Phase I Study of Single/Multiple Ascending Doses of JKN2501 for Injection in Chinese Healthy Volunteers

* Voluntary informed consent; able to comply with study requirements and communicate effectively.

* Healthy subjects aged 18-45 years (inclusive) at screening.

* BMI 19.0-26.0 kg/m² (inclusive); weight ≥50 kg (male) or ≥45 kg (female).

* Vital signs, physical examination, ECG, laboratory tests, chest X-ray, and abdominal ultrasound results judged as normal or clinically insignificant by the investigator.

* Agreement to use effective non-pharmaceutical contraception from signing ICF until 90 days after last dose; no sperm/egg donation plans during this period.

* Pregnant/lactating women; positive pregnancy test; unprotected sex within 2 weeks prior to dosing.

* Investigator-determined history or presence of clinically significant disorder that may affect safety or trial participation.

* Use of drugs known to inhibit/induce hepatic metabolism within 4 weeks, or any medication (prescription, OTC, herbal, vitamins) within 2 weeks prior to dosing; planned use during the trial.

* Major surgery within 3 months prior to screening or planned during trial; history of surgery potentially affecting results.

* History of febrile illness or active infection within 2 weeks prior to screening.

* Blood loss/donation >400 mL within 3 months prior to screening, or received blood products; plans to donate blood during trial or within 30 days after last dose.

* History of significant food/drug allergy, or allergy to JKN2501/excipients.

* Excessive alcohol consumption; inability to abstain from alcohol from 48h pre-dose until end of study.

* Smoking ≥5 cigarettes/day within 3 months prior to screening; inability to abstain from smoking from 48h pre-dose until end of study.

* History of drug abuse; positive urine drug screen at baseline (Day -1).

* Positive alcohol breath test at baseline (Day -1).

* Participation in another interventional clinical trial within 3 months prior to screening or planned during this trial.

* Estimated glomerular filtration rate (eGFR) <90 mL/min.

* Serum total calcium below lower limit of normal at screening.

* Investigator-determined unsuitable venous access for PK sampling/infusion, or history of adverse symptoms/phobias related to infusion/phlebotomy.

* Excessive daily intake of tea, coffee, or caffeinated beverages within 3 months prior to screening.

* Consumption of grapefruit, Seville oranges, caffeine, or xanthine-rich foods/beverages within 48h prior to first dose; inability to abstain during the trial.

* History of QTc prolongation; or investigator-determined clinically significant ECG abnormalities at screening/baseline.

* Any other condition deemed by the investigator to make the subject unsuitable for participation.