 After randomization, there is a placebo-controlled parallel group treatment with 10 mg OLN in combination with the standard treatment of Riluzole 100mgdayGroup 1 in comparison to treatment with placebo in combination with 100 mg RIL Group 2. Study drug will be provided as 5 mg tablets. OLN will be begun in an initial dosage of 5 mgday for one week. The intake will occur in the evening hours in the form of a capsule containing 5 mg OLN. The evening dose of Riluzole can be taken together with the OLN medication. After one week day 8, the dose will be increase to 10 mg OLNday, which will be taken in the form of two capsules at the same timepoint in the evening hours. This dose will be continued for 51 weeks. 