 - are of child-bearing potential and are not practising an acceptable method of birth control, or do not plan to continue using this method throughout the study and do not agree to submit to periodic pregnancy testing during participation in the trial. Acceptable methods of birth control include tubal ligation, transdermal patch, intra uterine devicessystems IUDsIUSs, oral, implantable or injectable contraceptives,sexual abstinence, if acceptable by local authorities double barrier method and vasectomised partner. 