Clamp Study to Estimate the Relative Potency of GZR33 Versus Insulin Degludec at Steady State

Inclusion Criteria: type 1 diabetes for at least 12 months * 18-64 years of age * HbA1c \<= 9.0%. * Body Mass Index (BMI) between 18.5 and 29.0 kg/m\^2 * treated with a stable insulin regimen for at least 2 months, in a dose \> 0.2 and \< 1.2 U/kg/day Exclusion Criteria: * blood pressure outside the range 90 to 140 mmHg (systolic) or 50 to 99 mmHg (diastolic) * clinically significant concomitant diseases * recurrent severe hypoglycemia (more than 1 severe hypoglycemic episode requiring assistance from another person within 180 days before screening) * hypoglycemia unawareness * estimated glomerular filtration rate (eGFR) \<60.0 mL/min/1.73 m2