Effects of Dorzagliatin on 1st Phase Insulin and Beta-cell Glucose Sensitivity in T2D and Monogenic Diabetes

Inclusion Criteria: 1. Individuals aged ≥ 18 years but \< 65years 2. Male or female 3. Body mass index of over 18 kg/m2 and \< 30 kg/m2 Additional Inclusion criteria for recent-onset T2D group * Diagnosis of T2D for at least 3 months and less than 2 years * On diet control only * HbA1c\>6.5 % and \<8% Additional Inclusion criteria for GK MODY-2 group * Abnormal fasting plasma glucose \>5.6 mmol/l and known heterozygous carrier of pathogenic GK mutation Exclusion Criteria: 1. Subjects who do not agree to participate in this study. 2. Country of birth is unknown 3. Body weight less than 45kg 4. Acute phase of cerebrovascular and cardiovascular diseases (within 6 months of recruitment). 5. Subjects with severe renal dysfunction as defined by eGFR \<30 ml/min/1.73m2 or patients receiving renal dialysis (such as haemodialysis or continuous ambulatory peritoneal dialysis). 6. Severe hepatic dysfunction as defined by AST and/or ALT \> 3 times upper limit of normal 7. Severe cardiovascular disease, history of stroke, heart failure (NYHA III or IV) or history of myocardial infarction within last 12 months 8. History of drug abuse or excessive alcohol intake based on investigator judgment 9. Severe hypoglycaemia resulting in seizure/unconsciousness/coma/hospitalization in the last 3 months before screening 10. Diagnosis with Type 1 Diabetes Mellitus (T1DM) or any previous episodes of diabetic ketoacidosis. 11. Dehydration, diarrhoea or vomiting at the time of recruitment 12. Subjects with severe infection, in perioperative period or with serious injury at the time of recruitment 13. Subjects with anaemia (Haemoglobin \<9.0mg/dL) 14. Pregnant or lactating or intending to become pregnant within 30 days after last dose of study drug. 15. Participation in a clinical trial within 30 days before enrolment 16. Donation or loss of blood (excluding the volume of blood that will be drawn during screening procedures) as follows: \>=300 mL of blood within 30 days prior to study drug administration. 17. Subjects judged unsuitable for the study based on investigator judgment 18. Use of metformin, sulfonylureas, dipeptidyl peptidase-4 inhibitors, glucagon-like peptide 1 \[GLP-1\] agonists, sodium glucose transporter 2 inhibitors, insulin, thiazolidinediones, acarbose in the 3 months prior to study enrolment will not be permitted. 19. Use of strong or moderate CYP3A4 inhibitors or inducers and cannot be discontinued 20. Unwilling or unable to follow protocol requirements.