Selegiline orally disintegrating tablets in patients with Parkinson disease and "wearing off" symptoms

BACKGROUND: Selegiline orally disintegrating tablet (ODT; Zelapar) is a selective monoamine oxidase B inhibitor developed as an adjunct to levodopa (LD) for Parkinson disease. Most patients on long-term LD therapy eventually experience deterioration at the end of the LD dosing interval, with predictable "wearing off" and "on-off" fluctuations. METHODS: We conducted a 12-week, double-blind, placebo-controlled, parallel-design trial of selegiline ODT. The primary efficacy point was reduction in the percentage of average daily "off" time. Secondary measures included reductions in daily off hours and total daily off time, Clinical Global Impressions- Improvement (CGI-I), and Patient Global Impression-Improvement (PGI-I). Patients on LD received selegiline ODT (1.25 mg/d for 6 weeks, then 2.5 mg/d for 6 weeks) or placebo. Safety and tolerability were measured. RESULTS: The intent-to-treat population included 98 patients receiving selegiline ODT and 50 patients receiving placebo. Combined efficacy results for weeks 10 and 12 revealed an 11.6% reduction in percentage of daily off time for selegiline ODT versus a 9.8% reduction for placebo (NS). PGI-I detected a statistically significant difference between treatment groups in favor of selegiline ODT (P = 0.02), whereas CGI-I detected a strong trend toward improvement (P = 0.06). Selegiline ODT was safe and well tolerated. CONCLUSIONS: This study showed no significant difference in improvement in percentage of off time with selegiline ODT versus placebo. Some clinical impressions (e.g., PGI-I, CGI-I) improved. This result contrasts with an identically designed study that showed a significant improvement in off time with selegiline ODT. A combined analysis of both studies suggested overall efficacy.