The main purpose of this study is to investigate the efficacy and safety of JY09 versus placebo in patients with type 2 diabetes mellitus (T2DM) inadequately controlled by diet and exercise alone

This study was designed as a multicenter, randomized, double-blind, placebo-parallel controlled Phase III clinical study to evaluate the efficacy and safety of Exendin-4Fc fusion protein (JY09) injection in adult subjects with type 2 diabetes mellitus (T2DM) who have poor glycemic control after dietary exercise intervention only.

The proposed plan is to enroll 270 subjects with T2DM, using stratified block group randomization, with the stratification factor being baseline HbA1c (≤8.5% or >8.5%), and randomly assign them to the 1.2 mg JY09 injection group (n=90 subjects), the 2.4 mg JY09 injection group (n=90 subjects), and the placebo group (n=90 subjects) in a 1:1:1 ratio.

The trial was divided into 4 phases, i.e., a screening period of 2 weeks, a single-blind introduction period of 4 weeks, a treatment period of 54 weeks (26 weeks for the core treatment period and 28 weeks for the extended treatment period), and a safety follow-up period of 4 weeks. Total 64 weeks.

Inclusion Criteria:

1. Male or female subjects ≥18 years of age and ≤75 years of age at the time of signing the informed consent form.
2. Those who meet the World Health Organization（WHO）1999 diagnostic criteria for type 2 diabetes mellitus and the WHO Recommendations for the Use of Glycosylated Haemoglobin (HbA1c) for Diagnosis (2011) supplemental diagnostic criteria for a diagnosis of T2DM for ≥ 12 weeks.
3. Those who received dietary and exercise interventions for ≥8 weeks prior to screening and who had not received any antidiabetic medications in the 8 weeks prior to screening.
4. HbA1c ≥7.5% and ≤11.0% at screening (local laboratory) and HbA1c ≥7.0% and ≤10.5% before randomization (V3) (central laboratory).
5. FPG 13.9 mmol/L at screening (local laboratory) and FPG 13.9 mmol/L before randomization (V3) (central laboratory).
6. Body mass index (BMI) ≥18.5 kg/m2 and ≤35.0 kg/m2 at screening and before randomization (V3).
7. Able to understand and willing to sign a written informed consent form (ICF) and comply with the study protocol.

Exclusion Criteria:

1. People diagnosed with type 1 diabetes or other types of diabetes.
2. Those who have used other hypoglycemic agents within 8 weeks prior to screening or prior to randomization (V4), or those who have used medications that may affect glucose metabolism, such as systemic glucocorticoids (except for inhalation or topical topical use), growth hormones, etc.
3. Acute complications of diabetes, such as diabetic ketoacidosis or hyperglycemic hyperosmolar state, within 6 months prior to screening or prior to randomization.
4. Severe chronic complications of diabetes mellitus (e.g., proliferative diabetic retinopathy, severe diabetic neuropathy, diabetic foot, etc.) within 6 months prior to screening, which are assessed by the investigator to be unsuitable for participation in this clinical study.
5. Persons who have had a severe trauma or serious infection within 1 month prior to screening or prior to randomization (V4) that may affect glycemic control, and persons who currently have a complicated or refractory urinary or genital tract infection.
6. Suffering from any condition at screening or prior to randomization (V4) that may cause hemolysis or red blood cell instability that would interfere with the measurement of HbA1c levels, such as hemolytic anemia.
7. Subjects who have abnormal thyroid function tests at Screening and require medication, or subjects who are being treated with thyroid-related medications whose thyroid function is still not well controlled at Screening.
8. Those with any of the following abnormalities on serologic testing at screening:

1）Positive human immunodeficiency virus antibodies or syphilis spirochete-specific antibodies; 2）Hepatitis C antibody positive; 3）Hepatitis B virus surface antigen (HBsAg) positive and hepatitis B viral load (HBV-DNA) above the lower limit of laboratory testing (HBV-DNA is added only if HBsAg is positive); 9. The subject has other conditions that, in the judgment of the investigator, make participation in this clinical study inappropriate.

This study uses a double-blind technique, which means that neither the investigator nor the subject knows what drug is being used. The sponsor will provide the study drug and the control drug, ensuring that the placebo shape, color, and weight are identical to the study drug.