Masitinib in the Treatment of Patients With Primary Progressive or Non-active Secondary Progressive Multiple Sclerosis

Main inclusion criteria include: * Patients with either primary progressive or secondary progressive multiple sclerosis with onset of symptoms at least five years before baseline and with no relapse diagnosed according to the 2017 revised McDonald's criteria at least two years before screening * Patients with Expanded Disability Status Scale (EDSS) score between 3.0 to 6.0 (both inclusive) at screening and baseline * Patients with an EDSS score progression ≥1 point with no improvement during 2 years * Absence of T1 Gadolinium-enhancing brain lesions as measured by MRI at screening Main exclusion criteria include: * Patients suffering from a disease other than MS that would better explain the patient's neurological clinical signs and symptoms and/or MRI lesions observed at screening * Inability to complete screening MRI (contraindications for MRI) and/or any known allergy or hypersensitivity or any contra-indication to gadolinium macrocyclic * Patients treated with other disease modifying treatments in the time frames and conditions mentioned under previous treatment wash out period, assessed at baseline * Patients with lymphocytes \<1.0 × 10\^9/L at screening and at baseline