This is a Phase 1 randomized, double blinded, placebo-controlled, single dose escalation study to evaluate the safety, tolerability, and PK of 611 in healthy volunteers.

Total duration of the study period per subject is about 4 months broken down as follows:

The screening period is up to 28 days, one dose treatment, and follow- up period is up to 71±7 days (90±9 days for Cohorts 1 and 2).

Inclusion Criteria:

1. Able to understand and willing to sign the ICF
2. Healthy male and female subjects, non-smokers, 18-55 years of age
3. In the opinion of the investigator, with no significant medical history, and in good health.
4. Body mass index 19.0-32.0 kg/m2 and body weight ≥ 50.0 kg for males and ≥ 45.0 kg for females.
5. Subjects are able to follow the study protocol and complete the trial.

Exclusion Criteria:

1. History of hypersensitivity to similar drugs to 611 or their excipients.
2. Pregnant, or nursing females.
3. HepBsAg or HepCAb positive.
4. Human immunodeficiency virus (HIV) positive.
5. Positive urine drug screen, or cotinine test.
6. Any reason which, in the opinion of the Qualified Investigator, would prevent the subject from participating in the study.