New Extended-Release Parkinson’s Drug Approved

The FDA approved an oral extended-release formulation of levodopa and carbidopa known as IPX203 (Crexont) to treat Parkinson’s disease, Amneal Pharmaceuticals announced Wednesday.

The treatment is a novel formulation that combines immediate-release granules of carbidopa and levodopa with extended-release pellets of levodopa. Its design means that therapeutic levels of levodopa and carbidopa may be maintained with less frequent dosing to maximize “good on” time, defined as time without troublesome dyskinesia.

“The treatment goals for people living with Parkinson’s disease include achieving a more robust duration of benefit per dose of levodopa, reducing ‘off’ time, and simplifying dosing regimens,” Robert Hauser, MD, of the University of South Florida in Tampa, said in a statement.

IPX203 represents “a substantial advancement in managing motor symptoms and maintaining more consistent therapeutic effects, which is very encouraging for both patients and the Parkinson’s community,” he added.

The FDA’s decision was based largely on data from the 20-week phase III RISE-PD trial, which tested IPX203 against an immediate-release formulation of levodopa and carbidopa in 506 Parkinson’s patients.

In RISE-PD, IPX203 showed an improvement of 0.53 (95% CI 0.09-0.97, P=0.02) more hours of good on-time per day than immediate-release carbidopa-levodopa, comparing change from baseline to the end of the study.

IPX203 was dosed an average of three times a day, compared with five times a day for immediate-release carbidopa-levodopa. Good on-time per dose increased by 1.55 hours (95% CI 1.37-1.73, P

The most common adverse events with IPX203 were nausea (4.3%) and anxiety (2.7%). The drug’s safety and tolerability profile was maintained in an open-label extension study.

Prescribing information states that IPX203 is indicated for the treatment of Parkinson’s disease, post-encephalitic parkinsonism, and parkinsonism that may follow carbon monoxide intoxication or manganese intoxication in adults.

The drug label says IPX203 should not be used with nonselective monoamine oxidase (MAO) inhibitors. It also warns that the drug should not be taken with alcohol. Patients treated with levodopa have reported falling asleep during activities of daily living, including driving.

The commercial launch of IPX203 is expected in September 2024, Amneal said.

In 2023, the FDA rejected Amneal’s request to approve IPX203, saying it needed more pharmacokinetic safety data about the drug’s carbidopa component.