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

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