Study to Assess the Safety and Tolerability of Single Doses of REGN1500

Inclusion Criteria:

1. Body mass index 18.0 to 40.0 kg/m2, inclusive

2. Normal standard 12-lead ECG

3. Willing to refrain from the consumption of alcohol for 24 hours prior to each study
visit

4. Willing to consistently maintain his/her usual diet for the duration of the study

5. Willing to refrain from strenuous exercise for the duration of the trial

6. Willing and able to comply with clinic visits and study-related procedures

7. Provide signed informed consent

8. For sexually active men and women, willingness to utilize adequate contraception and
not have their partner[s] become pregnant during the full duration of the study.

Exclusion Criteria:

1. Any clinically significant abnormalities observed during the screening visit

2. History of drug or alcohol abuse within 1 year of screening

3. Receipt of 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.

4. Significant concomitant illness or history of significant illness such as cardiac,
renal, neurological, endocrinological, metabolic or lymphatic disease, or any other
illness or condition that may adversely affect the subjects participation in this
study

5. Known history of human immunodeficiency virus (HIV) antibody; and/or positive
hepatitis B surface antigen (HBsAg), and/or positive hepatitis C antibody (HCV) at
the screening visit

6. Hospitalization for any reason within 60 days of screening

7. History or presence of malignancy within 5 years prior to the screening visit (other
than successfully treated non-metastatic cutaneous squamous cell or basal cell
carcinoma, and/or localized carcinoma in situ of the cervix

8. Any medical or psychiatric condition which, in the opinion of the investigator, would
place the subject at risk, interfere with participation in the study or interfere
with the interpretation of the study results

9. Any subject who is the investigator or any sub-investigator, research assistant,
pharmacist, study coordinator, or other staff directly involved in the conduct of the
protocol, or family member of staff involved in the conduct of the protocol

10. Pregnant or breast-feeding women

(The inclusion/ exclusion criteria provided above are not intended to contain all
considerations relevant to a patient's potential participation in this clinical trial).