The main purpose of this study is to evaluate the safety, tolerability and pharmacokinetics (PK) of Debio 1453P compared to placebo across different dose levels in healthy adults after single and repeated oral dosing.

Inclusion Criteria

1. Signed and dated written informed consent obtained before undertaking any trial-specific procedures.
2. Be within the age range of 18 to 55 years, inclusive, at the time of screening.
3. Have a body mass index (BMI) ≥18.5 and ≤30.0 kg/m^2.

Exclusion criteria

1. History and/or physical examination evidence of any clinically significant disease or disorder, such as cardiovascular, pulmonary, renal, hepatic, neurological, gastrointestinal, endocrine, immunological, psychiatric or mental disease or disorder, or mental or legal incapacitation, which, in the opinion of the Investigator, may either put the participant at risk for taking part in the trial, influence the results of the trial, influence the participant's ability to take part in the trial.
2. Any medication (including vaccines, over the counter (OTC) and/or prescription medication, dietary supplements, nutraceuticals, vitamins and/or herbal supplements, and hormonal replacement therapy for postmenopausal participants) for 2 weeks or 5 half-lives of the drug, whichever is longer, prior to first administration of trial drug (except occasional paracetamol (maximum dose of 2 g/day and maximum of 10 g/2 weeks).
3. History of chronic drug or alcohol abuse (defined as an average intake of more than 21 units of alcohol per week for males and 14 for females. 1 unit of alcohol equals approximately 250 mL of beer, 100 mL of wine, or 35 mL of spirits) in the last 2 years.