Long-term Extension to Study AC-058B301 to Investigate Safety, Tolerability and Disease Control of Ponesimod 20 mg in Patients With Relapsing Multiple Sclerosis

The study AC-058B301 (OPTIMUM; NCT02425644) has been designed to investigate the efficacy, safety and tolerability of ponesimod in subjects with relapsing multiple sclerosis (RMS). The AC-058B303 study is the long-term extension for the core study AC-058B301. The purpose of this long term extension of the core study AC-058B301 is to characterize the long-term safety, tolerability, and control of disease of ponesimod 20 mg in subjects with RMS.

The AC-058B303 study (extension study) is the long-term extension for the AC-058B301 study (core study). The core study has been designed to investigate the efficacy, safety and tolerability of ponesimod in subjects with RMS. The subjects are treated with either ponesimod or the active comparator, teriflunomide in the core study. The purpose of this long term extension of the core study is to characterize the long-term safety and control of disease of ponesimod in subjects with RMS. In particular, the study will allow to observe potential adverse events which may only occur after long term treatment with ponesimod. The study will also investigate the effect of re-initiation of ponesimod after a brief interruption in a relatively large population (all subjects treated with ponesimod in the core study and eligible for the extension study) on disease activity in terms of relapses and MS-related MRI lesions. There is currently limited guidance on when a new MS treatment should be started after discontinuation of teriflunomide and the study will contribute with data on safety and efficacy of switching from teriflunomide to ponesimod after an interruption as mandated by the protocol. The study will also allow confirmation of sustained efficacy of ponesimod in terms of relapses, MRI lesions and reduction of disability accumulation during long-term treatment. In addition, combined data from the core study together with the results of the current extension study will allow comparison of MS activity in subjects who were switched from teriflunomide to ponesimod versus those who were treated with ponesimod in both studies.

Eligibility Criteria:
Inclusion Criteria:

1. Signed informed consent
2. Subjects with MS having completed the double-blind treatment in the core study as scheduled
3. Compliance with teriflunomide elimination procedure
4. Women of childbearing potential (WOCBP) must have a negative pre-treatment urine pregnancy test, must agree to undertake 4-weekly urine pregnancy tests, and must have been using reliable methods of contraception. Fertile male subjects participating in the study must agree to use a condom.

Exclusion Criteria:

1. Any of the following cardiovascular conditions on Day 1 pre-dose:

   1. Resting heart rate (HR) \< 50 bpm;
   2. Presence of second degree atrioventricular (AV) block or third degree AV block or a QTcF interval \> 470 ms (females), \> 450 ms (males);
2. Any of the following alerts from central laboratory at Visit 14 of the core study (EOT) which was confirmed as an alert at repeated testing or not repeated prior to FU1 of the core study:

   1. Lymphocyte count: \< 0.2 x 109/L;
   2. Neutrophil count \<1.0 × 109/L;
   3. Platelet count \< 50 × 109/L;
   4. Creatinine clearance \< 30 mL/min
3. At Visit 14 of the core study (EOT) \>30% decrease from core study baseline FEV1 and/or FVC;
4. Clinically significant, persistent respiratory AEs (e.g., dyspnea) not resolved prior to first dosing in the extension study.
5. Macular edema at any time between Visit 1 (Screening) in the core study and Day 1 of the extension study.
6. Presence of the following at core study Visit 14 (EOT, Week 108), FU1, or abbreviated visit FU2, or on Day 1 of the extension study pre-dose:

   1. Suspected opportunistic infection of the CNS or any other infection which, in the opinion of the investigator, contraindicates re-start of the study drug;
   2. Stevens-Johnson syndrome or toxic epidermal necrolysis or drug reaction with eosinophilia and systemic symptoms.
7. Need for and intention to administer forbidden study treatment-concomitant therapy
8. Women who are pregnant or lactating.
9. Male subjects wishing to parent a child;
10. Treatment with any MS Disease Modifying Therapies;
11. Any other clinically relevant medical or surgical condition, which, in the opinion of the investigator, would put the subject at risk by participating in the study;
12. Subjects unlikely to comply with the extension study protocol based on investigator best judgment