A Study to Evaluate the Long-term Safety of Arbaclofen Extended-Release Tablets for Patients With Spasticity Due to MS

This is a multicenter, open-label, long-term extension study to evaluate the safety and tolerability of oral AERT in patients with spasticity due to MS. Subjects from the double blind study (Study OS440-3004) may rollover into this open-label extension study, as well as de novo subjects. The maintenance dose will be 80 mg/day or the highest tolerated dose. Once the subject has reached the maintenance dose, they will remain on that dose for approximately 1 year.