4. Subjects and their partners must be willing to avoid pregnancy during the trial and until 1 month after the last trial drug administration. Subjects must therefore be willing to use adequate contraception as approved by the Investigator such as two barrier methods or one barrier method with spermicide or intrauterine device, 2 weeks before, during the trial and 1 month after. The use of hormonal contraceptives should be avoided due to a possible drug-drug interaction in female subjects of childbearing age