The purpose of this study is to evaluate the safety, tolerability, pharmacokinetics, and immunogenicity of single-ascending IV doses of FB825

Inclusion Criteria:

1. The subject is male or female between 18 and 55 years of age, inclusive.
2. All female subjects must have a negative serum pregnancy test at screening and on Day -1.
3. The subject has a body weight ≥50 kg at screening and a body mass index of 18 to 30 kg/m2, inclusive.
4. The subject has a good health condition based upon the results of medical history, physical examination, vital signs, laboratory profile and ECG.
5. The subject has a negative urine drug screen for alcohol, cotinine.

Exclusion Criteria:

1. Female subjects who are pregnant or lactating.
2. The subject has a past history of heart arrhythmias.
3. The subject has history of clinically significant diseases.
4. The subject has any history of a previous anaphylactic reaction.
5. Use of prescribed medication within 6 months of Day -1.