To evaluate the pharmacokinetic (PK) characteristics and pharmacological effect of GR2002 injection in Chinese healthy volunteers

This is a randomized, double-blind, placebo-controlled phase I clinical trial to evaluate the safety, tolerability, pharmacokinetics, preliminary pharmacodynamics, and immunogenicity characteristics of single subcutaneous administration of GR2002 injection in healthy adult Chinese subjects.

The initial dose group is 35mg, and the subsequent doses will gradually increase. Only after all subjects in the current dose group have completed at least 2 weeks of safety and tolerance observation and confirmed safe tolerance, can they enter the next dose group for medication observation until the "dose increase termination standard" is reached.

Follow up will be conducted for at least 12 weeks ± 3 days after completion of medication administration.

Inclusion Criteria:

• 1. Age of 18 to 55 years, inclusive, male or female 2. BMI between 19 kg/m2 and 26 kg/m2 (inclusive) 3. Healthy volunteers

Exclusion Criteria:

• 1. History of chronic disease or serious disease 2. Subject with severe psychological or mental illness 3. Not enough washing-out period for previous therapy 4. Other.