 Eligible patients who provide written informed consent will take one TNX-102 SL tablet daily at bedtime sublingually under the tongue for 12 weeks. All patients will be assigned to receive tthe same dosage of TNX-102 SL, regardless of their treatment assignment in the lead-in study. No patients, investigators, or study staff will know the assigned study treatment from the lead-in study, P201, at the time of entry into the extension study. Patient data collected at the Week 12 visit Visit 9 in the lead-in P201 study will be used as one of the baseline values for this study. 