb) or hepatitis C virus (HCV) antibody at the screening visit

5. History of drug or alcohol abuse within 1 year prior to screening

6. Participation in any clinical research study evaluating another investigational drug or therapy within 30 days or at least 5 half-lives (whichever is longer), of the investigational drug prior to the screening visit

7. Any history of receiving treatment, vaccine or mAbs against the Ebola virus

8. Pregnant or breast-feeding women

9. Sexually active men* or women of childbearing potential** who are unwilling to practice adequate contraception during the study (adequate contraceptive measures include stable use of oral contraceptives or other prescription pharmaceutical contraceptives for 2 or more menstrual cycles prior to screening; intrauterine device [IUD]; bilateral tubal ligation; vasectomy; condom plus contraceptive sponge, foam, or jelly, or diaphragm plus contraceptive sponge, foam, or jelly).

   • Contraception is not required for men with documented vasectomy.
   • Postmenopausal women must be amenorrheic for at least 12 months in order not to be considered of childbearing potential. A baseline follicle-stimulating hormone (FSH) test will be performed for confirmation of menopausal status. Pregnancy testing and contraception are not required for women with documented hysterectomy or tubal ligation.