Question  Can extended-release carbidopa-levodopa (IPX203) improve symptomatic control in patients with Parkinson disease who are experiencing motor fluctuations while taking immediate-release carbidopa-levodopa?

Findings  In this phase 3 randomized clinical trial involving 506 participants, IPX203 showed statistically significant improvement in daily good on-time compared to immediate-release carbidopa-levodopa when dosed a mean of 3 times per day compared to 5 times per day for immediate-release carbidopa-levodopa.

Meaning  The results of this study suggest that IPX203 vs immediate-release carbidopa-levodopa may be useful in patients with Parkinson disease and motor fluctuations by providing more sustained benefit throughout the day, even with fewer daily doses.