During the study, five visits to the clinical center are scheduled: one at Screening and three in the double-blind treatment period (Day 1, Day 14, Day 28 and Day 56). A safety follow-up visit will take place about 2 weeks after the final study visit. If a patient is withdrawn from the study before Day 56, they will be asked to attend the study center as soon as possible thereafter so that the Final visit assessments can be conducted.