Following the Baseline visit, subjects will return to the clinical site at Week 6, Week 12, Week 20 and every 12 weeks thereafter. Subjects will undergo all scheduled efficacy and safety assessments, as defined by the protocol. Between scheduled clinical site visits, the clinical site staff will be required to contact the subject by a telephone call to assess tolerability to study drug and change subject's dosage as appropriate. Telephone calls should occur at least once weekly for the first 20 study weeks when dose changes will occur most frequently and subjects are becoming familiar with the study procedures. Telephone calls will occur at least once monthly thereafter. Subjects will be provided with an electronic diary to record doses taken and help in tracking of health issues for conversations with the clinical site staff.