General Information

Xadago (safinamide) is a monoamine oxidase type B (MAO-B) inhibitor.

Xadago is specifically indicated as adjunctive treatment to levodopa/carbidopa in patients with Parkinson’s disease (PD) experiencing “off” episodes.

Xadago is supplied as a tablet for oral administration. The recommended starting dosage is 50 mg administered orally once daily (at the same time of day), without regard to meals. After two weeks, the dosage may be increased to 100 mg once daily, based on individual need and tolerability. Daily dosages of Xadago above 100 mg have not been shown to provide additional benefit, and higher dosages increase the risk for adverse reactions. Xadago has been shown to be effective only in combination with levodopa/carbidopa. If a dose is missed, the next dose should be taken at the same time the next day. Xadago 100 mg should be tapered by decreasing the dose to 50 mg for one week before stopping.

Mechanism of Action

Xadago (safinamide) is a monoamine oxidase type B (MAO-B) inhibitor. The precise mechanism by which Xadago exerts is effect in Parkinson's disease is unknown. Inhibition of MAO-B activity, by blocking the catabolism of dopamine, is thought to result in an increase in dopamine levels and a subsequent increase in dopaminergic activity in the brain.

Clinical Trial Results

The FDA approval of Xadago was based on two double-blind, placebo-controlled, multi-national, 24-week studies (Study 1 and Study 2) conducted in PD patients experiencing “OFF” Time during treatment with carbidopa/levodopa and other PD medications. In both studies, the primary measure of effectiveness was the change from baseline in total daily “ON” Time without troublesome dyskinesia, based on 18-hour diaries completed by patients for at least 3 days before each of the scheduled visits. Secondary endpoints included “OFF” Time during the diary period and reduction in Uniform Parkinson’s Disease Rating Scale (UPDRS) Part III (motor examination). In Study 1, 645 subjects were randomized equally to treatment with Xadago 50 mg/day (n=217 patients), Xadago 100 mg/day (n=216 patients), or placebo (n=212 patients), and had at least one post-baseline assessment of “ON” Time. Xadago 50 mg/day and 100 mg/day significantly increased “ON” Time compared to placebo. The increase in “ON” Time without troublesome dyskinesia was accompanied by a similar significant reduction in “OFF” Time and a reduction in UPDRS III scores assessed during “ON” Time. Improvement in “ON Time” occurred without an increase in troublesome dyskinesia. In Study 2 549 subjects were randomized to treatment with Xadago 100 mg daily (n=274 patients) or placebo (n=275 patients) for up to 24 weeks. Xadago was significantly better than placebo for increasing “ON” Time. The observed increase in “ON” Time without troublesome dyskinesia was accompanied by a reduction in “OFF” Time of similar magnitude and a reduction in UPDRS III score (assessed during “ON” Time). As in Study 1, the increase in “ON” Time without troublesome dyskinesia was accompanied by a similar significant reduction in “OFF” Time and a reduction in Unified Parkinson’s Disease Rating Scale Part III (UPDRS III) scores assessed during “ON” Time.