Ascending Dose Tolerability Trial and PK Assessment in Healthy Volunteers After Single & Multiple Oral Intake of DF2755A

Primary objective: •To evaluate the tolerability and safety of ascending single doses of DF2755A in healthy adult male and female volunteers. Secondary Objectives: * To determine the pharmacokinetics parameters of DF2755A * To establish a dose concentration-response relationship over a wide range of doses in order to select a narrower range of dose and dosing regimen to be subsequently studied in patients after single administration * To evaluate the effect of ascending single doses on the pharmacodynamics parameters * To compare metabolites pathway in Human with the one observed in animals Please note that the study has been closed after Part A (single ascending doses), so all the objectives were revised accordingly.