The objective is to compare the efficacy and safety of masitinib in combination with riluzole in the treatment of patients suffering from Amyotrophic Lateral Sclerosis (ALS).

Masitinib is novel tyrosine kinase inhibitor that targets microglia and mast cells through inhibiting a limited number of kinases. Masitinib blocks microglia proliferation and activation, and mast cell-mediated degranulation, the release of cytotoxic substances that might further damage the motor nerves.

There are two distinct populations of ALS patients: population of "Normal progressors" and population of "Faster progressors". Targeted population for primary analysis is population of "Normal progressors".

"Normal progressors" are ALS patients whose progression of ALSFRS-R score before randomization is less than 1.1 point per month.

Inclusion Criteria:

Main inclusion criteria:

1. Familial or sporadic ALS
2. Patient diagnosed with probable of definite ALS
3. Patient treated with a stable dose of riluzole (100 mg/day) for at least 30 days prior to screening

Exclusion Criteria:

1. Patient who underwent tracheostomy and/or gastrostomy