Stuart Isaacson, MD, from the University of South Florida, in Tampa, and colleagues randomized 225 patients with Parkinson's disease to receive placebo or droxidopa, an oral pro-drug converted to norepinephrine, for an eight-week treatment period. The researchers found that, at week one, patients receiving droxidopa experienced significant improvement in dizziness/lightheadedness, with a trend toward improvement at week eight. There was a significant improvement in standing systolic blood pressure at week one with droxidopa, and a numerical improvement at week eight.
C. Warren Olanow, MD, from the Mount Sinai School of Medicine, in New York City, and colleagues randomized 337 patients with stable dosages of levodopa to tozadenant (60, 120, 180, or 240 mg twice daily) or placebo. The researchers found that patients in the 120 mg and 180 mg tozadenant groups experienced significant reductions in OFF time at 12 weeks, compared with baseline, with no increase in ON time with troublesome dyskinesia. In a third study, Robert A. Hauser, MD, of the University of South Florida, in Tampa, and colleagues found that, for patients receiving dopamine agonist monotherapy with suboptimal symptom control, treatment with add-on rasagiline resulted in a significant improvement in the Unified Parkinson's Disease Rating Scale (UPDRS) score and in UPDRS-motor scores compared with placebo.
"All of these treatments are promising news for people with Parkinson's disease, which is the second most common neurodegenerative disease after Alzheimer's disease," Hauser said in a statement.
The first, second, and third studies were funded by Chelsea Therapeutics, Biotie Therapies, and Teva Pharmaceuticals, respectively.