Study of HX15001 in Adult Healthy Volunteers.

Part A (Single Ascending Dose), participants will receive a single intravenous dose of HX15001 at escalating dose levels in sequential cohorts (Cohorts 1-7).

Participants will receive matching placebo across cohorts 1-7 of the study.

In Part B (Multiple Ascending Dose), participants will receive multiple intravenous doses of HX15001 in cohorts 8 and 9 to assess safety, tolerability, and pharmacokinetics.

Participants will receive matching placebo across cohorts 8-9 of the study.