Long-Term Effects of Safinamide on Dyskinesia in Mid- to Late-Stage Parkinson's Disease: A Post-Hoc Analysis.

Abstract

BACKGROUND:

Safinamide is a novel α-aminoamide with dopaminergic and non-dopaminergic properties developed as adjunctive therapy for patients with PD. Results from a 24-month double-blind controlled study suggested that as add-on to levodopa (and other PD medications) the benefits of safinamide on dyskinesia may be related to severity of dyskinesia at baseline.

OBJECTIVE:

This post-hoc analysis further characterized the effects of safinamide on dyskinesia in mid- to late-stage PD patients.

METHODS:

Patients were stratified by the presence or absence of dyskinesia at baseline, and by whether or not the dose of levodopa had been changed during the 24-month treatment period. Differences between safinamide and placebo were evaluated using the Wilcoxon rank-sum test.

RESULTS:

For the overall treated population (with or without baseline dyskinesia), safinamide 100 mg/day significantly improved the dyskinesia rating scale score, compared with placebo, in the subgroup of patients with no change in levodopa dose (p = 0.0488). For patients with baseline dyskinesia, improvements over placebo were also significant (p = 0.0153) in patients with or without changes in levodopa dose, and nearly significant (p = 0.0546) in patients with no change in levodopa dose, suggesting that these improvements were not due to levodopa dose reductions.

CONCLUSIONS:

While no statistically significant difference in mean DRS scores was seen between safinamide and placebo in the original study population, the present post-hoc analysis helps to provide a meaningful interpretation of the long-term effects of safinamide on dyskinesia. These results may be related to safinamide state- and use-dependent inhibition of sodium channels and stimulated glutamate release, and are unlikely due to reduced dopaminergic stimulation.

• Authors: Carlo Cattaneo, R La Ferla, Erminio Bonizzoni, Marco Sardina
• Journal: Journal of Parkinson's disease (J Parkinsons Dis) Vol. 5 Issue 3 Pg. 475-81 ( 2015) ISSN: 1877-718X [Electronic] Netherlands
• PMID: 26406127 (Publication Type: Clinical Trial, Journal Article, Multicenter Study)

Chemical References

• Antiparkinson Agents
• Benzylamines
• Levodopa
• safinamide
• Alanine

Topics

• Alanine (analogs & derivatives, therapeutic use)
• Antiparkinson Agents (therapeutic use)
• Benzylamines (therapeutic use)
• Dose-Response Relationship, Drug
• Drug Therapy, Combination
• Dyskinesias (drug therapy, etiology)
• Follow-Up Studies
• Humans
• Levodopa (therapeutic use)
• Parkinson Disease (complications, drug therapy, physiopathology)
• Severity of Illness Index
• Treatment Outcome