Single-dose,First-in-human of KLA478

This study is a single-center, randomized/non-randomized, single ascending dose（SAD）, Phase I clinical trial conducted in healthy subjects, divided into two parts:

Part 1 is an open-label single-dose study of active comparator to evaluate the pharmacokinetic characteristics of active comparator in healthy subjects； Part 2 is a randomized, double-blind, placebo-controlled single ascending dose study of KLA478: The purpose of this study is to evaluate the safety and tolerability and pharmacokinetics of single doses of KLA478 in healthy volunteers；

Inclusion criteria

• Sign the informed consent form
• Health participants (Age: 18~45 years);
• Body Weight: Male≥50.0kg, Female≥45.0kg; 19 ≤BMI≤ 28.0kg/m2;
• Clinical examination normal, or abnormal with no clinical significance；
• Agreed to use contraception for 3-6 months.

Exclusion criteria

• Allergy or Drug hypersensitivity;
• Clinically significant Medical History；
• Subjects with difficult venous blood collection/intolerance to venipuncture, or with a history of needle phobia/blood phobia；
• Assess injection site abnormalities；
• History of drugs that may interact with pramipexole within 1 month；
• History of any Medication within 2 weeks；
• Massive blood loss (> 200 mL) in the past 3 months；
• History of any surgery within 3 months, or plan to undergo surgery during the trial；
• History of any clinical study within 90 days；
• History of any vaccine within 1 month，or Plan to get vaccinated during the trial period；
• systolic blood pressure decreased ≥20 mmHg or diastolic blood pressure decreased ≥10 mmHg within 3 minutes from supine to upright position；
• QTcF>450 ms；
• Abnormal vital signs with clinical significance ；
• Serum potassium level exceeds the reference range.；
• Pre-transfusion test abnormal；
• Lactation or pregnancy test positive ；
• History of any drug abuse or positive drugs of abuse test result；
• Previous alcohol abuse or unwillingness to stop drinking or alcohol breath test positive；
• more than 3 cigarettes per day in 3 months, or unwilling to stop during the trial；
• Intake of special diets that affect drug absorption, distribution, metabolism and excretion within 48 hours；
• Have special requirements for diet；
• Unprotected sexual behavior within 2 weeks;
• engaged in driving vehicles, operating machinery, high-altitude work or other potentially dangerous behavior;
• Inappropriate for participation in this trial as judged by the investigator.