HEC-88473

Primary objective: To evaluate the efficacy of HEC88473 in subjects with type 2 diabetes who have poor glycemic control after diet and exercise alone or stable doses of metformin. Secondary objectives: 1) To evaluate the safety of HEC88473 in subjects with type 2 diabetes who have poor glycemic control after diet and exercise alone or stable doses of metformin; 2) To evaluate the pharmacokinetic characteristics of HEC88473 in Chinese adult subjects with type 2 diabetes based on population pharmacokinetic analysis methods; 3) If data permit, to evaluate the relationship between the exposure of HEC88473 and efficacy and adverse events. Exploratory objective: To evaluate the immunogenicity characteristics of HEC88473.