Shanghai WD Pharmaceutical Co., Ltd. has recently successfully completed a randomized, parallel, double-blind, placebo-controlled, multi-center Phase II clinical trial of WD-1603 (carbidopa/levodopa controlled-release tablets) for the efficacy and safety in patients with Parkinson's disease. The patients with early-stage Parkinson's disease were randomized to receive 4 weeks of treatment with WD-1603 25/100 mg (low dose group), WD-1603 25/150 mg (medium dose group), WD-1603 2x25/100 mg (high dose group), or placebo. The efficacy was assessed by blinded investigators using the Movement Disorder Society-Unified Parkinson's Disease Rating Scale Part II and III (MDS-UPDRS-II and III) on days 1st, 14th, and 27th of each treatment group. Steady-state pharmacokinetic testing was performed on day 28th for the WD-1603 treatment groups.

The results showed that on days 14 and 27 after treatment, compared to baseline, the total MDS-UPDRS-II and III scores of patients treated with WD-1603 decreased significantly by 7.2, 10.0, and 14.4 in the low, medium, and high groups, respectively, demonstrating a dose-dependent relationship. The steady-state levodopa plasma concentration profiles were flat across the three treatment groups, and the peak-to-trough fluctuation indices of levodopa for the WD-1603 25/100 mg, 25/150 mg, and 2x25/100 mg dose groups were 1.27, 1.08, and 1.10, respectively. These fluctuation index values were significantly lower than those of various oral levodopa formulations currently available on the market.

In conclusion, all the efficacy indicators and steady-state plasma concentration fluctuation indices of WD-1603 in the treatment of Parkinson's disease met the expected targets, and the safety and tolerability were good in all treatment groups.