Study design and stepwise dose-escalation scheme. Stepwise dose-escalation scheme for healthy male Japanese subjects (part A) and white subjects (part B) is shown. A total of 40 Japanese subjects were recruited to part A, and a total of 24 white subjects were recruited to part B. Part A: Japanese subjects were randomized to receive a single subcutaneous dose of ACE910 (n = 6 for each dose group) or placebo (n = 2 for each dose group). The Japanese subjects were observed for 4 weeks at each dose, and data were reviewed prior to dose escalation. Part B: white subjects were randomized to receive a single subcutaneous injection of ACE910 (n = 6 for each dose group) or placebo (n = 2 for each dose group). The white subjects were observed for 4 weeks at each dose, and data were reviewed prior to dose escalation.