Efficacy and Safety of Teriflunomide in Patients With Relapsing Multiple Sclerosis and Treated With Interferon-beta

The study period per patient is expected to be between 56 and 160 weeks depending on when
the patient is randomized and this would include the following:

- a screening period up to 4 weeks,

- a treatment period expected to be between 48 and 152 weeks,

- 4-week post washout follow-up period.

Patients will continue on treatment until a fixed common end date which will be
approximately 48 weeks after randomization of the last patient.

For those patients who complete the treatment period, a long term extension study of
approximately 1 year (including Teriflunomide alone) is planned to be proposed.

Inclusion criteria :

Patient with relapsing forms of multiple sclerosis (MS) treated with Interferon beta
(IFN-β) defined by:

- Stable dose of IFN-β for at least 6 months prior to randomization, and

- Disease activity in the 12 months prior to randomization and after first 3 months of
IFN-β treatment (at least one relapse supported by Expanded Disability status Scale
(EDSS) or equivalent neurological examination, or, at least one brain or spinal cord
Magnetic Resonance Imaging (MRI) with at least one T1 gadolinium enhancing lesion).

Exclusion criteria:

- < 18 years of age or ≥ 56 years of age.

- McDonald criteria for MS diagnosis not met at time of screening visit.

- EDSS score > 5.5 at randomization visits.

- A relapse within 30 days prior randomization.

- Human Immunodeficiency Virus (HIV) positive patient.

- Prior use within 6 months preceding randomization or concomitant use of natalizumab
or any other immunosuppressive agents such as azathioprine, cyclophosphamide,
cyclosporine, methotrexate, mycophenolate, or fingolimod.

- Prior use in the 3 months preceding randomization of cytokine therapy (except
baseline IFN-β), glatiramer acetate or intravenous immunoglobulins, or concomitant
use of these treatments.

- Prior use within 2 years preceding randomization or concomitant use of cladribine and
mitoxantrone.

- Pregnant or breast-feeding women or those who plan to become pregnant during the
study.

The above information is not intended to contain all considerations relevant to a
patient's potential participation in a clinical trial.