In phase I of this study, a multi-center, randomized, placebo parallel control design was adopted. Enrolled subjects were randomly assigned to the experimental group or the placebo group.A total of 40 subjects are expected to be enrolled in about 4 centers.~In phase II of this study, a multi-center, randomized, double-blind parallel, placebo-controlled design was adopted. Enrolled subjects were randomly assigned to the experimental group or the placebo group.About 120 subjects are expected to be enrolled in about 10 centers.
This study includes a dose escalation part(phase I) and a dose extension part(phase II).