Placebo-controlled Study of Single and Multiple Ascending Doses of UDP-003 in Healthy Human Participants and Followed by an Open-label Patient Cohort

The goal of this clinical trial is to learn if UDP-003 is safe in healthy human participants and patients, assess the pharmacokinetics (PK)/pharmacodynamics (PD) of UDP-003 in healthy human participants and patients and its potential efficacy in patients. Researchers will compare UDP-003 to a placebo in a blinded manner. This first in human, randomised, double-blind, placebo-controlled, prospective, single-centre trial with a modular dose-finding design will be conducted in 3 parts: * Part 1: 6 cohorts of 6 healthy participants receiving Single Ascending Doses (SADs), * Part 2: 3 cohorts of 12 healthy participants receiving Multiple Ascending Doses (MADs) (6 doses over 16 days), * Part 3: 1 cohort of up to 9 evaluable participants diagnosed with acute coronary syndrome (ACS; non-ST elevation myocardial infarction \[NSTEMI\] or unstable angina) at least 12 months post-event receiving multiple doses (6 administrations of the 25 mg/kg dose over 6 weeks). The planned duration of the study for each participant will be: * 4 weeks for SAD Participants (1-day treatment period, 4-week safety follow-up) * 6 weeks for MAD Participants (16-day treatment period,4-week safety follow-up) * 180 Days for MD Patients (6-week treatment period, 6-month safety follow-up) Prior to participants being randomised to panels of increasing doses, all safety data will be reviewed for completed panels.